1 /* Copyright (C) 1995, 96, 97, 98, 99, 2000 Free Software Foundation, Inc.
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation; either version 2, or (at your option)
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
13 * You should have received a copy of the GNU General Public License
14 * along with this software; see the file COPYING. If not, write to
15 * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
16 * Boston, MA 02111-1307 USA
18 * As a special exception, the Free Software Foundation gives permission
19 * for additional uses of the text contained in its release of GUILE.
21 * The exception is that, if you link the GUILE library with other files
22 * to produce an executable, this does not by itself cause the
23 * resulting executable to be covered by the GNU General Public License.
24 * Your use of that executable is in no way restricted on account of
25 * linking the GUILE library code into it.
27 * This exception does not however invalidate any other reasons why
28 * the executable file might be covered by the GNU General Public License.
30 * This exception applies only to the code released by the
31 * Free Software Foundation under the name GUILE. If you copy
32 * code from other Free Software Foundation releases into a copy of
33 * GUILE, as the General Public License permits, the exception does
34 * not apply to the code that you add in this way. To avoid misleading
35 * anyone as to the status of such modified files, you must delete
36 * this exception notice from them.
38 * If you write modifications of your own for GUILE, it is your choice
39 * whether to permit this exception to apply to your modifications.
40 * If you do not wish that, delete this exception notice. */
42 /* Software engineering face-lift by Greg J. Badros, 11-Dec-1999,
43 gjb@cs.washington.edu, http://www.cs.washington.edu/homes/gjb */
45 /* #define DEBUGINFO */
49 #include "libguile/_scm.h"
50 #include "libguile/stime.h"
51 #include "libguile/stackchk.h"
52 #include "libguile/struct.h"
53 #include "libguile/smob.h"
54 #include "libguile/unif.h"
55 #include "libguile/async.h"
56 #include "libguile/ports.h"
57 #include "libguile/root.h"
58 #include "libguile/strings.h"
59 #include "libguile/vectors.h"
60 #include "libguile/weaks.h"
61 #include "libguile/hashtab.h"
63 #include "libguile/validate.h"
64 #include "libguile/gc.h"
66 #ifdef GUILE_DEBUG_MALLOC
67 #include "libguile/debug-malloc.h"
80 #define var_start(x, y) va_start(x, y)
83 #define var_start(x, y) va_start(x)
87 /* {heap tuning parameters}
89 * These are parameters for controlling memory allocation. The heap
90 * is the area out of which scm_cons, and object headers are allocated.
92 * Each heap cell is 8 bytes on a 32 bit machine and 16 bytes on a
93 * 64 bit machine. The units of the _SIZE parameters are bytes.
94 * Cons pairs and object headers occupy one heap cell.
96 * SCM_INIT_HEAP_SIZE is the initial size of heap. If this much heap is
97 * allocated initially the heap will grow by half its current size
98 * each subsequent time more heap is needed.
100 * If SCM_INIT_HEAP_SIZE heap cannot be allocated initially, SCM_HEAP_SEG_SIZE
101 * will be used, and the heap will grow by SCM_HEAP_SEG_SIZE when more
102 * heap is needed. SCM_HEAP_SEG_SIZE must fit into type scm_sizet. This code
103 * is in scm_init_storage() and alloc_some_heap() in sys.c
105 * If SCM_INIT_HEAP_SIZE can be allocated initially, the heap will grow by
106 * SCM_EXPHEAP(scm_heap_size) when more heap is needed.
108 * SCM_MIN_HEAP_SEG_SIZE is minimum size of heap to accept when more heap
111 * INIT_MALLOC_LIMIT is the initial amount of malloc usage which will
114 * SCM_MTRIGGER_HYSTERESIS is the amount of malloc storage that must be
115 * reclaimed by a GC triggered by must_malloc. If less than this is
116 * reclaimed, the trigger threshold is raised. [I don't know what a
117 * good value is. I arbitrarily chose 1/10 of the INIT_MALLOC_LIMIT to
118 * work around a oscillation that caused almost constant GC.]
122 * Heap size 45000 and 40% min yield gives quick startup and no extra
123 * heap allocation. Having higher values on min yield may lead to
124 * large heaps, especially if code behaviour is varying its
125 * maximum consumption between different freelists.
127 int scm_default_init_heap_size_1
= (45000L * sizeof (scm_cell
));
128 int scm_default_min_yield_1
= 40;
129 #define SCM_CLUSTER_SIZE_1 2000L
131 int scm_default_init_heap_size_2
= (2500L * 2 * sizeof (scm_cell
));
132 /* The following value may seem large, but note that if we get to GC at
133 * all, this means that we have a numerically intensive application
135 int scm_default_min_yield_2
= 40;
136 #define SCM_CLUSTER_SIZE_2 1000L
138 int scm_default_max_segment_size
= 2097000L;/* a little less (adm) than 2 Mb */
140 #define SCM_MIN_HEAP_SEG_SIZE (2048L * sizeof (scm_cell))
142 # define SCM_HEAP_SEG_SIZE 32768L
145 # define SCM_HEAP_SEG_SIZE (7000L * sizeof (scm_cell))
147 # define SCM_HEAP_SEG_SIZE (16384L * sizeof (scm_cell))
150 /* Make heap grow with factor 1.5 */
151 #define SCM_EXPHEAP(scm_heap_size) (scm_heap_size / 2)
152 #define SCM_INIT_MALLOC_LIMIT 100000
153 #define SCM_MTRIGGER_HYSTERESIS (SCM_INIT_MALLOC_LIMIT/10)
155 /* CELL_UP and CELL_DN are used by scm_init_heap_seg to find scm_cell aligned inner
156 bounds for allocated storage */
159 /*in 386 protected mode we must only adjust the offset */
160 # define CELL_UP(p, span) MK_FP(FP_SEG(p), ~(8*(span)-1)&(FP_OFF(p)+8*(span)-1))
161 # define CELL_DN(p, span) MK_FP(FP_SEG(p), ~(8*(span)-1)&FP_OFF(p))
164 # define CELL_UP(p, span) (SCM_CELLPTR)(~(span) & ((long)(p)+(span)))
165 # define CELL_DN(p, span) (SCM_CELLPTR)(~(span) & (long)(p))
167 # define CELL_UP(p, span) (SCM_CELLPTR)(~(sizeof(scm_cell)*(span)-1L) & ((long)(p)+sizeof(scm_cell)*(span)-1L))
168 # define CELL_DN(p, span) (SCM_CELLPTR)(~(sizeof(scm_cell)*(span)-1L) & (long)(p))
171 #define CLUSTER_SIZE_IN_BYTES(freelist) ((freelist)->cluster_size * (freelist)->span * sizeof(scm_cell))
172 #define ALIGNMENT_SLACK(freelist) (sizeof (scm_cell) * (freelist)->span - 1)
173 #define SCM_HEAP_SIZE \
174 (scm_master_freelist.heap_size + scm_master_freelist2.heap_size)
175 #define SCM_MAX(A, B) ((A) > (B) ? (A) : (B))
182 typedef struct scm_freelist_t
{
183 /* collected cells */
185 /* number of cells left to collect before cluster is full */
186 unsigned int left_to_collect
;
187 /* number of clusters which have been allocated */
188 unsigned int clusters_allocated
;
189 /* a list of freelists, each of size cluster_size,
190 * except the last one which may be shorter
194 /* this is the number of objects in each cluster, including the spine cell */
196 /* indicates that we should grow heap instead of GC:ing
199 /* minimum yield on this list in order not to grow the heap
202 /* defines min_yield as percent of total heap size
204 int min_yield_fraction
;
205 /* number of cells per object on this list */
207 /* number of collected cells during last GC */
209 /* number of collected cells during penultimate GC */
211 /* total number of cells in heap segments
212 * belonging to this list.
217 SCM scm_freelist
= SCM_EOL
;
218 scm_freelist_t scm_master_freelist
= {
219 SCM_EOL
, 0, 0, SCM_EOL
, 0, SCM_CLUSTER_SIZE_1
, 0, 0, 0, 1, 0, 0
221 SCM scm_freelist2
= SCM_EOL
;
222 scm_freelist_t scm_master_freelist2
= {
223 SCM_EOL
, 0, 0, SCM_EOL
, 0, SCM_CLUSTER_SIZE_2
, 0, 0, 0, 2, 0, 0
227 * is the number of bytes of must_malloc allocation needed to trigger gc.
229 unsigned long scm_mtrigger
;
233 * If set, don't expand the heap. Set only during gc, during which no allocation
234 * is supposed to take place anyway.
236 int scm_gc_heap_lock
= 0;
239 * Don't pause for collection if this is set -- just
243 int scm_block_gc
= 1;
245 /* If fewer than MIN_GC_YIELD cells are recovered during a garbage
246 * collection (GC) more space is allocated for the heap.
