1 /* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2002 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. */
43 /* #define DEBUGINFO */
53 extern unsigned long * __libc_ia64_register_backing_store_base
;
56 #include "libguile/_scm.h"
57 #include "libguile/eval.h"
58 #include "libguile/stime.h"
59 #include "libguile/stackchk.h"
60 #include "libguile/struct.h"
61 #include "libguile/smob.h"
62 #include "libguile/unif.h"
63 #include "libguile/async.h"
64 #include "libguile/ports.h"
65 #include "libguile/root.h"
66 #include "libguile/strings.h"
67 #include "libguile/vectors.h"
68 #include "libguile/weaks.h"
69 #include "libguile/hashtab.h"
70 #include "libguile/tags.h"
72 #include "libguile/private-gc.h"
73 #include "libguile/validate.h"
74 #include "libguile/deprecation.h"
75 #include "libguile/gc.h"
77 #ifdef GUILE_DEBUG_MALLOC
78 #include "libguile/debug-malloc.h"
91 unsigned int scm_gc_running_p
= 0;
93 /* Set this to != 0 if every cell that is accessed shall be checked:
95 int scm_debug_cell_accesses_p
= 0;
96 int scm_expensive_debug_cell_accesses_p
= 0;
98 /* Set this to 0 if no additional gc's shall be performed, otherwise set it to
99 * the number of cell accesses after which a gc shall be called.
101 int scm_debug_cells_gc_interval
= 0;
104 Global variable, so you can switch it off at runtime by setting
105 scm_i_cell_validation_already_running.
107 int scm_i_cell_validation_already_running
;
109 #if (SCM_DEBUG_CELL_ACCESSES == 1)
114 Assert that the given object is a valid reference to a valid cell. This
115 test involves to determine whether the object is a cell pointer, whether
116 this pointer actually points into a heap segment and whether the cell
117 pointed to is not a free cell. Further, additional garbage collections may
118 get executed after a user defined number of cell accesses. This helps to
119 find places in the C code where references are dropped for extremely short
124 scm_i_expensive_validation_check (SCM cell
)
126 if (!scm_in_heap_p (cell
))
128 fprintf (stderr
, "scm_assert_cell_valid: this object does not live in the heap: %lux\n",
129 (unsigned long) SCM_UNPACK (cell
));
133 /* If desired, perform additional garbage collections after a user
134 * defined number of cell accesses.
136 if (scm_debug_cells_gc_interval
)
138 static unsigned int counter
= 0;
146 counter
= scm_debug_cells_gc_interval
;
147 scm_i_thread_put_to_sleep ();
148 scm_igc ("scm_assert_cell_valid");
149 scm_i_thread_wake_up ();
155 scm_assert_cell_valid (SCM cell
)
157 if (!scm_i_cell_validation_already_running
&& scm_debug_cell_accesses_p
)
159 scm_i_cell_validation_already_running
= 1; /* set to avoid recursion */
162 During GC, no user-code should be run, and the guile core
163 should use non-protected accessors.
165 if (scm_gc_running_p
)
169 Only scm_in_heap_p and rescanning the heap is wildly
172 if (scm_expensive_debug_cell_accesses_p
)
173 scm_i_expensive_validation_check (cell
);
175 if (!SCM_GC_MARK_P (cell
))
178 "scm_assert_cell_valid: this object is unmarked. \n"
179 "It has been garbage-collected in the last GC run: "
181 (unsigned long) SCM_UNPACK (cell
));
185 scm_i_cell_validation_already_running
= 0; /* re-enable */
191 SCM_DEFINE (scm_set_debug_cell_accesses_x
, "set-debug-cell-accesses!", 1, 0, 0,
193 "If @var{flag} is @code{#f}, cell access checking is disabled.\n"
194 "If @var{flag} is @code{#t}, cheap cell access checking is enabled,\n"
195 "but no additional calls to garbage collection are issued.\n"
196 "If @var{flag} is a number, strict cell access checking is enabled,\n"
197 "with an additional garbage collection after the given\n"
198 "number of cell accesses.\n"
199 "This procedure only exists when the compile-time flag\n"
200 "@code{SCM_DEBUG_CELL_ACCESSES} was set to 1.")
