Make Lisp_Save_Value more versatile storage for up to four objects.
[bpt/emacs.git] / src / alloc.c
1 /* Storage allocation and gc for GNU Emacs Lisp interpreter.
2
3 Copyright (C) 1985-1986, 1988, 1993-1995, 1997-2013 Free Software
4 Foundation, Inc.
5
6 This file is part of GNU Emacs.
7
8 GNU Emacs is free software: you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation, either version 3 of the License, or
11 (at your option) any later version.
12
13 GNU Emacs is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */
20
21 #include <config.h>
22
23 #define LISP_INLINE EXTERN_INLINE
24
25 #include <stdio.h>
26 #include <limits.h> /* For CHAR_BIT. */
27
28 #ifdef ENABLE_CHECKING
29 #include <signal.h> /* For SIGABRT. */
30 #endif
31
32 #ifdef HAVE_PTHREAD
33 #include <pthread.h>
34 #endif
35
36 #include "lisp.h"
37 #include "process.h"
38 #include "intervals.h"
39 #include "puresize.h"
40 #include "character.h"
41 #include "buffer.h"
42 #include "window.h"
43 #include "keyboard.h"
44 #include "frame.h"
45 #include "blockinput.h"
46 #include "termhooks.h" /* For struct terminal. */
47
48 #include <verify.h>
49
50 /* GC_CHECK_MARKED_OBJECTS means do sanity checks on allocated objects.
51 Doable only if GC_MARK_STACK. */
52 #if ! GC_MARK_STACK
53 # undef GC_CHECK_MARKED_OBJECTS
54 #endif
55
56 /* GC_MALLOC_CHECK defined means perform validity checks of malloc'd
57 memory. Can do this only if using gmalloc.c and if not checking
58 marked objects. */
59
60 #if (defined SYSTEM_MALLOC || defined DOUG_LEA_MALLOC \
61 || defined GC_CHECK_MARKED_OBJECTS)
62 #undef GC_MALLOC_CHECK
63 #endif
64
65 #include <unistd.h>
66 #include <fcntl.h>
67
68 #ifdef USE_GTK
69 # include "gtkutil.h"
70 #endif
71 #ifdef WINDOWSNT
72 #include "w32.h"
73 #include "w32heap.h" /* for sbrk */
74 #endif
75
76 #ifdef DOUG_LEA_MALLOC
77
78 #include <malloc.h>
79
80 /* Specify maximum number of areas to mmap. It would be nice to use a
81 value that explicitly means "no limit". */
82
83 #define MMAP_MAX_AREAS 100000000
84
85 #endif /* not DOUG_LEA_MALLOC */
86
87 /* Mark, unmark, query mark bit of a Lisp string. S must be a pointer
88 to a struct Lisp_String. */
89
90 #define MARK_STRING(S) ((S)->size |= ARRAY_MARK_FLAG)
91 #define UNMARK_STRING(S) ((S)->size &= ~ARRAY_MARK_FLAG)
92 #define STRING_MARKED_P(S) (((S)->size & ARRAY_MARK_FLAG) != 0)
93
94 #define VECTOR_MARK(V) ((V)->header.size |= ARRAY_MARK_FLAG)
95 #define VECTOR_UNMARK(V) ((V)->header.size &= ~ARRAY_MARK_FLAG)
96 #define VECTOR_MARKED_P(V) (((V)->header.size & ARRAY_MARK_FLAG) != 0)
97
98 /* Default value of gc_cons_threshold (see below). */
99
100 #define GC_DEFAULT_THRESHOLD (100000 * word_size)
101
102 /* Global variables. */
103 struct emacs_globals globals;
104
105 /* Number of bytes of consing done since the last gc. */
106
107 EMACS_INT consing_since_gc;
108
109 /* Similar minimum, computed from Vgc_cons_percentage. */
110
111 EMACS_INT gc_relative_threshold;
112
113 /* Minimum number of bytes of consing since GC before next GC,
114 when memory is full. */
115
116 EMACS_INT memory_full_cons_threshold;
117
118 /* True during GC. */
119
120 bool gc_in_progress;
121
122 /* True means abort if try to GC.
123 This is for code which is written on the assumption that
124 no GC will happen, so as to verify that assumption. */
125
126 bool abort_on_gc;
127
128 /* Number of live and free conses etc. */
129
130 static EMACS_INT total_conses, total_markers, total_symbols, total_buffers;
131 static EMACS_INT total_free_conses, total_free_markers, total_free_symbols;
132 static EMACS_INT total_free_floats, total_floats;
133
134 /* Points to memory space allocated as "spare", to be freed if we run
135 out of memory. We keep one large block, four cons-blocks, and
136 two string blocks. */
137
138 static char *spare_memory[7];
139
140 /* Amount of spare memory to keep in large reserve block, or to see
141 whether this much is available when malloc fails on a larger request. */
142
143 #define SPARE_MEMORY (1 << 14)
144
145 /* Initialize it to a nonzero value to force it into data space
146 (rather than bss space). That way unexec will remap it into text
147 space (pure), on some systems. We have not implemented the
148 remapping on more recent systems because this is less important
149 nowadays than in the days of small memories and timesharing. */
150
151 EMACS_INT pure[(PURESIZE + sizeof (EMACS_INT) - 1) / sizeof (EMACS_INT)] = {1,};
152 #define PUREBEG (char *) pure
153
154 /* Pointer to the pure area, and its size. */
155
156 static char *purebeg;
157 static ptrdiff_t pure_size;
158
159 /* Number of bytes of pure storage used before pure storage overflowed.
160 If this is non-zero, this implies that an overflow occurred. */
161
162 static ptrdiff_t pure_bytes_used_before_overflow;
163
164 /* True if P points into pure space. */
165
166 #define PURE_POINTER_P(P) \
167 ((uintptr_t) (P) - (uintptr_t) purebeg <= pure_size)
168
169 /* Index in pure at which next pure Lisp object will be allocated.. */
170
171 static ptrdiff_t pure_bytes_used_lisp;
172
173 /* Number of bytes allocated for non-Lisp objects in pure storage. */
174
175 static ptrdiff_t pure_bytes_used_non_lisp;
176
177 /* If nonzero, this is a warning delivered by malloc and not yet
178 displayed. */
179
180 const char *pending_malloc_warning;
181
182 /* Maximum amount of C stack to save when a GC happens. */
183
184 #ifndef MAX_SAVE_STACK
185 #define MAX_SAVE_STACK 16000
186 #endif
187
188 /* Buffer in which we save a copy of the C stack at each GC. */
189
190 #if MAX_SAVE_STACK > 0
191 static char *stack_copy;
192 static ptrdiff_t stack_copy_size;
193 #endif
194
195 static Lisp_Object Qconses;
196 static Lisp_Object Qsymbols;
197 static Lisp_Object Qmiscs;
198 static Lisp_Object Qstrings;
199 static Lisp_Object Qvectors;
200 static Lisp_Object Qfloats;
201 static Lisp_Object Qintervals;
202 static Lisp_Object Qbuffers;
203 static Lisp_Object Qstring_bytes, Qvector_slots, Qheap;
204 static Lisp_Object Qgc_cons_threshold;
205 Lisp_Object Qautomatic_gc;
206 Lisp_Object Qchar_table_extra_slots;
207
208 /* Hook run after GC has finished. */
209
210 static Lisp_Object Qpost_gc_hook;
211
212 static void mark_terminals (void);
213 static void gc_sweep (void);
214 static Lisp_Object make_pure_vector (ptrdiff_t);
215 static void mark_buffer (struct buffer *);
216
217 #if !defined REL_ALLOC || defined SYSTEM_MALLOC
218 static void refill_memory_reserve (void);
219 #endif
220 static void compact_small_strings (void);
221 static void free_large_strings (void);
222 extern Lisp_Object which_symbols (Lisp_Object, EMACS_INT) EXTERNALLY_VISIBLE;
223
224 /* When scanning the C stack for live Lisp objects, Emacs keeps track of
225 what memory allocated via lisp_malloc and lisp_align_malloc is intended
226 for what purpose. This enumeration specifies the type of memory. */
227
228 enum mem_type
229 {
230 MEM_TYPE_NON_LISP,
231 MEM_TYPE_BUFFER,
232 MEM_TYPE_CONS,
233 MEM_TYPE_STRING,
234 MEM_TYPE_MISC,
235 MEM_TYPE_SYMBOL,
236 MEM_TYPE_FLOAT,
237 /* Since all non-bool pseudovectors are small enough to be
238 allocated from vector blocks, this memory type denotes
239 large regular vectors and large bool pseudovectors. */
240 MEM_TYPE_VECTORLIKE,
241 /* Special type to denote vector blocks. */
242 MEM_TYPE_VECTOR_BLOCK,
243 /* Special type to denote reserved memory. */
244 MEM_TYPE_SPARE
245 };
246
247 #if GC_MARK_STACK || defined GC_MALLOC_CHECK
248
249 #if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
250 #include <stdio.h> /* For fprintf. */
251 #endif
252
253 /* A unique object in pure space used to make some Lisp objects
254 on free lists recognizable in O(1). */
255
256 static Lisp_Object Vdead;
257 #define DEADP(x) EQ (x, Vdead)
258
259 #ifdef GC_MALLOC_CHECK
260
261 enum mem_type allocated_mem_type;
262
263 #endif /* GC_MALLOC_CHECK */
264
265 /* A node in the red-black tree describing allocated memory containing
266 Lisp data. Each such block is recorded with its start and end
267 address when it is allocated, and removed from the tree when it
268 is freed.
269
270 A red-black tree is a balanced binary tree with the following
271 properties:
272
273 1. Every node is either red or black.
274 2. Every leaf is black.
275 3. If a node is red, then both of its children are black.
276 4. Every simple path from a node to a descendant leaf contains
277 the same number of black nodes.
278 5. The root is always black.
279
280 When nodes are inserted into the tree, or deleted from the tree,
281 the tree is "fixed" so that these properties are always true.
282
283 A red-black tree with N internal nodes has height at most 2
284 log(N+1). Searches, insertions and deletions are done in O(log N).
285 Please see a text book about data structures for a detailed
286 description of red-black trees. Any book worth its salt should
287 describe them. */
288
289 struct mem_node
290 {
291 /* Children of this node. These pointers are never NULL. When there
292 is no child, the value is MEM_NIL, which points to a dummy node. */
293 struct mem_node *left, *right;
294
295 /* The parent of this node. In the root node, this is NULL. */
296 struct mem_node *parent;
297
298 /* Start and end of allocated region. */
299 void *start, *end;
300
301 /* Node color. */
302 enum {MEM_BLACK, MEM_RED} color;
303
304 /* Memory type. */
305 enum mem_type type;
306 };
307
308 /* Base address of stack. Set in main. */
309
310 Lisp_Object *stack_base;
311
312 /* Root of the tree describing allocated Lisp memory. */
313
314 static struct mem_node *mem_root;
315
316 /* Lowest and highest known address in the heap. */
317
318 static void *min_heap_address, *max_heap_address;
319
320 /* Sentinel node of the tree. */
321
322 static struct mem_node mem_z;
323 #define MEM_NIL &mem_z
324
325 static struct Lisp_Vector *allocate_vectorlike (ptrdiff_t);
326 static void lisp_free (void *);
327 static void mark_stack (void);
328 static bool live_vector_p (struct mem_node *, void *);
329 static bool live_buffer_p (struct mem_node *, void *);
330 static bool live_string_p (struct mem_node *, void *);
331 static bool live_cons_p (struct mem_node *, void *);
332 static bool live_symbol_p (struct mem_node *, void *);
333 static bool live_float_p (struct mem_node *, void *);
334 static bool live_misc_p (struct mem_node *, void *);
335 static void mark_maybe_object (Lisp_Object);
336 static void mark_memory (void *, void *);
337 #if GC_MARK_STACK || defined GC_MALLOC_CHECK
338 static void mem_init (void);
339 static struct mem_node *mem_insert (void *, void *, enum mem_type);
340 static void mem_insert_fixup (struct mem_node *);
341 static void mem_rotate_left (struct mem_node *);
342 static void mem_rotate_right (struct mem_node *);
343 static void mem_delete (struct mem_node *);
344 static void mem_delete_fixup (struct mem_node *);
345 static struct mem_node *mem_find (void *);
346 #endif
347
348
349 #if GC_MARK_STACK == GC_MARK_STACK_CHECK_GCPROS
350 static void check_gcpros (void);
351 #endif
352
353 #endif /* GC_MARK_STACK || GC_MALLOC_CHECK */
354
355 #ifndef DEADP
356 # define DEADP(x) 0
357 #endif
358
359 /* Recording what needs to be marked for gc. */
360
361 struct gcpro *gcprolist;
362
363 /* Addresses of staticpro'd variables. Initialize it to a nonzero
364 value; otherwise some compilers put it into BSS. */
365
366 #define NSTATICS 0x800
367 static Lisp_Object *staticvec[NSTATICS] = {&Vpurify_flag};
368
369 /* Index of next unused slot in staticvec. */
370
371 static int staticidx;
372
373 static void *pure_alloc (size_t, int);
374
375
376 /* Value is SZ rounded up to the next multiple of ALIGNMENT.
377 ALIGNMENT must be a power of 2. */
378
379 #define ALIGN(ptr, ALIGNMENT) \
380 ((void *) (((uintptr_t) (ptr) + (ALIGNMENT) - 1) \
381 & ~ ((ALIGNMENT) - 1)))
382
383
384 \f
385 /************************************************************************
386 Malloc
387 ************************************************************************/
388
389 /* Function malloc calls this if it finds we are near exhausting storage. */
390
391 void
392 malloc_warning (const char *str)
393 {
394 pending_malloc_warning = str;
395 }
396
397
398 /* Display an already-pending malloc warning. */
399
400 void
401 display_malloc_warning (void)
402 {
403 call3 (intern ("display-warning"),
404 intern ("alloc"),
405 build_string (pending_malloc_warning),
406 intern ("emergency"));
407 pending_malloc_warning = 0;
408 }
409 \f
410 /* Called if we can't allocate relocatable space for a buffer. */
411
412 void
413 buffer_memory_full (ptrdiff_t nbytes)
414 {
415 /* If buffers use the relocating allocator, no need to free
416 spare_memory, because we may have plenty of malloc space left
417 that we could get, and if we don't, the malloc that fails will
418 itself cause spare_memory to be freed. If buffers don't use the
419 relocating allocator, treat this like any other failing
420 malloc. */
421
422 #ifndef REL_ALLOC
423 memory_full (nbytes);
424 #endif
425
426 /* This used to call error, but if we've run out of memory, we could
427 get infinite recursion trying to build the string. */
428 xsignal (Qnil, Vmemory_signal_data);
429 }
430
431 /* A common multiple of the positive integers A and B. Ideally this
432 would be the least common multiple, but there's no way to do that
433 as a constant expression in C, so do the best that we can easily do. */
434 #define COMMON_MULTIPLE(a, b) \
435 ((a) % (b) == 0 ? (a) : (b) % (a) == 0 ? (b) : (a) * (b))
436
437 #ifndef XMALLOC_OVERRUN_CHECK
438 #define XMALLOC_OVERRUN_CHECK_OVERHEAD 0
439 #else
440
441 /* Check for overrun in malloc'ed buffers by wrapping a header and trailer
442 around each block.
443
444 The header consists of XMALLOC_OVERRUN_CHECK_SIZE fixed bytes
445 followed by XMALLOC_OVERRUN_SIZE_SIZE bytes containing the original
446 block size in little-endian order. The trailer consists of
447 XMALLOC_OVERRUN_CHECK_SIZE fixed bytes.
448
449 The header is used to detect whether this block has been allocated
450 through these functions, as some low-level libc functions may
451 bypass the malloc hooks. */
452
453 #define XMALLOC_OVERRUN_CHECK_SIZE 16
454 #define XMALLOC_OVERRUN_CHECK_OVERHEAD \
455 (2 * XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE)
456
457 /* Define XMALLOC_OVERRUN_SIZE_SIZE so that (1) it's large enough to
458 hold a size_t value and (2) the header size is a multiple of the
459 alignment that Emacs needs for C types and for USE_LSB_TAG. */
460 #define XMALLOC_BASE_ALIGNMENT \
461 alignof (union { long double d; intmax_t i; void *p; })
462
463 #if USE_LSB_TAG
464 # define XMALLOC_HEADER_ALIGNMENT \
465 COMMON_MULTIPLE (GCALIGNMENT, XMALLOC_BASE_ALIGNMENT)
466 #else
467 # define XMALLOC_HEADER_ALIGNMENT XMALLOC_BASE_ALIGNMENT
468 #endif
469 #define XMALLOC_OVERRUN_SIZE_SIZE \
470 (((XMALLOC_OVERRUN_CHECK_SIZE + sizeof (size_t) \
471 + XMALLOC_HEADER_ALIGNMENT - 1) \
472 / XMALLOC_HEADER_ALIGNMENT * XMALLOC_HEADER_ALIGNMENT) \
473 - XMALLOC_OVERRUN_CHECK_SIZE)
474
475 static char const xmalloc_overrun_check_header[XMALLOC_OVERRUN_CHECK_SIZE] =
476 { '\x9a', '\x9b', '\xae', '\xaf',
477 '\xbf', '\xbe', '\xce', '\xcf',
478 '\xea', '\xeb', '\xec', '\xed',
479 '\xdf', '\xde', '\x9c', '\x9d' };
480
481 static char const xmalloc_overrun_check_trailer[XMALLOC_OVERRUN_CHECK_SIZE] =
482 { '\xaa', '\xab', '\xac', '\xad',
483 '\xba', '\xbb', '\xbc', '\xbd',
484 '\xca', '\xcb', '\xcc', '\xcd',
485 '\xda', '\xdb', '\xdc', '\xdd' };
486
487 /* Insert and extract the block size in the header. */
488
489 static void
490 xmalloc_put_size (unsigned char *ptr, size_t size)
491 {
492 int i;
493 for (i = 0; i < XMALLOC_OVERRUN_SIZE_SIZE; i++)
494 {
495 *--ptr = size & ((1 << CHAR_BIT) - 1);
496 size >>= CHAR_BIT;
497 }
498 }
499
500 static size_t
501 xmalloc_get_size (unsigned char *ptr)
502 {
503 size_t size = 0;
504 int i;
505 ptr -= XMALLOC_OVERRUN_SIZE_SIZE;
506 for (i = 0; i < XMALLOC_OVERRUN_SIZE_SIZE; i++)
507 {
508 size <<= CHAR_BIT;
509 size += *ptr++;
510 }
511 return size;
512 }
513
514
515 /* Like malloc, but wraps allocated block with header and trailer. */
516
517 static void *
518 overrun_check_malloc (size_t size)
519 {
520 register unsigned char *val;
521 if (SIZE_MAX - XMALLOC_OVERRUN_CHECK_OVERHEAD < size)
522 emacs_abort ();
523
524 val = malloc (size + XMALLOC_OVERRUN_CHECK_OVERHEAD);
525 if (val)
526 {
527 memcpy (val, xmalloc_overrun_check_header, XMALLOC_OVERRUN_CHECK_SIZE);
528 val += XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE;
529 xmalloc_put_size (val, size);
530 memcpy (val + size, xmalloc_overrun_check_trailer,
531 XMALLOC_OVERRUN_CHECK_SIZE);
532 }
533 return val;
534 }
535
536
537 /* Like realloc, but checks old block for overrun, and wraps new block
538 with header and trailer. */
539
540 static void *
541 overrun_check_realloc (void *block, size_t size)
542 {
543 register unsigned char *val = (unsigned char *) block;
544 if (SIZE_MAX - XMALLOC_OVERRUN_CHECK_OVERHEAD < size)
545 emacs_abort ();
546
547 if (val
548 && memcmp (xmalloc_overrun_check_header,
549 val - XMALLOC_OVERRUN_CHECK_SIZE - XMALLOC_OVERRUN_SIZE_SIZE,
550 XMALLOC_OVERRUN_CHECK_SIZE) == 0)
551 {
552 size_t osize = xmalloc_get_size (val);
553 if (memcmp (xmalloc_overrun_check_trailer, val + osize,
554 XMALLOC_OVERRUN_CHECK_SIZE))
555 emacs_abort ();
556 memset (val + osize, 0, XMALLOC_OVERRUN_CHECK_SIZE);
557 val -= XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE;
558 memset (val, 0, XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE);
559 }
560
561 val = realloc (val, size + XMALLOC_OVERRUN_CHECK_OVERHEAD);
562
563 if (val)
564 {
565 memcpy (val, xmalloc_overrun_check_header, XMALLOC_OVERRUN_CHECK_SIZE);
566 val += XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE;
567 xmalloc_put_size (val, size);
568 memcpy (val + size, xmalloc_overrun_check_trailer,
569 XMALLOC_OVERRUN_CHECK_SIZE);
570 }
571 return val;
572 }
573
574 /* Like free, but checks block for overrun. */
575
576 static void
577 overrun_check_free (void *block)
578 {
579 unsigned char *val = (unsigned char *) block;
580
581 if (val
582 && memcmp (xmalloc_overrun_check_header,
583 val - XMALLOC_OVERRUN_CHECK_SIZE - XMALLOC_OVERRUN_SIZE_SIZE,
584 XMALLOC_OVERRUN_CHECK_SIZE) == 0)
585 {
586 size_t osize = xmalloc_get_size (val);
587 if (memcmp (xmalloc_overrun_check_trailer, val + osize,
588 XMALLOC_OVERRUN_CHECK_SIZE))
589 emacs_abort ();
590 #ifdef XMALLOC_CLEAR_FREE_MEMORY
591 val -= XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE;
592 memset (val, 0xff, osize + XMALLOC_OVERRUN_CHECK_OVERHEAD);
593 #else
594 memset (val + osize, 0, XMALLOC_OVERRUN_CHECK_SIZE);
595 val -= XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE;
596 memset (val, 0, XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE);
597 #endif
598 }
599
600 free (val);
601 }
602
603 #undef malloc
604 #undef realloc
605 #undef free
606 #define malloc overrun_check_malloc
607 #define realloc overrun_check_realloc
608 #define free overrun_check_free
609 #endif
610
611 /* If compiled with XMALLOC_BLOCK_INPUT_CHECK, define a symbol
612 BLOCK_INPUT_IN_MEMORY_ALLOCATORS that is visible to the debugger.
613 If that variable is set, block input while in one of Emacs's memory
614 allocation functions. There should be no need for this debugging
615 option, since signal handlers do not allocate memory, but Emacs
616 formerly allocated memory in signal handlers and this compile-time
617 option remains as a way to help debug the issue should it rear its
618 ugly head again. */
619 #ifdef XMALLOC_BLOCK_INPUT_CHECK
620 bool block_input_in_memory_allocators EXTERNALLY_VISIBLE;
621 static void
622 malloc_block_input (void)
623 {
624 if (block_input_in_memory_allocators)
625 block_input ();
626 }
627 static void
628 malloc_unblock_input (void)
629 {
630 if (block_input_in_memory_allocators)
631 unblock_input ();
632 }
633 # define MALLOC_BLOCK_INPUT malloc_block_input ()
634 # define MALLOC_UNBLOCK_INPUT malloc_unblock_input ()
635 #else
636 # define MALLOC_BLOCK_INPUT ((void) 0)
637 # define MALLOC_UNBLOCK_INPUT ((void) 0)
638 #endif
639
640 #define MALLOC_PROBE(size) \
641 do { \
642 if (profiler_memory_running) \
643 malloc_probe (size); \
644 } while (0)
645
646
647 /* Like malloc but check for no memory and block interrupt input.. */
648
649 void *
650 xmalloc (size_t size)
651 {
652 void *val;
653
654 MALLOC_BLOCK_INPUT;
655 val = malloc (size);
656 MALLOC_UNBLOCK_INPUT;
657
658 if (!val && size)
659 memory_full (size);
660 MALLOC_PROBE (size);
661 return val;
662 }
663
664 /* Like the above, but zeroes out the memory just allocated. */
665
666 void *
667 xzalloc (size_t size)
668 {
669 void *val;
670
671 MALLOC_BLOCK_INPUT;
672 val = malloc (size);
673 MALLOC_UNBLOCK_INPUT;
674
675 if (!val && size)
676 memory_full (size);
677 memset (val, 0, size);
678 MALLOC_PROBE (size);
679 return val;
680 }
681
682 /* Like realloc but check for no memory and block interrupt input.. */
683
684 void *
685 xrealloc (void *block, size_t size)
686 {
687 void *val;
688
689 MALLOC_BLOCK_INPUT;
690 /* We must call malloc explicitly when BLOCK is 0, since some
691 reallocs don't do this. */
692 if (! block)
693 val = malloc (size);
694 else
695 val = realloc (block, size);
696 MALLOC_UNBLOCK_INPUT;
697
698 if (!val && size)
699 memory_full (size);
700 MALLOC_PROBE (size);
701 return val;
702 }
703
704
705 /* Like free but block interrupt input. */
706
707 void
708 xfree (void *block)
709 {
710 if (!block)
711 return;
712 MALLOC_BLOCK_INPUT;
713 free (block);
714 MALLOC_UNBLOCK_INPUT;
715 /* We don't call refill_memory_reserve here
716 because in practice the call in r_alloc_free seems to suffice. */
717 }
718
719
720 /* Other parts of Emacs pass large int values to allocator functions
721 expecting ptrdiff_t. This is portable in practice, but check it to
722 be safe. */
723 verify (INT_MAX <= PTRDIFF_MAX);
724
725
726 /* Allocate an array of NITEMS items, each of size ITEM_SIZE.
727 Signal an error on memory exhaustion, and block interrupt input. */
728
729 void *
730 xnmalloc (ptrdiff_t nitems, ptrdiff_t item_size)
731 {
732 eassert (0 <= nitems && 0 < item_size);
733 if (min (PTRDIFF_MAX, SIZE_MAX) / item_size < nitems)
734 memory_full (SIZE_MAX);
735 return xmalloc (nitems * item_size);
736 }
737
738
739 /* Reallocate an array PA to make it of NITEMS items, each of size ITEM_SIZE.
740 Signal an error on memory exhaustion, and block interrupt input. */
741
742 void *
743 xnrealloc (void *pa, ptrdiff_t nitems, ptrdiff_t item_size)
744 {
745 eassert (0 <= nitems && 0 < item_size);
746 if (min (PTRDIFF_MAX, SIZE_MAX) / item_size < nitems)
747 memory_full (SIZE_MAX);
748 return xrealloc (pa, nitems * item_size);
749 }
750
751
752 /* Grow PA, which points to an array of *NITEMS items, and return the
753 location of the reallocated array, updating *NITEMS to reflect its
754 new size. The new array will contain at least NITEMS_INCR_MIN more
755 items, but will not contain more than NITEMS_MAX items total.
756 ITEM_SIZE is the size of each item, in bytes.
757
758 ITEM_SIZE and NITEMS_INCR_MIN must be positive. *NITEMS must be
759 nonnegative. If NITEMS_MAX is -1, it is treated as if it were
760 infinity.
761
762 If PA is null, then allocate a new array instead of reallocating
763 the old one.
764
765 Block interrupt input as needed. If memory exhaustion occurs, set
766 *NITEMS to zero if PA is null, and signal an error (i.e., do not
767 return).
768
769 Thus, to grow an array A without saving its old contents, do
770 { xfree (A); A = NULL; A = xpalloc (NULL, &AITEMS, ...); }.