248 #define MIN_GC_YIELD(freelist) (freelist->heap_size / 4)
250 /* During collection, this accumulates objects holding
253 SCM scm_weak_vectors
;
255 /* GC Statistics Keeping
257 unsigned long scm_cells_allocated
= 0;
258 long scm_mallocated
= 0;
259 unsigned long scm_gc_cells_collected
;
260 unsigned long scm_gc_yield
;
261 static unsigned long scm_gc_yield_1
= 0; /* previous GC yield */
262 unsigned long scm_gc_malloc_collected
;
263 unsigned long scm_gc_ports_collected
;
264 unsigned long scm_gc_rt
;
265 unsigned long scm_gc_time_taken
= 0;
267 SCM_SYMBOL (sym_cells_allocated
, "cells-allocated");
268 SCM_SYMBOL (sym_heap_size
, "cell-heap-size");
269 SCM_SYMBOL (sym_mallocated
, "bytes-malloced");
270 SCM_SYMBOL (sym_mtrigger
, "gc-malloc-threshold");
271 SCM_SYMBOL (sym_heap_segments
, "cell-heap-segments");
272 SCM_SYMBOL (sym_gc_time_taken
, "gc-time-taken");
274 typedef struct scm_heap_seg_data_t
276 /* lower and upper bounds of the segment */
277 SCM_CELLPTR bounds
[2];
279 /* address of the head-of-freelist pointer for this segment's cells.
280 All segments usually point to the same one, scm_freelist. */
281 scm_freelist_t
*freelist
;
283 /* number of cells per object in this segment */
285 } scm_heap_seg_data_t
;
289 static scm_sizet
init_heap_seg (SCM_CELLPTR
, scm_sizet
, scm_freelist_t
*);
290 static void alloc_some_heap (scm_freelist_t
*);
294 /* Debugging functions. */
296 #if defined (GUILE_DEBUG) || defined (GUILE_DEBUG_FREELIST)
298 /* Return the number of the heap segment containing CELL. */
304 for (i
= 0; i
< scm_n_heap_segs
; i
++)
305 if (SCM_PTR_LE (scm_heap_table
[i
].bounds
[0], SCM2PTR (cell
))
306 && SCM_PTR_GT (scm_heap_table
[i
].bounds
[1], SCM2PTR (cell
)))
308 fprintf (stderr
, "which_seg: can't find segment containing cell %lx\n",
315 map_free_list (scm_freelist_t
*master
, SCM freelist
)
317 int last_seg
= -1, count
= 0;
320 for (f
= freelist
; SCM_NIMP (f
); f
= SCM_CDR (f
))
322 int this_seg
= which_seg (f
);
324 if (this_seg
!= last_seg
)
327 fprintf (stderr
, " %5d %d-cells in segment %d\n",
328 count
, master
->span
, last_seg
);
335 fprintf (stderr
, " %5d %d-cells in segment %d\n",
336 count
, master
->span
, last_seg
);
339 SCM_DEFINE (scm_map_free_list
, "map-free-list", 0, 0, 0,
341 "Print debugging information about the free-list.\n"
342 "`map-free-list' is only included in --enable-guile-debug builds of Guile.")
343 #define FUNC_NAME s_scm_map_free_list
346 fprintf (stderr
, "%d segments total (%d:%d",
348 scm_heap_table
[0].span
,
349 scm_heap_table
[0].bounds
[1] - scm_heap_table
[0].bounds
[0]);
350 for (i
= 1; i
< scm_n_heap_segs
; i
++)
351 fprintf (stderr
, ", %d:%d",
352 scm_heap_table
[i
].span
,
353 scm_heap_table
[i
].bounds
[1] - scm_heap_table
[i
].bounds
[0]);
354 fprintf (stderr
, ")\n");
355 map_free_list (&scm_master_freelist
, scm_freelist
);
356 map_free_list (&scm_master_freelist2
, scm_freelist2
);
359 return SCM_UNSPECIFIED
;
363 static int last_cluster
;
364 static int last_size
;
367 free_list_length (char *title
, int i
, SCM freelist
)
371 for (ls
= freelist
; SCM_NNULLP (ls
); ls
= SCM_CDR (ls
))
372 if (SCM_CELL_TYPE (ls
) == scm_tc_free_cell
)
376 fprintf (stderr
, "bad cell in %s at position %d\n", title
, n
);
383 if (last_cluster
== i
- 1)
384 fprintf (stderr
, "\t%d\n", last_size
);
386 fprintf (stderr
, "-%d\t%d\n", i
- 1, last_size
);
389 fprintf (stderr
, "%s %d", title
, i
);
391 fprintf (stderr
, "%s\t%d\n", title
, n
);
399 free_list_lengths (char *title
, scm_freelist_t
*master
, SCM freelist
)
402 int i
= 0, len
, n
= 0;
403 fprintf (stderr
, "%s\n\n", title
);
404 n
+= free_list_length ("free list", -1, freelist
);
405 for (clusters
= master
->clusters
;
406 SCM_NNULLP (clusters
);
407 clusters
= SCM_CDR (clusters
))
409 len
= free_list_length ("cluster", i
++, SCM_CAR (clusters
));
412 if (last_cluster
== i
- 1)
413 fprintf (stderr
, "\t%d\n", last_size
);
415 fprintf (stderr
, "-%d\t%d\n", i
- 1, last_size
);
416 fprintf (stderr
, "\ntotal %d objects\n\n", n
);
419 SCM_DEFINE (scm_free_list_length
, "free-list-length", 0, 0, 0,
421 "Print debugging information about the free-list.\n"
422 "`free-list-length' is only included in --enable-guile-debug builds of Guile.")
423 #define FUNC_NAME s_scm_free_list_length
425 free_list_lengths ("1-cells", &scm_master_freelist
, scm_freelist
);
426 free_list_lengths ("2-cells", &scm_master_freelist2
, scm_freelist2
);
427 return SCM_UNSPECIFIED
;
433 #ifdef GUILE_DEBUG_FREELIST
435 /* Number of calls to SCM_NEWCELL since startup. */
436 static unsigned long scm_newcell_count
;
437 static unsigned long scm_newcell2_count
;
439 /* Search freelist for anything that isn't marked as a free cell.
440 Abort if we find something. */
442 scm_check_freelist (SCM freelist
)
447 for (f
= freelist
; SCM_NIMP (f
); f
= SCM_CDR (f
), i
++)
448 if (SCM_CAR (f
) != (SCM
) scm_tc_free_cell
)
450 fprintf (stderr
, "Bad cell in freelist on newcell %lu: %d'th elt\n",
451 scm_newcell_count
, i
);
457 static int scm_debug_check_freelist
= 0;
459 SCM_DEFINE (scm_gc_set_debug_check_freelist_x
, "gc-set-debug-check-freelist!", 1, 0, 0,
461 "If FLAG is #t, check the freelist for consistency on each cell allocation.\n"
462 "This procedure only exists because the GUILE_DEBUG_FREELIST \n"
463 "compile-time flag was selected.\n")
464 #define FUNC_NAME s_scm_gc_set_debug_check_freelist_x
466 SCM_VALIDATE_BOOL_COPY (1, flag
, scm_debug_check_freelist
);
467 return SCM_UNSPECIFIED
;
473 scm_debug_newcell (void)
478 if (scm_debug_check_freelist
)
480 scm_check_freelist (scm_freelist
);
484 /* The rest of this is supposed to be identical to the SCM_NEWCELL
486 if (SCM_IMP (scm_freelist
))
487 new = scm_gc_for_newcell (&scm_master_freelist
, &scm_freelist
);
491 scm_freelist
= SCM_CDR (scm_freelist
);
492 SCM_SETCAR (new, scm_tc16_allocated
);
499 scm_debug_newcell2 (void)
503 scm_newcell2_count
++;
504 if (scm_debug_check_freelist
)
506 scm_check_freelist (scm_freelist2
);
510 /* The rest of this is supposed to be identical to the SCM_NEWCELL
512 if (SCM_IMP (scm_freelist2
))
513 new = scm_gc_for_newcell (&scm_master_freelist2
, &scm_freelist2
);
517 scm_freelist2
= SCM_CDR (scm_freelist2
);
518 SCM_SETCAR (new, scm_tc16_allocated
);
524 #endif /* GUILE_DEBUG_FREELIST */
529 master_cells_allocated (scm_freelist_t
*master
)
531 int objects
= master
->clusters_allocated
* (master
->cluster_size
- 1);
532 if (SCM_NULLP (master
->clusters
))
533 objects
-= master
->left_to_collect
;
534 return master
->span
* objects
;
538 freelist_length (SCM freelist
)
541 for (n
= 0; SCM_NNULLP (freelist
); freelist
= SCM_CDR (freelist
))
547 compute_cells_allocated ()
549 return (scm_cells_allocated
550 + master_cells_allocated (&scm_master_freelist
)
551 + master_cells_allocated (&scm_master_freelist2
)
552 - scm_master_freelist
.span
* freelist_length (scm_freelist
)
553 - scm_master_freelist2
.span
* freelist_length (scm_freelist2
));
556 /* {Scheme Interface to GC}
559 SCM_DEFINE (scm_gc_stats
, "gc-stats", 0, 0, 0,
561 "Returns an association list of statistics about Guile's current use of storage. ")
562 #define FUNC_NAME s_scm_gc_stats
567 long int local_scm_mtrigger
;
568 long int local_scm_mallocated
;
569 long int local_scm_heap_size
;
570 long int local_scm_cells_allocated
;
571 long int local_scm_gc_time_taken
;
579 for (i
= scm_n_heap_segs
; i
--; )
580 heap_segs
= scm_cons (scm_cons (scm_ulong2num ((unsigned long)scm_heap_table
[i
].bounds
[1]),
581 scm_ulong2num ((unsigned long)scm_heap_table
[i
].bounds
[0])),
583 if (scm_n_heap_segs
!= n
)
587 /* Below, we cons to produce the resulting list. We want a snapshot of
588 * the heap situation before consing.