201 #define FUNC_NAME s_scm_set_debug_cell_accesses_x
203 if (SCM_FALSEP (flag
))
205 scm_debug_cell_accesses_p
= 0;
207 else if (SCM_EQ_P (flag
, SCM_BOOL_T
))
209 scm_debug_cells_gc_interval
= 0;
210 scm_debug_cell_accesses_p
= 1;
211 scm_expensive_debug_cell_accesses_p
= 0;
213 else if (SCM_INUMP (flag
))
215 long int f
= SCM_INUM (flag
);
217 SCM_OUT_OF_RANGE (1, flag
);
218 scm_debug_cells_gc_interval
= f
;
219 scm_debug_cell_accesses_p
= 1;
220 scm_expensive_debug_cell_accesses_p
= 1;
224 SCM_WRONG_TYPE_ARG (1, flag
);
226 return SCM_UNSPECIFIED
;
232 Provide a stub, so people can use their Scheme code on non-debug
233 versions of GUILE as well.
235 SCM_DEFINE (scm_set_debug_cell_accesses_x
, "set-debug-cell-accesses!", 1, 0, 0,
237 "This function is used to turn on checking for a debug version of GUILE. This version does not support this functionality\n")
238 #define FUNC_NAME s_scm_set_debug_cell_accesses_x
244 fprintf (stderr
, "\nWARNING: GUILE was not compiled with SCM_DEBUG_CELL_ACCESSES");
245 scm_remember_upto_here (flag
);
246 return SCM_UNSPECIFIED
;
250 #endif /* SCM_DEBUG_CELL_ACCESSES == 1 */
254 scm_t_key scm_i_freelist
;
255 scm_t_key scm_i_freelist2
;
259 * is the number of bytes of malloc allocation needed to trigger gc.
261 unsigned long scm_mtrigger
;
264 * If set, don't expand the heap. Set only during gc, during which no allocation
265 * is supposed to take place anyway.
267 int scm_gc_heap_lock
= 0;
270 * Don't pause for collection if this is set -- just
273 int scm_block_gc
= 1;
275 /* During collection, this accumulates objects holding
278 SCM scm_weak_vectors
;
280 /* GC Statistics Keeping
282 unsigned long scm_cells_allocated
= 0;
283 unsigned long scm_mallocated
= 0;
284 unsigned long scm_gc_cells_collected
;
285 unsigned long scm_gc_cells_collected_1
= 0; /* previous GC yield */
286 unsigned long scm_gc_malloc_collected
;
287 unsigned long scm_gc_ports_collected
;
288 unsigned long scm_gc_time_taken
= 0;
289 static unsigned long t_before_gc
;
290 unsigned long scm_gc_mark_time_taken
= 0;
291 unsigned long scm_gc_times
= 0;
292 unsigned long scm_gc_cells_swept
= 0;
293 double scm_gc_cells_marked_acc
= 0.;
294 double scm_gc_cells_swept_acc
= 0.;
295 int scm_gc_cell_yield_percentage
=0;
296 int scm_gc_malloc_yield_percentage
= 0;
299 SCM_SYMBOL (sym_cells_allocated
, "cells-allocated");
300 SCM_SYMBOL (sym_heap_size
, "cell-heap-size");
301 SCM_SYMBOL (sym_mallocated
, "bytes-malloced");
302 SCM_SYMBOL (sym_mtrigger
, "gc-malloc-threshold");
303 SCM_SYMBOL (sym_heap_segments
, "cell-heap-segments");
304 SCM_SYMBOL (sym_gc_time_taken
, "gc-time-taken");
305 SCM_SYMBOL (sym_gc_mark_time_taken
, "gc-mark-time-taken");
306 SCM_SYMBOL (sym_times
, "gc-times");
307 SCM_SYMBOL (sym_cells_marked
, "cells-marked");
308 SCM_SYMBOL (sym_cells_swept
, "cells-swept");
309 SCM_SYMBOL (sym_malloc_yield
, "malloc-yield");
310 SCM_SYMBOL (sym_cell_yield
, "cell-yield");
315 /* Number of calls to SCM_NEWCELL since startup. */
316 unsigned scm_newcell_count