771 The A = NULL avoids a dangling pointer if xpalloc exhausts memory
772 and signals an error, and later this code is reexecuted and
773 attempts to free A. */
774
775 void *
776 xpalloc (void *pa, ptrdiff_t *nitems, ptrdiff_t nitems_incr_min,
777 ptrdiff_t nitems_max, ptrdiff_t item_size)
778 {
779 /* The approximate size to use for initial small allocation
780 requests. This is the largest "small" request for the GNU C
781 library malloc. */
782 enum { DEFAULT_MXFAST = 64 * sizeof (size_t) / 4 };
783
784 /* If the array is tiny, grow it to about (but no greater than)
785 DEFAULT_MXFAST bytes. Otherwise, grow it by about 50%. */
786 ptrdiff_t n = *nitems;
787 ptrdiff_t tiny_max = DEFAULT_MXFAST / item_size - n;
788 ptrdiff_t half_again = n >> 1;
789 ptrdiff_t incr_estimate = max (tiny_max, half_again);
790
791 /* Adjust the increment according to three constraints: NITEMS_INCR_MIN,
792 NITEMS_MAX, and what the C language can represent safely. */
793 ptrdiff_t C_language_max = min (PTRDIFF_MAX, SIZE_MAX) / item_size;
794 ptrdiff_t n_max = (0 <= nitems_max && nitems_max < C_language_max
795 ? nitems_max : C_language_max);
796 ptrdiff_t nitems_incr_max = n_max - n;
797 ptrdiff_t incr = max (nitems_incr_min, min (incr_estimate, nitems_incr_max));
798
799 eassert (0 < item_size && 0 < nitems_incr_min && 0 <= n && -1 <= nitems_max);
800 if (! pa)
801 *nitems = 0;
802 if (nitems_incr_max < incr)
803 memory_full (SIZE_MAX);
804 n += incr;
805 pa = xrealloc (pa, n * item_size);
806 *nitems = n;
807 return pa;
808 }
809
810
811 /* Like strdup, but uses xmalloc. */
812
813 char *
814 xstrdup (const char *s)
815 {
816 size_t len = strlen (s) + 1;
817 char *p = xmalloc (len);
818 memcpy (p, s, len);
819 return p;
820 }
821
822 /* Like putenv, but (1) use the equivalent of xmalloc and (2) the
823 argument is a const pointer. */
824
825 void
826 xputenv (char const *string)
827 {
828 if (putenv ((char *) string) != 0)
829 memory_full (0);
830 }
831
832 /* Unwind for SAFE_ALLOCA */
833
834 Lisp_Object
835 safe_alloca_unwind (Lisp_Object arg)
836 {
837 free_save_value (arg);
838 return Qnil;
839 }
840
841 /* Return a newly allocated memory block of SIZE bytes, remembering
842 to free it when unwinding. */
843 void *
844 record_xmalloc (size_t size)
845 {
846 void *p = xmalloc (size);
847 record_unwind_protect (safe_alloca_unwind, make_save_value (p, 0));
848 return p;
849 }
850
851
852 /* Like malloc but used for allocating Lisp data. NBYTES is the
853 number of bytes to allocate, TYPE describes the intended use of the
854 allocated memory block (for strings, for conses, ...). */
855
856 #if ! USE_LSB_TAG
857 void *lisp_malloc_loser EXTERNALLY_VISIBLE;
858 #endif
859
860 static void *
861 lisp_malloc (size_t nbytes, enum mem_type type)
862 {
863 register void *val;
864
865 MALLOC_BLOCK_INPUT;
866
867 #ifdef GC_MALLOC_CHECK
868 allocated_mem_type = type;
869 #endif
870
871 val = malloc (nbytes);
872
873 #if ! USE_LSB_TAG
874 /* If the memory just allocated cannot be addressed thru a Lisp
875 object's pointer, and it needs to be,
876 that's equivalent to running out of memory. */
877 if (val && type != MEM_TYPE_NON_LISP)
878 {
879 Lisp_Object tem;
880 XSETCONS (tem, (char *) val + nbytes - 1);
881 if ((char *) XCONS (tem) != (char *) val + nbytes - 1)
882 {
883 lisp_malloc_loser = val;
884 free (val);
885 val = 0;
886 }
887 }
888 #endif
889
890 #if GC_MARK_STACK && !defined GC_MALLOC_CHECK
891 if (val && type != MEM_TYPE_NON_LISP)
892 mem_insert (val, (char *) val + nbytes, type);
893 #endif
894
895 MALLOC_UNBLOCK_INPUT;
896 if (!val && nbytes)
897 memory_full (nbytes);
898 MALLOC_PROBE (nbytes);
899 return val;
900 }
901
902 /* Free BLOCK. This must be called to free memory allocated with a
903 call to lisp_malloc. */
904
905 static void
906 lisp_free (void *block)
907 {
908 MALLOC_BLOCK_INPUT;
909 free (block);
910 #if GC_MARK_STACK && !defined GC_MALLOC_CHECK
911 mem_delete (mem_find (block));
912 #endif
913 MALLOC_UNBLOCK_INPUT;
914 }
915
916 /***** Allocation of aligned blocks of memory to store Lisp data. *****/
917
918 /* The entry point is lisp_align_malloc which returns blocks of at most
919 BLOCK_BYTES and guarantees they are aligned on a BLOCK_ALIGN boundary. */
920
921 #if defined (HAVE_POSIX_MEMALIGN) && defined (SYSTEM_MALLOC)
922 #define USE_POSIX_MEMALIGN 1
923 #endif
924
925 /* BLOCK_ALIGN has to be a power of 2. */
926 #define BLOCK_ALIGN (1 << 10)
927
928 /* Padding to leave at the end of a malloc'd block. This is to give
929 malloc a chance to minimize the amount of memory wasted to alignment.
930 It should be tuned to the particular malloc library used.
931 On glibc-2.3.2, malloc never tries to align, so a padding of 0 is best.
932 posix_memalign on the other hand would ideally prefer a value of 4
933 because otherwise, there's 1020 bytes wasted between each ablocks.
934 In Emacs, testing shows that those 1020 can most of the time be
935 efficiently used by malloc to place other objects, so a value of 0 can
936 still preferable unless you have a lot of aligned blocks and virtually
937 nothing else. */
938 #define BLOCK_PADDING 0
939 #define BLOCK_BYTES \
940 (BLOCK_ALIGN - sizeof (struct ablocks *) - BLOCK_PADDING)
941
942 /* Internal data structures and constants. */
943
944 #define ABLOCKS_SIZE 16
945
946 /* An aligned block of memory. */
947 struct ablock
948 {
949 union
950 {
951 char payload[BLOCK_BYTES];
952 struct ablock *next_free;
953 } x;
954 /* `abase' is the aligned base of the ablocks. */
955 /* It is overloaded to hold the virtual `busy' field that counts
956 the number of used ablock in the parent ablocks.
957 The first ablock has the `busy' field, the others have the `abase'
958 field. To tell the difference, we assume that pointers will have
959 integer values larger than 2 * ABLOCKS_SIZE. The lowest bit of `busy'
960 is used to tell whether the real base of the parent ablocks is `abase'
961 (if not, the word before the first ablock holds a pointer to the
962 real base). */
963 struct ablocks *abase;
964 /* The padding of all but the last ablock is unused. The padding of
965 the last ablock in an ablocks is not allocated. */
966 #if BLOCK_PADDING
967 char padding[BLOCK_PADDING];
968 #endif
969 };
970
971 /* A bunch of consecutive aligned blocks. */
972 struct ablocks
973 {
974 struct ablock blocks[ABLOCKS_SIZE];
975 };
976
977 /* Size of the block requested from malloc or posix_memalign. */
978 #define ABLOCKS_BYTES (sizeof (struct ablocks) - BLOCK_PADDING)
979
980 #define ABLOCK_ABASE(block) \
981 (((uintptr_t) (block)->abase) <= (1 + 2 * ABLOCKS_SIZE) \
982 ? (struct ablocks *)(block) \
983 : (block)->abase)
984
985 /* Virtual `busy' field. */
986 #define ABLOCKS_BUSY(abase) ((abase)->blocks[0].abase)
987
988 /* Pointer to the (not necessarily aligned) malloc block. */
989 #ifdef USE_POSIX_MEMALIGN
990 #define ABLOCKS_BASE(abase) (abase)
991 #else
992 #define ABLOCKS_BASE(abase) \
993 (1 & (intptr_t) ABLOCKS_BUSY (abase) ? abase : ((void**)abase)[-1])
994 #endif
995
996 /* The list of free ablock. */
997 static struct ablock *free_ablock;
998
999 /* Allocate an aligned block of nbytes.
1000 Alignment is on a multiple of BLOCK_ALIGN and `nbytes' has to be
1001 smaller or equal to BLOCK_BYTES. */
1002 static void *
1003 lisp_align_malloc (size_t nbytes, enum mem_type type)
1004 {
1005 void *base, *val;
1006 struct ablocks *abase;
1007
1008 eassert (nbytes <= BLOCK_BYTES);
1009
1010 MALLOC_BLOCK_INPUT;
1011
1012 #ifdef GC_MALLOC_CHECK
1013 allocated_mem_type = type;
1014 #endif
1015
1016 if (!free_ablock)
1017 {
1018 int i;
1019 intptr_t aligned; /* int gets warning casting to 64-bit pointer. */
1020
1021 #ifdef DOUG_LEA_MALLOC
1022 /* Prevent mmap'ing the chunk. Lisp data may not be mmap'ed
1023 because mapped region contents are not preserved in
1024 a dumped Emacs. */
1025 mallopt (M_MMAP_MAX, 0);
1026 #endif
1027
1028 #ifdef USE_POSIX_MEMALIGN
1029 {
1030 int err = posix_memalign (&base, BLOCK_ALIGN, ABLOCKS_BYTES);
1031 if (err)
1032 base = NULL;
1033 abase = base;
1034 }
1035 #else
1036 base = malloc (ABLOCKS_BYTES);
1037 abase = ALIGN (base, BLOCK_ALIGN);
1038 #endif
1039
1040 if (base == 0)
1041 {
1042 MALLOC_UNBLOCK_INPUT;
1043 memory_full (ABLOCKS_BYTES);
1044 }
1045
1046 aligned = (base == abase);
1047 if (!aligned)
1048 ((void**)abase)[-1] = base;
1049
1050 #ifdef DOUG_LEA_MALLOC
1051 /* Back to a reasonable maximum of mmap'ed areas. */
1052 mallopt (M_MMAP_MAX, MMAP_MAX_AREAS);
1053 #endif
1054
1055 #if ! USE_LSB_TAG
1056 /* If the memory just allocated cannot be addressed thru a Lisp
1057 object's pointer, and it needs to be, that's equivalent to
1058 running out of memory. */
1059 if (type != MEM_TYPE_NON_LISP)
1060 {
1061 Lisp_Object tem;
1062 char *end = (char *) base + ABLOCKS_BYTES - 1;
1063 XSETCONS (tem, end);
1064 if ((char *) XCONS (tem) != end)
1065 {
1066 lisp_malloc_loser = base;
1067 free (base);
1068 MALLOC_UNBLOCK_INPUT;
1069 memory_full (SIZE_MAX);
1070 }
1071 }
1072 #endif
1073
1074 /* Initialize the blocks and put them on the free list.
1075 If `base' was not properly aligned, we can't use the last block. */
1076 for (i = 0; i < (aligned ? ABLOCKS_SIZE : ABLOCKS_SIZE - 1); i++)
1077 {
1078 abase->blocks[i].abase = abase;
1079 abase->blocks[i].x.next_free = free_ablock;
1080 free_ablock = &abase->blocks[i];
1081 }
1082 ABLOCKS_BUSY (abase) = (struct ablocks *) aligned;
1083
1084 eassert (0 == ((uintptr_t) abase) % BLOCK_ALIGN);
1085 eassert (ABLOCK_ABASE (&abase->blocks[3]) == abase); /* 3 is arbitrary */
1086 eassert (ABLOCK_ABASE (&abase->blocks[0]) == abase);
1087 eassert (ABLOCKS_BASE (abase) == base);
1088 eassert (aligned == (intptr_t) ABLOCKS_BUSY (abase));
1089 }
1090
1091 abase = ABLOCK_ABASE (free_ablock);
1092 ABLOCKS_BUSY (abase) =
1093 (struct ablocks *) (2 + (intptr_t) ABLOCKS_BUSY (abase));
1094 val = free_ablock;
1095 free_ablock = free_ablock->x.next_free;
1096
1097 #if GC_MARK_STACK && !defined GC_MALLOC_CHECK
1098 if (type != MEM_TYPE_NON_LISP)
1099 mem_insert (val, (char *) val + nbytes, type);
1100 #endif
1101
1102 MALLOC_UNBLOCK_INPUT;
1103
1104 MALLOC_PROBE (nbytes);
1105
1106 eassert (0 == ((uintptr_t) val) % BLOCK_ALIGN);
1107 return val;
1108 }
1109
1110 static void
1111 lisp_align_free (void *block)
1112 {
1113 struct ablock *ablock = block;
1114 struct ablocks *abase = ABLOCK_ABASE (ablock);
1115
1116 MALLOC_BLOCK_INPUT;
1117 #if GC_MARK_STACK && !defined GC_MALLOC_CHECK
1118 mem_delete (mem_find (block));
1119 #endif
1120 /* Put on free list. */
1121 ablock->x.next_free = free_ablock;
1122 free_ablock = ablock;
1123 /* Update busy count. */
1124 ABLOCKS_BUSY (abase)
1125 = (struct ablocks *) (-2 + (intptr_t) ABLOCKS_BUSY (abase));
1126
1127 if (2 > (intptr_t) ABLOCKS_BUSY (abase))
1128 { /* All the blocks are free. */
1129 int i = 0, aligned = (intptr_t) ABLOCKS_BUSY (abase);
1130 struct ablock **tem = &free_ablock;
1131 struct ablock *atop = &abase->blocks[aligned ? ABLOCKS_SIZE : ABLOCKS_SIZE - 1];
1132
1133 while (*tem)
1134 {
1135 if (*tem >= (struct ablock *) abase && *tem < atop)
1136 {
1137 i++;
1138 *tem = (*tem)->x.next_free;
1139 }
1140 else
1141 tem = &(*tem)->x.next_free;
1142 }
1143 eassert ((aligned & 1) == aligned);
1144 eassert (i == (aligned ? ABLOCKS_SIZE : ABLOCKS_SIZE - 1));
1145 #ifdef USE_POSIX_MEMALIGN
1146 eassert ((uintptr_t) ABLOCKS_BASE (abase) % BLOCK_ALIGN == 0);
1147 #endif
1148 free (ABLOCKS_BASE (abase));
1149 }
1150 MALLOC_UNBLOCK_INPUT;
1151 }
1152
1153 \f
1154 /***********************************************************************
1155 Interval Allocation
1156 ***********************************************************************/
1157
1158 /* Number of intervals allocated in an interval_block structure.
1159 The 1020 is 1024 minus malloc overhead. */
1160
1161 #define INTERVAL_BLOCK_SIZE \
1162 ((1020 - sizeof (struct interval_block *)) / sizeof (struct interval))
1163
1164 /* Intervals are allocated in chunks in form of an interval_block
1165 structure. */
1166
1167 struct interval_block
1168 {
1169 /* Place `intervals' first, to preserve alignment. */
1170 struct interval intervals[INTERVAL_BLOCK_SIZE];
1171 struct interval_block *next;
1172 };
1173
1174 /* Current interval block. Its `next' pointer points to older
1175 blocks. */
1176
1177 static struct interval_block *interval_block;
1178
1179 /* Index in interval_block above of the next unused interval
1180 structure. */
1181
1182 static int interval_block_index = INTERVAL_BLOCK_SIZE;
1183
1184 /* Number of free and live intervals. */
1185
1186 static EMACS_INT total_free_intervals, total_intervals;
1187
1188 /* List of free intervals. */
1189
1190 static INTERVAL interval_free_list;
1191
1192 /* Return a new interval. */
1193
1194 INTERVAL
1195 make_interval (void)
1196 {
1197 INTERVAL val;
1198
1199 MALLOC_BLOCK_INPUT;
1200
1201 if (interval_free_list)
1202 {
1203 val = interval_free_list;
1204 interval_free_list = INTERVAL_PARENT (interval_free_list);
1205 }
1206 else
1207 {
1208 if (interval_block_index == INTERVAL_BLOCK_SIZE)
1209 {
1210 struct interval_block *newi
1211 = lisp_malloc (sizeof *newi, MEM_TYPE_NON_LISP);
1212
1213 newi->next = interval_block;
1214 interval_block = newi;
1215 interval_block_index = 0;
1216 total_free_intervals += INTERVAL_BLOCK_SIZE;
1217 }
1218 val = &interval_block->intervals[interval_block_index++];
1219 }
1220
1221 MALLOC_UNBLOCK_INPUT;
1222
1223 consing_since_gc += sizeof (struct interval);
1224 intervals_consed++;
1225 total_free_intervals--;
1226 RESET_INTERVAL (val);
1227 val->gcmarkbit = 0;
1228 return val;
1229 }
1230
1231
1232 /* Mark Lisp objects in interval I. */
1233
1234 static void
1235 mark_interval (register INTERVAL i, Lisp_Object dummy)
1236 {
1237 /* Intervals should never be shared. So, if extra internal checking is
1238 enabled, GC aborts if it seems to have visited an interval twice. */
1239 eassert (!i->gcmarkbit);
1240 i->gcmarkbit = 1;
1241 mark_object (i->plist);
1242 }
1243
1244 /* Mark the interval tree rooted in I. */
1245
1246 #define MARK_INTERVAL_TREE(i) \
1247 do { \
1248 if (i && !i->gcmarkbit) \
1249 traverse_intervals_noorder (i, mark_interval, Qnil); \
1250 } while (0)
1251
1252 /***********************************************************************
1253 String Allocation
1254 ***********************************************************************/
1255
1256 /* Lisp_Strings are allocated in string_block structures. When a new
1257 string_block is allocated, all the Lisp_Strings it contains are
1258 added to a free-list string_free_list. When a new Lisp_String is
1259 needed, it is taken from that list. During the sweep phase of GC,
1260 string_blocks that are entirely free are freed, except two which
1261 we keep.
1262
1263 String data is allocated from sblock structures. Strings larger
1264 than LARGE_STRING_BYTES, get their own sblock, data for smaller
1265 strings is sub-allocated out of sblocks of size SBLOCK_SIZE.
1266
1267 Sblocks consist internally of sdata structures, one for each
1268 Lisp_String. The sdata structure points to the Lisp_String it
1269 belongs to. The Lisp_String points back to the `u.data' member of
1270 its sdata structure.
1271
1272 When a Lisp_String is freed during GC, it is put back on
1273 string_free_list, and its `data' member and its sdata's `string'
1274 pointer is set to null. The size of the string is recorded in the
1275 `u.nbytes' member of the sdata. So, sdata structures that are no
1276 longer used, can be easily recognized, and it's easy to compact the
1277 sblocks of small strings which we do in compact_small_strings. */
1278
1279 /* Size in bytes of an sblock structure used for small strings. This
1280 is 8192 minus malloc overhead. */
1281
1282 #define SBLOCK_SIZE 8188
1283
1284 /* Strings larger than this are considered large strings. String data
1285 for large strings is allocated from individual sblocks. */
1286
1287 #define LARGE_STRING_BYTES 1024
1288
1289 /* Structure describing string memory sub-allocated from an sblock.
1290 This is where the contents of Lisp strings are stored. */
1291
1292 struct sdata
1293 {
1294 /* Back-pointer to the string this sdata belongs to. If null, this
1295 structure is free, and the NBYTES member of the union below
1296 contains the string's byte size (the same value that STRING_BYTES
1297 would return if STRING were non-null). If non-null, STRING_BYTES
1298 (STRING) is the size of the data, and DATA contains the string's
1299 contents. */
1300 struct Lisp_String *string;
1301
1302 #ifdef GC_CHECK_STRING_BYTES
1303
1304 ptrdiff_t nbytes;
1305 unsigned char data[1];
1306
1307 #define SDATA_NBYTES(S) (S)->nbytes
1308 #define SDATA_DATA(S) (S)->data
1309 #define SDATA_SELECTOR(member) member
1310
1311 #else /* not GC_CHECK_STRING_BYTES */
1312
1313 union
1314 {
1315 /* When STRING is non-null. */
1316 unsigned char data[1];
1317
1318 /* When STRING is null. */
1319 ptrdiff_t nbytes;
1320 } u;
1321
1322 #define SDATA_NBYTES(S) (S)->u.nbytes
1323 #define SDATA_DATA(S) (S)->u.data
1324 #define SDATA_SELECTOR(member) u.member
1325
1326 #endif /* not GC_CHECK_STRING_BYTES */
1327
1328 #define SDATA_DATA_OFFSET offsetof (struct sdata, SDATA_SELECTOR (data))
1329 };
1330
1331
1332 /* Structure describing a block of memory which is sub-allocated to
1333 obtain string data memory for strings. Blocks for small strings
1334 are of fixed size SBLOCK_SIZE. Blocks for large strings are made
1335 as large as needed. */
1336
1337 struct sblock
1338 {
1339 /* Next in list. */
1340 struct sblock *next;
1341
1342 /* Pointer to the next free sdata block. This points past the end
1343 of the sblock if there isn't any space left in this block. */
1344 struct sdata *next_free;
1345
1346 /* Start of data. */
1347 struct sdata first_data;
1348 };
1349
1350 /* Number of Lisp strings in a string_block structure. The 1020 is
1351 1024 minus malloc overhead. */
1352
1353 #define STRING_BLOCK_SIZE \
1354 ((1020 - sizeof (struct string_block *)) / sizeof (struct Lisp_String))
1355
1356 /* Structure describing a block from which Lisp_String structures
1357 are allocated. */
1358
1359 struct string_block
1360 {
1361 /* Place `strings' first, to preserve alignment. */
1362 struct Lisp_String strings[STRING_BLOCK_SIZE];
1363 struct string_block *next;
1364 };
1365
1366 /* Head and tail of the list of sblock structures holding Lisp string
1367 data. We always allocate from current_sblock. The NEXT pointers
1368 in the sblock structures go from oldest_sblock to current_sblock. */
1369
1370 static struct sblock *oldest_sblock, *current_sblock;
1371
1372 /* List of sblocks for large strings. */
1373
1374 static struct sblock *large_sblocks;
1375
1376 /* List of string_block structures. */
1377
1378 static struct string_block *string_blocks;
1379
1380 /* Free-list of Lisp_Strings. */
1381
1382 static struct Lisp_String *string_free_list;
1383
1384 /* Number of live and free Lisp_Strings. */
1385
1386 static EMACS_INT total_strings, total_free_strings;
1387
1388 /* Number of bytes used by live strings. */
1389
1390 static EMACS_INT total_string_bytes;
1391
1392 /* Given a pointer to a Lisp_String S which is on the free-list
1393 string_free_list, return a pointer to its successor in the
1394 free-list. */
1395
1396 #define NEXT_FREE_LISP_STRING(S) (*(struct Lisp_String **) (S))
1397
1398 /* Return a pointer to the sdata structure belonging to Lisp string S.
1399 S must be live, i.e. S->data must not be null. S->data is actually
1400 a pointer to the `u.data' member of its sdata structure; the
1401 structure starts at a constant offset in front of that. */
1402
1403 #define SDATA_OF_STRING(S) ((struct sdata *) ((S)->data - SDATA_DATA_OFFSET))
1404
1405
1406 #ifdef GC_CHECK_STRING_OVERRUN
1407
1408 /* We check for overrun in string data blocks by appending a small
1409 "cookie" after each allocated string data block, and check for the
1410 presence of this cookie during GC. */
1411
1412 #define GC_STRING_OVERRUN_COOKIE_SIZE 4
1413 static char const string_overrun_cookie[GC_STRING_OVERRUN_COOKIE_SIZE] =
1414 { '\xde', '\xad', '\xbe', '\xef' };
1415
1416 #else
1417 #define GC_STRING_OVERRUN_COOKIE_SIZE 0
1418 #endif
1419
1420 /* Value is the size of an sdata structure large enough to hold NBYTES
1421 bytes of string data. The value returned includes a terminating
1422 NUL byte, the size of the sdata structure, and padding. */
1423
1424 #ifdef GC_CHECK_STRING_BYTES
1425
1426 #define SDATA_SIZE(NBYTES) \
1427 ((SDATA_DATA_OFFSET \
1428 + (NBYTES) + 1 \
1429 + sizeof (ptrdiff_t) - 1) \
1430 & ~(sizeof (ptrdiff_t) - 1))
1431
1432 #else /* not GC_CHECK_STRING_BYTES */
1433
1434 /* The 'max' reserves space for the nbytes union member even when NBYTES + 1 is
1435 less than the size of that member. The 'max' is not needed when
1436 SDATA_DATA_OFFSET is a multiple of sizeof (ptrdiff_t), because then the
1437 alignment code reserves enough space. */
1438
1439 #define SDATA_SIZE(NBYTES) \
1440 ((SDATA_DATA_OFFSET \
1441 + (SDATA_DATA_OFFSET % sizeof (ptrdiff_t) == 0 \
1442 ? NBYTES \
1443 : max (NBYTES, sizeof (ptrdiff_t) - 1)) \
1444 + 1 \
1445 + sizeof (ptrdiff_t) - 1) \
1446 & ~(sizeof (ptrdiff_t) - 1))
1447
1448 #endif /* not GC_CHECK_STRING_BYTES */
1449
1450 /* Extra bytes to allocate for each string. */
1451
1452 #define GC_STRING_EXTRA (GC_STRING_OVERRUN_COOKIE_SIZE)
1453
1454 /* Exact bound on the number of bytes in a string, not counting the
1455 terminating null. A string cannot contain more bytes than
1456 STRING_BYTES_BOUND, nor can it be so long that the size_t
1457 arithmetic in allocate_string_data would overflow while it is
1458 calculating a value to be passed to malloc. */
1459 static ptrdiff_t const STRING_BYTES_MAX =
1460 min (STRING_BYTES_BOUND,
1461 ((SIZE_MAX - XMALLOC_OVERRUN_CHECK_OVERHEAD
1462 - GC_STRING_EXTRA
1463 - offsetof (struct sblock, first_data)
1464 - SDATA_DATA_OFFSET)
1465 & ~(sizeof (EMACS_INT) - 1)));
1466
1467 /* Initialize string allocation. Called from init_alloc_once. */
1468
1469 static void
1470 init_strings (void)
1471 {
1472 empty_unibyte_string = make_pure_string ("", 0, 0, 0);
1473 empty_multibyte_string = make_pure_string ("", 0, 0, 1);
1474 }
1475
1476
1477 #ifdef GC_CHECK_STRING_BYTES
1478
1479 static int check_string_bytes_count;
1480
1481 /* Like STRING_BYTES, but with debugging check. Can be
1482 called during GC, so pay attention to the mark bit. */
1483
1484 ptrdiff_t
1485 string_bytes (struct Lisp_String *s)
1486 {
1487 ptrdiff_t nbytes =
1488 (s->size_byte < 0 ? s->size & ~ARRAY_MARK_FLAG : s->size_byte);
1489
1490 if (!PURE_POINTER_P (s)
1491 && s->data
1492 && nbytes != SDATA_NBYTES (SDATA_OF_STRING (s)))
1493 emacs_abort ();
1494 return nbytes;
1495 }
1496
1497 /* Check validity of Lisp strings' string_bytes member in B. */
1498
1499 static void
1500 check_sblock (struct sblock *b)
1501 {
1502 struct sdata *from, *end, *from_end;
1503
1504 end = b->next_free;
1505
1506 for (from = &b->first_data; from < end; from = from_end)
1507 {
1508 /* Compute the next FROM here because copying below may
1509 overwrite data we need to compute it. */
1510 ptrdiff_t nbytes;
1511
1512 /* Check that the string size recorded in the string is the
1513 same as the one recorded in the sdata structure. */
1514 nbytes = SDATA_SIZE (from->string ? string_bytes (from->string)
1515 : SDATA_NBYTES (from));
1516 from_end = (struct sdata *) ((char *) from + nbytes + GC_STRING_EXTRA);
1517 }
1518 }
1519
1520
1521 /* Check validity of Lisp strings' string_bytes member. ALL_P
1522 means check all strings, otherwise check only most
1523 recently allocated strings. Used for hunting a bug. */
1524
1525 static void
1526 check_string_bytes (bool all_p)
1527 {
1528 if (all_p)
1529 {
1530 struct sblock *b;
1531
1532 for (b = large_sblocks; b; b = b->next)
1533 {
1534 struct Lisp_String *s = b->first_data.string;
1535 if (s)
1536 string_bytes (s);
1537 }
1538
1539 for (b = oldest_sblock; b; b = b->next)
1540 check_sblock (b);
1541 }
1542 else if (current_sblock)
1543 check_sblock (current_sblock);
1544 }
1545
1546 #else /* not GC_CHECK_STRING_BYTES */
1547
1548 #define check_string_bytes(all) ((void) 0)
1549
1550 #endif /* GC_CHECK_STRING_BYTES */
1551
1552 #ifdef GC_CHECK_STRING_FREE_LIST
1553
1554 /* Walk through the string free list looking for bogus next pointers.
1555 This may catch buffer overrun from a previous string. */
1556
1557 static void
1558 check_string_free_list (void)
1559 {
1560 struct Lisp_String *s;
1561
1562 /* Pop a Lisp_String off the free-list. */
1563 s = string_free_list;
1564 while (s != NULL)
1565 {
1566 if ((uintptr_t) s < 1024)
1567 emacs_abort ();
1568 s = NEXT_FREE_LISP_STRING (s);
1569 }
1570 }
1571 #else
1572 #define check_string_free_list()
1573 #endif
1574
1575 /* Return a new Lisp_String. */
1576
1577 static struct Lisp_String *
1578 allocate_string (void)
1579 {
1580 struct Lisp_String *s;
1581
1582 MALLOC_BLOCK_INPUT;
1583
1584 /* If the free-list is empty, allocate a new string_block, and
1585 add all the Lisp_Strings in it to the free-list. */
1586 if (string_free_list == NULL)
1587 {
1588 struct string_block *b = lisp_malloc (sizeof *b, MEM_TYPE_STRING);
1589 int i;
1590
1591 b->next = string_blocks;
1592 string_blocks = b;
1593
1594 for (i = STRING_BLOCK_SIZE - 1; i >= 0; --i)
1595 {
1596 s = b->strings + i;
1597 /* Every string on a free list should have NULL data pointer. */
1598 s->data = NULL;
1599 NEXT_FREE_LISP_STRING (s) = string_free_list;
1600 string_free_list = s;
1601 }
1602
1603 total_free_strings += STRING_BLOCK_SIZE;
1604 }
1605
1606 check_string_free_list ();
1607
1608 /* Pop a Lisp_String off the free-list. */
1609 s = string_free_list;
1610 string_free_list = NEXT_FREE_LISP_STRING (s);
1611
1612 MALLOC_UNBLOCK_INPUT;
1613
1614 --total_free_strings;
1615 ++total_strings;
1616 ++strings_consed;
1617 consing_since_gc += sizeof *s;
1618
1619 #ifdef GC_CHECK_STRING_BYTES
1620 if (!noninteractive)
1621 {
1622 if (++check_string_bytes_count == 200)
1623 {
1624 check_string_bytes_count = 0;
1625 check_string_bytes (1);
1626 }
1627 else
1628 check_string_bytes (0);
1629 }
1630 #endif /* GC_CHECK_STRING_BYTES */
1631
1632 return s;
1633 }
1634
1635
1636 /* Set up Lisp_String S for holding NCHARS characters, NBYTES bytes,
1637 plus a NUL byte at the end. Allocate an sdata structure for S, and
1638 set S->data to its `u.data' member. Store a NUL byte at the end of
1639 S->data. Set S->size to NCHARS and S->size_byte to NBYTES. Free
1640 S->data if it was initially non-null. */
1641
1642 void
1643 allocate_string_data (struct Lisp_String *s,
1644 EMACS_INT nchars, EMACS_INT nbytes)
1645 {
1646 struct sdata *data, *old_data;
1647 struct sblock *b;
1648 ptrdiff_t needed, old_nbytes;
1649
1650 if (STRING_BYTES_MAX < nbytes)
1651 string_overflow ();
1652
1653 /* Determine the number of bytes needed to store NBYTES bytes
1654 of string data. */
1655 needed = SDATA_SIZE (nbytes);
1656 if (s->data)
1657 {
1658 old_data = SDATA_OF_STRING (s);
1659 old_nbytes = STRING_BYTES (s);
1660 }
1661 else
1662 old_data = NULL;
1663
1664 MALLOC_BLOCK_INPUT;
1665
1666 if (nbytes > LARGE_STRING_BYTES)
1667 {
1668 size_t size = offsetof (struct sblock, first_data) + needed;
1669
1670 #ifdef DOUG_LEA_MALLOC
1671 /* Prevent mmap'ing the chunk. Lisp data may not be mmap'ed
1672 because mapped region contents are not preserved in
1673 a dumped Emacs.