590 local_scm_mtrigger
= scm_mtrigger
;
591 local_scm_mallocated
= scm_mallocated
;
592 local_scm_heap_size
= SCM_HEAP_SIZE
;
593 local_scm_cells_allocated
= compute_cells_allocated ();
594 local_scm_gc_time_taken
= scm_gc_time_taken
;
596 answer
= scm_listify (scm_cons (sym_gc_time_taken
, scm_ulong2num (local_scm_gc_time_taken
)),
597 scm_cons (sym_cells_allocated
, scm_ulong2num (local_scm_cells_allocated
)),
598 scm_cons (sym_heap_size
, scm_ulong2num (local_scm_heap_size
)),
599 scm_cons (sym_mallocated
, scm_ulong2num (local_scm_mallocated
)),
600 scm_cons (sym_mtrigger
, scm_ulong2num (local_scm_mtrigger
)),
601 scm_cons (sym_heap_segments
, heap_segs
),
610 scm_gc_start (const char *what
)
612 scm_gc_rt
= SCM_INUM (scm_get_internal_run_time ());
613 scm_gc_cells_collected
= 0;
614 scm_gc_yield_1
= scm_gc_yield
;
615 scm_gc_yield
= (scm_cells_allocated
616 + master_cells_allocated (&scm_master_freelist
)
617 + master_cells_allocated (&scm_master_freelist2
));
618 scm_gc_malloc_collected
= 0;
619 scm_gc_ports_collected
= 0;
625 scm_gc_rt
= SCM_INUM (scm_get_internal_run_time ()) - scm_gc_rt
;
626 scm_gc_time_taken
+= scm_gc_rt
;
627 scm_system_async_mark (scm_gc_async
);
631 SCM_DEFINE (scm_object_address
, "object-address", 1, 0, 0,
633 "Return an integer that for the lifetime of @var{obj} is uniquely\n"
634 "returned by this function for @var{obj}")
635 #define FUNC_NAME s_scm_object_address
637 return scm_ulong2num ((unsigned long) SCM_UNPACK (obj
));
642 SCM_DEFINE (scm_gc
, "gc", 0, 0, 0,
644 "Scans all of SCM objects and reclaims for further use those that are\n"
645 "no longer accessible.")
646 #define FUNC_NAME s_scm_gc
651 return SCM_UNSPECIFIED
;
657 /* {C Interface For When GC is Triggered}
661 adjust_min_yield (scm_freelist_t
*freelist
)
663 /* min yield is adjusted upwards so that next predicted total yield
664 * (allocated cells actually freed by GC) becomes
665 * `min_yield_fraction' of total heap size. Note, however, that
666 * the absolute value of min_yield will correspond to `collected'
667 * on one master (the one which currently is triggering GC).
669 * The reason why we look at total yield instead of cells collected
670 * on one list is that we want to take other freelists into account.
671 * On this freelist, we know that (local) yield = collected cells,
672 * but that's probably not the case on the other lists.
674 * (We might consider computing a better prediction, for example
675 * by computing an average over multiple GC:s.)
677 if (freelist
->min_yield_fraction
)
679 /* Pick largest of last two yields. */
680 int delta
= ((SCM_HEAP_SIZE
* freelist
->min_yield_fraction
/ 100)
681 - (long) SCM_MAX (scm_gc_yield_1
, scm_gc_yield
));
683 fprintf (stderr
, " after GC = %d, delta = %d\n",
688 freelist
->min_yield
+= delta
;
692 /* When we get POSIX threads support, the master will be global and
693 * common while the freelist will be individual for each thread.
697 scm_gc_for_newcell (scm_freelist_t
*master
, SCM
*freelist
)
703 if (SCM_NULLP (master
->clusters
))
705 if (master
->grow_heap_p
)
707 master
->grow_heap_p
= 0;
708 alloc_some_heap (master
);
713 fprintf (stderr
, "allocated = %d, ",
715 + master_cells_allocated (&scm_master_freelist
)
716 + master_cells_allocated (&scm_master_freelist2
));
719 adjust_min_yield (master
);
722 cell
= SCM_CAR (master
->clusters
);
723 master
->clusters
= SCM_CDR (master
->clusters
);
724 ++master
->clusters_allocated
;
726 while (SCM_NULLP (cell
));
728 *freelist
= SCM_CDR (cell
);
729 SCM_SET_CELL_TYPE (cell
, scm_tc16_allocated
);
734 /* This is a support routine which can be used to reserve a cluster
735 * for some special use, such as debugging. It won't be useful until
736 * free cells are preserved between garbage collections.
740 scm_alloc_cluster (scm_freelist_t
*master
)
743 cell
= scm_gc_for_newcell (master
, &freelist
);
744 SCM_SETCDR (cell
, freelist
);
749 SCM scm_after_gc_hook
;
751 scm_c_hook_t scm_before_gc_c_hook
;
752 scm_c_hook_t scm_before_mark_c_hook
;
753 scm_c_hook_t scm_before_sweep_c_hook
;
754 scm_c_hook_t scm_after_sweep_c_hook
;
755 scm_c_hook_t scm_after_gc_c_hook
;
758 scm_igc (const char *what
)
762 scm_c_hook_run (&scm_before_gc_c_hook
, 0);
765 SCM_NULLP (scm_freelist
)
767 : (SCM_NULLP (scm_freelist2
) ? "o" : "m"));
770 /* During the critical section, only the current thread may run. */
771 SCM_THREAD_CRITICAL_SECTION_START
;
774 /* fprintf (stderr, "gc: %s\n", what); */
778 if (!scm_stack_base
|| scm_block_gc
)
784 if (scm_mallocated
< 0)
785 /* The byte count of allocated objects has underflowed. This is
786 probably because you forgot to report the sizes of objects you
787 have allocated, by calling scm_done_malloc or some such. When
788 the GC freed them, it subtracted their size from
789 scm_mallocated, which underflowed. */
792 if (scm_gc_heap_lock
)
793 /* We've invoked the collector while a GC is already in progress.
794 That should never happen. */
799 /* flush dead entries from the continuation stack */
804 elts
= SCM_VELTS (scm_continuation_stack
);
805 bound
= SCM_LENGTH (scm_continuation_stack
);
806 x
= SCM_INUM (scm_continuation_stack_ptr
);
809 elts
[x
] = SCM_BOOL_F
;
814 scm_c_hook_run (&scm_before_mark_c_hook
, 0);
818 /* Protect from the C stack. This must be the first marking
819 * done because it provides information about what objects
820 * are "in-use" by the C code. "in-use" objects are those
821 * for which the values from SCM_LENGTH and SCM_CHARS must remain
822 * usable. This requirement is stricter than a liveness
823 * requirement -- in particular, it constrains the implementation
824 * of scm_vector_set_length_x.
826 SCM_FLUSH_REGISTER_WINDOWS
;
827 /* This assumes that all registers are saved into the jmp_buf */
828 setjmp (scm_save_regs_gc_mark
);
829 scm_mark_locations ((SCM_STACKITEM
*) scm_save_regs_gc_mark
,
830 ( (scm_sizet
) (sizeof (SCM_STACKITEM
) - 1 +
831 sizeof scm_save_regs_gc_mark
)
832 / sizeof (SCM_STACKITEM
)));
835 scm_sizet stack_len
= scm_stack_size (scm_stack_base
);
836 #ifdef SCM_STACK_GROWS_UP
837 scm_mark_locations (scm_stack_base
, stack_len
);
839 scm_mark_locations (scm_stack_base
- stack_len
, stack_len
);
843 #else /* USE_THREADS */
845 /* Mark every thread's stack and registers */
846 scm_threads_mark_stacks ();
848 #endif /* USE_THREADS */
850 /* FIXME: insert a phase to un-protect string-data preserved
851 * in scm_vector_set_length_x.