;
317 unsigned scm_newcell2_count
;
320 /* {Scheme Interface to GC}
322 extern int scm_gc_malloc_yield_percentage
;
323 SCM_DEFINE (scm_gc_stats
, "gc-stats", 0, 0, 0,
325 "Return an association list of statistics about Guile's current\n"
327 #define FUNC_NAME s_scm_gc_stats
330 SCM heap_segs
= SCM_EOL
;
331 unsigned long int local_scm_mtrigger
;
332 unsigned long int local_scm_mallocated
;
333 unsigned long int local_scm_heap_size
;
334 int local_scm_gc_cell_yield_percentage
;
335 int local_scm_gc_malloc_yield_percentage
;
336 unsigned long int local_scm_cells_allocated
;
337 unsigned long int local_scm_gc_time_taken
;
338 unsigned long int local_scm_gc_times
;
339 unsigned long int local_scm_gc_mark_time_taken
;
340 double local_scm_gc_cells_swept
;
341 double local_scm_gc_cells_marked
;
343 unsigned long *bounds
= 0;
344 int table_size
= scm_i_heap_segment_table_size
;
348 temporarily store the numbers, so as not to cause GC.
351 bounds
= malloc (sizeof (int) * table_size
* 2);
354 for (i
= table_size
; i
--; )
356 bounds
[2*i
] = (unsigned long)scm_i_heap_segment_table
[i
]->bounds
[0];
357 bounds
[2*i
+1] = (unsigned long)scm_i_heap_segment_table
[i
]->bounds
[1];
361 /* Below, we cons to produce the resulting list. We want a snapshot of
362 * the heap situation before consing.
364 local_scm_mtrigger
= scm_mtrigger
;
365 local_scm_mallocated
= scm_mallocated
;
366 local_scm_heap_size
= SCM_HEAP_SIZE
;
368 local_scm_cells_allocated
= scm_cells_allocated
;
370 local_scm_gc_time_taken
= scm_gc_time_taken
;
371 local_scm_gc_mark_time_taken
= scm_gc_mark_time_taken
;
372 local_scm_gc_times
= scm_gc_times
;
373 local_scm_gc_malloc_yield_percentage
= scm_gc_malloc_yield_percentage
;
374 local_scm_gc_cell_yield_percentage
= scm_gc_cell_yield_percentage
;
376 local_scm_gc_cells_swept
=
377 (double) scm_gc_cells_swept_acc
378 + (double) scm_gc_cells_swept
;
379 local_scm_gc_cells_marked
= scm_gc_cells_marked_acc
380 +(double) scm_gc_cells_swept
381 -(double) scm_gc_cells_collected
;
383 for (i
= table_size
; i
--;)
385 heap_segs
= scm_cons (scm_cons (scm_ulong2num (bounds
[2*i
]),
386 scm_ulong2num (bounds
[2*i
+1])),
390 answer
= scm_list_n (scm_cons (sym_gc_time_taken
, scm_ulong2num (local_scm_gc_time_taken
)),
391 scm_cons (sym_cells_allocated
, scm_ulong2num (local_scm_cells_allocated
)),
392 scm_cons (sym_heap_size
, scm_ulong2num (local_scm_heap_size
)),
393 scm_cons (sym_mallocated
, scm_ulong2num (local_scm_mallocated
)),
394 scm_cons (sym_mtrigger
, scm_ulong2num (local_scm_mtrigger
)),
395 scm_cons (sym_times
, scm_ulong2num (local_scm_gc_times
)),
396 scm_cons (sym_gc_mark_time_taken
, scm_ulong2num (local_scm_gc_mark_time_taken
)),
397 scm_cons (sym_cells_marked
, scm_i_dbl2big (local_scm_gc_cells_marked
)),
398 scm_cons (sym_cells_swept
, scm_i_dbl2big (local_scm_gc_cells_swept
)),
399 scm_cons (sym_malloc_yield
, scm_long2num (local_scm_gc_malloc_yield_percentage
)),
400 scm_cons (sym_cell_yield
, scm_long2num (local_scm_gc_cell_yield_percentage