1674
1675 In case you think of allowing it in a dumped Emacs at the
1676 cost of not being able to re-dump, there's another reason:
1677 mmap'ed data typically have an address towards the top of the
1678 address space, which won't fit into an EMACS_INT (at least on
1679 32-bit systems with the current tagging scheme). --fx */
1680 mallopt (M_MMAP_MAX, 0);
1681 #endif
1682
1683 b = lisp_malloc (size + GC_STRING_EXTRA, MEM_TYPE_NON_LISP);
1684
1685 #ifdef DOUG_LEA_MALLOC
1686 /* Back to a reasonable maximum of mmap'ed areas. */
1687 mallopt (M_MMAP_MAX, MMAP_MAX_AREAS);
1688 #endif
1689
1690 b->next_free = &b->first_data;
1691 b->first_data.string = NULL;
1692 b->next = large_sblocks;
1693 large_sblocks = b;
1694 }
1695 else if (current_sblock == NULL
1696 || (((char *) current_sblock + SBLOCK_SIZE
1697 - (char *) current_sblock->next_free)
1698 < (needed + GC_STRING_EXTRA)))
1699 {
1700 /* Not enough room in the current sblock. */
1701 b = lisp_malloc (SBLOCK_SIZE, MEM_TYPE_NON_LISP);
1702 b->next_free = &b->first_data;
1703 b->first_data.string = NULL;
1704 b->next = NULL;
1705
1706 if (current_sblock)
1707 current_sblock->next = b;
1708 else
1709 oldest_sblock = b;
1710 current_sblock = b;
1711 }
1712 else
1713 b = current_sblock;
1714
1715 data = b->next_free;
1716 b->next_free = (struct sdata *) ((char *) data + needed + GC_STRING_EXTRA);
1717
1718 MALLOC_UNBLOCK_INPUT;
1719
1720 data->string = s;
1721 s->data = SDATA_DATA (data);
1722 #ifdef GC_CHECK_STRING_BYTES
1723 SDATA_NBYTES (data) = nbytes;
1724 #endif
1725 s->size = nchars;
1726 s->size_byte = nbytes;
1727 s->data[nbytes] = '\0';
1728 #ifdef GC_CHECK_STRING_OVERRUN
1729 memcpy ((char *) data + needed, string_overrun_cookie,
1730 GC_STRING_OVERRUN_COOKIE_SIZE);
1731 #endif
1732
1733 /* Note that Faset may call to this function when S has already data
1734 assigned. In this case, mark data as free by setting it's string
1735 back-pointer to null, and record the size of the data in it. */
1736 if (old_data)
1737 {
1738 SDATA_NBYTES (old_data) = old_nbytes;
1739 old_data->string = NULL;
1740 }
1741
1742 consing_since_gc += needed;
1743 }
1744
1745
1746 /* Sweep and compact strings. */
1747
1748 static void
1749 sweep_strings (void)
1750 {
1751 struct string_block *b, *next;
1752 struct string_block *live_blocks = NULL;
1753
1754 string_free_list = NULL;
1755 total_strings = total_free_strings = 0;
1756 total_string_bytes = 0;
1757
1758 /* Scan strings_blocks, free Lisp_Strings that aren't marked. */
1759 for (b = string_blocks; b; b = next)
1760 {
1761 int i, nfree = 0;
1762 struct Lisp_String *free_list_before = string_free_list;
1763
1764 next = b->next;
1765
1766 for (i = 0; i < STRING_BLOCK_SIZE; ++i)
1767 {
1768 struct Lisp_String *s = b->strings + i;
1769
1770 if (s->data)
1771 {
1772 /* String was not on free-list before. */
1773 if (STRING_MARKED_P (s))
1774 {
1775 /* String is live; unmark it and its intervals. */
1776 UNMARK_STRING (s);
1777
1778 /* Do not use string_(set|get)_intervals here. */
1779 s->intervals = balance_intervals (s->intervals);
1780
1781 ++total_strings;
1782 total_string_bytes += STRING_BYTES (s);
1783 }
1784 else
1785 {
1786 /* String is dead. Put it on the free-list. */
1787 struct sdata *data = SDATA_OF_STRING (s);
1788
1789 /* Save the size of S in its sdata so that we know
1790 how large that is. Reset the sdata's string
1791 back-pointer so that we know it's free. */
1792 #ifdef GC_CHECK_STRING_BYTES
1793 if (string_bytes (s) != SDATA_NBYTES (data))
1794 emacs_abort ();
1795 #else
1796 data->u.nbytes = STRING_BYTES (s);
1797 #endif
1798 data->string = NULL;
1799
1800 /* Reset the strings's `data' member so that we
1801 know it's free. */
1802 s->data = NULL;
1803
1804 /* Put the string on the free-list. */
1805 NEXT_FREE_LISP_STRING (s) = string_free_list;
1806 string_free_list = s;
1807 ++nfree;
1808 }
1809 }
1810 else
1811 {
1812 /* S was on the free-list before. Put it there again. */
1813 NEXT_FREE_LISP_STRING (s) = string_free_list;
1814 string_free_list = s;
1815 ++nfree;
1816 }
1817 }
1818
1819 /* Free blocks that contain free Lisp_Strings only, except
1820 the first two of them. */
1821 if (nfree == STRING_BLOCK_SIZE
1822 && total_free_strings > STRING_BLOCK_SIZE)
1823 {
1824 lisp_free (b);
1825 string_free_list = free_list_before;
1826 }
1827 else
1828 {
1829 total_free_strings += nfree;
1830 b->next = live_blocks;
1831 live_blocks = b;
1832 }
1833 }
1834
1835 check_string_free_list ();
1836
1837 string_blocks = live_blocks;
1838 free_large_strings ();
1839 compact_small_strings ();
1840
1841 check_string_free_list ();
1842 }
1843
1844
1845 /* Free dead large strings. */
1846
1847 static void
1848 free_large_strings (void)
1849 {
1850 struct sblock *b, *next;
1851 struct sblock *live_blocks = NULL;
1852
1853 for (b = large_sblocks; b; b = next)
1854 {
1855 next = b->next;
1856
1857 if (b->first_data.string == NULL)
1858 lisp_free (b);
1859 else
1860 {
1861 b->next = live_blocks;
1862 live_blocks = b;
1863 }
1864 }
1865
1866 large_sblocks = live_blocks;
1867 }
1868
1869
1870 /* Compact data of small strings. Free sblocks that don't contain
1871 data of live strings after compaction. */
1872
1873 static void
1874 compact_small_strings (void)
1875 {
1876 struct sblock *b, *tb, *next;
1877 struct sdata *from, *to, *end, *tb_end;
1878 struct sdata *to_end, *from_end;
1879
1880 /* TB is the sblock we copy to, TO is the sdata within TB we copy
1881 to, and TB_END is the end of TB. */
1882 tb = oldest_sblock;
1883 tb_end = (struct sdata *) ((char *) tb + SBLOCK_SIZE);
1884 to = &tb->first_data;
1885
1886 /* Step through the blocks from the oldest to the youngest. We
1887 expect that old blocks will stabilize over time, so that less
1888 copying will happen this way. */
1889 for (b = oldest_sblock; b; b = b->next)
1890 {
1891 end = b->next_free;
1892 eassert ((char *) end <= (char *) b + SBLOCK_SIZE);
1893
1894 for (from = &b->first_data; from < end; from = from_end)
1895 {
1896 /* Compute the next FROM here because copying below may
1897 overwrite data we need to compute it. */
1898 ptrdiff_t nbytes;
1899 struct Lisp_String *s = from->string;
1900
1901 #ifdef GC_CHECK_STRING_BYTES
1902 /* Check that the string size recorded in the string is the
1903 same as the one recorded in the sdata structure. */
1904 if (s && string_bytes (s) != SDATA_NBYTES (from))
1905 emacs_abort ();
1906 #endif /* GC_CHECK_STRING_BYTES */
1907
1908 nbytes = s ? STRING_BYTES (s) : SDATA_NBYTES (from);
1909 eassert (nbytes <= LARGE_STRING_BYTES);
1910
1911 nbytes = SDATA_SIZE (nbytes);
1912 from_end = (struct sdata *) ((char *) from + nbytes + GC_STRING_EXTRA);
1913
1914 #ifdef GC_CHECK_STRING_OVERRUN
1915 if (memcmp (string_overrun_cookie,
1916 (char *) from_end - GC_STRING_OVERRUN_COOKIE_SIZE,
1917 GC_STRING_OVERRUN_COOKIE_SIZE))
1918 emacs_abort ();
1919 #endif
1920
1921 /* Non-NULL S means it's alive. Copy its data. */
1922 if (s)
1923 {
1924 /* If TB is full, proceed with the next sblock. */
1925 to_end = (struct sdata *) ((char *) to + nbytes + GC_STRING_EXTRA);
1926 if (to_end > tb_end)
1927 {
1928 tb->next_free = to;
1929 tb = tb->next;
1930 tb_end = (struct sdata *) ((char *) tb + SBLOCK_SIZE);
1931 to = &tb->first_data;
1932 to_end = (struct sdata *) ((char *) to + nbytes + GC_STRING_EXTRA);
1933 }
1934
1935 /* Copy, and update the string's `data' pointer. */
1936 if (from != to)
1937 {
1938 eassert (tb != b || to < from);
1939 memmove (to, from, nbytes + GC_STRING_EXTRA);
1940 to->string->data = SDATA_DATA (to);
1941 }
1942
1943 /* Advance past the sdata we copied to. */
1944 to = to_end;
1945 }
1946 }
1947 }
1948
1949 /* The rest of the sblocks following TB don't contain live data, so
1950 we can free them. */
1951 for (b = tb->next; b; b = next)
1952 {
1953 next = b->next;
1954 lisp_free (b);
1955 }
1956
1957 tb->next_free = to;
1958 tb->next = NULL;
1959 current_sblock = tb;
1960 }
1961
1962 void
1963 string_overflow (void)
1964 {
1965 error ("Maximum string size exceeded");
1966 }
1967
1968 DEFUN ("make-string", Fmake_string, Smake_string, 2, 2, 0,
1969 doc: /* Return a newly created string of length LENGTH, with INIT in each element.
1970 LENGTH must be an integer.
1971 INIT must be an integer that represents a character. */)
1972 (Lisp_Object length, Lisp_Object init)
1973 {
1974 register Lisp_Object val;
1975 register unsigned char *p, *end;
1976 int c;
1977 EMACS_INT nbytes;
1978
1979 CHECK_NATNUM (length);
1980 CHECK_CHARACTER (init);
1981
1982 c = XFASTINT (init);
1983 if (ASCII_CHAR_P (c))
1984 {
1985 nbytes = XINT (length);
1986 val = make_uninit_string (nbytes);
1987 p = SDATA (val);
1988 end = p + SCHARS (val);
1989 while (p != end)
1990 *p++ = c;
1991 }
1992 else
1993 {
1994 unsigned char str[MAX_MULTIBYTE_LENGTH];
1995 int len = CHAR_STRING (c, str);
1996 EMACS_INT string_len = XINT (length);
1997
1998 if (string_len > STRING_BYTES_MAX / len)
1999 string_overflow ();
2000 nbytes = len * string_len;
2001 val = make_uninit_multibyte_string (string_len, nbytes);
2002 p = SDATA (val);
2003 end = p + nbytes;
2004 while (p != end)
2005 {
2006 memcpy (p, str, len);
2007 p += len;
2008 }
2009 }
2010
2011 *p = 0;
2012 return val;
2013 }
2014
2015
2016 DEFUN ("make-bool-vector", Fmake_bool_vector, Smake_bool_vector, 2, 2, 0,
2017 doc: /* Return a new bool-vector of length LENGTH, using INIT for each element.
2018 LENGTH must be a number. INIT matters only in whether it is t or nil. */)
2019 (Lisp_Object length, Lisp_Object init)
2020 {
2021 register Lisp_Object val;
2022 struct Lisp_Bool_Vector *p;
2023 ptrdiff_t length_in_chars;
2024 EMACS_INT length_in_elts;
2025 int bits_per_value;
2026 int extra_bool_elts = ((bool_header_size - header_size + word_size - 1)
2027 / word_size);
2028
2029 CHECK_NATNUM (length);
2030
2031 bits_per_value = sizeof (EMACS_INT) * BOOL_VECTOR_BITS_PER_CHAR;
2032
2033 length_in_elts = (XFASTINT (length) + bits_per_value - 1) / bits_per_value;
2034
2035 val = Fmake_vector (make_number (length_in_elts + extra_bool_elts), Qnil);
2036
2037 /* No Lisp_Object to trace in there. */
2038 XSETPVECTYPESIZE (XVECTOR (val), PVEC_BOOL_VECTOR, 0, 0);
2039
2040 p = XBOOL_VECTOR (val);
2041 p->size = XFASTINT (length);
2042
2043 length_in_chars = ((XFASTINT (length) + BOOL_VECTOR_BITS_PER_CHAR - 1)
2044 / BOOL_VECTOR_BITS_PER_CHAR);
2045 if (length_in_chars)
2046 {
2047 memset (p->data, ! NILP (init) ? -1 : 0, length_in_chars);
2048
2049 /* Clear any extraneous bits in the last byte. */
2050 p->data[length_in_chars - 1]
2051 &= (1 << ((XFASTINT (length) - 1) % BOOL_VECTOR_BITS_PER_CHAR + 1)) - 1;
2052 }
2053
2054 return val;
2055 }
2056
2057
2058 /* Make a string from NBYTES bytes at CONTENTS, and compute the number
2059 of characters from the contents. This string may be unibyte or
2060 multibyte, depending on the contents. */
2061
2062 Lisp_Object
2063 make_string (const char *contents, ptrdiff_t nbytes)
2064 {
2065 register Lisp_Object val;
2066 ptrdiff_t nchars, multibyte_nbytes;
2067
2068 parse_str_as_multibyte ((const unsigned char *) contents, nbytes,
2069 &nchars, &multibyte_nbytes);
2070 if (nbytes == nchars || nbytes != multibyte_nbytes)
2071 /* CONTENTS contains no multibyte sequences or contains an invalid
2072 multibyte sequence. We must make unibyte string. */
2073 val = make_unibyte_string (contents, nbytes);
2074 else
2075 val = make_multibyte_string (contents, nchars, nbytes);
2076 return val;
2077 }
2078
2079
2080 /* Make an unibyte string from LENGTH bytes at CONTENTS. */
2081
2082 Lisp_Object
2083 make_unibyte_string (const char *contents, ptrdiff_t length)
2084 {
2085 register Lisp_Object val;
2086 val = make_uninit_string (length);
2087 memcpy (SDATA (val), contents, length);
2088 return val;
2089 }
2090
2091
2092 /* Make a multibyte string from NCHARS characters occupying NBYTES
2093 bytes at CONTENTS. */
2094
2095 Lisp_Object
2096 make_multibyte_string (const char *contents,
2097 ptrdiff_t nchars, ptrdiff_t nbytes)
2098 {
2099 register Lisp_Object val;
2100 val = make_uninit_multibyte_string (nchars, nbytes);
2101 memcpy (SDATA (val), contents, nbytes);
2102 return val;
2103 }
2104
2105
2106 /* Make a string from NCHARS characters occupying NBYTES bytes at
2107 CONTENTS. It is a multibyte string if NBYTES != NCHARS. */
2108
2109 Lisp_Object
2110 make_string_from_bytes (const char *contents,
2111 ptrdiff_t nchars, ptrdiff_t nbytes)
2112 {
2113 register Lisp_Object val;
2114 val = make_uninit_multibyte_string (nchars, nbytes);
2115 memcpy (SDATA (val), contents, nbytes);
2116 if (SBYTES (val) == SCHARS (val))
2117 STRING_SET_UNIBYTE (val);
2118 return val;
2119 }
2120
2121
2122 /* Make a string from NCHARS characters occupying NBYTES bytes at
2123 CONTENTS. The argument MULTIBYTE controls whether to label the
2124 string as multibyte. If NCHARS is negative, it counts the number of
2125 characters by itself. */
2126
2127 Lisp_Object
2128 make_specified_string (const char *contents,
2129 ptrdiff_t nchars, ptrdiff_t nbytes, bool multibyte)
2130 {
2131 Lisp_Object val;
2132
2133 if (nchars < 0)
2134 {
2135 if (multibyte)
2136 nchars = multibyte_chars_in_text ((const unsigned char *) contents,
2137 nbytes);
2138 else
2139 nchars = nbytes;
2140 }
2141 val = make_uninit_multibyte_string (nchars, nbytes);
2142 memcpy (SDATA (val), contents, nbytes);
2143 if (!multibyte)
2144 STRING_SET_UNIBYTE (val);
2145 return val;
2146 }
2147
2148
2149 /* Return an unibyte Lisp_String set up to hold LENGTH characters
2150 occupying LENGTH bytes. */
2151
2152 Lisp_Object
2153 make_uninit_string (EMACS_INT length)
2154 {
2155 Lisp_Object val;
2156
2157 if (!length)
2158 return empty_unibyte_string;
2159 val = make_uninit_multibyte_string (length, length);
2160 STRING_SET_UNIBYTE (val);
2161 return val;
2162 }
2163
2164
2165 /* Return a multibyte Lisp_String set up to hold NCHARS characters
2166 which occupy NBYTES bytes. */
2167
2168 Lisp_Object
2169 make_uninit_multibyte_string (EMACS_INT nchars, EMACS_INT nbytes)
2170 {
2171 Lisp_Object string;
2172 struct Lisp_String *s;
2173
2174 if (nchars < 0)
2175 emacs_abort ();
2176 if (!nbytes)
2177 return empty_multibyte_string;
2178
2179 s = allocate_string ();
2180 s->intervals = NULL;
2181 allocate_string_data (s, nchars, nbytes);
2182 XSETSTRING (string, s);
2183 string_chars_consed += nbytes;
2184 return string;
2185 }
2186
2187 /* Print arguments to BUF according to a FORMAT, then return
2188 a Lisp_String initialized with the data from BUF. */
2189
2190 Lisp_Object
2191 make_formatted_string (char *buf, const char *format, ...)
2192 {
2193 va_list ap;
2194 int length;
2195
2196 va_start (ap, format);
2197 length = vsprintf (buf, format, ap);
2198 va_end (ap);
2199 return make_string (buf, length);
2200 }
2201
2202 \f
2203 /***********************************************************************
2204 Float Allocation
2205 ***********************************************************************/
2206
2207 /* We store float cells inside of float_blocks, allocating a new
2208 float_block with malloc whenever necessary. Float cells reclaimed
2209 by GC are put on a free list to be reallocated before allocating
2210 any new float cells from the latest float_block. */
2211
2212 #define FLOAT_BLOCK_SIZE \
2213 (((BLOCK_BYTES - sizeof (struct float_block *) \
2214 /* The compiler might add padding at the end. */ \
2215 - (sizeof (struct Lisp_Float) - sizeof (int))) * CHAR_BIT) \
2216 / (sizeof (struct Lisp_Float) * CHAR_BIT + 1))
2217
2218 #define GETMARKBIT(block,n) \
2219 (((block)->gcmarkbits[(n) / (sizeof (int) * CHAR_BIT)] \
2220 >> ((n) % (sizeof (int) * CHAR_BIT))) \
2221 & 1)
2222
2223 #define SETMARKBIT(block,n) \
2224 (block)->gcmarkbits[(n) / (sizeof (int) * CHAR_BIT)] \
2225 |= 1 << ((n) % (sizeof (int) * CHAR_BIT))
2226
2227 #define UNSETMARKBIT(block,n) \
2228 (block)->gcmarkbits[(n) / (sizeof (int) * CHAR_BIT)] \
2229 &= ~(1 << ((n) % (sizeof (int) * CHAR_BIT)))
2230
2231 #define FLOAT_BLOCK(fptr) \
2232 ((struct float_block *) (((uintptr_t) (fptr)) & ~(BLOCK_ALIGN - 1)))
2233
2234 #define FLOAT_INDEX(fptr) \
2235 ((((uintptr_t) (fptr)) & (BLOCK_ALIGN - 1)) / sizeof (struct Lisp_Float))
2236
2237 struct float_block
2238 {
2239 /* Place `floats' at the beginning, to ease up FLOAT_INDEX's job. */
2240 struct Lisp_Float floats[FLOAT_BLOCK_SIZE];
2241 int gcmarkbits[1 + FLOAT_BLOCK_SIZE / (sizeof (int) * CHAR_BIT)];
2242 struct float_block *next;
2243 };
2244
2245 #define FLOAT_MARKED_P(fptr) \
2246 GETMARKBIT (FLOAT_BLOCK (fptr), FLOAT_INDEX ((fptr)))
2247
2248 #define FLOAT_MARK(fptr) \
2249 SETMARKBIT (FLOAT_BLOCK (fptr), FLOAT_INDEX ((fptr)))
2250
2251 #define FLOAT_UNMARK(fptr) \
2252 UNSETMARKBIT (FLOAT_BLOCK (fptr), FLOAT_INDEX ((fptr)))
2253
2254 /* Current float_block. */
2255
2256 static struct float_block *float_block;
2257
2258 /* Index of first unused Lisp_Float in the current float_block. */
2259
2260 static int float_block_index = FLOAT_BLOCK_SIZE;
2261
2262 /* Free-list of Lisp_Floats. */
2263
2264 static struct Lisp_Float *float_free_list;
2265
2266 /* Return a new float object with value FLOAT_VALUE. */
2267
2268 Lisp_Object
2269 make_float (double float_value)
2270 {
2271 register Lisp_Object val;
2272
2273 MALLOC_BLOCK_INPUT;
2274
2275 if (float_free_list)
2276 {
2277 /* We use the data field for chaining the free list
2278 so that we won't use the same field that has the mark bit. */
2279 XSETFLOAT (val, float_free_list);
2280 float_free_list = float_free_list->u.chain;
2281 }
2282 else
2283 {
2284 if (float_block_index == FLOAT_BLOCK_SIZE)
2285 {
2286 struct float_block *new
2287 = lisp_align_malloc (sizeof *new, MEM_TYPE_FLOAT);
2288 new->next = float_block;
2289 memset (new->gcmarkbits, 0, sizeof new->gcmarkbits);
2290 float_block = new;
2291 float_block_index = 0;
2292 total_free_floats += FLOAT_BLOCK_SIZE;
2293 }
2294 XSETFLOAT (val, &float_block->floats[float_block_index]);
2295 float_block_index++;
2296 }
2297
2298 MALLOC_UNBLOCK_INPUT;
2299
2300 XFLOAT_INIT (val, float_value);
2301 eassert (!FLOAT_MARKED_P (XFLOAT (val)));
2302 consing_since_gc += sizeof (struct Lisp_Float);
2303 floats_consed++;
2304 total_free_floats--;
2305 return val;
2306 }
2307
2308
2309 \f
2310 /***********************************************************************
2311 Cons Allocation
2312 ***********************************************************************/
2313
2314 /* We store cons cells inside of cons_blocks, allocating a new
2315 cons_block with malloc whenever necessary. Cons cells reclaimed by
2316 GC are put on a free list to be reallocated before allocating
2317 any new cons cells from the latest cons_block. */
2318
2319 #define CONS_BLOCK_SIZE \
2320 (((BLOCK_BYTES - sizeof (struct cons_block *) \
2321 /* The compiler might add padding at the end. */ \
2322 - (sizeof (struct Lisp_Cons) - sizeof (int))) * CHAR_BIT) \
2323 / (sizeof (struct Lisp_Cons) * CHAR_BIT + 1))
2324
2325 #define CONS_BLOCK(fptr) \
2326 ((struct cons_block *) ((uintptr_t) (fptr) & ~(BLOCK_ALIGN - 1)))
2327
2328 #define CONS_INDEX(fptr) \
2329 (((uintptr_t) (fptr) & (BLOCK_ALIGN - 1)) / sizeof (struct Lisp_Cons))
2330
2331 struct cons_block
2332 {
2333 /* Place `conses' at the beginning, to ease up CONS_INDEX's job. */
2334 struct Lisp_Cons conses[CONS_BLOCK_SIZE];
2335 int gcmarkbits[1 + CONS_BLOCK_SIZE / (sizeof (int) * CHAR_BIT)];
2336 struct cons_block *next;
2337 };
2338
2339 #define CONS_MARKED_P(fptr) \
2340 GETMARKBIT (CONS_BLOCK (fptr), CONS_INDEX ((fptr)))
2341
2342 #define CONS_MARK(fptr) \
2343 SETMARKBIT (CONS_BLOCK (fptr), CONS_INDEX ((fptr)))
2344
2345 #define CONS_UNMARK(fptr) \
2346 UNSETMARKBIT (CONS_BLOCK (fptr), CONS_INDEX ((fptr)))
2347
2348 /* Current cons_block. */
2349
2350 static struct cons_block *cons_block;
2351
2352 /* Index of first unused Lisp_Cons in the current block. */
2353
2354 static int cons_block_index = CONS_BLOCK_SIZE;
2355
2356 /* Free-list of Lisp_Cons structures. */
2357
2358 static struct Lisp_Cons *cons_free_list;
2359
2360 /* Explicitly free a cons cell by putting it on the free-list. */
2361
2362 void
2363 free_cons (struct Lisp_Cons *ptr)
2364 {
2365 ptr->u.chain = cons_free_list;
2366 #if GC_MARK_STACK
2367 ptr->car = Vdead;
2368 #endif
2369 cons_free_list = ptr;
2370 consing_since_gc -= sizeof *ptr;
2371 total_free_conses++;
2372 }
2373
2374 DEFUN ("cons", Fcons, Scons, 2, 2, 0,
2375 doc: /* Create a new cons, give it CAR and CDR as components, and return it. */)
2376 (Lisp_Object car, Lisp_Object cdr)
2377 {
2378 register Lisp_Object val;
2379
2380 MALLOC_BLOCK_INPUT;
2381
2382 if (cons_free_list)
2383 {
2384 /* We use the cdr for chaining the free list
2385 so that we won't use the same field that has the mark bit. */
2386 XSETCONS (val, cons_free_list);
2387 cons_free_list = cons_free_list->u.chain;
2388 }
2389 else
2390 {
2391 if (cons_block_index == CONS_BLOCK_SIZE)
2392 {
2393 struct cons_block *new
2394 = lisp_align_malloc (sizeof *new, MEM_TYPE_CONS);
2395 memset (new->gcmarkbits, 0, sizeof new->gcmarkbits);
2396 new->next = cons_block;
2397 cons_block = new;
2398 cons_block_index = 0;
2399 total_free_conses += CONS_BLOCK_SIZE;
2400 }
2401 XSETCONS (val, &cons_block->conses[cons_block_index]);
2402 cons_block_index++;
2403 }
2404
2405 MALLOC_UNBLOCK_INPUT;
2406
2407 XSETCAR (val, car);
2408 XSETCDR (val, cdr);
2409 eassert (!CONS_MARKED_P (XCONS (val)));
2410 consing_since_gc += sizeof (struct Lisp_Cons);
2411 total_free_conses--;
2412 cons_cells_consed++;
2413 return val;
2414 }
2415
2416 #ifdef GC_CHECK_CONS_LIST
2417 /* Get an error now if there's any junk in the cons free list. */
2418 void
2419 check_cons_list (void)
2420 {
2421 struct Lisp_Cons *tail = cons_free_list;
2422
2423 while (tail)
2424 tail = tail->u.chain;
2425 }
2426 #endif
2427
2428 /* Make a list of 1, 2, 3, 4 or 5 specified objects. */
2429
2430 Lisp_Object
2431 list1 (Lisp_Object arg1)
2432 {
2433 return Fcons (arg1, Qnil);
2434 }
2435
2436 Lisp_Object
2437 list2 (Lisp_Object arg1, Lisp_Object arg2)
2438 {
2439 return Fcons (arg1, Fcons (arg2, Qnil));
2440 }
2441
2442
2443 Lisp_Object
2444 list3 (Lisp_Object arg1, Lisp_Object arg2, Lisp_Object arg3)
2445 {
2446 return Fcons (arg1, Fcons (arg2, Fcons (arg3, Qnil)));
2447 }
2448
2449
2450 Lisp_Object
2451 list4 (Lisp_Object arg1, Lisp_Object arg2, Lisp_Object arg3, Lisp_Object arg4)
2452 {
2453 return Fcons (arg1, Fcons (arg2, Fcons (arg3, Fcons (arg4, Qnil))));
2454 }
2455
2456
2457 Lisp_Object
2458 list5 (Lisp_Object arg1, Lisp_Object arg2, Lisp_Object arg3, Lisp_Object arg4, Lisp_Object arg5)
2459 {
2460 return Fcons (arg1, Fcons (arg2, Fcons (arg3, Fcons (arg4,
2461 Fcons (arg5, Qnil)))));
2462 }
2463
2464 /* Make a list of COUNT Lisp_Objects, where ARG is the
2465 first one. Allocate conses from pure space if TYPE
2466 is CONSTYPE_PURE, or allocate as usual if type is CONSTYPE_HEAP. */
2467
2468 Lisp_Object
2469 listn (enum constype type, ptrdiff_t count, Lisp_Object arg, ...)
2470 {
2471 va_list ap;
2472 ptrdiff_t i;
2473 Lisp_Object val, *objp;
2474
2475 /* Change to SAFE_ALLOCA if you hit this eassert. */
2476 eassert (count <= MAX_ALLOCA / word_size);
2477
2478 objp = alloca (count * word_size);
2479 objp[0] = arg;
2480 va_start (ap, arg);
2481 for (i = 1; i < count; i++)
2482 objp[i] = va_arg (ap, Lisp_Object);
2483 va_end (ap);
2484
2485 for (val = Qnil, i = count - 1; i >= 0; i--)
2486 {
2487 if (type == CONSTYPE_PURE)
2488 val = pure_cons (objp[i], val);
2489 else if (type == CONSTYPE_HEAP)
2490 val = Fcons (objp[i], val);
2491 else
2492 emacs_abort ();
2493 }
2494 return val;
2495 }
2496
2497 DEFUN ("list", Flist, Slist, 0, MANY, 0,
2498 doc: /* Return a newly created list with specified arguments as elements.