854 j
= SCM_NUM_PROTECTS
;
856 scm_gc_mark (scm_sys_protects
[j
]);
858 /* FIXME: we should have a means to register C functions to be run
859 * in different phases of GC
861 scm_mark_subr_table ();
864 scm_gc_mark (scm_root
->handle
);
867 scm_c_hook_run (&scm_before_sweep_c_hook
, 0);
871 scm_c_hook_run (&scm_after_sweep_c_hook
, 0);
877 SCM_THREAD_CRITICAL_SECTION_END
;
879 scm_c_hook_run (&scm_after_gc_c_hook
, 0);
888 /* Mark an object precisely.
903 if (SCM_NCELLP (ptr
))
904 scm_wta (ptr
, "rogue pointer in heap", NULL
);
906 switch (SCM_TYP7 (ptr
))
908 case scm_tcs_cons_nimcar
:
909 if (SCM_GCMARKP (ptr
))
912 if (SCM_IMP (SCM_CDR (ptr
))) /* SCM_IMP works even with a GC mark */
917 scm_gc_mark (SCM_CAR (ptr
));
918 ptr
= SCM_GCCDR (ptr
);
920 case scm_tcs_cons_imcar
:
921 if (SCM_GCMARKP (ptr
))
924 ptr
= SCM_GCCDR (ptr
);
927 if (SCM_GCMARKP (ptr
))
930 scm_gc_mark (SCM_CELL_OBJECT_2 (ptr
));
931 ptr
= SCM_GCCDR (ptr
);
933 case scm_tcs_cons_gloc
:
934 if (SCM_GCMARKP (ptr
))
938 /* Dirk:FIXME:: The following code is super ugly: ptr may be a struct
939 * or a gloc. If it is a gloc, the cell word #0 of ptr is a pointer
940 * to a heap cell. If it is a struct, the cell word #0 of ptr is a
941 * pointer to a struct vtable data region. The fact that these are
942 * accessed in the same way restricts the possibilites to change the
943 * data layout of structs or heap cells.
945 scm_bits_t word0
= SCM_CELL_WORD_0 (ptr
) - scm_tc3_cons_gloc
;
946 scm_bits_t
* vtable_data
= (scm_bits_t
*) word0
; /* access as struct */
947 switch (vtable_data
[scm_vtable_index_vcell
])
952 SCM gloc_car
= SCM_PACK (word0
);
953 scm_gc_mark (gloc_car
);
954 ptr
= SCM_GCCDR (ptr
);
960 /* ptr is a struct */
961 SCM layout
= SCM_PACK (vtable_data
[scm_vtable_index_layout
]);
962 int len
= SCM_LENGTH (layout
);
963 char * fields_desc
= SCM_CHARS (layout
);
964 /* We're using SCM_GCCDR here like STRUCT_DATA, except
965 that it removes the mark */
966 scm_bits_t
* struct_data
= (scm_bits_t
*) SCM_UNPACK (SCM_GCCDR (ptr
));
968 if (vtable_data
[scm_struct_i_flags
] & SCM_STRUCTF_ENTITY
)
970 scm_gc_mark (SCM_PACK (struct_data
[scm_struct_i_procedure
]));
971 scm_gc_mark (SCM_PACK (struct_data
[scm_struct_i_setter
]));
977 for (x
= 0; x
< len
- 2; x
+= 2, ++struct_data
)
978 if (fields_desc
[x
] == 'p')
979 scm_gc_mark (SCM_PACK (*struct_data
));
980 if (fields_desc
[x
] == 'p')
982 if (SCM_LAYOUT_TAILP (fields_desc
[x
+ 1]))
983 for (x
= *struct_data
; x
; --x
)
984 scm_gc_mark (SCM_PACK (*++struct_data
));
986 scm_gc_mark (SCM_PACK (*struct_data
));
989 if (vtable_data
[scm_vtable_index_vcell
] == 0)
991 vtable_data
[scm_vtable_index_vcell
] = 1;
992 ptr
= SCM_PACK (vtable_data
[scm_vtable_index_vtable
]);
999 case scm_tcs_closures
:
1000 if (SCM_GCMARKP (ptr
))
1002 SCM_SETGCMARK (ptr
);
1003 if (SCM_IMP (SCM_CDR (ptr
)))
1005 ptr
= SCM_CLOSCAR (ptr
);
1008 scm_gc_mark (SCM_CLOSCAR (ptr
));
1009 ptr
= SCM_GCCDR (ptr
);
1011 case scm_tc7_vector
:
1012 case scm_tc7_lvector
:
1016 if (SCM_GC8MARKP (ptr
))
1018 SCM_SETGC8MARK (ptr
);
1019 i
= SCM_LENGTH (ptr
);
1023 if (SCM_NIMP (SCM_VELTS (ptr
)[i
]))
1024 scm_gc_mark (SCM_VELTS (ptr
)[i
]);
1025 ptr
= SCM_VELTS (ptr
)[0];
1027 case scm_tc7_contin
:
1030 SCM_SETGC8MARK (ptr
);
1031 if (SCM_VELTS (ptr
))
1032 scm_mark_locations (SCM_VELTS_AS_STACKITEMS (ptr
),
1035 (sizeof (SCM_STACKITEM
) + -1 +
1036 sizeof (scm_contregs
)) /
1037 sizeof (SCM_STACKITEM
)));
1041 case scm_tc7_byvect
:
1048 #ifdef HAVE_LONG_LONGS
1049 case scm_tc7_llvect
:
1052 case scm_tc7_string
:
1053 SCM_SETGC8MARK (ptr
);
1056 case scm_tc7_substring
:
1057 if (SCM_GC8MARKP(ptr
))
1059 SCM_SETGC8MARK (ptr
);
1060 ptr
= SCM_CDR (ptr
);
1064 if (SCM_GC8MARKP(ptr
))
1066 SCM_WVECT_GC_CHAIN (ptr
) = scm_weak_vectors
;
1067 scm_weak_vectors
= ptr
;
1068 SCM_SETGC8MARK (ptr
);
1069 if (SCM_IS_WHVEC_ANY (ptr
))
1076 len
= SCM_LENGTH (ptr
);
1077 weak_keys
= SCM_IS_WHVEC (ptr
) || SCM_IS_WHVEC_B (ptr
);
1078 weak_values
= SCM_IS_WHVEC_V (ptr
) || SCM_IS_WHVEC_B (ptr
);
1080 for (x
= 0; x
< len
; ++x
)
1083 alist
= SCM_VELTS (ptr
)[x
];
1085 /* mark everything on the alist except the keys or
1086 * values, according to weak_values and weak_keys. */
1087 while ( SCM_CONSP (alist
)
1088 && !SCM_GCMARKP (alist
)
1089 && SCM_CONSP (SCM_CAR (alist
)))
1094 kvpair
= SCM_CAR (alist
);
1095 next_alist
= SCM_CDR (alist
);
1098 * SCM_SETGCMARK (alist);
1099 * SCM_SETGCMARK (kvpair);
1101 * It may be that either the key or value is protected by
1102 * an escaped reference to part of the spine of this alist.
1103 * If we mark the spine here, and only mark one or neither of the
1104 * key and value, they may never be properly marked.
1105 * This leads to a horrible situation in which an alist containing
1106 * freelist cells is exported.
1108 * So only mark the spines of these arrays last of all marking.
1109 * If somebody confuses us by constructing a weak vector
1110 * with a circular alist then we are hosed, but at least we
1111 * won't prematurely drop table entries.