)),
401 scm_cons (sym_heap_segments
, heap_segs
),
411 gc_start_stats (const char *what SCM_UNUSED
)
413 t_before_gc
= scm_c_get_internal_run_time ();
415 scm_gc_cells_marked_acc
+= (double) scm_gc_cells_swept
416 - (double) scm_gc_cells_collected
;
417 scm_gc_cells_swept_acc
+= (double) scm_gc_cells_swept
;
419 scm_gc_cell_yield_percentage
= ( scm_gc_cells_collected
* 100 ) / SCM_HEAP_SIZE
;
421 scm_gc_cells_swept
= 0;
422 scm_gc_cells_collected_1
= scm_gc_cells_collected
;
425 CELLS SWEPT is another word for the number of cells that were
426 examined during GC. YIELD is the number that we cleaned
427 out. MARKED is the number that weren't cleaned.
429 scm_gc_cells_collected
= 0;
430 scm_gc_malloc_collected
= 0;
431 scm_gc_ports_collected
= 0;
437 unsigned long t
= scm_c_get_internal_run_time ();
438 scm_gc_time_taken
+= (t
- t_before_gc
);
444 SCM_DEFINE (scm_object_address
, "object-address", 1, 0, 0,
446 "Return an integer that for the lifetime of @var{obj} is uniquely\n"
447 "returned by this function for @var{obj}")
448 #define FUNC_NAME s_scm_object_address
450 return scm_ulong2num ((unsigned long) SCM_UNPACK (obj
));
455 SCM_DEFINE (scm_gc
, "gc", 0, 0, 0,
457 "Scans all of SCM objects and reclaims for further use those that are\n"
458 "no longer accessible.")
459 #define FUNC_NAME s_scm_gc
462 scm_i_thread_put_to_sleep ();
464 scm_i_thread_wake_up ();
466 return SCM_UNSPECIFIED
;
473 /* When we get POSIX threads support, the master will be global and
474 * common while the freelist will be individual for each thread.
478 scm_gc_for_newcell (scm_t_cell_type_statistics
*freelist
, SCM
*free_cells
)
482 scm_i_thread_put_to_sleep ();
484 *free_cells
= scm_i_sweep_some_segments (freelist
);
485 if (*free_cells
== SCM_EOL
&& scm_i_gc_grow_heap_p (freelist
))
487 freelist
->heap_segment_idx
= scm_i_get_new_heap_segment (freelist
, abort_on_error
);
488 *free_cells
= scm_i_sweep_some_segments (freelist
);
491 if (*free_cells
== SCM_EOL
&& !scm_block_gc
)
494 with the advent of lazy sweep, GC yield is only know just
497 scm_i_adjust_min_yield (freelist
);
500 out of fresh cells. Try to get some new ones.
505 *free_cells
= scm_i_sweep_some_segments (freelist
);
508 if (*free_cells
== SCM_EOL
)
511 failed getting new cells. Get new juice or die.
513 freelist
->heap_segment_idx
= scm_i_get_new_heap_segment (freelist
, abort_on_error
);
514 *free_cells
= scm_i_sweep_some_segments (freelist
);
517 if (*free_cells
== SCM_EOL
)
522 *free_cells
= SCM_FREE_CELL_CDR (cell
);
524 scm_i_thread_wake_up ();
530 scm_t_c_hook scm_before_gc_c_hook
;
531 scm_t_c_hook scm_before_mark_c_hook
;
532 scm_t_c_hook scm_before_sweep_c_hook
;
533 scm_t_c_hook scm_after_sweep_c_hook
;
534 scm_t_c_hook scm_after_gc_c_hook
;
537 scm_igc (const char *what
)
540 scm_c_hook_run (&scm_before_gc_c_hook
, 0);
543 fprintf (stderr
,"gc reason %s\n", what
);
546 SCM_NULLP (*SCM_FREELIST_LOC (scm_i_freelist
))
548 : (SCM_NULLP (*SCM_FREELIST_LOC (scm_i_freelist2
)) ? "o" : "m"));