2499 Any number of arguments, even zero arguments, are allowed.
2500 usage: (list &rest OBJECTS) */)
2501 (ptrdiff_t nargs, Lisp_Object *args)
2502 {
2503 register Lisp_Object val;
2504 val = Qnil;
2505
2506 while (nargs > 0)
2507 {
2508 nargs--;
2509 val = Fcons (args[nargs], val);
2510 }
2511 return val;
2512 }
2513
2514
2515 DEFUN ("make-list", Fmake_list, Smake_list, 2, 2, 0,
2516 doc: /* Return a newly created list of length LENGTH, with each element being INIT. */)
2517 (register Lisp_Object length, Lisp_Object init)
2518 {
2519 register Lisp_Object val;
2520 register EMACS_INT size;
2521
2522 CHECK_NATNUM (length);
2523 size = XFASTINT (length);
2524
2525 val = Qnil;
2526 while (size > 0)
2527 {
2528 val = Fcons (init, val);
2529 --size;
2530
2531 if (size > 0)
2532 {
2533 val = Fcons (init, val);
2534 --size;
2535
2536 if (size > 0)
2537 {
2538 val = Fcons (init, val);
2539 --size;
2540
2541 if (size > 0)
2542 {
2543 val = Fcons (init, val);
2544 --size;
2545
2546 if (size > 0)
2547 {
2548 val = Fcons (init, val);
2549 --size;
2550 }
2551 }
2552 }
2553 }
2554
2555 QUIT;
2556 }
2557
2558 return val;
2559 }
2560
2561
2562 \f
2563 /***********************************************************************
2564 Vector Allocation
2565 ***********************************************************************/
2566
2567 /* This value is balanced well enough to avoid too much internal overhead
2568 for the most common cases; it's not required to be a power of two, but
2569 it's expected to be a mult-of-ROUNDUP_SIZE (see below). */
2570
2571 #define VECTOR_BLOCK_SIZE 4096
2572
2573 /* Align allocation request sizes to be a multiple of ROUNDUP_SIZE. */
2574 enum
2575 {
2576 roundup_size = COMMON_MULTIPLE (word_size, USE_LSB_TAG ? GCALIGNMENT : 1)
2577 };
2578
2579 /* ROUNDUP_SIZE must be a power of 2. */
2580 verify ((roundup_size & (roundup_size - 1)) == 0);
2581
2582 /* Verify assumptions described above. */
2583 verify ((VECTOR_BLOCK_SIZE % roundup_size) == 0);
2584 verify (VECTOR_BLOCK_SIZE <= (1 << PSEUDOVECTOR_SIZE_BITS));
2585
2586 /* Round up X to nearest mult-of-ROUNDUP_SIZE. */
2587
2588 #define vroundup(x) (((x) + (roundup_size - 1)) & ~(roundup_size - 1))
2589
2590 /* Rounding helps to maintain alignment constraints if USE_LSB_TAG. */
2591
2592 #define VECTOR_BLOCK_BYTES (VECTOR_BLOCK_SIZE - vroundup (sizeof (void *)))
2593
2594 /* Size of the minimal vector allocated from block. */
2595
2596 #define VBLOCK_BYTES_MIN vroundup (sizeof (struct Lisp_Vector))
2597
2598 /* Size of the largest vector allocated from block. */
2599
2600 #define VBLOCK_BYTES_MAX \
2601 vroundup ((VECTOR_BLOCK_BYTES / 2) - word_size)
2602
2603 /* We maintain one free list for each possible block-allocated
2604 vector size, and this is the number of free lists we have. */
2605
2606 #define VECTOR_MAX_FREE_LIST_INDEX \
2607 ((VECTOR_BLOCK_BYTES - VBLOCK_BYTES_MIN) / roundup_size + 1)
2608
2609 /* Common shortcut to advance vector pointer over a block data. */
2610
2611 #define ADVANCE(v, nbytes) ((struct Lisp_Vector *) ((char *) (v) + (nbytes)))
2612
2613 /* Common shortcut to calculate NBYTES-vector index in VECTOR_FREE_LISTS. */
2614
2615 #define VINDEX(nbytes) (((nbytes) - VBLOCK_BYTES_MIN) / roundup_size)
2616
2617 /* Get and set the next field in block-allocated vectorlike objects on
2618 the free list. Doing it this way respects C's aliasing rules.
2619 We could instead make 'contents' a union, but that would mean
2620 changes everywhere that the code uses 'contents'. */
2621 static struct Lisp_Vector *
2622 next_in_free_list (struct Lisp_Vector *v)
2623 {
2624 intptr_t i = XLI (v->contents[0]);
2625 return (struct Lisp_Vector *) i;
2626 }
2627 static void
2628 set_next_in_free_list (struct Lisp_Vector *v, struct Lisp_Vector *next)
2629 {
2630 v->contents[0] = XIL ((intptr_t) next);
2631 }
2632
2633 /* Common shortcut to setup vector on a free list. */
2634
2635 #define SETUP_ON_FREE_LIST(v, nbytes, tmp) \
2636 do { \
2637 (tmp) = ((nbytes - header_size) / word_size); \
2638 XSETPVECTYPESIZE (v, PVEC_FREE, 0, (tmp)); \
2639 eassert ((nbytes) % roundup_size == 0); \
2640 (tmp) = VINDEX (nbytes); \
2641 eassert ((tmp) < VECTOR_MAX_FREE_LIST_INDEX); \
2642 set_next_in_free_list (v, vector_free_lists[tmp]); \
2643 vector_free_lists[tmp] = (v); \
2644 total_free_vector_slots += (nbytes) / word_size; \
2645 } while (0)
2646
2647 /* This internal type is used to maintain the list of large vectors
2648 which are allocated at their own, e.g. outside of vector blocks. */
2649
2650 struct large_vector
2651 {
2652 union {
2653 struct large_vector *vector;
2654 #if USE_LSB_TAG
2655 /* We need to maintain ROUNDUP_SIZE alignment for the vector member. */
2656 unsigned char c[vroundup (sizeof (struct large_vector *))];
2657 #endif
2658 } next;
2659 struct Lisp_Vector v;
2660 };
2661
2662 /* This internal type is used to maintain an underlying storage
2663 for small vectors. */
2664
2665 struct vector_block
2666 {
2667 char data[VECTOR_BLOCK_BYTES];
2668 struct vector_block *next;
2669 };
2670
2671 /* Chain of vector blocks. */
2672
2673 static struct vector_block *vector_blocks;
2674
2675 /* Vector free lists, where NTH item points to a chain of free
2676 vectors of the same NBYTES size, so NTH == VINDEX (NBYTES). */
2677
2678 static struct Lisp_Vector *vector_free_lists[VECTOR_MAX_FREE_LIST_INDEX];
2679
2680 /* Singly-linked list of large vectors. */
2681
2682 static struct large_vector *large_vectors;
2683
2684 /* The only vector with 0 slots, allocated from pure space. */
2685
2686 Lisp_Object zero_vector;
2687
2688 /* Number of live vectors. */
2689
2690 static EMACS_INT total_vectors;
2691
2692 /* Total size of live and free vectors, in Lisp_Object units. */
2693
2694 static EMACS_INT total_vector_slots, total_free_vector_slots;
2695
2696 /* Get a new vector block. */
2697
2698 static struct vector_block *
2699 allocate_vector_block (void)
2700 {
2701 struct vector_block *block = xmalloc (sizeof *block);
2702
2703 #if GC_MARK_STACK && !defined GC_MALLOC_CHECK
2704 mem_insert (block->data, block->data + VECTOR_BLOCK_BYTES,
2705 MEM_TYPE_VECTOR_BLOCK);
2706 #endif
2707
2708 block->next = vector_blocks;
2709 vector_blocks = block;
2710 return block;
2711 }
2712
2713 /* Called once to initialize vector allocation. */
2714
2715 static void
2716 init_vectors (void)
2717 {
2718 zero_vector = make_pure_vector (0);
2719 }
2720
2721 /* Allocate vector from a vector block. */
2722
2723 static struct Lisp_Vector *
2724 allocate_vector_from_block (size_t nbytes)
2725 {
2726 struct Lisp_Vector *vector;
2727 struct vector_block *block;
2728 size_t index, restbytes;
2729
2730 eassert (VBLOCK_BYTES_MIN <= nbytes && nbytes <= VBLOCK_BYTES_MAX);
2731 eassert (nbytes % roundup_size == 0);
2732
2733 /* First, try to allocate from a free list
2734 containing vectors of the requested size. */
2735 index = VINDEX (nbytes);
2736 if (vector_free_lists[index])
2737 {
2738 vector = vector_free_lists[index];
2739 vector_free_lists[index] = next_in_free_list (vector);
2740 total_free_vector_slots -= nbytes / word_size;
2741 return vector;
2742 }
2743
2744 /* Next, check free lists containing larger vectors. Since
2745 we will split the result, we should have remaining space
2746 large enough to use for one-slot vector at least. */
2747 for (index = VINDEX (nbytes + VBLOCK_BYTES_MIN);
2748 index < VECTOR_MAX_FREE_LIST_INDEX; index++)
2749 if (vector_free_lists[index])
2750 {
2751 /* This vector is larger than requested. */
2752 vector = vector_free_lists[index];
2753 vector_free_lists[index] = next_in_free_list (vector);
2754 total_free_vector_slots -= nbytes / word_size;
2755
2756 /* Excess bytes are used for the smaller vector,
2757 which should be set on an appropriate free list. */
2758 restbytes = index * roundup_size + VBLOCK_BYTES_MIN - nbytes;
2759 eassert (restbytes % roundup_size == 0);
2760 SETUP_ON_FREE_LIST (ADVANCE (vector, nbytes), restbytes, index);
2761 return vector;
2762 }
2763
2764 /* Finally, need a new vector block. */
2765 block = allocate_vector_block ();
2766
2767 /* New vector will be at the beginning of this block. */
2768 vector = (struct Lisp_Vector *) block->data;
2769
2770 /* If the rest of space from this block is large enough
2771 for one-slot vector at least, set up it on a free list. */
2772 restbytes = VECTOR_BLOCK_BYTES - nbytes;
2773 if (restbytes >= VBLOCK_BYTES_MIN)
2774 {
2775 eassert (restbytes % roundup_size == 0);
2776 SETUP_ON_FREE_LIST (ADVANCE (vector, nbytes), restbytes, index);
2777 }
2778 return vector;
2779 }
2780
2781 /* Nonzero if VECTOR pointer is valid pointer inside BLOCK. */
2782
2783 #define VECTOR_IN_BLOCK(vector, block) \
2784 ((char *) (vector) <= (block)->data \
2785 + VECTOR_BLOCK_BYTES - VBLOCK_BYTES_MIN)
2786
2787 /* Return the memory footprint of V in bytes. */
2788
2789 static ptrdiff_t
2790 vector_nbytes (struct Lisp_Vector *v)
2791 {
2792 ptrdiff_t size = v->header.size & ~ARRAY_MARK_FLAG;
2793
2794 if (size & PSEUDOVECTOR_FLAG)
2795 {
2796 if (PSEUDOVECTOR_TYPEP (&v->header, PVEC_BOOL_VECTOR))
2797 size = (bool_header_size
2798 + (((struct Lisp_Bool_Vector *) v)->size
2799 + BOOL_VECTOR_BITS_PER_CHAR - 1)
2800 / BOOL_VECTOR_BITS_PER_CHAR);
2801 else
2802 size = (header_size
2803 + ((size & PSEUDOVECTOR_SIZE_MASK)
2804 + ((size & PSEUDOVECTOR_REST_MASK)
2805 >> PSEUDOVECTOR_SIZE_BITS)) * word_size);
2806 }
2807 else
2808 size = header_size + size * word_size;
2809 return vroundup (size);
2810 }
2811
2812 /* Reclaim space used by unmarked vectors. */
2813
2814 static void
2815 sweep_vectors (void)
2816 {
2817 struct vector_block *block = vector_blocks, **bprev = &vector_blocks;
2818 struct large_vector *lv, **lvprev = &large_vectors;
2819 struct Lisp_Vector *vector, *next;
2820
2821 total_vectors = total_vector_slots = total_free_vector_slots = 0;
2822 memset (vector_free_lists, 0, sizeof (vector_free_lists));
2823
2824 /* Looking through vector blocks. */
2825
2826 for (block = vector_blocks; block; block = *bprev)
2827 {
2828 bool free_this_block = 0;
2829 ptrdiff_t nbytes;
2830
2831 for (vector = (struct Lisp_Vector *) block->data;
2832 VECTOR_IN_BLOCK (vector, block); vector = next)
2833 {
2834 if (VECTOR_MARKED_P (vector))
2835 {
2836 VECTOR_UNMARK (vector);
2837 total_vectors++;
2838 nbytes = vector_nbytes (vector);
2839 total_vector_slots += nbytes / word_size;
2840 next = ADVANCE (vector, nbytes);
2841 }
2842 else
2843 {
2844 ptrdiff_t total_bytes;
2845
2846 nbytes = vector_nbytes (vector);
2847 total_bytes = nbytes;
2848 next = ADVANCE (vector, nbytes);
2849
2850 /* While NEXT is not marked, try to coalesce with VECTOR,
2851 thus making VECTOR of the largest possible size. */
2852
2853 while (VECTOR_IN_BLOCK (next, block))
2854 {
2855 if (VECTOR_MARKED_P (next))
2856 break;
2857 nbytes = vector_nbytes (next);
2858 total_bytes += nbytes;
2859 next = ADVANCE (next, nbytes);
2860 }
2861
2862 eassert (total_bytes % roundup_size == 0);
2863
2864 if (vector == (struct Lisp_Vector *) block->data
2865 && !VECTOR_IN_BLOCK (next, block))
2866 /* This block should be freed because all of it's
2867 space was coalesced into the only free vector. */
2868 free_this_block = 1;
2869 else
2870 {
2871 int tmp;
2872 SETUP_ON_FREE_LIST (vector, total_bytes, tmp);
2873 }
2874 }
2875 }
2876
2877 if (free_this_block)
2878 {
2879 *bprev = block->next;
2880 #if GC_MARK_STACK && !defined GC_MALLOC_CHECK
2881 mem_delete (mem_find (block->data));
2882 #endif
2883 xfree (block);
2884 }
2885 else
2886 bprev = &block->next;
2887 }
2888
2889 /* Sweep large vectors. */
2890
2891 for (lv = large_vectors; lv; lv = *lvprev)
2892 {
2893 vector = &lv->v;
2894 if (VECTOR_MARKED_P (vector))
2895 {
2896 VECTOR_UNMARK (vector);
2897 total_vectors++;
2898 if (vector->header.size & PSEUDOVECTOR_FLAG)
2899 {
2900 struct Lisp_Bool_Vector *b = (struct Lisp_Bool_Vector *) vector;
2901
2902 /* All non-bool pseudovectors are small enough to be allocated
2903 from vector blocks. This code should be redesigned if some
2904 pseudovector type grows beyond VBLOCK_BYTES_MAX. */
2905 eassert (PSEUDOVECTOR_TYPEP (&vector->header, PVEC_BOOL_VECTOR));
2906
2907 total_vector_slots
2908 += (bool_header_size
2909 + ((b->size + BOOL_VECTOR_BITS_PER_CHAR - 1)
2910 / BOOL_VECTOR_BITS_PER_CHAR)) / word_size;
2911 }
2912 else
2913 total_vector_slots
2914 += header_size / word_size + vector->header.size;
2915 lvprev = &lv->next.vector;
2916 }
2917 else
2918 {
2919 *lvprev = lv->next.vector;
2920 lisp_free (lv);
2921 }
2922 }
2923 }
2924
2925 /* Value is a pointer to a newly allocated Lisp_Vector structure
2926 with room for LEN Lisp_Objects. */
2927
2928 static struct Lisp_Vector *
2929 allocate_vectorlike (ptrdiff_t len)
2930 {
2931 struct Lisp_Vector *p;
2932
2933 MALLOC_BLOCK_INPUT;
2934
2935 if (len == 0)
2936 p = XVECTOR (zero_vector);
2937 else
2938 {
2939 size_t nbytes = header_size + len * word_size;
2940
2941 #ifdef DOUG_LEA_MALLOC
2942 /* Prevent mmap'ing the chunk. Lisp data may not be mmap'ed
2943 because mapped region contents are not preserved in
2944 a dumped Emacs. */
2945 mallopt (M_MMAP_MAX, 0);
2946 #endif
2947
2948 if (nbytes <= VBLOCK_BYTES_MAX)
2949 p = allocate_vector_from_block (vroundup (nbytes));
2950 else
2951 {
2952 struct large_vector *lv
2953 = lisp_malloc (sizeof (*lv) + (len - 1) * word_size,
2954 MEM_TYPE_VECTORLIKE);
2955 lv->next.vector = large_vectors;
2956 large_vectors = lv;
2957 p = &lv->v;
2958 }
2959
2960 #ifdef DOUG_LEA_MALLOC
2961 /* Back to a reasonable maximum of mmap'ed areas. */
2962 mallopt (M_MMAP_MAX, MMAP_MAX_AREAS);
2963 #endif
2964
2965 consing_since_gc += nbytes;
2966 vector_cells_consed += len;
2967 }
2968
2969 MALLOC_UNBLOCK_INPUT;
2970
2971 return p;
2972 }
2973
2974
2975 /* Allocate a vector with LEN slots. */
2976
2977 struct Lisp_Vector *
2978 allocate_vector (EMACS_INT len)
2979 {
2980 struct Lisp_Vector *v;
2981 ptrdiff_t nbytes_max = min (PTRDIFF_MAX, SIZE_MAX);
2982
2983 if (min ((nbytes_max - header_size) / word_size, MOST_POSITIVE_FIXNUM) < len)
2984 memory_full (SIZE_MAX);
2985 v = allocate_vectorlike (len);
2986 v->header.size = len;
2987 return v;
2988 }
2989
2990
2991 /* Allocate other vector-like structures. */
2992
2993 struct Lisp_Vector *
2994 allocate_pseudovector (int memlen, int lisplen, enum pvec_type tag)
2995 {
2996 struct Lisp_Vector *v = allocate_vectorlike (memlen);
2997 int i;
2998
2999 /* Catch bogus values. */
3000 eassert (tag <= PVEC_FONT);
3001 eassert (memlen - lisplen <= (1 << PSEUDOVECTOR_REST_BITS) - 1);
3002 eassert (lisplen <= (1 << PSEUDOVECTOR_SIZE_BITS) - 1);
3003
3004 /* Only the first lisplen slots will be traced normally by the GC. */
3005 for (i = 0; i < lisplen; ++i)
3006 v->contents[i] = Qnil;
3007
3008 XSETPVECTYPESIZE (v, tag, lisplen, memlen - lisplen);
3009 return v;
3010 }
3011
3012 struct buffer *
3013 allocate_buffer (void)
3014 {
3015 struct buffer *b = lisp_malloc (sizeof *b, MEM_TYPE_BUFFER);
3016
3017 BUFFER_PVEC_INIT (b);
3018 /* Put B on the chain of all buffers including killed ones. */
3019 b->next = all_buffers;
3020 all_buffers = b;
3021 /* Note that the rest fields of B are not initialized. */
3022 return b;
3023 }
3024
3025 struct Lisp_Hash_Table *
3026 allocate_hash_table (void)
3027 {
3028 return ALLOCATE_PSEUDOVECTOR (struct Lisp_Hash_Table, count, PVEC_HASH_TABLE);
3029 }
3030
3031 struct window *
3032 allocate_window (void)
3033 {
3034 struct window *w;
3035
3036 w = ALLOCATE_PSEUDOVECTOR (struct window, current_matrix, PVEC_WINDOW);
3037 /* Users assumes that non-Lisp data is zeroed. */
3038 memset (&w->current_matrix, 0,
3039 sizeof (*w) - offsetof (struct window, current_matrix));
3040 return w;
3041 }
3042
3043 struct terminal *
3044 allocate_terminal (void)
3045 {
3046 struct terminal *t;
3047
3048 t = ALLOCATE_PSEUDOVECTOR (struct terminal, next_terminal, PVEC_TERMINAL);
3049 /* Users assumes that non-Lisp data is zeroed. */
3050 memset (&t->next_terminal, 0,
3051 sizeof (*t) - offsetof (struct terminal, next_terminal));
3052 return t;
3053 }
3054
3055 struct frame *
3056 allocate_frame (void)
3057 {
3058 struct frame *f;
3059
3060 f = ALLOCATE_PSEUDOVECTOR (struct frame, face_cache, PVEC_FRAME);
3061 /* Users assumes that non-Lisp data is zeroed. */
3062 memset (&f->face_cache, 0,
3063 sizeof (*f) - offsetof (struct frame, face_cache));
3064 return f;
3065 }
3066
3067 struct Lisp_Process *
3068 allocate_process (void)
3069 {
3070 struct Lisp_Process *p;
3071
3072 p = ALLOCATE_PSEUDOVECTOR (struct Lisp_Process, pid, PVEC_PROCESS);
3073 /* Users assumes that non-Lisp data is zeroed. */
3074 memset (&p->pid, 0,
3075 sizeof (*p) - offsetof (struct Lisp_Process, pid));
3076 return p;
3077 }
3078
3079 DEFUN ("make-vector", Fmake_vector, Smake_vector, 2, 2, 0,
3080 doc: /* Return a newly created vector of length LENGTH, with each element being INIT.
3081 See also the function `vector'. */)
3082 (register Lisp_Object length, Lisp_Object init)
3083 {
3084 Lisp_Object vector;
3085 register ptrdiff_t sizei;
3086 register ptrdiff_t i;
3087 register struct Lisp_Vector *p;
3088
3089 CHECK_NATNUM (length);
3090
3091 p = allocate_vector (XFASTINT (length));
3092 sizei = XFASTINT (length);
3093 for (i = 0; i < sizei; i++)
3094 p->contents[i] = init;
3095
3096 XSETVECTOR (vector, p);
3097 return vector;
3098 }
3099
3100
3101 DEFUN ("vector", Fvector, Svector, 0, MANY, 0,
3102 doc: /* Return a newly created vector with specified arguments as elements.
3103 Any number of arguments, even zero arguments, are allowed.
3104 usage: (vector &rest OBJECTS) */)
3105 (ptrdiff_t nargs, Lisp_Object *args)
3106 {
3107 register Lisp_Object len, val;
3108 ptrdiff_t i;
3109 register struct Lisp_Vector *p;
3110
3111 XSETFASTINT (len, nargs);
3112 val = Fmake_vector (len, Qnil);
3113 p = XVECTOR (val);
3114 for (i = 0; i < nargs; i++)
3115 p->contents[i] = args[i];
3116 return val;
3117 }
3118
3119 void
3120 make_byte_code (struct Lisp_Vector *v)
3121 {
3122 if (v->header.size > 1 && STRINGP (v->contents[1])
3123 && STRING_MULTIBYTE (v->contents[1]))
3124 /* BYTECODE-STRING must have been produced by Emacs 20.2 or the
3125 earlier because they produced a raw 8-bit string for byte-code
3126 and now such a byte-code string is loaded as multibyte while
3127 raw 8-bit characters converted to multibyte form. Thus, now we
3128 must convert them back to the original unibyte form. */
3129 v->contents[1] = Fstring_as_unibyte (v->contents[1]);
3130 XSETPVECTYPE (v, PVEC_COMPILED);
3131 }
3132
3133 DEFUN ("make-byte-code", Fmake_byte_code, Smake_byte_code, 4, MANY, 0,
3134 doc: /* Create a byte-code object with specified arguments as elements.
3135 The arguments should be the ARGLIST, bytecode-string BYTE-CODE, constant
3136 vector CONSTANTS, maximum stack size DEPTH, (optional) DOCSTRING,
3137 and (optional) INTERACTIVE-SPEC.
3138 The first four arguments are required; at most six have any
3139 significance.
3140 The ARGLIST can be either like the one of `lambda', in which case the arguments
3141 will be dynamically bound before executing the byte code, or it can be an
3142 integer of the form NNNNNNNRMMMMMMM where the 7bit MMMMMMM specifies the
3143 minimum number of arguments, the 7-bit NNNNNNN specifies the maximum number
3144 of arguments (ignoring &rest) and the R bit specifies whether there is a &rest
3145 argument to catch the left-over arguments. If such an integer is used, the
3146 arguments will not be dynamically bound but will be instead pushed on the
3147 stack before executing the byte-code.
3148 usage: (make-byte-code ARGLIST BYTE-CODE CONSTANTS DEPTH &optional DOCSTRING INTERACTIVE-SPEC &rest ELEMENTS) */)
3149 (ptrdiff_t nargs, Lisp_Object *args)
3150 {
3151 register Lisp_Object len, val;
3152 ptrdiff_t i;
3153 register struct Lisp_Vector *p;
3154
3155 /* We used to purecopy everything here, if purify-flag was set. This worked
3156 OK for Emacs-23, but with Emacs-24's lexical binding code, it can be
3157 dangerous, since make-byte-code is used during execution to build
3158 closures, so any closure built during the preload phase would end up
3159 copied into pure space, including its free variables, which is sometimes
3160 just wasteful and other times plainly wrong (e.g. those free vars may want
3161 to be setcar'd). */
3162
3163 XSETFASTINT (len, nargs);
3164 val = Fmake_vector (len, Qnil);
3165
3166 p = XVECTOR (val);
3167 for (i = 0; i < nargs; i++)
3168 p->contents[i] = args[i];
3169 make_byte_code (p);
3170 XSETCOMPILED (val, p);
3171 return val;
3172 }
3173
3174
3175 \f
3176 /***********************************************************************
3177 Symbol Allocation
3178 ***********************************************************************/
3179
3180 /* Like struct Lisp_Symbol, but padded so that the size is a multiple
3181 of the required alignment if LSB tags are used. */
3182
3183 union aligned_Lisp_Symbol
3184 {
3185 struct Lisp_Symbol s;
3186 #if USE_LSB_TAG
3187 unsigned char c[(sizeof (struct Lisp_Symbol) + GCALIGNMENT - 1)
3188 & -GCALIGNMENT];
3189 #endif
3190 };
3191
3192 /* Each symbol_block is just under 1020 bytes long, since malloc
3193 really allocates in units of powers of two and uses 4 bytes for its
3194 own overhead. */
3195
3196 #define SYMBOL_BLOCK_SIZE \
3197 ((1020 - sizeof (struct symbol_block *)) / sizeof (union aligned_Lisp_Symbol))
3198
3199 struct symbol_block
3200 {
3201 /* Place `symbols' first, to preserve alignment. */
3202 union aligned_Lisp_Symbol symbols[SYMBOL_BLOCK_SIZE];
3203 struct symbol_block *next;
3204 };
3205
3206 /* Current symbol block and index of first unused Lisp_Symbol
3207 structure in it. */
3208
3209 static struct symbol_block *symbol_block;
3210 static int symbol_block_index = SYMBOL_BLOCK_SIZE;
3211
3212 /* List of free symbols. */
3213
3214 static struct Lisp_Symbol *symbol_free_list;
3215
3216 DEFUN ("make-symbol", Fmake_symbol, Smake_symbol, 1, 1, 0,
3217 doc: /* Return a newly allocated uninterned symbol whose name is NAME.
3218 Its value is void, and its function definition and property list are nil. */)
3219 (Lisp_Object name)
3220 {
3221 register Lisp_Object val;
3222 register struct Lisp_Symbol *p;
3223
3224 CHECK_STRING (name);
3225
3226 MALLOC_BLOCK_INPUT;
3227
3228 if (symbol_free_list)
3229 {
3230 XSETSYMBOL (val, symbol_free_list);
3231 symbol_free_list = symbol_free_list->next;
3232 }
3233 else
3234 {
3235 if (symbol_block_index == SYMBOL_BLOCK_SIZE)
3236 {
3237 struct symbol_block *new
3238 = lisp_malloc (sizeof *new, MEM_TYPE_SYMBOL);
3239 new->next = symbol_block;
3240 symbol_block = new;
3241 symbol_block_index = 0;
3242 total_free_symbols += SYMBOL_BLOCK_SIZE;
3243 }
3244 XSETSYMBOL (val, &symbol_block->symbols[symbol_block_index].s);
3245 symbol_block_index++;
3246 }
3247
3248 MALLOC_UNBLOCK_INPUT;
3249
3250 p = XSYMBOL (val);
3251 set_symbol_name (val, name);
3252 set_symbol_plist (val, Qnil);
3253 p->redirect = SYMBOL_PLAINVAL;
3254 SET_SYMBOL_VAL (p, Qunbound);
3255 set_symbol_function (val, Qnil);
3256 set_symbol_next (val, NULL);
3257 p->gcmarkbit = 0;
3258 p->interned = SYMBOL_UNINTERNED;
3259 p->constant = 0;
3260 p->declared_special = 0;
3261 consing_since_gc += sizeof (struct Lisp_Symbol);
3262 symbols_consed++;
3263 total_free_symbols--;
3264 return val;
3265 }
3266
3267
3268 \f
3269 /***********************************************************************
3270 Marker (Misc) Allocation
3271 ***********************************************************************/
3272
3273 /* Like union Lisp_Misc, but padded so that its size is a multiple of
3274 the required alignment when LSB tags are used. */
3275
3276 union aligned_Lisp_Misc
3277 {
3278 union Lisp_Misc m;
3279 #if USE_LSB_TAG
3280 unsigned char c[(sizeof (union Lisp_Misc) + GCALIGNMENT - 1)
3281 & -GCALIGNMENT];
3282 #endif
3283 };
3284
3285 /* Allocation of markers and other objects that share that structure.