1114 scm_gc_mark (SCM_CAR (kvpair
));
1116 scm_gc_mark (SCM_GCCDR (kvpair
));
1119 if (SCM_NIMP (alist
))
1120 scm_gc_mark (alist
);
1125 case scm_tc7_msymbol
:
1126 if (SCM_GC8MARKP(ptr
))
1128 SCM_SETGC8MARK (ptr
);
1129 scm_gc_mark (SCM_SYMBOL_FUNC (ptr
));
1130 ptr
= SCM_SYMBOL_PROPS (ptr
);
1132 case scm_tc7_ssymbol
:
1133 if (SCM_GC8MARKP(ptr
))
1135 SCM_SETGC8MARK (ptr
);
1140 i
= SCM_PTOBNUM (ptr
);
1141 if (!(i
< scm_numptob
))
1143 if (SCM_GC8MARKP (ptr
))
1145 SCM_SETGC8MARK (ptr
);
1146 if (SCM_PTAB_ENTRY(ptr
))
1147 scm_gc_mark (SCM_PTAB_ENTRY(ptr
)->file_name
);
1148 if (scm_ptobs
[i
].mark
)
1150 ptr
= (scm_ptobs
[i
].mark
) (ptr
);
1157 if (SCM_GC8MARKP (ptr
))
1159 SCM_SETGC8MARK (ptr
);
1160 switch (SCM_GCTYP16 (ptr
))
1161 { /* should be faster than going through scm_smobs */
1162 case scm_tc_free_cell
:
1163 /* printf("found free_cell %X ", ptr); fflush(stdout); */
1164 case scm_tc16_allocated
:
1167 case scm_tc16_complex
:
1170 i
= SCM_SMOBNUM (ptr
);
1171 if (!(i
< scm_numsmob
))
1173 if (scm_smobs
[i
].mark
)
1175 ptr
= (scm_smobs
[i
].mark
) (ptr
);
1183 def
:scm_wta (ptr
, "unknown type in ", "gc_mark");
1188 /* Mark a Region Conservatively
1192 scm_mark_locations (SCM_STACKITEM x
[], scm_sizet n
)
1194 register long m
= n
;
1196 register SCM_CELLPTR ptr
;
1199 if (SCM_CELLP (* (SCM
*) &x
[m
]))
1201 ptr
= SCM2PTR (* (SCM
*) &x
[m
]);
1203 j
= scm_n_heap_segs
- 1;
1204 if ( SCM_PTR_LE (scm_heap_table
[i
].bounds
[0], ptr
)
1205 && SCM_PTR_GT (scm_heap_table
[j
].bounds
[1], ptr
))
1212 || SCM_PTR_GT (scm_heap_table
[i
].bounds
[1], ptr
))
1214 else if (SCM_PTR_LE (scm_heap_table
[j
].bounds
[0], ptr
))
1222 if (SCM_PTR_GT (scm_heap_table
[k
].bounds
[1], ptr
))
1226 if (SCM_PTR_LE (scm_heap_table
[i
].bounds
[0], ptr
))
1231 else if (SCM_PTR_LE (scm_heap_table
[k
].bounds
[0], ptr
))
1235 if (SCM_PTR_GT (scm_heap_table
[j
].bounds
[1], ptr
))
1241 if (scm_heap_table
[seg_id
].span
== 1
1242 || SCM_DOUBLE_CELLP (* (SCM
*) &x
[m
]))
1243 scm_gc_mark (* (SCM
*) &x
[m
]);
1252 /* The function scm_cellp determines whether an SCM value can be regarded as a
1253 * pointer to a cell on the heap. Binary search is used in order to determine
1254 * the heap segment that contains the cell.
1257 scm_cellp (SCM value
)
1259 if (SCM_CELLP (value
)) {
1260 scm_cell
* ptr
= SCM2PTR (value
);
1262 unsigned int j
= scm_n_heap_segs
- 1;
1265 int k
= (i
+ j
) / 2;
1266 if (SCM_PTR_GT (scm_heap_table
[k
].bounds
[1], ptr
)) {
1268 } else if (SCM_PTR_LE (scm_heap_table
[k
].bounds
[0], ptr
)) {
1273 if (SCM_PTR_LE (scm_heap_table
[i
].bounds
[0], ptr
)
1274 && SCM_PTR_GT (scm_heap_table
[i
].bounds
[1], ptr
)
1275 && (scm_heap_table
[i
].span
== 1 || SCM_DOUBLE_CELLP (value
))) {
1287 gc_sweep_freelist_start (scm_freelist_t
*freelist
)
1289 freelist
->cells
= SCM_EOL
;
1290 freelist
->left_to_collect
= freelist
->cluster_size
;
1291 freelist
->clusters_allocated
= 0;
1292 freelist
->clusters
= SCM_EOL
;
1293 freelist
->clustertail
= &freelist
->clusters
;
1294 freelist
->collected_1
= freelist
->collected
;
1295 freelist
->collected
= 0;
1299 gc_sweep_freelist_finish (scm_freelist_t
*freelist
)
1302 *freelist
->clustertail
= freelist
->cells
;
1303 if (SCM_NNULLP (freelist
->cells
))
1305 SCM c
= freelist
->cells
;
1306 SCM_SETCAR (c
, SCM_CDR (c
));
1307 SCM_SETCDR (c
, SCM_EOL
);
1308 freelist
->collected
+=
1309 freelist
->span
* (freelist
->cluster_size
- freelist
->left_to_collect
);
1311 scm_gc_cells_collected
+= freelist
->collected
;
1313 /* Although freelist->min_yield is used to test freelist->collected
1314 * (which is the local GC yield for freelist), it is adjusted so
1315 * that *total* yield is freelist->min_yield_fraction of total heap
1316 * size. This means that a too low yield is compensated by more
1317 * heap on the list which is currently doing most work, which is
1318 * just what we want.
1320 collected
= SCM_MAX (freelist
->collected_1
, freelist
->collected
);
1321 freelist
->grow_heap_p
= (collected
< freelist
->min_yield
);
1327 register SCM_CELLPTR ptr
;
1328 register SCM nfreelist
;
1329 register scm_freelist_t
*freelist
;
1337 gc_sweep_freelist_start (&scm_master_freelist
);
1338 gc_sweep_freelist_start (&scm_master_freelist2
);
1340 for (i
= 0; i
< scm_n_heap_segs
; i
++)
1342 register unsigned int left_to_collect
;
1343 register scm_sizet j
;
1345 /* Unmarked cells go onto the front of the freelist this heap
1346 segment points to. Rather than updating the real freelist
1347 pointer as we go along, we accumulate the new head in
1348 nfreelist. Then, if it turns out that the entire segment is
1349 free, we free (i.e., malloc's free) the whole segment, and
1350 simply don't assign nfreelist back into the real freelist. */
1351 freelist
= scm_heap_table
[i
].freelist
;
1352 nfreelist
= freelist
->cells
;
1353 left_to_collect
= freelist
->left_to_collect
;
1354 span
= scm_heap_table
[i
].span
;
1356 ptr
= CELL_UP (scm_heap_table
[i
].bounds
[0], span
);
1357 seg_size
= CELL_DN (scm_heap_table
[i
].bounds
[1], span
) - ptr
;
1358 for (j
= seg_size
+ span
; j
-= span
; ptr
+= span
)
1360 SCM scmptr
= PTR2SCM (ptr
);
1362 switch SCM_TYP7 (scmptr
)
1364 case scm_tcs_cons_gloc
:
1366 /* Dirk:FIXME:: Again, super ugly code: scmptr may be a
1367 * struct or a gloc. See the corresponding comment in
1370 scm_bits_t word0
= SCM_CELL_WORD_0 (scmptr
) - scm_tc3_cons_gloc
;
1371 scm_bits_t
* vtable_data
= (scm_bits_t
*) word0
; /* access as struct */
1372 if (SCM_GCMARKP (scmptr
))
1374 if (vtable_data
[scm_vtable_index_vcell
] == 1)
1375 vtable_data
[scm_vtable_index_vcell
] = 0;
1380 if (vtable_data
[scm_vtable_index_vcell
] == 0
1381 || vtable_data
[scm_vtable_index_vcell
] == 1)
1383 scm_struct_free_t free
1384 = (scm_struct_free_t
) vtable_data
[scm_struct_i_free
];
1385 m
+= free (vtable_data
, (scm_bits_t
*) SCM_UNPACK (SCM_GCCDR (scmptr
)));
1390 case scm_tcs_cons_imcar
:
1391 case scm_tcs_cons_nimcar
:
1392 case scm_tcs_closures
:
1394 if (SCM_GCMARKP (scmptr
))
1398 if (SCM_GC8MARKP (scmptr
))
1404 m
+= (2 + SCM_LENGTH (scmptr
)) * sizeof (SCM
);
1405 scm_must_free ((char *)(SCM_VELTS (scmptr
) - 2));
1409 case scm_tc7_vector
:
1410 case scm_tc7_lvector
:
1414 if (SCM_GC8MARKP (scmptr
))
1417 m
+= (SCM_LENGTH (scmptr
) * sizeof (SCM
));
1419 scm_must_free (SCM_CHARS (scmptr
));
1420 /* SCM_SETCHARS(scmptr, 0);*/
1424 if SCM_GC8MARKP (scmptr
)
1426 m
+= sizeof (long) * ((SCM_HUGE_LENGTH (scmptr
) + SCM_LONG_BIT
- 1) / SCM_LONG_BIT
);
1428 case scm_tc7_byvect
:
1429 if SCM_GC8MARKP (scmptr
)
1431 m
+= SCM_HUGE_LENGTH (scmptr
) * sizeof (char);
1435 if SCM_GC8MARKP (scmptr
)
1437 m
+= SCM_HUGE_LENGTH (scmptr
) * sizeof (long);
1440 if SCM_GC8MARKP (scmptr
)
1442 m
+= SCM_HUGE_LENGTH (scmptr
) * sizeof (short);
1444 #ifdef HAVE_LONG_LONGS
1445 case scm_tc7_llvect
:
1446 if SCM_GC8MARKP (scmptr
)
1448 m
+= SCM_HUGE_LENGTH (scmptr
) * sizeof (long_long
);
1452 if SCM_GC8MARKP (scmptr
)
1454 m