551 /* During the critical section, only the current thread may run. */
552 #if 0 /* MDJ 021207 <djurfeldt@nada.kth.se>
553 Currently, a much larger piece of the GC is single threaded.
554 Can we shrink it again? */
555 SCM_CRITICAL_SECTION_START
;
558 if (!scm_root
|| !scm_stack_base
|| scm_block_gc
)
564 gc_start_stats (what
);
566 if (scm_gc_heap_lock
)
567 /* We've invoked the collector while a GC is already in progress.
568 That should never happen. */
574 Let's finish the sweep. The conservative GC might point into the
575 garbage, and marking that would create a mess.
577 scm_i_sweep_all_segments("GC");
578 if (scm_mallocated
< scm_i_deprecated_memory_return
)
580 /* The byte count of allocated objects has underflowed. This is
581 probably because you forgot to report the sizes of objects you
582 have allocated, by calling scm_done_malloc or some such. When
583 the GC freed them, it subtracted their size from
584 scm_mallocated, which underflowed. */
586 "scm_gc_sweep: Byte count of allocated objects has underflowed.\n"
587 "This is probably because the GC hasn't been correctly informed\n"
588 "about object sizes\n");
591 scm_mallocated
-= scm_i_deprecated_memory_return
;
595 scm_c_hook_run (&scm_before_mark_c_hook
, 0);
599 scm_gc_mark_time_taken
+= (scm_c_get_internal_run_time () - t_before_gc
);
601 scm_c_hook_run (&scm_before_sweep_c_hook
, 0);
604 Moved this lock upwards so that we can alloc new heap at the end of a sweep.
606 DOCME: why should the heap be locked anyway?
614 TODO: this hook should probably be moved to just before the mark,
615 since that's where the sweep is finished in lazy sweeping.
617 scm_c_hook_run (&scm_after_sweep_c_hook
, 0);
620 #if 0 /* MDJ 021207 <djurfeldt@nada.kth.se> */
621 SCM_CRITICAL_SECTION_END
;
627 scm_c_hook_run (&scm_after_gc_c_hook
, 0);
631 For debugging purposes, you could do
632 scm_i_sweep_all_segments("debug"), but then the remains of the
633 cell aren't left to analyse.
638 /* {GC Protection Helper Functions}
643 * If within a function you need to protect one or more scheme objects from
644 * garbage collection, pass them as parameters to one of the
645 * scm_remember_upto_here* functions below. These functions don't do
646 * anything, but since the compiler does not know that they are actually
647 * no-ops, it will generate code that calls these functions with the given
648 * parameters. Therefore, you can be sure that the compiler will keep those
649 * scheme values alive (on the stack or in a register) up to the point where
650 * scm_remember_upto_here* is called. In other words, place the call to
651 * scm_remember_upto_here* _behind_ the last code in your function, that
652 * depends on the scheme object to exist.
654 * Example: We want to make sure that the string object str does not get
655 * garbage collected during the execution of 'some_function' in the code
656 * below, because otherwise the characters belonging to str would be freed and
657 * 'some_function' might access freed memory. To make sure that the compiler
658 * keeps str alive on the stack or in a register such that it is visible to
659 * the conservative gc we add the call to scm_remember_upto_here_1 _after_ the
660 * call to 'some_function'. Note that this would not be necessary if str was
661 * used anyway after the call to 'some_function'.
662 * char *chars = SCM_STRING_CHARS (str);
663 * some_function (chars);
664 * scm_remember_upto_here_1 (str); // str will be alive up to this point.