3286 Works like allocation of conses. */
3287
3288 #define MARKER_BLOCK_SIZE \
3289 ((1020 - sizeof (struct marker_block *)) / sizeof (union aligned_Lisp_Misc))
3290
3291 struct marker_block
3292 {
3293 /* Place `markers' first, to preserve alignment. */
3294 union aligned_Lisp_Misc markers[MARKER_BLOCK_SIZE];
3295 struct marker_block *next;
3296 };
3297
3298 static struct marker_block *marker_block;
3299 static int marker_block_index = MARKER_BLOCK_SIZE;
3300
3301 static union Lisp_Misc *marker_free_list;
3302
3303 /* Return a newly allocated Lisp_Misc object of specified TYPE. */
3304
3305 Lisp_Object
3306 allocate_misc (enum Lisp_Misc_Type type)
3307 {
3308 Lisp_Object val;
3309
3310 MALLOC_BLOCK_INPUT;
3311
3312 if (marker_free_list)
3313 {
3314 XSETMISC (val, marker_free_list);
3315 marker_free_list = marker_free_list->u_free.chain;
3316 }
3317 else
3318 {
3319 if (marker_block_index == MARKER_BLOCK_SIZE)
3320 {
3321 struct marker_block *new = lisp_malloc (sizeof *new, MEM_TYPE_MISC);
3322 new->next = marker_block;
3323 marker_block = new;
3324 marker_block_index = 0;
3325 total_free_markers += MARKER_BLOCK_SIZE;
3326 }
3327 XSETMISC (val, &marker_block->markers[marker_block_index].m);
3328 marker_block_index++;
3329 }
3330
3331 MALLOC_UNBLOCK_INPUT;
3332
3333 --total_free_markers;
3334 consing_since_gc += sizeof (union Lisp_Misc);
3335 misc_objects_consed++;
3336 XMISCTYPE (val) = type;
3337 XMISCANY (val)->gcmarkbit = 0;
3338 return val;
3339 }
3340
3341 /* Free a Lisp_Misc object. */
3342
3343 void
3344 free_misc (Lisp_Object misc)
3345 {
3346 XMISCTYPE (misc) = Lisp_Misc_Free;
3347 XMISC (misc)->u_free.chain = marker_free_list;
3348 marker_free_list = XMISC (misc);
3349 consing_since_gc -= sizeof (union Lisp_Misc);
3350 total_free_markers++;
3351 }
3352
3353 /* Return a Lisp_Save_Value object containing POINTER and INTEGER.
3354 Most code should use this to package C integers and pointers
3355 to call record_unwind_protect. The unwind function can get the
3356 C values back using XSAVE_POINTER and XSAVE_INTEGER. */
3357
3358 Lisp_Object
3359 make_save_value (void *pointer, ptrdiff_t integer)
3360 {
3361 register Lisp_Object val;
3362 register struct Lisp_Save_Value *p;
3363
3364 val = allocate_misc (Lisp_Misc_Save_Value);
3365 p = XSAVE_VALUE (val);
3366 p->type0 = SAVE_POINTER;
3367 p->data[0].pointer = pointer;
3368 p->type1 = SAVE_INTEGER;
3369 p->data[1].integer = integer;
3370 p->type2 = p->type3 = SAVE_UNUSED;
3371 p->area = 0;
3372 return val;
3373 }
3374
3375 /* Free a Lisp_Save_Value object. Do not use this function
3376 if SAVE contains pointer other than returned by xmalloc. */
3377
3378 void
3379 free_save_value (Lisp_Object save)
3380 {
3381 xfree (XSAVE_POINTER (save));
3382 free_misc (save);
3383 }
3384
3385 /* Return a Lisp_Misc_Overlay object with specified START, END and PLIST. */
3386
3387 Lisp_Object
3388 build_overlay (Lisp_Object start, Lisp_Object end, Lisp_Object plist)
3389 {
3390 register Lisp_Object overlay;
3391
3392 overlay = allocate_misc (Lisp_Misc_Overlay);
3393 OVERLAY_START (overlay) = start;
3394 OVERLAY_END (overlay) = end;
3395 set_overlay_plist (overlay, plist);
3396 XOVERLAY (overlay)->next = NULL;
3397 return overlay;
3398 }
3399
3400 DEFUN ("make-marker", Fmake_marker, Smake_marker, 0, 0, 0,
3401 doc: /* Return a newly allocated marker which does not point at any place. */)
3402 (void)
3403 {
3404 register Lisp_Object val;
3405 register struct Lisp_Marker *p;
3406
3407 val = allocate_misc (Lisp_Misc_Marker);
3408 p = XMARKER (val);
3409 p->buffer = 0;
3410 p->bytepos = 0;
3411 p->charpos = 0;
3412 p->next = NULL;
3413 p->insertion_type = 0;
3414 return val;
3415 }
3416
3417 /* Return a newly allocated marker which points into BUF
3418 at character position CHARPOS and byte position BYTEPOS. */
3419
3420 Lisp_Object
3421 build_marker (struct buffer *buf, ptrdiff_t charpos, ptrdiff_t bytepos)
3422 {
3423 Lisp_Object obj;
3424 struct Lisp_Marker *m;
3425
3426 /* No dead buffers here. */
3427 eassert (BUFFER_LIVE_P (buf));
3428
3429 /* Every character is at least one byte. */
3430 eassert (charpos <= bytepos);
3431
3432 obj = allocate_misc (Lisp_Misc_Marker);
3433 m = XMARKER (obj);
3434 m->buffer = buf;
3435 m->charpos = charpos;
3436 m->bytepos = bytepos;
3437 m->insertion_type = 0;
3438 m->next = BUF_MARKERS (buf);
3439 BUF_MARKERS (buf) = m;
3440 return obj;
3441 }
3442
3443 /* Put MARKER back on the free list after using it temporarily. */
3444
3445 void
3446 free_marker (Lisp_Object marker)
3447 {
3448 unchain_marker (XMARKER (marker));
3449 free_misc (marker);
3450 }
3451
3452 \f
3453 /* Return a newly created vector or string with specified arguments as
3454 elements. If all the arguments are characters that can fit
3455 in a string of events, make a string; otherwise, make a vector.
3456
3457 Any number of arguments, even zero arguments, are allowed. */
3458
3459 Lisp_Object
3460 make_event_array (register int nargs, Lisp_Object *args)
3461 {
3462 int i;
3463
3464 for (i = 0; i < nargs; i++)
3465 /* The things that fit in a string
3466 are characters that are in 0...127,
3467 after discarding the meta bit and all the bits above it. */
3468 if (!INTEGERP (args[i])
3469 || (XINT (args[i]) & ~(-CHAR_META)) >= 0200)
3470 return Fvector (nargs, args);
3471
3472 /* Since the loop exited, we know that all the things in it are
3473 characters, so we can make a string. */
3474 {
3475 Lisp_Object result;
3476
3477 result = Fmake_string (make_number (nargs), make_number (0));
3478 for (i = 0; i < nargs; i++)
3479 {
3480 SSET (result, i, XINT (args[i]));
3481 /* Move the meta bit to the right place for a string char. */
3482 if (XINT (args[i]) & CHAR_META)
3483 SSET (result, i, SREF (result, i) | 0x80);
3484 }
3485
3486 return result;
3487 }
3488 }
3489
3490
3491 \f
3492 /************************************************************************
3493 Memory Full Handling
3494 ************************************************************************/
3495
3496
3497 /* Called if malloc (NBYTES) returns zero. If NBYTES == SIZE_MAX,
3498 there may have been size_t overflow so that malloc was never
3499 called, or perhaps malloc was invoked successfully but the
3500 resulting pointer had problems fitting into a tagged EMACS_INT. In
3501 either case this counts as memory being full even though malloc did
3502 not fail. */
3503
3504 void
3505 memory_full (size_t nbytes)
3506 {
3507 /* Do not go into hysterics merely because a large request failed. */
3508 bool enough_free_memory = 0;
3509 if (SPARE_MEMORY < nbytes)
3510 {
3511 void *p;
3512
3513 MALLOC_BLOCK_INPUT;
3514 p = malloc (SPARE_MEMORY);
3515 if (p)
3516 {
3517 free (p);
3518 enough_free_memory = 1;
3519 }
3520 MALLOC_UNBLOCK_INPUT;
3521 }
3522
3523 if (! enough_free_memory)
3524 {
3525 int i;
3526
3527 Vmemory_full = Qt;
3528
3529 memory_full_cons_threshold = sizeof (struct cons_block);
3530
3531 /* The first time we get here, free the spare memory. */
3532 for (i = 0; i < sizeof (spare_memory) / sizeof (char *); i++)
3533 if (spare_memory[i])
3534 {
3535 if (i == 0)
3536 free (spare_memory[i]);
3537 else if (i >= 1 && i <= 4)
3538 lisp_align_free (spare_memory[i]);
3539 else
3540 lisp_free (spare_memory[i]);
3541 spare_memory[i] = 0;
3542 }
3543 }
3544
3545 /* This used to call error, but if we've run out of memory, we could
3546 get infinite recursion trying to build the string. */
3547 xsignal (Qnil, Vmemory_signal_data);
3548 }
3549
3550 /* If we released our reserve (due to running out of memory),
3551 and we have a fair amount free once again,
3552 try to set aside another reserve in case we run out once more.
3553
3554 This is called when a relocatable block is freed in ralloc.c,
3555 and also directly from this file, in case we're not using ralloc.c. */
3556
3557 void
3558 refill_memory_reserve (void)
3559 {
3560 #ifndef SYSTEM_MALLOC
3561 if (spare_memory[0] == 0)
3562 spare_memory[0] = malloc (SPARE_MEMORY);
3563 if (spare_memory[1] == 0)
3564 spare_memory[1] = lisp_align_malloc (sizeof (struct cons_block),
3565 MEM_TYPE_SPARE);
3566 if (spare_memory[2] == 0)
3567 spare_memory[2] = lisp_align_malloc (sizeof (struct cons_block),
3568 MEM_TYPE_SPARE);
3569 if (spare_memory[3] == 0)
3570 spare_memory[3] = lisp_align_malloc (sizeof (struct cons_block),
3571 MEM_TYPE_SPARE);
3572 if (spare_memory[4] == 0)
3573 spare_memory[4] = lisp_align_malloc (sizeof (struct cons_block),
3574 MEM_TYPE_SPARE);
3575 if (spare_memory[5] == 0)
3576 spare_memory[5] = lisp_malloc (sizeof (struct string_block),
3577 MEM_TYPE_SPARE);
3578 if (spare_memory[6] == 0)
3579 spare_memory[6] = lisp_malloc (sizeof (struct string_block),
3580 MEM_TYPE_SPARE);
3581 if (spare_memory[0] && spare_memory[1] && spare_memory[5])
3582 Vmemory_full = Qnil;
3583 #endif
3584 }
3585 \f
3586 /************************************************************************
3587 C Stack Marking
3588 ************************************************************************/
3589
3590 #if GC_MARK_STACK || defined GC_MALLOC_CHECK
3591
3592 /* Conservative C stack marking requires a method to identify possibly
3593 live Lisp objects given a pointer value. We do this by keeping
3594 track of blocks of Lisp data that are allocated in a red-black tree
3595 (see also the comment of mem_node which is the type of nodes in
3596 that tree). Function lisp_malloc adds information for an allocated
3597 block to the red-black tree with calls to mem_insert, and function
3598 lisp_free removes it with mem_delete. Functions live_string_p etc
3599 call mem_find to lookup information about a given pointer in the
3600 tree, and use that to determine if the pointer points to a Lisp
3601 object or not. */
3602
3603 /* Initialize this part of alloc.c. */
3604
3605 static void
3606 mem_init (void)
3607 {
3608 mem_z.left = mem_z.right = MEM_NIL;
3609 mem_z.parent = NULL;
3610 mem_z.color = MEM_BLACK;
3611 mem_z.start = mem_z.end = NULL;
3612 mem_root = MEM_NIL;
3613 }
3614
3615
3616 /* Value is a pointer to the mem_node containing START. Value is
3617 MEM_NIL if there is no node in the tree containing START. */
3618
3619 static struct mem_node *
3620 mem_find (void *start)
3621 {
3622 struct mem_node *p;
3623
3624 if (start < min_heap_address || start > max_heap_address)
3625 return MEM_NIL;
3626
3627 /* Make the search always successful to speed up the loop below. */
3628 mem_z.start = start;
3629 mem_z.end = (char *) start + 1;
3630
3631 p = mem_root;
3632 while (start < p->start || start >= p->end)
3633 p = start < p->start ? p->left : p->right;
3634 return p;
3635 }
3636
3637
3638 /* Insert a new node into the tree for a block of memory with start
3639 address START, end address END, and type TYPE. Value is a
3640 pointer to the node that was inserted. */
3641
3642 static struct mem_node *
3643 mem_insert (void *start, void *end, enum mem_type type)
3644 {
3645 struct mem_node *c, *parent, *x;
3646
3647 if (min_heap_address == NULL || start < min_heap_address)
3648 min_heap_address = start;
3649 if (max_heap_address == NULL || end > max_heap_address)
3650 max_heap_address = end;
3651
3652 /* See where in the tree a node for START belongs. In this
3653 particular application, it shouldn't happen that a node is already
3654 present. For debugging purposes, let's check that. */
3655 c = mem_root;
3656 parent = NULL;
3657
3658 #if GC_MARK_STACK != GC_MAKE_GCPROS_NOOPS
3659
3660 while (c != MEM_NIL)
3661 {
3662 if (start >= c->start && start < c->end)
3663 emacs_abort ();
3664 parent = c;
3665 c = start < c->start ? c->left : c->right;
3666 }
3667
3668 #else /* GC_MARK_STACK == GC_MARK_STACK_CHECK_GCPROS */
3669
3670 while (c != MEM_NIL)
3671 {
3672 parent = c;
3673 c = start < c->start ? c->left : c->right;
3674 }
3675
3676 #endif /* GC_MARK_STACK == GC_MARK_STACK_CHECK_GCPROS */
3677
3678 /* Create a new node. */
3679 #ifdef GC_MALLOC_CHECK
3680 x = malloc (sizeof *x);
3681 if (x == NULL)
3682 emacs_abort ();
3683 #else
3684 x = xmalloc (sizeof *x);
3685 #endif
3686 x->start = start;
3687 x->end = end;
3688 x->type = type;
3689 x->parent = parent;
3690 x->left = x->right = MEM_NIL;
3691 x->color = MEM_RED;
3692
3693 /* Insert it as child of PARENT or install it as root. */
3694 if (parent)
3695 {
3696 if (start < parent->start)
3697 parent->left = x;
3698 else
3699 parent->right = x;
3700 }
3701 else
3702 mem_root = x;
3703
3704 /* Re-establish red-black tree properties. */
3705 mem_insert_fixup (x);
3706
3707 return x;
3708 }
3709
3710
3711 /* Re-establish the red-black properties of the tree, and thereby
3712 balance the tree, after node X has been inserted; X is always red. */
3713
3714 static void
3715 mem_insert_fixup (struct mem_node *x)
3716 {
3717 while (x != mem_root && x->parent->color == MEM_RED)
3718 {
3719 /* X is red and its parent is red. This is a violation of
3720 red-black tree property #3. */
3721
3722 if (x->parent == x->parent->parent->left)
3723 {
3724 /* We're on the left side of our grandparent, and Y is our
3725 "uncle". */
3726 struct mem_node *y = x->parent->parent->right;
3727
3728 if (y->color == MEM_RED)
3729 {
3730 /* Uncle and parent are red but should be black because
3731 X is red. Change the colors accordingly and proceed
3732 with the grandparent. */
3733 x->parent->color = MEM_BLACK;
3734 y->color = MEM_BLACK;
3735 x->parent->parent->color = MEM_RED;
3736 x = x->parent->parent;
3737 }
3738 else
3739 {
3740 /* Parent and uncle have different colors; parent is
3741 red, uncle is black. */
3742 if (x == x->parent->right)
3743 {
3744 x = x->parent;
3745 mem_rotate_left (x);
3746 }
3747
3748 x->parent->color = MEM_BLACK;
3749 x->parent->parent->color = MEM_RED;
3750 mem_rotate_right (x->parent->parent);
3751 }
3752 }
3753 else
3754 {
3755 /* This is the symmetrical case of above. */
3756 struct mem_node *y = x->parent->parent->left;
3757
3758 if (y->color == MEM_RED)
3759 {
3760 x->parent->color = MEM_BLACK;
3761 y->color = MEM_BLACK;
3762 x->parent->parent->color = MEM_RED;
3763 x = x->parent->parent;
3764 }
3765 else
3766 {
3767 if (x == x->parent->left)
3768 {
3769 x = x->parent;
3770 mem_rotate_right (x);
3771 }
3772
3773 x->parent->color = MEM_BLACK;
3774 x->parent->parent->color = MEM_RED;
3775 mem_rotate_left (x->parent->parent);
3776 }
3777 }
3778 }
3779
3780 /* The root may have been changed to red due to the algorithm. Set
3781 it to black so that property #5 is satisfied. */
3782 mem_root->color = MEM_BLACK;
3783 }
3784
3785
3786 /* (x) (y)
3787 / \ / \
3788 a (y) ===> (x) c
3789 / \ / \
3790 b c a b */
3791
3792 static void
3793 mem_rotate_left (struct mem_node *x)
3794 {
3795 struct mem_node *y;
3796
3797 /* Turn y's left sub-tree into x's right sub-tree. */
3798 y = x->right;
3799 x->right = y->left;
3800 if (y->left != MEM_NIL)
3801 y->left->parent = x;
3802
3803 /* Y's parent was x's parent. */
3804 if (y != MEM_NIL)
3805 y->parent = x->parent;
3806
3807 /* Get the parent to point to y instead of x. */
3808 if (x->parent)
3809 {
3810 if (x == x->parent->left)
3811 x->parent->left = y;
3812 else
3813 x->parent->right = y;
3814 }
3815 else
3816 mem_root = y;
3817
3818 /* Put x on y's left. */
3819 y->left = x;
3820 if (x != MEM_NIL)
3821 x->parent = y;
3822 }
3823
3824
3825 /* (x) (Y)
3826 / \ / \
3827 (y) c ===> a (x)
3828 / \ / \
3829 a b b c */
3830
3831 static void
3832 mem_rotate_right (struct mem_node *x)
3833 {
3834 struct mem_node *y = x->left;
3835
3836 x->left = y->right;
3837 if (y->right != MEM_NIL)
3838 y->right->parent = x;
3839
3840 if (y != MEM_NIL)
3841 y->parent = x->parent;
3842 if (x->parent)
3843 {
3844 if (x == x->parent->right)
3845 x->parent->right = y;
3846 else
3847 x->parent->left = y;
3848 }
3849 else
3850 mem_root = y;
3851
3852 y->right = x;
3853 if (x != MEM_NIL)
3854 x->parent = y;
3855 }
3856
3857
3858 /* Delete node Z from the tree. If Z is null or MEM_NIL, do nothing. */
3859
3860 static void
3861 mem_delete (struct mem_node *z)
3862 {
3863 struct mem_node *x, *y;
3864
3865 if (!z || z == MEM_NIL)
3866 return;
3867
3868 if (z->left == MEM_NIL || z->right == MEM_NIL)
3869 y = z;
3870 else
3871 {
3872 y = z->right;
3873 while (y->left != MEM_NIL)
3874 y = y->left;
3875 }
3876
3877 if (y->left != MEM_NIL)
3878 x = y->left;
3879 else
3880 x = y->right;
3881
3882 x->parent = y->parent;
3883 if (y->parent)
3884 {
3885 if (y == y->parent->left)
3886 y->parent->left = x;
3887 else
3888 y->parent->right = x;
3889 }
3890 else
3891 mem_root = x;
3892
3893 if (y != z)
3894 {
3895 z->start = y->start;
3896 z->end = y->end;
3897 z->type = y->type;
3898 }
3899
3900 if (y->color == MEM_BLACK)
3901 mem_delete_fixup (x);
3902
3903 #ifdef GC_MALLOC_CHECK
3904 free (y);
3905 #else
3906 xfree (y);
3907 #endif
3908 }
3909
3910
3911 /* Re-establish the red-black properties of the tree, after a
3912 deletion. */
3913
3914 static void
3915 mem_delete_fixup (struct mem_node *x)
3916 {
3917 while (x != mem_root && x->color == MEM_BLACK)
3918 {
3919 if (x == x->parent->left)
3920 {
3921 struct mem_node *w = x->parent->right;
3922
3923 if (w->color == MEM_RED)
3924 {
3925 w->color = MEM_BLACK;
3926 x->parent->color = MEM_RED;
3927 mem_rotate_left (x->parent);
3928 w = x->parent->right;
3929 }
3930
3931 if (w->left->color == MEM_BLACK && w->right->color == MEM_BLACK)
3932 {
3933 w->color = MEM_RED;
3934 x = x->parent;
3935 }
3936 else
3937 {
3938 if (w->right->color == MEM_BLACK)
3939 {
3940 w->left->color = MEM_BLACK;
3941 w->color = MEM_RED;
3942 mem_rotate_right (w);
3943 w = x->parent->right;
3944 }
3945 w->color = x->parent->color;
3946 x->parent->color = MEM_BLACK;
3947 w->right->color = MEM_BLACK;
3948 mem_rotate_left (x->parent);
3949 x = mem_root;
3950 }
3951 }
3952 else
3953 {
3954 struct mem_node *w = x->parent->left;
3955
3956 if (w->color == MEM_RED)
3957 {
3958 w->color = MEM_BLACK;
3959 x->parent->color = MEM_RED;
3960 mem_rotate_right (x->parent);
3961 w = x->parent->left;
3962 }
3963
3964 if (w->right->color == MEM_BLACK && w->left->color == MEM_BLACK)
3965 {
3966 w->color = MEM_RED;
3967 x = x->parent;
3968 }
3969 else
3970 {
3971 if (w->left->color == MEM_BLACK)
3972 {
3973 w->right->color = MEM_BLACK;
3974 w->color = MEM_RED;
3975 mem_rotate_left (w);
3976 w = x->parent->left;
3977 }
3978
3979 w->color = x->parent->color;
3980 x->parent->color = MEM_BLACK;
3981 w->left->color = MEM_BLACK;
3982 mem_rotate_right (x->parent);
3983 x = mem_root;
3984 }
3985 }
3986 }
3987
3988 x->color = MEM_BLACK;
3989 }
3990
3991
3992 /* Value is non-zero if P is a pointer to a live Lisp string on
3993 the heap. M is a pointer to the mem_block for P. */
3994
3995 static bool
3996 live_string_p (struct mem_node *m, void *p)
3997 {
3998 if (m->type == MEM_TYPE_STRING)
3999 {
4000 struct string_block *b = (struct string_block *) m->start;
4001 ptrdiff_t offset = (char *) p - (char *) &b->strings[0];
4002
4003 /* P must point to the start of a Lisp_String structure, and it
4004 must not be on the free-list. */
4005 return (offset >= 0
4006 && offset % sizeof b->strings[0] == 0
4007 && offset < (STRING_BLOCK_SIZE * sizeof b->strings[0])
4008 && ((struct Lisp_String *) p)->data != NULL);
4009 }
4010 else
4011 return 0;
4012 }
4013
4014
4015 /* Value is non-zero if P is a pointer to a live Lisp cons on
4016 the heap. M is a pointer to the mem_block for P. */
4017
4018 static bool
4019 live_cons_p (struct mem_node *m, void *p)
4020 {
4021 if (m->type == MEM_TYPE_CONS)
4022 {
4023 struct cons_block *b = (struct cons_block *) m->start;
4024 ptrdiff_t offset = (char *) p - (char *) &b->conses[0];
4025
4026 /* P must point to the start of a Lisp_Cons, not be
4027 one of the unused cells in the current cons block,
4028 and not be on the free-list. */
4029 return (offset >= 0
4030 && offset % sizeof b->conses[0] == 0
4031 && offset < (CONS_BLOCK_SIZE * sizeof b->conses[0])
4032 && (b != cons_block
4033 || offset / sizeof b->conses[0] < cons_block_index)
4034 && !EQ (((struct Lisp_Cons *) p)->car, Vdead));
4035 }
4036 else
4037 return 0;
4038 }
4039
4040
4041 /* Value is non-zero if P is a pointer to a live Lisp symbol on
4042 the heap. M is a pointer to the mem_block for P. */
4043
4044 static bool
4045 live_symbol_p (struct mem_node *m, void *p)
4046 {
4047 if (m->type == MEM_TYPE_SYMBOL)
4048 {
4049 struct symbol_block *b = (struct symbol_block *) m->start;
4050 ptrdiff_t offset = (char *) p - (char *) &b->symbols[0];
4051
4052 /* P must point to the start of a Lisp_Symbol, not be
4053 one of the unused cells in the current symbol block,
4054 and not be on the free-list. */
4055 return (offset >= 0
4056 && offset % sizeof b->symbols[0] == 0
4057 && offset < (SYMBOL_BLOCK_SIZE * sizeof b->symbols[0])
4058 && (b != symbol_block
4059 || offset / sizeof b->symbols[0] < symbol_block_index)
4060 && !EQ (((struct Lisp_Symbol *)p)->function, Vdead));
4061 }
4062 else
4063 return 0;
4064 }
4065
4066
4067 /* Value is non-zero if P is a pointer to a live Lisp float on
4068 the heap. M is a pointer to the mem_block for P. */
4069
4070 static bool
4071 live_float_p (struct mem_node *m, void *p)
4072 {
4073 if (m->type == MEM_TYPE_FLOAT)
4074 {
4075 struct float_block *b = (struct float_block *) m->start;
4076 ptrdiff_t offset = (char *) p - (char *) &b->floats[0];
4077
4078 /* P must point to the start of a Lisp_Float and not be
4079 one of the unused cells in the current float block. */
4080 return (offset >= 0
4081 && offset % sizeof b->floats[0] == 0
4082 && offset < (FLOAT_BLOCK_SIZE * sizeof b->floats[0])
4083 && (b != float_block
4084 || offset / sizeof b->floats[0] < float_block_index));
4085 }
4086 else
4087 return 0;
4088 }
4089
4090
4091 /* Value is non-zero if P is a pointer to a live Lisp Misc on
4092 the heap. M is a pointer to the mem_block for P. */
4093
4094 static bool
4095 live_misc_p (struct mem_node *m, void *p)
4096 {
4097 if (m->type == MEM_TYPE_MISC)
4098 {
4099 struct marker_block *b = (struct marker_block *) m->start;
4100 ptrdiff_t offset = (char *) p - (char *) &b->markers[0];
4101
4102 /* P must point to the start of a Lisp_Misc, not be
4103 one of the unused cells in the current misc block,
4104 and not be on the free-list. */
4105 return (offset >= 0
4106 && offset % sizeof b->markers[0] == 0
4107 && offset < (MARKER_BLOCK_SIZE * sizeof b->markers[0])
4108 && (b != marker_block
4109 || offset / sizeof b->markers[0] < marker_block_index)
4110 && ((union Lisp_Misc *) p)->u_any.type != Lisp_Misc_Free);
4111 }
4112 else
4113 return 0;
4114 }
4115
4116
4117 /* Value is non-zero if P is a pointer to a live vector-like object.
4118 M is a pointer to the mem_block for P. */
4119
4120 static bool
4121 live_vector_p (struct mem_node *m, void *p)
4122 {
4123 if (m->type == MEM_TYPE_VECTOR_BLOCK)
4124 {
4125 /* This memory node corresponds to a vector block. */
4126 struct vector_block *block = (struct vector_block *) m->start;
4127 struct Lisp_Vector *vector = (struct Lisp_Vector *) block->data;
4128
4129 /* P is in the block's allocation range. Scan the block
4130 up to P and see whether P points to the start of some
4131 vector which is not on a free list. FIXME: check whether
4132 some allocation patterns (probably a lot of short vectors)
4133 may cause a substantial overhead of this loop. */
4134 while (VECTOR_IN_BLOCK (vector, block)
4135 && vector <= (struct Lisp_Vector *) p)
4136 {
4137 if (!PSEUDOVECTOR_TYPEP (&vector->header, PVEC_FREE) && vector == p)
4138 return 1;
4139 else
4140 vector = ADVANCE (vector, vector_nbytes (vector));
4141 }
4142 }
4143 else if (m->type == MEM_TYPE_VECTORLIKE
4144 && (char *) p == ((char *) m->start
4145 + offsetof (struct large_vector, v)))
4146 /* This memory node corresponds to a large vector. */
4147 return 1;
4148 return 0;
4149 }
4150
4151
4152 /* Value is non-zero if P is a pointer to a live buffer. M is a
4153 pointer to the mem_block for P. */
4154
4155 static bool
4156 live_buffer_p (struct mem_node *m, void *p)
4157 {
4158 /* P must point to the start of the block, and the buffer
4159 must not have been killed. */
4160 return (m->type == MEM_TYPE_BUFFER
4161 && p == m->start
4162 && !NILP (((struct buffer *) p)->INTERNAL_FIELD (name)));
4163 }
4164
4165 #endif /* GC_MARK_STACK || defined GC_MALLOC_CHECK */
4166
4167 #if GC_MARK_STACK
4168
4169 #if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
4170
4171 /* Array of objects that are kept alive because the C stack contains
4172 a pattern that looks like a reference to them . */
4173
4174 #define MAX_ZOMBIES 10
4175 static Lisp_Object zombies[MAX_ZOMBIES];
4176
4177 /* Number of zombie objects. */
4178
4179 static EMACS_INT nzombies;
4180
4181 /* Number of garbage collections. */
4182
4183 static EMACS_INT ngcs;
4184
4185 /* Average percentage of zombies per collection. */
4186
4187 static double avg_zombies;
4188
4189 /* Max. number of live and zombie objects. */
4190
4191 static EMACS_INT max_live, max_zombies;
4192
4193 /* Average number of live objects per GC. */
4194
4195 static double avg_live;
4196
4197 DEFUN ("gc-status", Fgc_status, Sgc_status, 0, 0, "",
4198 doc: /* Show information about live and zombie objects. */)
4199 (void)
4200 {
4201 Lisp_Object args[8], zombie_list = Qnil;
4202 EMACS_INT i;
4203 for (i = 0; i < min (MAX_ZOMBIES, nzombies); i++)
4204 zombie_list = Fcons (zombies[i], zombie_list);
4205 args[0] = build_string ("%d GCs, avg live/zombies = %.2f/%.2f (%f%%), max %d/%d\nzombies: %S");
4206 args[1] = make_number (ngcs);
4207 args[2] = make_float (avg_live);
4208 args[3] = make_float (avg_zombies);
4209 args[4] = make_float (avg_zombies / avg_live / 100);
4210 args[5] = make_number (max_live);
4211 args[6] = make_number (max_zombies);
4212 args[7] = zombie_list;
4213 return Fmessage (8, args);
4214 }
4215
4216 #endif /* GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES */
4217
4218
4219 /* Mark OBJ if we can prove it's a Lisp_Object. */
4220
4221 static void
4222 mark_maybe_object (Lisp_Object obj)
4223 {
4224 void *po;
4225 struct mem_node *m;
4226
4227 if (INTEGERP (obj))
4228 return;
4229
4230 po = (void *) XPNTR (obj);
4231 m = mem_find (po);
4232
4233 if (m != MEM_NIL)
4234 {
4235 bool mark_p = 0;
4236
4237 switch (XTYPE (obj))
4238 {
4239 case Lisp_String:
4240 mark_p = (live_string_p (m, po)
4241 && !STRING_MARKED_P ((struct Lisp_String *) po));
4242 break;
4243
4244 case Lisp_Cons:
4245 mark_p = (live_cons_p (m, po) && !CONS_MARKED_P (XCONS (obj)));
4246 break;
4247
4248 case Lisp_Symbol:
4249 mark_p = (live_symbol_p (m, po) && !XSYMBOL (obj)->gcmarkbit);
4250 break;
4251
4252 case Lisp_Float:
4253 mark_p = (live_float_p (m, po) && !FLOAT_MARKED_P (XFLOAT (obj)));
4254 break;
4255
4256 case Lisp_Vectorlike:
4257 /* Note: can't check BUFFERP before we know it's a
4258 buffer because checking that dereferences the pointer
4259 PO which might point anywhere. */
4260 if (live_vector_p (m, po))
4261 mark_p = !SUBRP (obj) && !VECTOR_MARKED_P (XVECTOR (obj));
4262 else if (live_buffer_p (m, po))
4263 mark_p = BUFFERP (obj) && !VECTOR_MARKED_P (XBUFFER (obj));
4264 break;
4265
4266 case Lisp_Misc:
4267 mark_p = (live_misc_p (m, po) && !XMISCANY (obj)->gcmarkbit);
4268 break;
4269
4270 default:
4271 break;
4272 }
4273
4274 if (mark_p)
4275 {
4276 #if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
4277 if (nzombies < MAX_ZOMBIES)
4278 zombies[nzombies] = obj;
4279 ++nzombies;
4280 #endif
4281 mark_object (obj);
4282 }
4283 }
4284 }
4285
4286
4287 /* If P points to Lisp data, mark that as live if it isn't already
4288 marked. */
4289
4290 static void
4291 mark_maybe_pointer (void *p)
4292 {
4293 struct mem_node *m;
4294
4295 /* Quickly rule out some values which can't point to Lisp data.