+= SCM_HUGE_LENGTH (scmptr
) * sizeof (float);
1457 if SCM_GC8MARKP (scmptr
)
1459 m
+= SCM_HUGE_LENGTH (scmptr
) * sizeof (double);
1462 if SCM_GC8MARKP (scmptr
)
1464 m
+= SCM_HUGE_LENGTH (scmptr
) * 2 * sizeof (double);
1467 case scm_tc7_substring
:
1468 if (SCM_GC8MARKP (scmptr
))
1471 case scm_tc7_string
:
1472 if (SCM_GC8MARKP (scmptr
))
1474 m
+= SCM_HUGE_LENGTH (scmptr
) + 1;
1476 case scm_tc7_msymbol
:
1477 if (SCM_GC8MARKP (scmptr
))
1479 m
+= (SCM_LENGTH (scmptr
) + 1
1480 + (SCM_CHARS (scmptr
) - (char *) SCM_SLOTS (scmptr
)));
1481 scm_must_free ((char *)SCM_SLOTS (scmptr
));
1483 case scm_tc7_contin
:
1484 if SCM_GC8MARKP (scmptr
)
1486 m
+= SCM_LENGTH (scmptr
) * sizeof (SCM_STACKITEM
) + sizeof (scm_contregs
);
1487 if (SCM_VELTS (scmptr
))
1489 case scm_tc7_ssymbol
:
1490 if SCM_GC8MARKP(scmptr
)
1496 if SCM_GC8MARKP (scmptr
)
1498 if SCM_OPENP (scmptr
)
1500 int k
= SCM_PTOBNUM (scmptr
);
1501 if (!(k
< scm_numptob
))
1503 /* Keep "revealed" ports alive. */
1504 if (scm_revealed_count (scmptr
) > 0)
1506 /* Yes, I really do mean scm_ptobs[k].free */
1507 /* rather than ftobs[k].close. .close */
1508 /* is for explicit CLOSE-PORT by user */
1509 m
+= (scm_ptobs
[k
].free
) (scmptr
);
1510 SCM_SETSTREAM (scmptr
, 0);
1511 scm_remove_from_port_table (scmptr
);
1512 scm_gc_ports_collected
++;
1513 SCM_SETAND_CAR (scmptr
, ~SCM_OPN
);
1517 switch SCM_GCTYP16 (scmptr
)
1519 case scm_tc_free_cell
:
1521 if SCM_GC8MARKP (scmptr
)
1526 if SCM_GC8MARKP (scmptr
)
1528 m
+= (SCM_NUMDIGS (scmptr
) * SCM_BITSPERDIG
/ SCM_CHAR_BIT
);
1530 #endif /* def SCM_BIGDIG */
1531 case scm_tc16_complex
:
1532 if SCM_GC8MARKP (scmptr
)
1534 m
+= 2 * sizeof (double);
1537 if SCM_GC8MARKP (scmptr
)
1542 k
= SCM_SMOBNUM (scmptr
);
1543 if (!(k
< scm_numsmob
))
1545 m
+= (scm_smobs
[k
].free
) (scmptr
);
1551 sweeperr
:scm_wta (scmptr
, "unknown type in ", "gc_sweep");
1554 if (SCM_CAR (scmptr
) == (SCM
) scm_tc_free_cell
)
1557 if (!--left_to_collect
)
1559 SCM_SETCAR (scmptr
, nfreelist
);
1560 *freelist
->clustertail
= scmptr
;
1561 freelist
->clustertail
= SCM_CDRLOC (scmptr
);
1563 nfreelist
= SCM_EOL
;
1564 freelist
->collected
+= span
* freelist
->cluster_size
;
1565 left_to_collect
= freelist
->cluster_size
;
1569 /* Stick the new cell on the front of nfreelist. It's
1570 critical that we mark this cell as freed; otherwise, the
1571 conservative collector might trace it as some other type
1573 SCM_SET_CELL_TYPE (scmptr
, scm_tc_free_cell
);
1574 SCM_SETCDR (scmptr
, nfreelist
);
1580 SCM_CLRGC8MARK (scmptr
);
1583 SCM_CLRGCMARK (scmptr
);
1585 #ifdef GC_FREE_SEGMENTS
1590 freelist
->heap_size
-= seg_size
;
1591 free ((char *) scm_heap_table
[i
].bounds
[0]);
1592 scm_heap_table
[i
].bounds
[0] = 0;
1593 for (j
= i
+ 1; j
< scm_n_heap_segs
; j
++)
1594 scm_heap_table
[j
- 1] = scm_heap_table
[j
];
1595 scm_n_heap_segs
-= 1;
1596 i
--; /* We need to scan the segment just moved. */
1599 #endif /* ifdef GC_FREE_SEGMENTS */
1601 /* Update the real freelist pointer to point to the head of
1602 the list of free cells we've built for this segment. */
1603 freelist
->cells
= nfreelist
;
1604 freelist
->left_to_collect
= left_to_collect
;
1607 #ifdef GUILE_DEBUG_FREELIST
1608 scm_check_freelist (freelist
== &scm_master_freelist
1611 scm_map_free_list ();
1615 gc_sweep_freelist_finish (&scm_master_freelist
);
1616 gc_sweep_freelist_finish (&scm_master_freelist2
);
1618 /* When we move to POSIX threads private freelists should probably
1619 be GC-protected instead. */
1620 scm_freelist
= SCM_EOL
;
1621 scm_freelist2
= SCM_EOL
;
1623 scm_cells_allocated
= (SCM_HEAP_SIZE
- scm_gc_cells_collected
);
1624 scm_gc_yield
-= scm_cells_allocated
;
1625 scm_mallocated
-= m
;
1626 scm_gc_malloc_collected
= m
;
1632 /* {Front end to malloc}
1634 * scm_must_malloc, scm_must_realloc, scm_must_free, scm_done_malloc
1636 * These functions provide services comperable to malloc, realloc, and
1637 * free. They are for allocating malloced parts of scheme objects.
1638 * The primary purpose of the front end is to impose calls to gc.
1643 * Return newly malloced storage or throw an error.
1645 * The parameter WHAT is a string for error reporting.
1646 * If the threshold scm_mtrigger will be passed by this
1647 * allocation, or if the first call to malloc fails,
1648 * garbage collect -- on the presumption that some objects
1649 * using malloced storage may be collected.
1651 * The limit scm_mtrigger may be raised by this allocation.
1654 scm_must_malloc (scm_sizet size
, const char *what
)
1657 unsigned long nm
= scm_mallocated
+ size
;
1659 if (nm
<= scm_mtrigger
)
1661 SCM_SYSCALL (ptr
= malloc (size
));
1664 scm_mallocated
= nm
;
1665 #ifdef GUILE_DEBUG_MALLOC
1666 scm_malloc_register (ptr
, what
);
1674 nm
= scm_mallocated
+ size
;
1675 SCM_SYSCALL (ptr
= malloc (size
));
1678 scm_mallocated
= nm
;
1679 if (nm
> scm_mtrigger
- SCM_MTRIGGER_HYSTERESIS
) {
1680 if (nm
> scm_mtrigger
)
1681 scm_mtrigger
= nm
+ nm
/ 2;
1683 scm_mtrigger
+= scm_mtrigger
/ 2;
1685 #ifdef GUILE_DEBUG_MALLOC
1686 scm_malloc_register (ptr
, what
);
1692 scm_wta (SCM_MAKINUM (size
), (char *) SCM_NALLOC
, what
);
1693 return 0; /* never reached */
1698 * is similar to scm_must_malloc.
1701 scm_must_realloc (void *where
,
1707 scm_sizet nm
= scm_mallocated
+ size
- old_size
;
1709 if (nm
<= scm_mtrigger
)
1711 SCM_SYSCALL (ptr
= realloc (where
, size
));
1714 scm_mallocated
= nm
;
1715 #ifdef GUILE_DEBUG_MALLOC
1716 scm_malloc_reregister (where
, ptr
, what
);
1724 nm
= scm_mallocated
+ size
- old_size
;
1725 SCM_SYSCALL (ptr
= realloc (where
, size
));
1728 scm_mallocated
= nm
;
1729 if (nm
> scm_mtrigger
- SCM_MTRIGGER_HYSTERESIS
) {
1730 if (nm
> scm_mtrigger
)
1731 scm_mtrigger
= nm
+ nm
/ 2;
1733 scm_mtrigger
+= scm_mtrigger
/ 2;
1735 #ifdef GUILE_DEBUG_MALLOC
1736 scm_malloc_reregister (where
, ptr
, what
);
1741 scm_wta (SCM_MAKINUM (size
), (char *) SCM_NALLOC
, what
);
1742 return 0; /* never reached */
1746 scm_must_free (void *obj
)
1748 #ifdef GUILE_DEBUG_MALLOC
1749 scm_malloc_unregister (obj
);
1754 scm_wta (SCM_INUM0
, "already free", "");
1757 /* Announce that there has been some malloc done that will be freed
1758 * during gc. A typical use is for a smob that uses some malloced
1759 * memory but can not get it from scm_must_malloc (for whatever
1760 * reason). When a new object of this smob is created you call
1761 * scm_done_malloc with the size of the object. When your smob free
1762 * function is called, be sure to include this size in the return
1766 scm_done_malloc (long size
)
1768 scm_mallocated
+= size
;
1770 if (scm_mallocated
> scm_mtrigger
)
1772 scm_igc ("foreign mallocs");
1773 if (scm_mallocated
> scm_mtrigger
- SCM_MTRIGGER_HYSTERESIS
)
1775 if (scm_mallocated
> scm_mtrigger
)
1776 scm_mtrigger
= scm_mallocated
+ scm_mallocated
/ 2;
1778 scm_mtrigger
+= scm_mtrigger
/ 2;
1788 * Each heap segment is an array of objects of a particular size.