668 scm_remember_upto_here_1 (SCM obj SCM_UNUSED
)
670 /* Empty. Protects a single object from garbage collection. */
674 scm_remember_upto_here_2 (SCM obj1 SCM_UNUSED
, SCM obj2 SCM_UNUSED
)
676 /* Empty. Protects two objects from garbage collection. */
680 scm_remember_upto_here (SCM obj SCM_UNUSED
, ...)
682 /* Empty. Protects any number of objects from garbage collection. */
686 These crazy functions prevent garbage collection
687 of arguments after the first argument by
688 ensuring they remain live throughout the
689 function because they are used in the last
690 line of the code block.
691 It'd be better to have a nice compiler hint to
692 aid the conservative stack-scanning GC. --03/09/00 gjb */
694 scm_return_first (SCM elt
, ...)
700 scm_return_first_int (int i
, ...)
707 scm_permanent_object (SCM obj
)
710 scm_permobjs
= scm_cons (obj
, scm_permobjs
);
716 /* Protect OBJ from the garbage collector. OBJ will not be freed, even if all
717 other references are dropped, until the object is unprotected by calling
718 scm_gc_unprotect_object (OBJ). Calls to scm_gc_protect/unprotect_object nest,
719 i. e. it is possible to protect the same object several times, but it is
720 necessary to unprotect the object the same number of times to actually get
721 the object unprotected. It is an error to unprotect an object more often
722 than it has been protected before. The function scm_protect_object returns
726 /* Implementation note: For every object X, there is a counter which
727 scm_gc_protect_object(X) increments and scm_gc_unprotect_object(X) decrements.
731 scm_gc_protect_object (SCM obj
)
735 /* This critical section barrier will be replaced by a mutex. */
738 handle
= scm_hashq_create_handle_x (scm_protects
, obj
, SCM_MAKINUM (0));
739 SCM_SETCDR (handle
, scm_sum (SCM_CDR (handle
), SCM_MAKINUM (1)));
747 /* Remove any protection for OBJ established by a prior call to
748 scm_protect_object. This function returns OBJ.
750 See scm_protect_object for more information. */
752 scm_gc_unprotect_object (SCM obj
)
756 /* This critical section barrier will be replaced by a mutex. */
759 handle
= scm_hashq_get_handle (scm_protects
, obj
);
761 if (SCM_FALSEP (handle
))
763 fprintf (stderr
, "scm_unprotect_object called on unprotected object\n");
768 SCM count
= scm_difference (SCM_CDR (handle
), SCM_MAKINUM (1));
769 if (SCM_EQ_P (count
, SCM_MAKINUM (0)))
770 scm_hashq_remove_x (scm_protects
, obj
);
772 SCM_SETCDR (handle
, count
);
781 scm_gc_register_root (SCM
*p
)
784 SCM key
= scm_long2num ((long) p
);
786 /* This critical section barrier will be replaced by a mutex. */
789 handle
= scm_hashv_create_handle_x (scm_gc_registered_roots
, key
, SCM_MAKINUM (0));
790 SCM_SETCDR (handle
, scm_sum (SCM_CDR (handle
), SCM_MAKINUM (1)));
796 scm_gc_unregister_root (SCM
*p
)
799 SCM key
= scm_long2num ((long) p
);
801 /* This critical section barrier will be replaced by a mutex. */
804 handle
= scm_hashv_get_handle (scm_gc_registered_roots
, key
);
806 if (SCM_FALSEP (handle
))
808 fprintf (stderr
, "scm_gc_unregister_root called on unregistered root\n");
813 SCM count
= scm_difference (SCM_CDR (handle
), SCM_MAKINUM (1));
814 if (SCM_EQ_P (count
, SCM_MAKINUM (0)))
815 scm_hashv_remove_x (scm_gc_registered_roots
, key
);
817 SCM_SETCDR (handle
, count
);
824 scm_gc_register_roots (SCM
*b
, unsigned long n
)
827 for (; p
< b
+ n
; ++p
)
828 scm_gc_register_root (p
);
832 scm_gc_unregister_roots (SCM
*b
, unsigned long n
)
835 for (; p
< b
+ n
; ++p
)
836 scm_gc_unregister_root (p
);
839 int scm_i_terminating
;
841 /* called on process termination. */
847 extern int on_exit (void (*procp
) (), int arg
);
850 cleanup (int status
, void *arg
)
852 #error Dont know how to setup a cleanup handler on your system.