4296 USE_LSB_TAG needs Lisp data to be aligned on multiples of GCALIGNMENT.
4297 Otherwise, assume that Lisp data is aligned on even addresses. */
4298 if ((intptr_t) p % (USE_LSB_TAG ? GCALIGNMENT : 2))
4299 return;
4300
4301 m = mem_find (p);
4302 if (m != MEM_NIL)
4303 {
4304 Lisp_Object obj = Qnil;
4305
4306 switch (m->type)
4307 {
4308 case MEM_TYPE_NON_LISP:
4309 case MEM_TYPE_SPARE:
4310 /* Nothing to do; not a pointer to Lisp memory. */
4311 break;
4312
4313 case MEM_TYPE_BUFFER:
4314 if (live_buffer_p (m, p) && !VECTOR_MARKED_P ((struct buffer *)p))
4315 XSETVECTOR (obj, p);
4316 break;
4317
4318 case MEM_TYPE_CONS:
4319 if (live_cons_p (m, p) && !CONS_MARKED_P ((struct Lisp_Cons *) p))
4320 XSETCONS (obj, p);
4321 break;
4322
4323 case MEM_TYPE_STRING:
4324 if (live_string_p (m, p)
4325 && !STRING_MARKED_P ((struct Lisp_String *) p))
4326 XSETSTRING (obj, p);
4327 break;
4328
4329 case MEM_TYPE_MISC:
4330 if (live_misc_p (m, p) && !((struct Lisp_Free *) p)->gcmarkbit)
4331 XSETMISC (obj, p);
4332 break;
4333
4334 case MEM_TYPE_SYMBOL:
4335 if (live_symbol_p (m, p) && !((struct Lisp_Symbol *) p)->gcmarkbit)
4336 XSETSYMBOL (obj, p);
4337 break;
4338
4339 case MEM_TYPE_FLOAT:
4340 if (live_float_p (m, p) && !FLOAT_MARKED_P (p))
4341 XSETFLOAT (obj, p);
4342 break;
4343
4344 case MEM_TYPE_VECTORLIKE:
4345 case MEM_TYPE_VECTOR_BLOCK:
4346 if (live_vector_p (m, p))
4347 {
4348 Lisp_Object tem;
4349 XSETVECTOR (tem, p);
4350 if (!SUBRP (tem) && !VECTOR_MARKED_P (XVECTOR (tem)))
4351 obj = tem;
4352 }
4353 break;
4354
4355 default:
4356 emacs_abort ();
4357 }
4358
4359 if (!NILP (obj))
4360 mark_object (obj);
4361 }
4362 }
4363
4364
4365 /* Alignment of pointer values. Use alignof, as it sometimes returns
4366 a smaller alignment than GCC's __alignof__ and mark_memory might
4367 miss objects if __alignof__ were used. */
4368 #define GC_POINTER_ALIGNMENT alignof (void *)
4369
4370 /* Define POINTERS_MIGHT_HIDE_IN_OBJECTS to 1 if marking via C pointers does
4371 not suffice, which is the typical case. A host where a Lisp_Object is
4372 wider than a pointer might allocate a Lisp_Object in non-adjacent halves.
4373 If USE_LSB_TAG, the bottom half is not a valid pointer, but it should
4374 suffice to widen it to to a Lisp_Object and check it that way. */
4375 #if USE_LSB_TAG || VAL_MAX < UINTPTR_MAX
4376 # if !USE_LSB_TAG && VAL_MAX < UINTPTR_MAX >> GCTYPEBITS
4377 /* If tag bits straddle pointer-word boundaries, neither mark_maybe_pointer
4378 nor mark_maybe_object can follow the pointers. This should not occur on
4379 any practical porting target. */
4380 # error "MSB type bits straddle pointer-word boundaries"
4381 # endif
4382 /* Marking via C pointers does not suffice, because Lisp_Objects contain
4383 pointer words that hold pointers ORed with type bits. */
4384 # define POINTERS_MIGHT_HIDE_IN_OBJECTS 1
4385 #else
4386 /* Marking via C pointers suffices, because Lisp_Objects contain pointer
4387 words that hold unmodified pointers. */
4388 # define POINTERS_MIGHT_HIDE_IN_OBJECTS 0
4389 #endif
4390
4391 /* Mark Lisp objects referenced from the address range START+OFFSET..END
4392 or END+OFFSET..START. */
4393
4394 static void
4395 mark_memory (void *start, void *end)
4396 #if defined (__clang__) && defined (__has_feature)
4397 #if __has_feature(address_sanitizer)
4398 /* Do not allow -faddress-sanitizer to check this function, since it
4399 crosses the function stack boundary, and thus would yield many
4400 false positives. */
4401 __attribute__((no_address_safety_analysis))
4402 #endif
4403 #endif
4404 {
4405 void **pp;
4406 int i;
4407
4408 #if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
4409 nzombies = 0;
4410 #endif
4411
4412 /* Make START the pointer to the start of the memory region,
4413 if it isn't already. */
4414 if (end < start)
4415 {
4416 void *tem = start;
4417 start = end;
4418 end = tem;
4419 }
4420
4421 /* Mark Lisp data pointed to. This is necessary because, in some
4422 situations, the C compiler optimizes Lisp objects away, so that
4423 only a pointer to them remains. Example:
4424
4425 DEFUN ("testme", Ftestme, Stestme, 0, 0, 0, "")
4426 ()
4427 {
4428 Lisp_Object obj = build_string ("test");
4429 struct Lisp_String *s = XSTRING (obj);
4430 Fgarbage_collect ();
4431 fprintf (stderr, "test `%s'\n", s->data);
4432 return Qnil;
4433 }
4434
4435 Here, `obj' isn't really used, and the compiler optimizes it
4436 away. The only reference to the life string is through the
4437 pointer `s'. */
4438
4439 for (pp = start; (void *) pp < end; pp++)
4440 for (i = 0; i < sizeof *pp; i += GC_POINTER_ALIGNMENT)
4441 {
4442 void *p = *(void **) ((char *) pp + i);
4443 mark_maybe_pointer (p);
4444 if (POINTERS_MIGHT_HIDE_IN_OBJECTS)
4445 mark_maybe_object (XIL ((intptr_t) p));
4446 }
4447 }
4448
4449 #if !defined GC_SAVE_REGISTERS_ON_STACK && !defined GC_SETJMP_WORKS
4450
4451 static bool setjmp_tested_p;
4452 static int longjmps_done;
4453
4454 #define SETJMP_WILL_LIKELY_WORK "\
4455 \n\
4456 Emacs garbage collector has been changed to use conservative stack\n\
4457 marking. Emacs has determined that the method it uses to do the\n\
4458 marking will likely work on your system, but this isn't sure.\n\
4459 \n\
4460 If you are a system-programmer, or can get the help of a local wizard\n\
4461 who is, please take a look at the function mark_stack in alloc.c, and\n\
4462 verify that the methods used are appropriate for your system.\n\
4463 \n\
4464 Please mail the result to <emacs-devel@gnu.org>.\n\
4465 "
4466
4467 #define SETJMP_WILL_NOT_WORK "\
4468 \n\
4469 Emacs garbage collector has been changed to use conservative stack\n\
4470 marking. Emacs has determined that the default method it uses to do the\n\
4471 marking will not work on your system. We will need a system-dependent\n\
4472 solution for your system.\n\
4473 \n\
4474 Please take a look at the function mark_stack in alloc.c, and\n\
4475 try to find a way to make it work on your system.\n\
4476 \n\
4477 Note that you may get false negatives, depending on the compiler.\n\
4478 In particular, you need to use -O with GCC for this test.\n\
4479 \n\
4480 Please mail the result to <emacs-devel@gnu.org>.\n\
4481 "
4482
4483
4484 /* Perform a quick check if it looks like setjmp saves registers in a
4485 jmp_buf. Print a message to stderr saying so. When this test
4486 succeeds, this is _not_ a proof that setjmp is sufficient for
4487 conservative stack marking. Only the sources or a disassembly
4488 can prove that. */
4489
4490 static void
4491 test_setjmp (void)
4492 {
4493 char buf[10];
4494 register int x;
4495 sys_jmp_buf jbuf;
4496
4497 /* Arrange for X to be put in a register. */
4498 sprintf (buf, "1");
4499 x = strlen (buf);
4500 x = 2 * x - 1;
4501
4502 sys_setjmp (jbuf);
4503 if (longjmps_done == 1)
4504 {
4505 /* Came here after the longjmp at the end of the function.
4506
4507 If x == 1, the longjmp has restored the register to its
4508 value before the setjmp, and we can hope that setjmp
4509 saves all such registers in the jmp_buf, although that
4510 isn't sure.
4511
4512 For other values of X, either something really strange is
4513 taking place, or the setjmp just didn't save the register. */
4514
4515 if (x == 1)
4516 fprintf (stderr, SETJMP_WILL_LIKELY_WORK);
4517 else
4518 {
4519 fprintf (stderr, SETJMP_WILL_NOT_WORK);
4520 exit (1);
4521 }
4522 }
4523
4524 ++longjmps_done;
4525 x = 2;
4526 if (longjmps_done == 1)
4527 sys_longjmp (jbuf, 1);
4528 }
4529
4530 #endif /* not GC_SAVE_REGISTERS_ON_STACK && not GC_SETJMP_WORKS */
4531
4532
4533 #if GC_MARK_STACK == GC_MARK_STACK_CHECK_GCPROS
4534
4535 /* Abort if anything GCPRO'd doesn't survive the GC. */
4536
4537 static void
4538 check_gcpros (void)
4539 {
4540 struct gcpro *p;
4541 ptrdiff_t i;
4542
4543 for (p = gcprolist; p; p = p->next)
4544 for (i = 0; i < p->nvars; ++i)
4545 if (!survives_gc_p (p->var[i]))
4546 /* FIXME: It's not necessarily a bug. It might just be that the
4547 GCPRO is unnecessary or should release the object sooner. */
4548 emacs_abort ();
4549 }
4550
4551 #elif GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
4552
4553 static void
4554 dump_zombies (void)
4555 {
4556 int i;
4557
4558 fprintf (stderr, "\nZombies kept alive = %"pI"d:\n", nzombies);
4559 for (i = 0; i < min (MAX_ZOMBIES, nzombies); ++i)
4560 {
4561 fprintf (stderr, " %d = ", i);
4562 debug_print (zombies[i]);
4563 }
4564 }
4565
4566 #endif /* GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES */
4567
4568
4569 /* Mark live Lisp objects on the C stack.
4570
4571 There are several system-dependent problems to consider when
4572 porting this to new architectures:
4573
4574 Processor Registers
4575
4576 We have to mark Lisp objects in CPU registers that can hold local
4577 variables or are used to pass parameters.
4578
4579 If GC_SAVE_REGISTERS_ON_STACK is defined, it should expand to
4580 something that either saves relevant registers on the stack, or
4581 calls mark_maybe_object passing it each register's contents.
4582
4583 If GC_SAVE_REGISTERS_ON_STACK is not defined, the current
4584 implementation assumes that calling setjmp saves registers we need
4585 to see in a jmp_buf which itself lies on the stack. This doesn't
4586 have to be true! It must be verified for each system, possibly
4587 by taking a look at the source code of setjmp.
4588
4589 If __builtin_unwind_init is available (defined by GCC >= 2.8) we
4590 can use it as a machine independent method to store all registers
4591 to the stack. In this case the macros described in the previous
4592 two paragraphs are not used.
4593
4594 Stack Layout
4595
4596 Architectures differ in the way their processor stack is organized.
4597 For example, the stack might look like this
4598
4599 +----------------+
4600 | Lisp_Object | size = 4
4601 +----------------+
4602 | something else | size = 2
4603 +----------------+
4604 | Lisp_Object | size = 4
4605 +----------------+
4606 | ... |
4607
4608 In such a case, not every Lisp_Object will be aligned equally. To
4609 find all Lisp_Object on the stack it won't be sufficient to walk
4610 the stack in steps of 4 bytes. Instead, two passes will be
4611 necessary, one starting at the start of the stack, and a second
4612 pass starting at the start of the stack + 2. Likewise, if the
4613 minimal alignment of Lisp_Objects on the stack is 1, four passes
4614 would be necessary, each one starting with one byte more offset
4615 from the stack start. */
4616
4617 static void
4618 mark_stack (void)
4619 {
4620 void *end;
4621
4622 #ifdef HAVE___BUILTIN_UNWIND_INIT
4623 /* Force callee-saved registers and register windows onto the stack.
4624 This is the preferred method if available, obviating the need for
4625 machine dependent methods. */
4626 __builtin_unwind_init ();
4627 end = &end;
4628 #else /* not HAVE___BUILTIN_UNWIND_INIT */
4629 #ifndef GC_SAVE_REGISTERS_ON_STACK
4630 /* jmp_buf may not be aligned enough on darwin-ppc64 */
4631 union aligned_jmpbuf {
4632 Lisp_Object o;
4633 sys_jmp_buf j;
4634 } j;
4635 volatile bool stack_grows_down_p = (char *) &j > (char *) stack_base;
4636 #endif
4637 /* This trick flushes the register windows so that all the state of
4638 the process is contained in the stack. */
4639 /* Fixme: Code in the Boehm GC suggests flushing (with `flushrs') is
4640 needed on ia64 too. See mach_dep.c, where it also says inline
4641 assembler doesn't work with relevant proprietary compilers. */
4642 #ifdef __sparc__
4643 #if defined (__sparc64__) && defined (__FreeBSD__)
4644 /* FreeBSD does not have a ta 3 handler. */
4645 asm ("flushw");
4646 #else
4647 asm ("ta 3");
4648 #endif
4649 #endif
4650
4651 /* Save registers that we need to see on the stack. We need to see
4652 registers used to hold register variables and registers used to
4653 pass parameters. */
4654 #ifdef GC_SAVE_REGISTERS_ON_STACK
4655 GC_SAVE_REGISTERS_ON_STACK (end);
4656 #else /* not GC_SAVE_REGISTERS_ON_STACK */
4657
4658 #ifndef GC_SETJMP_WORKS /* If it hasn't been checked yet that
4659 setjmp will definitely work, test it
4660 and print a message with the result
4661 of the test. */
4662 if (!setjmp_tested_p)
4663 {
4664 setjmp_tested_p = 1;
4665 test_setjmp ();
4666 }
4667 #endif /* GC_SETJMP_WORKS */
4668
4669 sys_setjmp (j.j);
4670 end = stack_grows_down_p ? (char *) &j + sizeof j : (char *) &j;
4671 #endif /* not GC_SAVE_REGISTERS_ON_STACK */
4672 #endif /* not HAVE___BUILTIN_UNWIND_INIT */
4673
4674 /* This assumes that the stack is a contiguous region in memory. If
4675 that's not the case, something has to be done here to iterate
4676 over the stack segments. */
4677 mark_memory (stack_base, end);
4678
4679 /* Allow for marking a secondary stack, like the register stack on the
4680 ia64. */
4681 #ifdef GC_MARK_SECONDARY_STACK
4682 GC_MARK_SECONDARY_STACK ();
4683 #endif
4684
4685 #if GC_MARK_STACK == GC_MARK_STACK_CHECK_GCPROS
4686 check_gcpros ();
4687 #endif
4688 }
4689
4690 #endif /* GC_MARK_STACK != 0 */
4691
4692
4693 /* Determine whether it is safe to access memory at address P. */
4694 static int
4695 valid_pointer_p (void *p)
4696 {
4697 #ifdef WINDOWSNT
4698 return w32_valid_pointer_p (p, 16);
4699 #else
4700 int fd[2];
4701
4702 /* Obviously, we cannot just access it (we would SEGV trying), so we
4703 trick the o/s to tell us whether p is a valid pointer.
4704 Unfortunately, we cannot use NULL_DEVICE here, as emacs_write may
4705 not validate p in that case. */
4706
4707 if (pipe (fd) == 0)
4708 {
4709 bool valid = emacs_write (fd[1], (char *) p, 16) == 16;
4710 emacs_close (fd[1]);
4711 emacs_close (fd[0]);
4712 return valid;
4713 }
4714
4715 return -1;
4716 #endif
4717 }
4718
4719 /* Return 2 if OBJ is a killed or special buffer object, 1 if OBJ is a
4720 valid lisp object, 0 if OBJ is NOT a valid lisp object, or -1 if we
4721 cannot validate OBJ. This function can be quite slow, so its primary
4722 use is the manual debugging. The only exception is print_object, where
4723 we use it to check whether the memory referenced by the pointer of
4724 Lisp_Save_Value object contains valid objects. */
4725
4726 int
4727 valid_lisp_object_p (Lisp_Object obj)
4728 {
4729 void *p;
4730 #if GC_MARK_STACK
4731 struct mem_node *m;
4732 #endif
4733
4734 if (INTEGERP (obj))
4735 return 1;
4736
4737 p = (void *) XPNTR (obj);
4738 if (PURE_POINTER_P (p))
4739 return 1;
4740
4741 if (p == &buffer_defaults || p == &buffer_local_symbols)
4742 return 2;
4743
4744 #if !GC_MARK_STACK
4745 return valid_pointer_p (p);
4746 #else
4747
4748 m = mem_find (p);
4749
4750 if (m == MEM_NIL)
4751 {
4752 int valid = valid_pointer_p (p);
4753 if (valid <= 0)
4754 return valid;
4755
4756 if (SUBRP (obj))
4757 return 1;
4758
4759 return 0;
4760 }
4761
4762 switch (m->type)
4763 {
4764 case MEM_TYPE_NON_LISP:
4765 case MEM_TYPE_SPARE:
4766 return 0;
4767
4768 case MEM_TYPE_BUFFER:
4769 return live_buffer_p (m, p) ? 1 : 2;
4770
4771 case MEM_TYPE_CONS:
4772 return live_cons_p (m, p);
4773
4774 case MEM_TYPE_STRING:
4775 return live_string_p (m, p);
4776
4777 case MEM_TYPE_MISC:
4778 return live_misc_p (m, p);
4779
4780 case MEM_TYPE_SYMBOL:
4781 return live_symbol_p (m, p);
4782
4783 case MEM_TYPE_FLOAT:
4784 return live_float_p (m, p);
4785
4786 case MEM_TYPE_VECTORLIKE:
4787 case MEM_TYPE_VECTOR_BLOCK:
4788 return live_vector_p (m, p);
4789
4790 default:
4791 break;
4792 }
4793
4794 return 0;
4795 #endif
4796 }
4797
4798
4799
4800 \f
4801 /***********************************************************************
4802 Pure Storage Management
4803 ***********************************************************************/
4804
4805 /* Allocate room for SIZE bytes from pure Lisp storage and return a
4806 pointer to it. TYPE is the Lisp type for which the memory is
4807 allocated. TYPE < 0 means it's not used for a Lisp object. */
4808
4809 static void *
4810 pure_alloc (size_t size, int type)
4811 {
4812 void *result;
4813 #if USE_LSB_TAG
4814 size_t alignment = GCALIGNMENT;
4815 #else
4816 size_t alignment = alignof (EMACS_INT);
4817
4818 /* Give Lisp_Floats an extra alignment. */
4819 if (type == Lisp_Float)
4820 alignment = alignof (struct Lisp_Float);
4821 #endif
4822
4823 again:
4824 if (type >= 0)
4825 {
4826 /* Allocate space for a Lisp object from the beginning of the free
4827 space with taking account of alignment. */
4828 result = ALIGN (purebeg + pure_bytes_used_lisp, alignment);
4829 pure_bytes_used_lisp = ((char *)result - (char *)purebeg) + size;
4830 }
4831 else
4832 {
4833 /* Allocate space for a non-Lisp object from the end of the free
4834 space. */
4835 pure_bytes_used_non_lisp += size;
4836 result = purebeg + pure_size - pure_bytes_used_non_lisp;
4837 }
4838 pure_bytes_used = pure_bytes_used_lisp + pure_bytes_used_non_lisp;
4839
4840 if (pure_bytes_used <= pure_size)
4841 return result;
4842
4843 /* Don't allocate a large amount here,
4844 because it might get mmap'd and then its address
4845 might not be usable. */
4846 purebeg = xmalloc (10000);
4847 pure_size = 10000;
4848 pure_bytes_used_before_overflow += pure_bytes_used - size;
4849 pure_bytes_used = 0;
4850 pure_bytes_used_lisp = pure_bytes_used_non_lisp = 0;
4851 goto again;
4852 }
4853
4854
4855 /* Print a warning if PURESIZE is too small. */
4856
4857 void
4858 check_pure_size (void)
4859 {
4860 if (pure_bytes_used_before_overflow)
4861 message (("emacs:0:Pure Lisp storage overflow (approx. %"pI"d"
4862 " bytes needed)"),
4863 pure_bytes_used + pure_bytes_used_before_overflow);
4864 }
4865
4866
4867 /* Find the byte sequence {DATA[0], ..., DATA[NBYTES-1], '\0'} from
4868 the non-Lisp data pool of the pure storage, and return its start
4869 address. Return NULL if not found. */
4870
4871 static char *
4872 find_string_data_in_pure (const char *data, ptrdiff_t nbytes)
4873 {
4874 int i;
4875 ptrdiff_t skip, bm_skip[256], last_char_skip, infinity, start, start_max;
4876 const unsigned char *p;
4877 char *non_lisp_beg;
4878
4879 if (pure_bytes_used_non_lisp <= nbytes)
4880 return NULL;
4881
4882 /* Set up the Boyer-Moore table. */
4883 skip = nbytes + 1;
4884 for (i = 0; i < 256; i++)
4885 bm_skip[i] = skip;
4886
4887 p = (const unsigned char *) data;
4888 while (--skip > 0)
4889 bm_skip[*p++] = skip;
4890
4891 last_char_skip = bm_skip['\0'];
4892
4893 non_lisp_beg = purebeg + pure_size - pure_bytes_used_non_lisp;
4894 start_max = pure_bytes_used_non_lisp - (nbytes + 1);
4895
4896 /* See the comments in the function `boyer_moore' (search.c) for the
4897 use of `infinity'. */
4898 infinity = pure_bytes_used_non_lisp + 1;
4899 bm_skip['\0'] = infinity;
4900
4901 p = (const unsigned char *) non_lisp_beg + nbytes;
4902 start = 0;
4903 do
4904 {
4905 /* Check the last character (== '\0'). */
4906 do
4907 {
4908 start += bm_skip[*(p + start)];
4909 }
4910 while (start <= start_max);
4911
4912 if (start < infinity)
4913 /* Couldn't find the last character. */
4914 return NULL;
4915
4916 /* No less than `infinity' means we could find the last
4917 character at `p[start - infinity]'. */
4918 start -= infinity;
4919
4920 /* Check the remaining characters. */
4921 if (memcmp (data, non_lisp_beg + start, nbytes) == 0)
4922 /* Found. */
4923 return non_lisp_beg + start;
4924
4925 start += last_char_skip;
4926 }
4927 while (start <= start_max);
4928
4929 return NULL;
4930 }
4931
4932
4933 /* Return a string allocated in pure space. DATA is a buffer holding
4934 NCHARS characters, and NBYTES bytes of string data. MULTIBYTE
4935 means make the result string multibyte.
4936
4937 Must get an error if pure storage is full, since if it cannot hold
4938 a large string it may be able to hold conses that point to that
4939 string; then the string is not protected from gc. */
4940
4941 Lisp_Object
4942 make_pure_string (const char *data,
4943 ptrdiff_t nchars, ptrdiff_t nbytes, bool multibyte)
4944 {
4945 Lisp_Object string;
4946 struct Lisp_String *s = pure_alloc (sizeof *s, Lisp_String);
4947 s->data = (unsigned char *) find_string_data_in_pure (data, nbytes);
4948 if (s->data == NULL)
4949 {
4950 s->data = pure_alloc (nbytes + 1, -1);
4951 memcpy (s->data, data, nbytes);
4952 s->data[nbytes] = '\0';
4953 }
4954 s->size = nchars;
4955 s->size_byte = multibyte ? nbytes : -1;
4956 s->intervals = NULL;
4957 XSETSTRING (string, s);
4958 return string;
4959 }
4960
4961 /* Return a string allocated in pure space. Do not
4962 allocate the string data, just point to DATA. */
4963
4964 Lisp_Object
4965 make_pure_c_string (const char *data, ptrdiff_t nchars)
4966 {
4967 Lisp_Object string;
4968 struct Lisp_String *s = pure_alloc (sizeof *s, Lisp_String);
4969 s->size = nchars;
4970 s->size_byte = -1;
4971 s->data = (unsigned char *) data;
4972 s->intervals = NULL;
4973 XSETSTRING (string, s);
4974 return string;
4975 }
4976
4977 /* Return a cons allocated from pure space. Give it pure copies
4978 of CAR as car and CDR as cdr. */
4979
4980 Lisp_Object
4981 pure_cons (Lisp_Object car, Lisp_Object cdr)
4982 {
4983 Lisp_Object new;
4984 struct Lisp_Cons *p = pure_alloc (sizeof *p, Lisp_Cons);
4985 XSETCONS (new, p);
4986 XSETCAR (new, Fpurecopy (car));
4987 XSETCDR (new, Fpurecopy (cdr));
4988 return new;
4989 }
4990
4991
4992 /* Value is a float object with value NUM allocated from pure space. */
4993
4994 static Lisp_Object
4995 make_pure_float (double num)
4996 {
4997 Lisp_Object new;
4998 struct Lisp_Float *p = pure_alloc (sizeof *p, Lisp_Float);
4999 XSETFLOAT (new, p);
5000 XFLOAT_INIT (new, num);
5001 return new;
5002 }
5003
5004
5005 /* Return a vector with room for LEN Lisp_Objects allocated from
5006 pure space. */
5007
5008 static Lisp_Object
5009 make_pure_vector (ptrdiff_t len)
5010 {
5011 Lisp_Object new;
5012 size_t size = header_size + len * word_size;
5013 struct Lisp_Vector *p = pure_alloc (size, Lisp_Vectorlike);
5014 XSETVECTOR (new, p);
5015 XVECTOR (new)->header.size = len;
5016 return new;
5017 }
5018
5019
5020 DEFUN ("purecopy", Fpurecopy, Spurecopy, 1, 1, 0,
5021 doc: /* Make a copy of object OBJ in pure storage.