1789 * Every segment has an associated (possibly shared) freelist.
1790 * A table of segment records is kept that records the upper and
1791 * lower extents of the segment; this is used during the conservative
1792 * phase of gc to identify probably gc roots (because they point
1793 * into valid segments at reasonable offsets). */
1796 * is true if the first segment was smaller than INIT_HEAP_SEG.
1797 * If scm_expmem is set to one, subsequent segment allocations will
1798 * allocate segments of size SCM_EXPHEAP(scm_heap_size).
1802 scm_sizet scm_max_segment_size
;
1805 * is the lowest base address of any heap segment.
1807 SCM_CELLPTR scm_heap_org
;
1809 scm_heap_seg_data_t
* scm_heap_table
= 0;
1810 int scm_n_heap_segs
= 0;
1813 * initializes a new heap segment and return the number of objects it contains.
1815 * The segment origin, segment size in bytes, and the span of objects
1816 * in cells are input parameters. The freelist is both input and output.
1818 * This function presume that the scm_heap_table has already been expanded
1819 * to accomodate a new segment record.
1824 init_heap_seg (SCM_CELLPTR seg_org
, scm_sizet size
, scm_freelist_t
*freelist
)
1826 register SCM_CELLPTR ptr
;
1827 SCM_CELLPTR seg_end
;
1830 int span
= freelist
->span
;
1832 if (seg_org
== NULL
)
1835 ptr
= CELL_UP (seg_org
, span
);
1837 /* Compute the ceiling on valid object pointers w/in this segment.
1839 seg_end
= CELL_DN ((char *) seg_org
+ size
, span
);
1841 /* Find the right place and insert the segment record.
1844 for (new_seg_index
= 0;
1845 ( (new_seg_index
< scm_n_heap_segs
)
1846 && SCM_PTR_LE (scm_heap_table
[new_seg_index
].bounds
[0], seg_org
));
1852 for (i
= scm_n_heap_segs
; i
> new_seg_index
; --i
)
1853 scm_heap_table
[i
] = scm_heap_table
[i
- 1];
1858 scm_heap_table
[new_seg_index
].span
= span
;
1859 scm_heap_table
[new_seg_index
].freelist
= freelist
;
1860 scm_heap_table
[new_seg_index
].bounds
[0] = ptr
;
1861 scm_heap_table
[new_seg_index
].bounds
[1] = seg_end
;
1864 /* Compute the least valid object pointer w/in this segment
1866 ptr
= CELL_UP (ptr
, span
);
1870 n_new_cells
= seg_end
- ptr
;
1872 freelist
->heap_size
+= n_new_cells
;
1874 /* Partition objects in this segment into clusters */
1877 SCM
*clusterp
= &clusters
;
1878 int n_cluster_cells
= span
* freelist
->cluster_size
;
1880 while (n_new_cells
> span
) /* at least one spine + one freecell */
1882 /* Determine end of cluster
1884 if (n_new_cells
>= n_cluster_cells
)
1886 seg_end
= ptr
+ n_cluster_cells
;
1887 n_new_cells
-= n_cluster_cells
;
1890 /* [cmm] looks like the segment size doesn't divide cleanly by
1891 cluster size. bad cmm! */
1894 /* Allocate cluster spine
1896 *clusterp
= PTR2SCM (ptr
);
1897 SCM_SETCAR (*clusterp
, PTR2SCM (ptr
+ span
));
1898 clusterp
= SCM_CDRLOC (*clusterp
);
1901 while (ptr
< seg_end
)
1903 SCM scmptr
= PTR2SCM (ptr
);
1905 SCM_SET_CELL_TYPE (scmptr
, scm_tc_free_cell
);
1906 SCM_SETCDR (scmptr
, PTR2SCM (ptr
+ span
));
1910 SCM_SETCDR (PTR2SCM (ptr
- span
), SCM_EOL
);
1913 /* Patch up the last cluster pointer in the segment
1914 * to join it to the input freelist.
1916 *clusterp
= freelist
->clusters
;
1917 freelist
->clusters
= clusters
;
1921 fprintf (stderr
, "H");
1927 round_to_cluster_size (scm_freelist_t
*freelist
, scm_sizet len
)
1929 scm_sizet cluster_size_in_bytes
= CLUSTER_SIZE_IN_BYTES (freelist
);
1932 (len
+ cluster_size_in_bytes
- 1) / cluster_size_in_bytes
* cluster_size_in_bytes
1933 + ALIGNMENT_SLACK (freelist
);
1937 alloc_some_heap (scm_freelist_t
*freelist
)
1939 scm_heap_seg_data_t
* tmptable
;
1943 /* Critical code sections (such as the garbage collector)
1944 * aren't supposed to add heap segments.
1946 if (scm_gc_heap_lock
)
1947 scm_wta (SCM_UNDEFINED
, "need larger initial", "heap");
1949 /* Expand the heap tables to have room for the new segment.
1950 * Do not yet increment scm_n_heap_segs -- that is done by init_heap_seg
1951 * only if the allocation of the segment itself succeeds.
1953 len
= (1 + scm_n_heap_segs
) * sizeof (scm_heap_seg_data_t
);
1955 SCM_SYSCALL (tmptable
= ((scm_heap_seg_data_t
*)
1956 realloc ((char *)scm_heap_table
, len
)));
1958 scm_wta (SCM_UNDEFINED
, "could not grow", "hplims");
1960 scm_heap_table
= tmptable
;
1963 /* Pick a size for the new heap segment.
1964 * The rule for picking the size of a segment is explained in
1968 /* Assure that the new segment is predicted to be large enough.
1970 * New yield should at least equal GC fraction of new heap size, i.e.
1972 * y + dh > f * (h + dh)
1975 * f : min yield fraction
1977 * dh : size of new heap segment
1979 * This gives dh > (f * h - y) / (1 - f)
1981 int f
= freelist
->min_yield_fraction
;
1982 long h
= SCM_HEAP_SIZE
;
1983 long min_cells
= (f
* h
- 100 * (long) scm_gc_yield
) / (99 - f
);
1984 len
= SCM_EXPHEAP (freelist
->heap_size
);
1986 fprintf (stderr
, "(%d < %d)", len
, min_cells
);
1988 if (len
< min_cells
)
1989 len
= min_cells
+ freelist
->cluster_size
;
1990 len
*= sizeof (scm_cell
);
1991 /* force new sampling */
1992 freelist
->collected
= LONG_MAX
;
1995 if (len
> scm_max_segment_size
)
1996 len
= scm_max_segment_size
;
2001 smallest
= CLUSTER_SIZE_IN_BYTES (freelist
);
2006 /* Allocate with decaying ambition. */
2007 while ((len
>= SCM_MIN_HEAP_SEG_SIZE
)
2008 && (len
>= smallest
))
2010 scm_sizet rounded_len
= round_to_cluster_size (freelist
, len
);
2011 SCM_SYSCALL (ptr
= (SCM_CELLPTR
) malloc (rounded_len
));
2014 init_heap_seg (ptr
, rounded_len
, freelist
);
2021 scm_wta (SCM_UNDEFINED
, "could not grow", "heap");
2025 SCM_DEFINE (scm_unhash_name
, "unhash-name", 1, 0, 0,
2028 #define FUNC_NAME s_scm_unhash_name
2032 SCM_VALIDATE_SYMBOL (1,name
);
2034 bound
= scm_n_heap_segs
;
2035 for (x
= 0; x
< bound
; ++x
)
2039 p
= scm_heap_table
[x
].bounds
[0];
2040 pbound
= scm_heap_table
[x
].bounds
[1];
2043 SCM cell
= PTR2SCM (p
);
2044 if (SCM_TYP3 (cell
) == scm_tc3_cons_gloc
)
2046 /* Dirk:FIXME:: Again, super ugly code: cell may be a gloc or a
2047 * struct cell. See the corresponding comment in scm_gc_mark.
2049 scm_bits_t word0
= SCM_CELL_WORD_0 (cell
) - scm_tc3_cons_gloc
;
2050 SCM gloc_car
= SCM_PACK (word0
); /* access as gloc */
2051 SCM vcell
= SCM_CELL_OBJECT_1 (gloc_car
);
2052 if ((SCM_EQ_P (name
, SCM_BOOL_T
) || SCM_EQ_P (SCM_CAR (gloc_car
), name
))
2053 && (SCM_UNPACK (vcell
) != 0) && (SCM_UNPACK (vcell
) != 1))
2055 SCM_SET_CELL_OBJECT_0 (cell
, name
);
2068 /* {GC Protection Helper Functions}
2073 scm_remember (SCM
*ptr
)
2078 These crazy functions prevent garbage collection
2079 of arguments after the first argument by
2080 ensuring they remain live throughout the
2081 function because they are used in the last
2082 line of the code block.
2083 It'd be better to have a nice compiler hint to
2084 aid the conservative stack-scanning GC. --03/09/00 gjb */
2086 scm_return_first (SCM elt
, ...)
2092 scm_return_first_int (int i
, ...)
2099 scm_permanent_object (SCM obj
)
2102 scm_permobjs
= scm_cons (obj
, scm_permobjs
);
2108 /* Protect OBJ from the garbage collector. OBJ will not be freed, even if all
2109 other references are dropped, until the object is unprotected by calling
2110 scm_unprotect_object (OBJ). Calls to scm_protect/unprotect_object nest,
2111 i. e. it is possible to protect the same object several times, but it is
2112 necessary to unprotect the object the same number of times to actually get
2113 the object unprotected. It is an error to unprotect an object more often
2114 than it has been protected before. The function scm_protect_object returns
2118 /* Implementation note: For every object X, there is a counter which
2119 scm_protect_object(X) increments and scm_unprotect_object(X) decrements.
2123 scm_protect_object (SCM obj
)
2127 /* This critical section barrier will be replaced by a mutex. */
2130 handle
= scm_hashq_create_handle_x (scm_protects
, obj
, SCM_MAKINUM (0));
2131 SCM_SETCDR (handle
, SCM_MAKINUM (SCM_INUM (SCM_CDR (handle
)) + 1));
2139 /* Remove any protection for OBJ established by a prior call to
2140 scm_protect_object. This function returns OBJ.
2142 See scm_protect_object for more information. */
2144 scm_unprotect_object (SCM obj
)
2148 /* This critical section barrier will be replaced by a mutex. */
2151 handle
= scm_hashq_get_handle (scm_protects
, obj
);
2153 if (SCM_IMP (handle
))
2155 fprintf (stderr
, "scm_unprotect_object called on unprotected object\n");
2160 unsigned long int count
= SCM_INUM (SCM_CDR (handle
)) - 1;
2162 scm_hashq_remove_x (scm_protects
, obj
);
2164 SCM_SETCDR (handle
, SCM_MAKINUM (count
));
2174 /* called on process termination. */
2180 extern int on_exit (void (*procp
) (), int arg
);
2183 cleanup (int status
, void *arg
)
2185 #error Dont know how to setup a cleanup handler on your system.
2190 scm_flush_all_ports ();
2195 make_initial_segment (scm_sizet init_heap_size
, scm_freelist_t
*freelist
)
2197 scm_sizet rounded_size
= round_to_cluster_size (freelist
, init_heap_size
);
2198 if (!init_heap_seg ((SCM_CELLPTR
) malloc (rounded_size
),
2202 rounded_size
= round_to_cluster_size (freelist
, SCM_HEAP_SEG_SIZE
);
2203 if (!init_heap_seg ((SCM_CELLPTR
) malloc (rounded_size
),
2211 if (freelist
->min_yield_fraction
)
2212 freelist
->min_yield
= (freelist
->heap_size
* freelist
->min_yield_fraction
2214 freelist
->grow_heap_p
= (freelist
->heap_size
< freelist
->min_yield
);
2221 init_freelist (scm_freelist_t
*freelist
,
2226 freelist
->clusters
= SCM_EOL
;
2227 freelist
->cluster_size
= cluster_size
+ 1;
2228 freelist
->left_to_collect
= 0;
2229 freelist
->clusters_allocated
= 0;
2230 freelist
->min_yield
= 0;
2231 freelist
->min_yield_fraction
= min_yield
;
2232 freelist
->span
= span
;
2233 freelist
->collected
= 0;
2234 freelist
->collected_1
= 0;
2235 freelist
->heap_size
= 0;
2239 scm_init_storage (scm_sizet init_heap_size_1
, int gc_trigger_1
,
2240 scm_sizet init_heap_size_2
, int gc_trigger_2
,
2241 scm_sizet max_segment_size
)
2245 if (!init_heap_size_1
)
2246 init_heap_size_1
= scm_default_init_heap_size_1
;
2247 if (!init_heap_size_2
)
2248 init_heap_size_2
= scm_default_init_heap_size_2
;
2250 j
= SCM_NUM_PROTECTS
;
2252 scm_sys_protects
[--j
] = SCM_BOOL_F
;
2255 scm_freelist
= SCM_EOL
;
2256 scm_freelist2
= SCM_EOL
;
2257 init_freelist (&scm_master_freelist
,
2258 1, SCM_CLUSTER_SIZE_1
,
2259 gc_trigger_1
? gc_trigger_1
: scm_default_min_yield_1
);
2260 init_freelist (&scm_master_freelist2
,
2261 2, SCM_CLUSTER_SIZE_2
,
2262 gc_trigger_2
? gc_trigger_2
: scm_default_min_yield_2
);
2263 scm_max_segment_size
2264 = max_segment_size
? max_segment_size
: scm_default_max_segment_size
;
2268 j
= SCM_HEAP_SEG_SIZE
;
2269 scm_mtrigger
= SCM_INIT_MALLOC_LIMIT
;
2270 scm_heap_table
= ((scm_heap_seg_data_t
*)
2271 scm_must_malloc (sizeof (scm_heap_seg_data_t
) * 2, "hplims"));
2273 if (make_initial_segment (init_heap_size_1
, &scm_master_freelist
) ||
2274 make_initial_segment (init_heap_size_2
, &scm_master_freelist2
))
2277 /* scm_hplims[0] can change. do not remove scm_heap_org */
2278 scm_heap_org
= CELL_UP (scm_heap_table
[0].bounds
[0], 1);
2280 scm_c_hook_init (&scm_before_gc_c_hook
, 0, SCM_C_HOOK_NORMAL
);
2281 scm_c_hook_init (&scm_before_mark_c_hook
, 0, SCM_C_HOOK_NORMAL
);
2282 scm_c_hook_init (&scm_before_sweep_c_hook
, 0, SCM_C_HOOK_NORMAL
);
2283 scm_c_hook_init (&scm_after_sweep_c_hook
, 0, SCM_C_HOOK_NORMAL
);
2284 scm_c_hook_init (&scm_after_gc_c_hook
, 0, SCM_C_HOOK_NORMAL
);
2286 /* Initialise the list of ports. */
2287 scm_port_table
= (scm_port
**)
2288 malloc (sizeof (scm_port
*) * scm_port_table_room
);
2289 if (!scm_port_table
)
2296 on_exit (cleanup
, 0);
2300 scm_undefineds
= scm_cons (SCM_UNDEFINED
, SCM_EOL
);
2301 SCM_SETCDR (scm_undefineds
, scm_undefineds
);
2303 scm_listofnull
= scm_cons (SCM_EOL
, SCM_EOL
);
2304 scm_nullstr
= scm_makstr (0L, 0);
2305 scm_nullvect
= scm_make_vector (SCM_INUM0
, SCM_UNDEFINED
);
2306 scm_symhash
= scm_make_vector (SCM_MAKINUM (scm_symhash_dim
), SCM_EOL
);
2307 scm_weak_symhash
= scm_make_weak_key_hash_table (SCM_MAKINUM (scm_symhash_dim
));
2308 scm_symhash_vars
= scm_make_vector (SCM_MAKINUM (scm_symhash_dim
), SCM_EOL
);
2309 scm_stand_in_procs
= SCM_EOL
;
2310 scm_permobjs
= SCM_EOL
;
2311 scm_protects
= scm_make_vector (SCM_MAKINUM (31), SCM_EOL
);
2312 scm_asyncs
= SCM_EOL
;
2313 scm_sysintern ("most-positive-fixnum", SCM_MAKINUM (SCM_MOST_POSITIVE_FIXNUM
));
2314 scm_sysintern ("most-negative-fixnum", SCM_MAKINUM (SCM_MOST_NEGATIVE_FIXNUM
));
2316 scm_sysintern ("bignum-radix", SCM_MAKINUM (SCM_BIGRAD
));
2325 scm_after_gc_hook
= scm_create_hook ("after-gc-hook", 0);
2326 #include "libguile/gc.x"