5022 Recursively copies contents of vectors and cons cells.
5023 Does not copy symbols. Copies strings without text properties. */)
5024 (register Lisp_Object obj)
5025 {
5026 if (NILP (Vpurify_flag))
5027 return obj;
5028
5029 if (PURE_POINTER_P (XPNTR (obj)))
5030 return obj;
5031
5032 if (HASH_TABLE_P (Vpurify_flag)) /* Hash consing. */
5033 {
5034 Lisp_Object tmp = Fgethash (obj, Vpurify_flag, Qnil);
5035 if (!NILP (tmp))
5036 return tmp;
5037 }
5038
5039 if (CONSP (obj))
5040 obj = pure_cons (XCAR (obj), XCDR (obj));
5041 else if (FLOATP (obj))
5042 obj = make_pure_float (XFLOAT_DATA (obj));
5043 else if (STRINGP (obj))
5044 obj = make_pure_string (SSDATA (obj), SCHARS (obj),
5045 SBYTES (obj),
5046 STRING_MULTIBYTE (obj));
5047 else if (COMPILEDP (obj) || VECTORP (obj))
5048 {
5049 register struct Lisp_Vector *vec;
5050 register ptrdiff_t i;
5051 ptrdiff_t size;
5052
5053 size = ASIZE (obj);
5054 if (size & PSEUDOVECTOR_FLAG)
5055 size &= PSEUDOVECTOR_SIZE_MASK;
5056 vec = XVECTOR (make_pure_vector (size));
5057 for (i = 0; i < size; i++)
5058 vec->contents[i] = Fpurecopy (AREF (obj, i));
5059 if (COMPILEDP (obj))
5060 {
5061 XSETPVECTYPE (vec, PVEC_COMPILED);
5062 XSETCOMPILED (obj, vec);
5063 }
5064 else
5065 XSETVECTOR (obj, vec);
5066 }
5067 else if (MARKERP (obj))
5068 error ("Attempt to copy a marker to pure storage");
5069 else
5070 /* Not purified, don't hash-cons. */
5071 return obj;
5072
5073 if (HASH_TABLE_P (Vpurify_flag)) /* Hash consing. */
5074 Fputhash (obj, obj, Vpurify_flag);
5075
5076 return obj;
5077 }
5078
5079
5080 \f
5081 /***********************************************************************
5082 Protection from GC
5083 ***********************************************************************/
5084
5085 /* Put an entry in staticvec, pointing at the variable with address
5086 VARADDRESS. */
5087
5088 void
5089 staticpro (Lisp_Object *varaddress)
5090 {
5091 staticvec[staticidx++] = varaddress;
5092 if (staticidx >= NSTATICS)
5093 fatal ("NSTATICS too small; try increasing and recompiling Emacs.");
5094 }
5095
5096 \f
5097 /***********************************************************************
5098 Protection from GC
5099 ***********************************************************************/
5100
5101 /* Temporarily prevent garbage collection. */
5102
5103 ptrdiff_t
5104 inhibit_garbage_collection (void)
5105 {
5106 ptrdiff_t count = SPECPDL_INDEX ();
5107
5108 specbind (Qgc_cons_threshold, make_number (MOST_POSITIVE_FIXNUM));
5109 return count;
5110 }
5111
5112 /* Used to avoid possible overflows when
5113 converting from C to Lisp integers. */
5114
5115 static Lisp_Object
5116 bounded_number (EMACS_INT number)
5117 {
5118 return make_number (min (MOST_POSITIVE_FIXNUM, number));
5119 }
5120
5121 /* Calculate total bytes of live objects. */
5122
5123 static size_t
5124 total_bytes_of_live_objects (void)
5125 {
5126 size_t tot = 0;
5127 tot += total_conses * sizeof (struct Lisp_Cons);
5128 tot += total_symbols * sizeof (struct Lisp_Symbol);
5129 tot += total_markers * sizeof (union Lisp_Misc);
5130 tot += total_string_bytes;
5131 tot += total_vector_slots * word_size;
5132 tot += total_floats * sizeof (struct Lisp_Float);
5133 tot += total_intervals * sizeof (struct interval);
5134 tot += total_strings * sizeof (struct Lisp_String);
5135 return tot;
5136 }
5137
5138 DEFUN ("garbage-collect", Fgarbage_collect, Sgarbage_collect, 0, 0, "",
5139 doc: /* Reclaim storage for Lisp objects no longer needed.
5140 Garbage collection happens automatically if you cons more than
5141 `gc-cons-threshold' bytes of Lisp data since previous garbage collection.
5142 `garbage-collect' normally returns a list with info on amount of space in use,
5143 where each entry has the form (NAME SIZE USED FREE), where:
5144 - NAME is a symbol describing the kind of objects this entry represents,
5145 - SIZE is the number of bytes used by each one,
5146 - USED is the number of those objects that were found live in the heap,
5147 - FREE is the number of those objects that are not live but that Emacs
5148 keeps around for future allocations (maybe because it does not know how
5149 to return them to the OS).
5150 However, if there was overflow in pure space, `garbage-collect'
5151 returns nil, because real GC can't be done.
5152 See Info node `(elisp)Garbage Collection'. */)
5153 (void)
5154 {
5155 struct specbinding *bind;
5156 struct buffer *nextb;
5157 char stack_top_variable;
5158 ptrdiff_t i;
5159 bool message_p;
5160 ptrdiff_t count = SPECPDL_INDEX ();
5161 EMACS_TIME start;
5162 Lisp_Object retval = Qnil;
5163 size_t tot_before = 0;
5164 struct backtrace backtrace;
5165
5166 if (abort_on_gc)
5167 emacs_abort ();
5168
5169 /* Can't GC if pure storage overflowed because we can't determine
5170 if something is a pure object or not. */
5171 if (pure_bytes_used_before_overflow)
5172 return Qnil;
5173
5174 /* Record this function, so it appears on the profiler's backtraces. */
5175 backtrace.next = backtrace_list;
5176 backtrace.function = Qautomatic_gc;
5177 backtrace.args = &Qnil;
5178 backtrace.nargs = 0;
5179 backtrace.debug_on_exit = 0;
5180 backtrace_list = &backtrace;
5181
5182 check_cons_list ();
5183
5184 /* Don't keep undo information around forever.
5185 Do this early on, so it is no problem if the user quits. */
5186 FOR_EACH_BUFFER (nextb)
5187 compact_buffer (nextb);
5188
5189 if (profiler_memory_running)
5190 tot_before = total_bytes_of_live_objects ();
5191
5192 start = current_emacs_time ();
5193
5194 /* In case user calls debug_print during GC,
5195 don't let that cause a recursive GC. */
5196 consing_since_gc = 0;
5197
5198 /* Save what's currently displayed in the echo area. */
5199 message_p = push_message ();
5200 record_unwind_protect (pop_message_unwind, Qnil);
5201
5202 /* Save a copy of the contents of the stack, for debugging. */
5203 #if MAX_SAVE_STACK > 0
5204 if (NILP (Vpurify_flag))
5205 {
5206 char *stack;
5207 ptrdiff_t stack_size;
5208 if (&stack_top_variable < stack_bottom)
5209 {
5210 stack = &stack_top_variable;
5211 stack_size = stack_bottom - &stack_top_variable;
5212 }
5213 else
5214 {
5215 stack = stack_bottom;
5216 stack_size = &stack_top_variable - stack_bottom;
5217 }
5218 if (stack_size <= MAX_SAVE_STACK)
5219 {
5220 if (stack_copy_size < stack_size)
5221 {
5222 stack_copy = xrealloc (stack_copy, stack_size);
5223 stack_copy_size = stack_size;
5224 }
5225 memcpy (stack_copy, stack, stack_size);
5226 }
5227 }
5228 #endif /* MAX_SAVE_STACK > 0 */
5229
5230 if (garbage_collection_messages)
5231 message1_nolog ("Garbage collecting...");
5232
5233 block_input ();
5234
5235 shrink_regexp_cache ();
5236
5237 gc_in_progress = 1;
5238
5239 /* Mark all the special slots that serve as the roots of accessibility. */
5240
5241 mark_buffer (&buffer_defaults);
5242 mark_buffer (&buffer_local_symbols);
5243
5244 for (i = 0; i < staticidx; i++)
5245 mark_object (*staticvec[i]);
5246
5247 for (bind = specpdl; bind != specpdl_ptr; bind++)
5248 {
5249 mark_object (bind->symbol);
5250 mark_object (bind->old_value);
5251 }
5252 mark_terminals ();
5253 mark_kboards ();
5254
5255 #ifdef USE_GTK
5256 xg_mark_data ();
5257 #endif
5258
5259 #if (GC_MARK_STACK == GC_MAKE_GCPROS_NOOPS \
5260 || GC_MARK_STACK == GC_MARK_STACK_CHECK_GCPROS)
5261 mark_stack ();
5262 #else
5263 {
5264 register struct gcpro *tail;
5265 for (tail = gcprolist; tail; tail = tail->next)
5266 for (i = 0; i < tail->nvars; i++)
5267 mark_object (tail->var[i]);
5268 }
5269 mark_byte_stack ();
5270 {
5271 struct catchtag *catch;
5272 struct handler *handler;
5273
5274 for (catch = catchlist; catch; catch = catch->next)
5275 {
5276 mark_object (catch->tag);
5277 mark_object (catch->val);
5278 }
5279 for (handler = handlerlist; handler; handler = handler->next)
5280 {
5281 mark_object (handler->handler);
5282 mark_object (handler->var);
5283 }
5284 }
5285 mark_backtrace ();
5286 #endif
5287
5288 #ifdef HAVE_WINDOW_SYSTEM
5289 mark_fringe_data ();
5290 #endif
5291
5292 #if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
5293 mark_stack ();
5294 #endif
5295
5296 /* Everything is now marked, except for the things that require special
5297 finalization, i.e. the undo_list.
5298 Look thru every buffer's undo list
5299 for elements that update markers that were not marked,
5300 and delete them. */
5301 FOR_EACH_BUFFER (nextb)
5302 {
5303 /* If a buffer's undo list is Qt, that means that undo is
5304 turned off in that buffer. Calling truncate_undo_list on
5305 Qt tends to return NULL, which effectively turns undo back on.
5306 So don't call truncate_undo_list if undo_list is Qt. */
5307 if (! EQ (nextb->INTERNAL_FIELD (undo_list), Qt))
5308 {
5309 Lisp_Object tail, prev;
5310 tail = nextb->INTERNAL_FIELD (undo_list);
5311 prev = Qnil;
5312 while (CONSP (tail))
5313 {
5314 if (CONSP (XCAR (tail))
5315 && MARKERP (XCAR (XCAR (tail)))
5316 && !XMARKER (XCAR (XCAR (tail)))->gcmarkbit)
5317 {
5318 if (NILP (prev))
5319 nextb->INTERNAL_FIELD (undo_list) = tail = XCDR (tail);
5320 else
5321 {
5322 tail = XCDR (tail);
5323 XSETCDR (prev, tail);
5324 }
5325 }
5326 else
5327 {
5328 prev = tail;
5329 tail = XCDR (tail);
5330 }
5331 }
5332 }
5333 /* Now that we have stripped the elements that need not be in the
5334 undo_list any more, we can finally mark the list. */
5335 mark_object (nextb->INTERNAL_FIELD (undo_list));
5336 }
5337
5338 gc_sweep ();
5339
5340 /* Clear the mark bits that we set in certain root slots. */
5341
5342 unmark_byte_stack ();
5343 VECTOR_UNMARK (&buffer_defaults);
5344 VECTOR_UNMARK (&buffer_local_symbols);
5345
5346 #if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES && 0
5347 dump_zombies ();
5348 #endif
5349
5350 check_cons_list ();
5351
5352 gc_in_progress = 0;
5353
5354 unblock_input ();
5355
5356 consing_since_gc = 0;
5357 if (gc_cons_threshold < GC_DEFAULT_THRESHOLD / 10)
5358 gc_cons_threshold = GC_DEFAULT_THRESHOLD / 10;
5359
5360 gc_relative_threshold = 0;
5361 if (FLOATP (Vgc_cons_percentage))
5362 { /* Set gc_cons_combined_threshold. */
5363 double tot = total_bytes_of_live_objects ();
5364
5365 tot *= XFLOAT_DATA (Vgc_cons_percentage);
5366 if (0 < tot)
5367 {
5368 if (tot < TYPE_MAXIMUM (EMACS_INT))
5369 gc_relative_threshold = tot;
5370 else
5371 gc_relative_threshold = TYPE_MAXIMUM (EMACS_INT);
5372 }
5373 }
5374
5375 if (garbage_collection_messages)
5376 {
5377 if (message_p || minibuf_level > 0)
5378 restore_message ();
5379 else
5380 message1_nolog ("Garbage collecting...done");
5381 }
5382
5383 unbind_to (count, Qnil);
5384 {
5385 Lisp_Object total[11];
5386 int total_size = 10;
5387
5388 total[0] = list4 (Qconses, make_number (sizeof (struct Lisp_Cons)),
5389 bounded_number (total_conses),
5390 bounded_number (total_free_conses));
5391
5392 total[1] = list4 (Qsymbols, make_number (sizeof (struct Lisp_Symbol)),
5393 bounded_number (total_symbols),
5394 bounded_number (total_free_symbols));
5395
5396 total[2] = list4 (Qmiscs, make_number (sizeof (union Lisp_Misc)),
5397 bounded_number (total_markers),
5398 bounded_number (total_free_markers));
5399
5400 total[3] = list4 (Qstrings, make_number (sizeof (struct Lisp_String)),
5401 bounded_number (total_strings),
5402 bounded_number (total_free_strings));
5403
5404 total[4] = list3 (Qstring_bytes, make_number (1),
5405 bounded_number (total_string_bytes));
5406
5407 total[5] = list3 (Qvectors, make_number (sizeof (struct Lisp_Vector)),
5408 bounded_number (total_vectors));
5409
5410 total[6] = list4 (Qvector_slots, make_number (word_size),
5411 bounded_number (total_vector_slots),
5412 bounded_number (total_free_vector_slots));
5413
5414 total[7] = list4 (Qfloats, make_number (sizeof (struct Lisp_Float)),
5415 bounded_number (total_floats),
5416 bounded_number (total_free_floats));
5417
5418 total[8] = list4 (Qintervals, make_number (sizeof (struct interval)),
5419 bounded_number (total_intervals),
5420 bounded_number (total_free_intervals));
5421
5422 total[9] = list3 (Qbuffers, make_number (sizeof (struct buffer)),
5423 bounded_number (total_buffers));
5424
5425 #ifdef DOUG_LEA_MALLOC
5426 total_size++;
5427 total[10] = list4 (Qheap, make_number (1024),
5428 bounded_number ((mallinfo ().uordblks + 1023) >> 10),
5429 bounded_number ((mallinfo ().fordblks + 1023) >> 10));
5430 #endif
5431 retval = Flist (total_size, total);
5432 }
5433
5434 #if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
5435 {
5436 /* Compute average percentage of zombies. */
5437 double nlive
5438 = (total_conses + total_symbols + total_markers + total_strings
5439 + total_vectors + total_floats + total_intervals + total_buffers);
5440
5441 avg_live = (avg_live * ngcs + nlive) / (ngcs + 1);
5442 max_live = max (nlive, max_live);
5443 avg_zombies = (avg_zombies * ngcs + nzombies) / (ngcs + 1);
5444 max_zombies = max (nzombies, max_zombies);
5445 ++ngcs;
5446 }
5447 #endif
5448
5449 if (!NILP (Vpost_gc_hook))
5450 {
5451 ptrdiff_t gc_count = inhibit_garbage_collection ();
5452 safe_run_hooks (Qpost_gc_hook);
5453 unbind_to (gc_count, Qnil);
5454 }
5455
5456 /* Accumulate statistics. */
5457 if (FLOATP (Vgc_elapsed))
5458 {
5459 EMACS_TIME since_start = sub_emacs_time (current_emacs_time (), start);
5460 Vgc_elapsed = make_float (XFLOAT_DATA (Vgc_elapsed)
5461 + EMACS_TIME_TO_DOUBLE (since_start));
5462 }
5463
5464 gcs_done++;
5465
5466 /* Collect profiling data. */
5467 if (profiler_memory_running)
5468 {
5469 size_t swept = 0;
5470 size_t tot_after = total_bytes_of_live_objects ();
5471 if (tot_before > tot_after)
5472 swept = tot_before - tot_after;
5473 malloc_probe (swept);
5474 }
5475
5476 backtrace_list = backtrace.next;
5477 return retval;
5478 }
5479
5480
5481 /* Mark Lisp objects in glyph matrix MATRIX. Currently the
5482 only interesting objects referenced from glyphs are strings. */
5483
5484 static void
5485 mark_glyph_matrix (struct glyph_matrix *matrix)
5486 {
5487 struct glyph_row *row = matrix->rows;
5488 struct glyph_row *end = row + matrix->nrows;
5489
5490 for (; row < end; ++row)
5491 if (row->enabled_p)
5492 {
5493 int area;
5494 for (area = LEFT_MARGIN_AREA; area < LAST_AREA; ++area)
5495 {
5496 struct glyph *glyph = row->glyphs[area];
5497 struct glyph *end_glyph = glyph + row->used[area];
5498
5499 for (; glyph < end_glyph; ++glyph)
5500 if (STRINGP (glyph->object)
5501 && !STRING_MARKED_P (XSTRING (glyph->object)))
5502 mark_object (glyph->object);
5503 }
5504 }
5505 }
5506
5507
5508 /* Mark Lisp faces in the face cache C. */
5509
5510 static void
5511 mark_face_cache (struct face_cache *c)
5512 {
5513 if (c)
5514 {
5515 int i, j;
5516 for (i = 0; i < c->used; ++i)
5517 {
5518 struct face *face = FACE_FROM_ID (c->f, i);
5519
5520 if (face)
5521 {
5522 for (j = 0; j < LFACE_VECTOR_SIZE; ++j)
5523 mark_object (face->lface[j]);
5524 }
5525 }
5526 }
5527 }
5528
5529
5530 \f
5531 /* Mark reference to a Lisp_Object.
5532 If the object referred to has not been seen yet, recursively mark
5533 all the references contained in it. */
5534
5535 #define LAST_MARKED_SIZE 500
5536 static Lisp_Object last_marked[LAST_MARKED_SIZE];
5537 static int last_marked_index;
5538
5539 /* For debugging--call abort when we cdr down this many
5540 links of a list, in mark_object. In debugging,
5541 the call to abort will hit a breakpoint.
5542 Normally this is zero and the check never goes off. */
5543 ptrdiff_t mark_object_loop_halt EXTERNALLY_VISIBLE;
5544
5545 static void
5546 mark_vectorlike (struct Lisp_Vector *ptr)
5547 {
5548 ptrdiff_t size = ptr->header.size;
5549 ptrdiff_t i;
5550
5551 eassert (!VECTOR_MARKED_P (ptr));
5552 VECTOR_MARK (ptr); /* Else mark it. */
5553 if (size & PSEUDOVECTOR_FLAG)
5554 size &= PSEUDOVECTOR_SIZE_MASK;
5555
5556 /* Note that this size is not the memory-footprint size, but only
5557 the number of Lisp_Object fields that we should trace.
5558 The distinction is used e.g. by Lisp_Process which places extra
5559 non-Lisp_Object fields at the end of the structure... */
5560 for (i = 0; i < size; i++) /* ...and then mark its elements. */
5561 mark_object (ptr->contents[i]);
5562 }
5563
5564 /* Like mark_vectorlike but optimized for char-tables (and
5565 sub-char-tables) assuming that the contents are mostly integers or
5566 symbols. */
5567
5568 static void
5569 mark_char_table (struct Lisp_Vector *ptr)
5570 {
5571 int size = ptr->header.size & PSEUDOVECTOR_SIZE_MASK;
5572 int i;
5573
5574 eassert (!VECTOR_MARKED_P (ptr));
5575 VECTOR_MARK (ptr);
5576 for (i = 0; i < size; i++)
5577 {
5578 Lisp_Object val = ptr->contents[i];
5579
5580 if (INTEGERP (val) || (SYMBOLP (val) && XSYMBOL (val)->gcmarkbit))
5581 continue;
5582 if (SUB_CHAR_TABLE_P (val))
5583 {
5584 if (! VECTOR_MARKED_P (XVECTOR (val)))
5585 mark_char_table (XVECTOR (val));
5586 }
5587 else
5588 mark_object (val);
5589 }
5590 }
5591
5592 /* Mark the chain of overlays starting at PTR. */
5593
5594 static void
5595 mark_overlay (struct Lisp_Overlay *ptr)
5596 {
5597 for (; ptr && !ptr->gcmarkbit; ptr = ptr->next)
5598 {
5599 ptr->gcmarkbit = 1;
5600 mark_object (ptr->start);
5601 mark_object (ptr->end);
5602 mark_object (ptr->plist);
5603 }
5604 }
5605
5606 /* Mark Lisp_Objects and special pointers in BUFFER. */
5607
5608 static void
5609 mark_buffer (struct buffer *buffer)
5610 {
5611 /* This is handled much like other pseudovectors... */
5612 mark_vectorlike ((struct Lisp_Vector *) buffer);
5613
5614 /* ...but there are some buffer-specific things. */
5615
5616 MARK_INTERVAL_TREE (buffer_intervals (buffer));
5617
5618 /* For now, we just don't mark the undo_list. It's done later in
5619 a special way just before the sweep phase, and after stripping
5620 some of its elements that are not needed any more. */
5621
5622 mark_overlay (buffer->overlays_before);
5623 mark_overlay (buffer->overlays_after);
5624
5625 /* If this is an indirect buffer, mark its base buffer. */
5626 if (buffer->base_buffer && !VECTOR_MARKED_P (buffer->base_buffer))
5627 mark_buffer (buffer->base_buffer);
5628 }
5629
5630 /* Remove killed buffers or items whose car is a killed buffer from
5631 LIST, and mark other items. Return changed LIST, which is marked. */
5632
5633 static Lisp_Object
5634 mark_discard_killed_buffers (Lisp_Object list)
5635 {
5636 Lisp_Object tail, *prev = &list;
5637
5638 for (tail = list; CONSP (tail) && !CONS_MARKED_P (XCONS (tail));
5639 tail = XCDR (tail))
5640 {
5641 Lisp_Object tem = XCAR (tail);
5642 if (CONSP (tem))
5643 tem = XCAR (tem);
5644 if (BUFFERP (tem) && !BUFFER_LIVE_P (XBUFFER (tem)))
5645 *prev = XCDR (tail);
5646 else
5647 {
5648 CONS_MARK (XCONS (tail));
5649 mark_object (XCAR (tail));
5650 prev = &XCDR_AS_LVALUE (tail);
5651 }
5652 }
5653 mark_object (tail);
5654 return list;
5655 }
5656
5657 /* Determine type of generic Lisp_Object and mark it accordingly. */
5658
5659 void
5660 mark_object (Lisp_Object arg)
5661 {
5662 register Lisp_Object obj = arg;
5663 #ifdef GC_CHECK_MARKED_OBJECTS
5664 void *po;
5665 struct mem_node *m;
5666 #endif
5667 ptrdiff_t cdr_count = 0;
5668
5669 loop:
5670
5671 if (PURE_POINTER_P (XPNTR (obj)))
5672 return;
5673
5674 last_marked[last_marked_index++] = obj;
5675 if (last_marked_index == LAST_MARKED_SIZE)
5676 last_marked_index = 0;
5677
5678 /* Perform some sanity checks on the objects marked here. Abort if
5679 we encounter an object we know is bogus. This increases GC time
5680 by ~80%, and requires compilation with GC_MARK_STACK != 0. */
5681 #ifdef GC_CHECK_MARKED_OBJECTS
5682
5683 po = (void *) XPNTR (obj);
5684
5685 /* Check that the object pointed to by PO is known to be a Lisp
5686 structure allocated from the heap. */
5687 #define CHECK_ALLOCATED() \
5688 do { \
5689 m = mem_find (po); \
5690 if (m == MEM_NIL) \
5691 emacs_abort (); \
5692 } while (0)
5693
5694 /* Check that the object pointed to by PO is live, using predicate
5695 function LIVEP. */
5696 #define CHECK_LIVE(LIVEP) \
5697 do { \
5698 if (!LIVEP (m, po)) \
5699 emacs_abort (); \
5700 } while (0)
5701
5702 /* Check both of the above conditions. */
5703 #define CHECK_ALLOCATED_AND_LIVE(LIVEP) \
5704 do { \
5705 CHECK_ALLOCATED (); \
5706 CHECK_LIVE (LIVEP); \
5707 } while (0) \
5708
5709 #else /* not GC_CHECK_MARKED_OBJECTS */
5710
5711 #define CHECK_LIVE(LIVEP) (void) 0
5712 #define CHECK_ALLOCATED_AND_LIVE(LIVEP) (void) 0
5713
5714 #endif /* not GC_CHECK_MARKED_OBJECTS */
5715
5716 switch (XTYPE (obj))
5717 {
5718 case Lisp_String:
5719 {
5720 register struct Lisp_String *ptr = XSTRING (obj);
5721 if (STRING_MARKED_P (ptr))
5722 break;
5723 CHECK_ALLOCATED_AND_LIVE (live_string_p);
5724 MARK_STRING (ptr);
5725 MARK_INTERVAL_TREE (ptr->intervals);
5726 #ifdef GC_CHECK_STRING_BYTES
5727 /* Check that the string size recorded in the string is the
5728 same as the one recorded in the sdata structure. */
5729 string_bytes (ptr);
5730 #endif /* GC_CHECK_STRING_BYTES */
5731 }
5732 break;
5733
5734 case Lisp_Vectorlike:
5735 {
5736 register struct Lisp_Vector *ptr = XVECTOR (obj);
5737 register ptrdiff_t pvectype;
5738
5739 if (VECTOR_MARKED_P (ptr))
5740 break;
5741
5742 #ifdef GC_CHECK_MARKED_OBJECTS
5743 m = mem_find (po);
5744 if (m == MEM_NIL && !SUBRP (obj))
5745 emacs_abort ();
5746 #endif /* GC_CHECK_MARKED_OBJECTS */
5747
5748 if (ptr->header.size & PSEUDOVECTOR_FLAG)
5749 pvectype = ((ptr->header.size & PVEC_TYPE_MASK)
5750 >> PSEUDOVECTOR_AREA_BITS);
5751 else
5752 pvectype = PVEC_NORMAL_VECTOR;
5753
5754 if (pvectype != PVEC_SUBR && pvectype != PVEC_BUFFER)
5755 CHECK_LIVE (live_vector_p);
5756
5757 switch (pvectype)
5758 {
5759 case PVEC_BUFFER:
5760 #ifdef GC_CHECK_MARKED_OBJECTS
5761 {
5762 struct buffer *b;
5763 FOR_EACH_BUFFER (b)
5764 if (b == po)
5765 break;
5766 if (b == NULL)
5767 emacs_abort ();
5768 }
5769 #endif /* GC_CHECK_MARKED_OBJECTS */
5770 mark_buffer ((struct buffer *) ptr);
5771 break;
5772
5773 case PVEC_COMPILED:
5774 { /* We could treat this just like a vector, but it is better
5775 to save the COMPILED_CONSTANTS element for last and avoid
5776 recursion there. */
5777 int size = ptr->header.size & PSEUDOVECTOR_SIZE_MASK;
5778 int i;
5779
5780 VECTOR_MARK (ptr);
5781 for (i = 0; i < size; i++)
5782 if (i != COMPILED_CONSTANTS)
5783 mark_object (ptr->contents[i]);
5784 if (size > COMPILED_CONSTANTS)
5785 {
5786 obj = ptr->contents[COMPILED_CONSTANTS];
5787 goto loop;
5788 }
5789 }
5790 break;
5791
5792 case PVEC_FRAME:
5793 mark_vectorlike (ptr);
5794 mark_face_cache (((struct frame *) ptr)->face_cache);
5795 break;
5796
5797 case PVEC_WINDOW:
5798 {
5799 struct window *w = (struct window *) ptr;
5800 bool leaf = NILP (w->hchild) && NILP (w->vchild);
5801
5802 mark_vectorlike (ptr);
5803
5804 /* Mark glyphs for leaf windows. Marking window
5805 matrices is sufficient because frame matrices
5806 use the same glyph memory. */
5807 if (leaf && w->current_matrix)
5808 {
5809 mark_glyph_matrix (w->current_matrix);
5810 mark_glyph_matrix (w->desired_matrix);
5811 }
5812
5813 /* Filter out killed buffers from both buffer lists
5814 in attempt to help GC to reclaim killed buffers faster.
5815 We can do it elsewhere for live windows, but this is the
5816 best place to do it for dead windows. */
5817 wset_prev_buffers
5818 (w, mark_discard_killed_buffers (w->prev_buffers));
5819 wset_next_buffers
5820 (w, mark_discard_killed_buffers (w->next_buffers));
5821 }
5822 break;
5823
5824 case PVEC_HASH_TABLE:
5825 {
5826 struct Lisp_Hash_Table *h = (struct Lisp_Hash_Table *) ptr;
5827
5828 mark_vectorlike (ptr);
5829 mark_object (h->test.name);
5830 mark_object (h->test.user_hash_function);
5831 mark_object (h->test.user_cmp_function);
5832 /* If hash table is not weak, mark all keys and values.
5833 For weak tables, mark only the vector. */
5834 if (NILP (h->weak))
5835 mark_object (h->key_and_value);
5836 else
5837 VECTOR_MARK (XVECTOR (h->key_and_value));
5838 }
5839 break;
5840
5841 case PVEC_CHAR_TABLE:
5842 mark_char_table (ptr);
5843 break;
5844
5845 case PVEC_BOOL_VECTOR:
5846 /* No Lisp_Objects to mark in a bool vector. */
5847 VECTOR_MARK (ptr);
5848 break;
5849
5850 case PVEC_SUBR:
5851 break;
5852
5853 case PVEC_FREE:
5854 emacs_abort ();
5855
5856 default:
5857 mark_vectorlike (ptr);
5858 }
5859 }
5860 break;
5861
5862 case Lisp_Symbol:
5863 {
5864 register struct Lisp_Symbol *ptr = XSYMBOL (obj);
5865 struct Lisp_Symbol *ptrx;
5866
5867 if (ptr->gcmarkbit)
5868 break;
5869 CHECK_ALLOCATED_AND_LIVE (live_symbol_p);
5870 ptr->gcmarkbit = 1;
5871 mark_object (ptr->function);
5872 mark_object (ptr->plist);
5873 switch (ptr->redirect)
5874 {
5875 case SYMBOL_PLAINVAL: mark_object (SYMBOL_VAL (ptr)); break;
5876 case SYMBOL_VARALIAS:
5877 {
5878 Lisp_Object tem;
5879 XSETSYMBOL (tem, SYMBOL_ALIAS (ptr));
5880 mark_object (tem);
5881 break;
5882 }
5883 case SYMBOL_LOCALIZED:
5884 {
5885 struct Lisp_Buffer_Local_Value *blv = SYMBOL_BLV (ptr);
5886 Lisp_Object where = blv->where;
5887 /* If the value is set up for a killed buffer or deleted
5888 frame, restore it's global binding. If the value is
5889 forwarded to a C variable, either it's not a Lisp_Object
5890 var, or it's staticpro'd already. */
5891 if ((BUFFERP (where) && !BUFFER_LIVE_P (XBUFFER (where)))
5892 || (FRAMEP (where) && !FRAME_LIVE_P (XFRAME (where))))
5893 swap_in_global_binding (ptr);
5894 mark_object (blv->where);
5895 mark_object (blv->valcell);
5896 mark_object (blv->defcell);
5897 break;
5898 }
5899 case SYMBOL_FORWARDED:
5900 /* If the value is forwarded to a buffer or keyboard field,
5901 these are marked when we see the corresponding object.
5902 And if it's forwarded to a C variable, either it's not
5903 a Lisp_Object var, or it's staticpro'd already. */
5904 break;
5905 default: emacs_abort ();
5906 }
5907 if (!PURE_POINTER_P (XSTRING (ptr->name)))
5908 MARK_STRING (XSTRING (ptr->name));
5909 MARK_INTERVAL_TREE (string_intervals (ptr->name));
5910
5911 ptr = ptr->next;
5912 if (ptr)
5913 {
5914 ptrx = ptr; /* Use of ptrx avoids compiler bug on Sun. */
5915 XSETSYMBOL (obj, ptrx);
5916 goto loop;
5917 }
5918 }
5919 break;
5920
5921 case Lisp_Misc:
5922 CHECK_ALLOCATED_AND_LIVE (live_misc_p);
5923
5924 if (XMISCANY (obj)->gcmarkbit)
5925 break;
5926
5927 switch (XMISCTYPE (obj))
5928 {
5929 case Lisp_Misc_Marker:
5930 /* DO NOT mark thru the marker's chain.
5931 The buffer's markers chain does not preserve markers from gc;
5932 instead, markers are removed from the chain when freed by gc. */
5933 XMISCANY (obj)->gcmarkbit = 1;
5934 break;
5935
5936 case Lisp_Misc_Save_Value:
5937 XMISCANY (obj)->gcmarkbit = 1;
5938 {
5939 register struct Lisp_Save_Value *ptr = XSAVE_VALUE (obj);
5940 /* If `area' is nonzero, `data[0].pointer' is the address
5941 of a memory area containing `data[1].integer' potential
5942 Lisp_Objects. */
5943 #if GC_MARK_STACK
5944 if (ptr->area)
5945 {
5946 Lisp_Object *p = (Lisp_Object *) ptr->data[0].pointer;
5947 ptrdiff_t nelt;
5948 for (nelt = ptr->data[1].integer; nelt > 0; nelt--, p++)
5949 mark_maybe_object (*p);
5950 }
5951 else
5952 #endif /* GC_MARK_STACK */
5953 {
5954 /* Find Lisp_Objects in `data[N]' slots and mark them. */
5955 if (ptr->type0 == SAVE_OBJECT)
5956 mark_object (ptr->data[0].object);
5957 if (ptr->type1 == SAVE_OBJECT)
5958 mark_object (ptr->data[1].object);
5959 if (ptr->type2 == SAVE_OBJECT)
5960 mark_object (ptr->data[2].object);
5961 if (ptr->type3 == SAVE_OBJECT)
5962 mark_object (ptr->data[3].object);
5963 }
5964 }
5965 break;
5966
5967 case Lisp_Misc_Overlay:
5968 mark_overlay (XOVERLAY (obj));
5969 break;
5970
5971 default:
5972 emacs_abort ();
5973 }
5974 break;
5975
5976 case Lisp_Cons:
5977 {
5978 register struct Lisp_Cons *ptr = XCONS (obj);
5979 if (CONS_MARKED_P (ptr))
5980 break;
5981 CHECK_ALLOCATED_AND_LIVE (live_cons_p);
5982 CONS_MARK (ptr);
5983 /* If the cdr is nil, avoid recursion for the car. */
5984 if (EQ (ptr->u.cdr, Qnil))
5985 {
5986 obj = ptr->car;
5987 cdr_count = 0;
5988 goto loop;
5989 }
5990 mark_object (ptr->car);
5991 obj = ptr->u.cdr;
5992 cdr_count++;
5993 if (cdr_count == mark_object_loop_halt)
5994 emacs_abort ();
5995 goto loop;
5996 }
5997
5998 case Lisp_Float:
5999 CHECK_ALLOCATED_AND_LIVE (live_float_p);
6000 FLOAT_MARK (XFLOAT (obj));
6001 break;
6002
6003 case_Lisp_Int:
6004 break;
6005
6006 default:
6007 emacs_abort ();
6008 }
6009
6010 #undef CHECK_LIVE
6011 #undef CHECK_ALLOCATED
6012 #undef CHECK_ALLOCATED_AND_LIVE
6013 }
6014 /* Mark the Lisp pointers in the terminal objects.
6015 Called by Fgarbage_collect. */
6016
6017 static void
6018 mark_terminals (void)
6019 {
6020 struct terminal *t;
6021 for (t = terminal_list; t; t = t->next_terminal)
6022 {
6023 eassert (t->name != NULL);
6024 #ifdef HAVE_WINDOW_SYSTEM
6025 /* If a terminal object is reachable from a stacpro'ed object,
6026 it might have been marked already. Make sure the image cache
6027 gets marked. */
6028 mark_image_cache (t->image_cache);
6029 #endif /* HAVE_WINDOW_SYSTEM */
6030 if (!VECTOR_MARKED_P (t))
6031 mark_vectorlike ((struct Lisp_Vector *)t);
6032 }
6033 }
6034
6035
6036
6037 /* Value is non-zero if OBJ will survive the current GC because it's
6038 either marked or does not need to be marked to survive. */
6039
6040 bool
6041 survives_gc_p (Lisp_Object obj)
6042 {
6043 bool survives_p;
6044
6045 switch (XTYPE (obj))
6046 {
6047 case_Lisp_Int:
6048 survives_p = 1;
6049 break;
6050
6051 case Lisp_Symbol:
6052 survives_p = XSYMBOL (obj)->gcmarkbit;
6053 break;
6054
6055 case Lisp_Misc:
6056 survives_p = XMISCANY (obj)->gcmarkbit;
6057 break;
6058
6059 case Lisp_String:
6060 survives_p = STRING_MARKED_P (XSTRING (obj));
6061 break;
6062
6063 case Lisp_Vectorlike:
6064 survives_p = SUBRP (obj) || VECTOR_MARKED_P (XVECTOR (obj));
6065 break;
6066
6067 case Lisp_Cons:
6068 survives_p = CONS_MARKED_P (XCONS (obj));
6069 break;
6070
6071 case Lisp_Float:
6072 survives_p = FLOAT_MARKED_P (XFLOAT (obj));
6073 break;
6074
6075 default:
6076 emacs_abort ();
6077 }
6078
6079 return survives_p || PURE_POINTER_P ((void *) XPNTR (obj));
6080 }
6081
6082
6083 \f
6084 /* Sweep: find all structures not marked, and free them. */
6085
6086 static void
6087 gc_sweep (void)
6088 {
6089 /* Remove or mark entries in weak hash tables.
6090 This must be done before any object is unmarked. */
6091 sweep_weak_hash_tables ();
6092
6093 sweep_strings ();
6094 check_string_bytes (!noninteractive);
6095
6096 /* Put all unmarked conses on free list */
6097 {
6098 register struct cons_block *cblk;
6099 struct cons_block **cprev = &cons_block;
6100 register int lim = cons_block_index;
6101 EMACS_INT num_free = 0, num_used = 0;
6102
6103 cons_free_list = 0;
6104
6105 for (cblk = cons_block; cblk; cblk = *cprev)
6106 {
6107 register int i = 0;
6108 int this_free = 0;
6109 int ilim = (lim + BITS_PER_INT - 1) / BITS_PER_INT;
6110
6111 /* Scan the mark bits an int at a time. */
6112 for (i = 0; i < ilim; i++)
6113 {
6114 if (cblk->gcmarkbits[i] == -1)
6115 {
6116 /* Fast path - all cons cells for this int are marked. */
6117 cblk->gcmarkbits[i] = 0;
6118 num_used += BITS_PER_INT;
6119 }
6120 else
6121 {
6122 /* Some cons cells for this int are not marked.
6123 Find which ones, and free them. */
6124 int start, pos, stop;
6125
6126 start = i * BITS_PER_INT;
6127 stop = lim - start;
6128 if (stop > BITS_PER_INT)
6129 stop = BITS_PER_INT;
6130 stop += start;
6131
6132 for (pos = start; pos < stop; pos++)
6133 {
6134 if (!CONS_MARKED_P (&cblk->conses[pos]))
6135 {
6136 this_free++;
6137 cblk->conses[pos].u.chain = cons_free_list;
6138 cons_free_list = &cblk->conses[pos];
6139 #if GC_MARK_STACK
6140 cons_free_list->car = Vdead;
6141 #endif
6142 }
6143 else
6144 {
6145 num_used++;
6146 CONS_UNMARK (&cblk->conses[pos]);
6147 }
6148 }
6149 }
6150 }
6151
6152 lim = CONS_BLOCK_SIZE;
6153 /* If this block contains only free conses and we have already
6154 seen more than two blocks worth of free conses then deallocate
6155 this block. */
6156 if (this_free == CONS_BLOCK_SIZE && num_free > CONS_BLOCK_SIZE)
6157 {
6158 *cprev = cblk->next;
6159 /* Unhook from the free list. */
6160 cons_free_list = cblk->conses[0].u.chain;
6161 lisp_align_free (cblk);
6162 }
6163 else
6164 {
6165 num_free += this_free;
6166 cprev = &cblk->next;
6167 }
6168 }
6169 total_conses = num_used;
6170 total_free_conses = num_free;
6171 }
6172
6173 /* Put all unmarked floats on free list */
6174 {
6175 register struct float_block *fblk;
6176 struct float_block **fprev = &float_block;
6177 register int lim = float_block_index;
6178 EMACS_INT num_free = 0, num_used = 0;
6179
6180 float_free_list = 0;
6181
6182 for (fblk = float_block; fblk; fblk = *fprev)
6183 {
6184 register int i;
6185 int this_free = 0;
6186 for (i = 0; i < lim; i++)
6187 if (!FLOAT_MARKED_P (&fblk->floats[i]))
6188 {
6189 this_free++;
6190 fblk->floats[i].u.chain = float_free_list;
6191 float_free_list = &fblk->floats[i];
6192 }
6193 else
6194 {
6195 num_used++;
6196 FLOAT_UNMARK (&fblk->floats[i]);
6197 }
6198 lim = FLOAT_BLOCK_SIZE;
6199 /* If this block contains only free floats and we have already
6200 seen more than two blocks worth of free floats then deallocate
6201 this block. */
6202 if (this_free == FLOAT_BLOCK_SIZE && num_free > FLOAT_BLOCK_SIZE)
6203 {
6204 *fprev = fblk->next;
6205 /* Unhook from the free list. */
6206 float_free_list = fblk->floats[0].u.chain;
6207 lisp_align_free (fblk);
6208 }
6209 else
6210 {
6211 num_free += this_free;
6212 fprev = &fblk->next;
6213 }
6214 }
6215 total_floats = num_used;
6216 total_free_floats = num_free;
6217 }
6218
6219 /* Put all unmarked intervals on free list */
6220 {
6221 register struct interval_block *iblk;
6222 struct interval_block **iprev = &interval_block;
6223 register int lim = interval_block_index;
6224 EMACS_INT num_free = 0, num_used = 0;
6225
6226 interval_free_list = 0;
6227
6228 for (iblk = interval_block; iblk; iblk = *iprev)
6229 {
6230 register int i;
6231 int this_free = 0;
6232
6233 for (i = 0; i < lim; i++)
6234 {
6235 if (!iblk->intervals[i].gcmarkbit)
6236 {
6237 set_interval_parent (&iblk->intervals[i], interval_free_list);
6238 interval_free_list = &iblk->intervals[i];
6239 this_free++;
6240 }
6241 else
6242 {
6243 num_used++;
6244 iblk->intervals[i].gcmarkbit = 0;
6245 }
6246 }
6247 lim = INTERVAL_BLOCK_SIZE;
6248 /* If this block contains only free intervals and we have already
6249 seen more than two blocks worth of free intervals then
6250 deallocate this block. */
6251 if (this_free == INTERVAL_BLOCK_SIZE && num_free > INTERVAL_BLOCK_SIZE)
6252 {
6253 *iprev = iblk->next;
6254 /* Unhook from the free list. */
6255 interval_free_list = INTERVAL_PARENT (&iblk->intervals[0]);
6256 lisp_free (iblk);
6257 }
6258 else
6259 {
6260 num_free += this_free;
6261 iprev = &iblk->next;
6262 }
6263 }
6264 total_intervals = num_used;
6265 total_free_intervals = num_free;
6266 }
6267
6268 /* Put all unmarked symbols on free list */
6269 {
6270 register struct symbol_block *sblk;
6271 struct symbol_block **sprev = &symbol_block;
6272 register int lim = symbol_block_index;
6273 EMACS_INT num_free = 0, num_used = 0;
6274
6275 symbol_free_list = NULL;
6276
6277 for (sblk = symbol_block; sblk; sblk = *sprev)
6278 {
6279 int this_free = 0;
6280 union aligned_Lisp_Symbol *sym = sblk->symbols;
6281 union aligned_Lisp_Symbol *end = sym + lim;
6282
6283 for (; sym < end; ++sym)
6284 {
6285 /* Check if the symbol was created during loadup. In such a case
6286 it might be pointed to by pure bytecode which we don't trace,
6287 so we conservatively assume that it is live. */
6288 bool pure_p = PURE_POINTER_P (XSTRING (sym->s.name));
6289
6290 if (!sym->s.gcmarkbit && !pure_p)
6291 {
6292 if (sym->s.redirect == SYMBOL_LOCALIZED)
6293 xfree (SYMBOL_BLV (&sym->s));
6294 sym->s.next = symbol_free_list;
6295 symbol_free_list = &sym->s;
6296 #if GC_MARK_STACK
6297 symbol_free_list->function = Vdead;
6298 #endif
6299 ++this_free;
6300 }
6301 else
6302 {
6303 ++num_used;
6304 if (!pure_p)
6305 UNMARK_STRING (XSTRING (sym->s.name));
6306 sym->s.gcmarkbit = 0;
6307 }
6308 }
6309
6310 lim = SYMBOL_BLOCK_SIZE;
6311 /* If this block contains only free symbols and we have already
6312 seen more than two blocks worth of free symbols then deallocate
6313 this block. */
6314 if (this_free == SYMBOL_BLOCK_SIZE && num_free > SYMBOL_BLOCK_SIZE)
6315 {
6316 *sprev = sblk->next;
6317 /* Unhook from the free list. */
6318 symbol_free_list = sblk->symbols[0].s.next;
6319 lisp_free (sblk);
6320 }
6321 else
6322 {
6323 num_free += this_free;
6324 sprev = &sblk->next;
6325 }
6326 }
6327 total_symbols = num_used;
6328 total_free_symbols = num_free;
6329 }
6330
6331 /* Put all unmarked misc's on free list.
6332 For a marker, first unchain it from the buffer it points into. */
6333 {
6334 register struct marker_block *mblk;
6335 struct marker_block **mprev = &marker_block;
6336 register int lim = marker_block_index;
6337 EMACS_INT num_free = 0, num_used = 0;
6338
6339 marker_free_list = 0;
6340
6341 for (mblk = marker_block; mblk; mblk = *mprev)
6342 {
6343 register int i;
6344 int this_free = 0;
6345
6346 for (i = 0; i < lim; i++)
6347 {
6348 if (!mblk->markers[i].m.u_any.gcmarkbit)
6349 {
6350 if (mblk->markers[i].m.u_any.type == Lisp_Misc_Marker)
6351 unchain_marker (&mblk->markers[i].m.u_marker);
6352 /* Set the type of the freed object to Lisp_Misc_Free.
6353 We could leave the type alone, since nobody checks it,
6354 but this might catch bugs faster. */
6355 mblk->markers[i].m.u_marker.type = Lisp_Misc_Free;
6356 mblk->markers[i].m.u_free.chain = marker_free_list;
6357 marker_free_list = &mblk->markers[i].m;
6358 this_free++;
6359 }
6360 else
6361 {
6362 num_used++;
6363 mblk->markers[i].m.u_any.gcmarkbit = 0;
6364 }
6365 }
6366 lim = MARKER_BLOCK_SIZE;
6367 /* If this block contains only free markers and we have already
6368 seen more than two blocks worth of free markers then deallocate
6369 this block. */
6370 if (this_free == MARKER_BLOCK_SIZE && num_free > MARKER_BLOCK_SIZE)
6371 {
6372 *mprev = mblk->next;
6373 /* Unhook from the free list. */
6374 marker_free_list = mblk->markers[0].m.u_free.chain;
6375 lisp_free (mblk);
6376 }
6377 else
6378 {
6379 num_free += this_free;
6380 mprev = &mblk->next;
6381 }
6382 }
6383
6384 total_markers = num_used;
6385 total_free_markers = num_free;
6386 }
6387
6388 /* Free all unmarked buffers */
6389 {
6390 register struct buffer *buffer, **bprev = &all_buffers;
6391
6392 total_buffers = 0;
6393 for (buffer = all_buffers; buffer; buffer = *bprev)
6394 if (!VECTOR_MARKED_P (buffer))
6395 {
6396 *bprev = buffer->next;
6397 lisp_free (buffer);
6398 }
6399 else
6400 {
6401 VECTOR_UNMARK (buffer);
6402 /* Do not use buffer_(set|get)_intervals here. */
6403 buffer->text->intervals = balance_intervals (buffer->text->intervals);
6404 total_buffers++;
6405 bprev = &buffer->next;
6406 }
6407 }
6408
6409 sweep_vectors ();
6410 check_string_bytes (!noninteractive);
6411 }
6412
6413
6414
6415 \f
6416 /* Debugging aids. */
6417
6418 DEFUN ("memory-limit", Fmemory_limit, Smemory_limit, 0, 0, 0,
6419 doc: /* Return the address of the last byte Emacs has allocated, divided by 1024.
6420 This may be helpful in debugging Emacs's memory usage.
6421 We divide the value by 1024 to make sure it fits in a Lisp integer. */)
6422 (void)
6423 {
6424 Lisp_Object end;
6425
6426 XSETINT (end, (intptr_t) (char *) sbrk (0) / 1024);
6427
6428 return end;
6429 }
6430
6431 DEFUN ("memory-use-counts", Fmemory_use_counts, Smemory_use_counts, 0, 0, 0,
6432 doc: /* Return a list of counters that measure how much consing there has been.
6433 Each of these counters increments for a certain kind of object.
6434 The counters wrap around from the largest positive integer to zero.
6435 Garbage collection does not decrease them.
6436 The elements of the value are as follows:
6437 (CONSES FLOATS VECTOR-CELLS SYMBOLS STRING-CHARS MISCS INTERVALS STRINGS)
6438 All are in units of 1 = one object consed
6439 except for VECTOR-CELLS and STRING-CHARS, which count the total length of
6440 objects consed.
6441 MISCS include overlays, markers, and some internal types.
6442 Frames, windows, buffers, and subprocesses count as vectors
6443 (but the contents of a buffer's text do not count here). */)
6444 (void)
6445 {
6446 return listn (CONSTYPE_HEAP, 8,
6447 bounded_number (cons_cells_consed),
6448 bounded_number (floats_consed),
6449 bounded_number (vector_cells_consed),
6450 bounded_number (symbols_consed),
6451 bounded_number (string_chars_consed),
6452 bounded_number (misc_objects_consed),
6453 bounded_number (intervals_consed),
6454 bounded_number (strings_consed));
6455 }
6456
6457 /* Find at most FIND_MAX symbols which have OBJ as their value or
6458 function. This is used in gdbinit's `xwhichsymbols' command. */
6459
6460 Lisp_Object
6461 which_symbols (Lisp_Object obj, EMACS_INT find_max)
6462 {
6463 struct symbol_block *sblk;
6464 ptrdiff_t gc_count = inhibit_garbage_collection ();
6465 Lisp_Object found = Qnil;
6466
6467 if (! DEADP (obj))
6468 {
6469 for (sblk = symbol_block; sblk; sblk = sblk->next)
6470 {
6471 union aligned_Lisp_Symbol *aligned_sym = sblk->symbols;
6472 int bn;
6473
6474 for (bn = 0; bn < SYMBOL_BLOCK_SIZE; bn++, aligned_sym++)
6475 {
6476 struct Lisp_Symbol *sym = &aligned_sym->s;
6477 Lisp_Object val;
6478 Lisp_Object tem;
6479
6480 if (sblk == symbol_block && bn >= symbol_block_index)
6481 break;
6482
6483 XSETSYMBOL (tem, sym);
6484 val = find_symbol_value (tem);
6485 if (EQ (val, obj)
6486 || EQ (sym->function, obj)
6487 || (!NILP (sym->function)
6488 && COMPILEDP (sym->function)
6489 && EQ (AREF (sym->function, COMPILED_BYTECODE), obj))
6490 || (!NILP (val)
6491 && COMPILEDP (val)
6492 && EQ (AREF (val, COMPILED_BYTECODE), obj)))
6493 {
6494 found = Fcons (tem, found);
6495 if (--find_max == 0)
6496 goto out;
6497 }
6498 }
6499 }
6500 }
6501
6502 out:
6503 unbind_to (gc_count, Qnil);
6504 return found;
6505 }
6506
6507 #ifdef ENABLE_CHECKING
6508
6509 bool suppress_checking;
6510
6511 void
6512 die (const char *msg, const char *file, int line)
6513 {
6514 fprintf (stderr, "\r\n%s:%d: Emacs fatal error: %s\r\n",
6515 file, line, msg);
6516 terminate_due_to_signal (SIGABRT, INT_MAX);
6517 }
6518 #endif
6519 \f
6520 /* Initialization */
6521
6522 void
6523 init_alloc_once (void)
6524 {
6525 /* Used to do Vpurify_flag = Qt here, but Qt isn't set up yet! */
6526 purebeg = PUREBEG;
6527 pure_size = PURESIZE;
6528
6529 #if GC_MARK_STACK || defined GC_MALLOC_CHECK
6530 mem_init ();
6531 Vdead = make_pure_string ("DEAD", 4, 4, 0);
6532 #endif
6533
6534 #ifdef DOUG_LEA_MALLOC
6535 mallopt (M_TRIM_THRESHOLD, 128*1024); /* trim threshold */
6536 mallopt (M_MMAP_THRESHOLD, 64*1024); /* mmap threshold */
6537 mallopt (M_MMAP_MAX, MMAP_MAX_AREAS); /* max. number of mmap'ed areas */
6538 #endif
6539 init_strings ();
6540 init_vectors ();
6541
6542 refill_memory_reserve ();
6543 gc_cons_threshold = GC_DEFAULT_THRESHOLD;
6544 }
6545
6546 void
6547 init_alloc (void)
6548 {
6549 gcprolist = 0;
6550 byte_stack_list = 0;
6551 #if GC_MARK_STACK
6552 #if !defined GC_SAVE_REGISTERS_ON_STACK && !defined GC_SETJMP_WORKS
6553 setjmp_tested_p = longjmps_done = 0;
6554 #endif
6555 #endif
6556 Vgc_elapsed = make_float (0.0);
6557 gcs_done = 0;
6558 }
6559
6560 void
6561 syms_of_alloc (void)
6562 {
6563 DEFVAR_INT ("gc-cons-threshold", gc_cons_threshold,
6564 doc: /* Number of bytes of consing between garbage collections.
6565 Garbage collection can happen automatically once this many bytes have been
6566 allocated since the last garbage collection. All data types count.
6567
6568 Garbage collection happens automatically only when `eval' is called.
6569
6570 By binding this temporarily to a large number, you can effectively
6571 prevent garbage collection during a part of the program.
6572 See also `gc-cons-percentage'. */);
6573
6574 DEFVAR_LISP ("gc-cons-percentage", Vgc_cons_percentage,
6575 doc: /* Portion of the heap used for allocation.
6576 Garbage collection can happen automatically once this portion of the heap
6577 has been allocated since the last garbage collection.
6578 If this portion is smaller than `gc-cons-threshold', this is ignored. */);
6579 Vgc_cons_percentage = make_float (0.1);
6580
6581 DEFVAR_INT ("pure-bytes-used", pure_bytes_used,
6582 doc: /* Number of bytes of shareable Lisp data allocated so far. */);
6583
6584 DEFVAR_INT ("cons-cells-consed", cons_cells_consed,
6585 doc: /* Number of cons cells that have been consed so far. */);
6586
6587 DEFVAR_INT ("floats-consed", floats_consed,
6588 doc: /* Number of floats that have been consed so far. */);
6589
6590 DEFVAR_INT ("vector-cells-consed", vector_cells_consed,
6591 doc: /* Number of vector cells that have been consed so far. */);
6592
6593 DEFVAR_INT ("symbols-consed", symbols_consed,
6594 doc: /* Number of symbols that have been consed so far. */);
6595
6596 DEFVAR_INT ("string-chars-consed", string_chars_consed,
6597 doc: /* Number of string characters that have been consed so far. */);
6598
6599 DEFVAR_INT ("misc-objects-consed", misc_objects_consed,
6600 doc: /* Number of miscellaneous objects that have been consed so far.
6601 These include markers and overlays, plus certain objects not visible
6602 to users. */);
6603
6604 DEFVAR_INT ("intervals-consed", intervals_consed,
6605 doc: /* Number of intervals that have been consed so far. */);
6606
6607 DEFVAR_INT ("strings-consed", strings_consed,
6608 doc: /* Number of strings that have been consed so far. */);
6609
6610 DEFVAR_LISP ("purify-flag", Vpurify_flag,
6611 doc: /* Non-nil means loading Lisp code in order to dump an executable.
6612 This means that certain objects should be allocated in shared (pure) space.
6613 It can also be set to a hash-table, in which case this table is used to
6614 do hash-consing of the objects allocated to pure space. */);
6615
6616 DEFVAR_BOOL ("garbage-collection-messages", garbage_collection_messages,
6617 doc: /* Non-nil means display messages at start and end of garbage collection. */);
6618 garbage_collection_messages = 0;
6619
6620 DEFVAR_LISP ("post-gc-hook", Vpost_gc_hook,
6621 doc: /* Hook run after garbage collection has finished. */);
6622 Vpost_gc_hook = Qnil;
6623 DEFSYM (Qpost_gc_hook, "post-gc-hook");
6624
6625 DEFVAR_LISP ("memory-signal-data", Vmemory_signal_data,
6626 doc: /* Precomputed `signal' argument for memory-full error. */);
6627 /* We build this in advance because if we wait until we need it, we might
6628 not be able to allocate the memory to hold it. */
6629 Vmemory_signal_data
6630 = listn (CONSTYPE_PURE, 2, Qerror,
6631 build_pure_c_string ("Memory exhausted--use M-x save-some-buffers then exit and restart Emacs"));
6632
6633 DEFVAR_LISP ("memory-full", Vmemory_full,
6634 doc: /* Non-nil means Emacs cannot get much more Lisp memory. */);
6635 Vmemory_full = Qnil;
6636
6637 DEFSYM (Qconses, "conses");
6638 DEFSYM (Qsymbols, "symbols");
6639 DEFSYM (Qmiscs, "miscs");
6640 DEFSYM (Qstrings, "strings");
6641 DEFSYM (Qvectors, "vectors");
6642 DEFSYM (Qfloats, "floats");
6643 DEFSYM (Qintervals, "intervals");
6644 DEFSYM (Qbuffers, "buffers");
6645 DEFSYM (Qstring_bytes, "string-bytes");
6646 DEFSYM (Qvector_slots, "vector-slots");
6647 DEFSYM (Qheap, "heap");
6648 DEFSYM (Qautomatic_gc, "Automatic GC");
6649
6650 DEFSYM (Qgc_cons_threshold, "gc-cons-threshold");
6651 DEFSYM (Qchar_table_extra_slots, "char-table-extra-slots");
6652
6653 DEFVAR_LISP ("gc-elapsed", Vgc_elapsed,
6654 doc: /* Accumulated time elapsed in garbage collections.
6655 The time is in seconds as a floating point value. */);
6656 DEFVAR_INT ("gcs-done", gcs_done,
6657 doc: /* Accumulated number of garbage collections done. */);
6658
6659 defsubr (&Scons);
6660 defsubr (&Slist);
6661 defsubr (&Svector);
6662 defsubr (&Smake_byte_code);
6663 defsubr (&Smake_list);
6664 defsubr (&Smake_vector);
6665 defsubr (&Smake_string);
6666 defsubr (&Smake_bool_vector);
6667 defsubr (&Smake_symbol);
6668 defsubr (&Smake_marker);
6669 defsubr (&Spurecopy);
6670 defsubr (&Sgarbage_collect);
6671 defsubr (&Smemory_limit);
6672 defsubr (&Smemory_use_counts);
6673
6674 #if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
6675 defsubr (&Sgc_status);
6676 #endif
6677 }
6678
6679 /* When compiled with GCC, GDB might say "No enum type named
6680 pvec_type" if we don't have at least one symbol with that type, and
6681 then xbacktrace could fail. Similarly for the other enums and
6682 their values. Some non-GCC compilers don't like these constructs. */
6683 #ifdef __GNUC__
6684 union
6685 {
6686 enum CHARTAB_SIZE_BITS CHARTAB_SIZE_BITS;
6687 enum CHAR_TABLE_STANDARD_SLOTS CHAR_TABLE_STANDARD_SLOTS;
6688 enum char_bits char_bits;
6689 enum CHECK_LISP_OBJECT_TYPE CHECK_LISP_OBJECT_TYPE;
6690 enum DEFAULT_HASH_SIZE DEFAULT_HASH_SIZE;
6691 enum enum_USE_LSB_TAG enum_USE_LSB_TAG;
6692 enum FLOAT_TO_STRING_BUFSIZE FLOAT_TO_STRING_BUFSIZE;
6693 enum Lisp_Bits Lisp_Bits;
6694 enum Lisp_Compiled Lisp_Compiled;
6695 enum maxargs maxargs;
6696 enum MAX_ALLOCA MAX_ALLOCA;
6697 enum More_Lisp_Bits More_Lisp_Bits;
6698 enum pvec_type pvec_type;
6699 #if USE_LSB_TAG
6700 enum lsb_bits lsb_bits;
6701 #endif
6702 } const EXTERNALLY_VISIBLE gdb_make_enums_visible = {0};
6703 #endif /* __GNUC__ */