856 scm_i_terminating
= 1;
857 scm_flush_all_ports ();
864 MOVE THIS FUNCTION. IT DOES NOT HAVE ANYTHING TODO WITH GC.
867 /* Get an integer from an environment variable. */
869 scm_getenv_int (const char *var
, int def
)
872 char *val
= getenv (var
);
876 res
= strtol (val
, &end
, 10);
888 j
= SCM_NUM_PROTECTS
;
890 scm_sys_protects
[--j
] = SCM_BOOL_F
;
893 scm_gc_init_freelist();
894 scm_gc_init_malloc ();
896 j
= SCM_HEAP_SEG_SIZE
;
900 scm_c_hook_init (&scm_before_gc_c_hook
, 0, SCM_C_HOOK_NORMAL
);
901 scm_c_hook_init (&scm_before_mark_c_hook
, 0, SCM_C_HOOK_NORMAL
);
902 scm_c_hook_init (&scm_before_sweep_c_hook
, 0, SCM_C_HOOK_NORMAL
);
903 scm_c_hook_init (&scm_after_sweep_c_hook
, 0, SCM_C_HOOK_NORMAL
);
904 scm_c_hook_init (&scm_after_gc_c_hook
, 0, SCM_C_HOOK_NORMAL
);
906 /* Initialise the list of ports. */
907 scm_i_port_table
= (scm_t_port
**)
908 malloc (sizeof (scm_t_port
*) * scm_i_port_table_room
);
909 if (!scm_i_port_table
)
916 on_exit (cleanup
, 0);
920 scm_stand_in_procs
= SCM_EOL
;
921 scm_permobjs
= SCM_EOL
;
922 scm_protects
= scm_c_make_hash_table (31);
923 scm_gc_registered_roots
= scm_c_make_hash_table (31);
930 SCM scm_after_gc_hook
;
934 /* The function gc_async_thunk causes the execution of the after-gc-hook. It
935 * is run after the gc, as soon as the asynchronous events are handled by the
939 gc_async_thunk (void)
941 scm_c_run_hook (scm_after_gc_hook
, SCM_EOL
);
942 return SCM_UNSPECIFIED
;
946 /* The function mark_gc_async is run by the scm_after_gc_c_hook at the end of
947 * the garbage collection. The only purpose of this function is to mark the
948 * gc_async (which will eventually lead to the execution of the
952 mark_gc_async (void * hook_data SCM_UNUSED
,
953 void *func_data SCM_UNUSED
,
954 void *data SCM_UNUSED
)
956 /* If cell access debugging is enabled, the user may choose to perform
957 * additional garbage collections after an arbitrary number of cell
958 * accesses. We don't want the scheme level after-gc-hook to be performed
959 * for each of these garbage collections for the following reason: The
960 * execution of the after-gc-hook causes cell accesses itself. Thus, if the
961 * after-gc-hook was performed with every gc, and if the gc was performed
962 * after a very small number of cell accesses, then the number of cell
963 * accesses during the execution of the after-gc-hook will suffice to cause
964 * the execution of the next gc. Then, guile would keep executing the
965 * after-gc-hook over and over again, and would never come to do other
968 * To overcome this problem, if cell access debugging with additional
969 * garbage collections is enabled, the after-gc-hook is never run by the
970 * garbage collecter. When running guile with cell access debugging and the
971 * execution of the after-gc-hook is desired, then it is necessary to run
972 * the hook explicitly from the user code. This has the effect, that from
973 * the scheme level point of view it seems that garbage collection is
974 * performed with a much lower frequency than it actually is. Obviously,
975 * this will not work for code that depends on a fixed one to one
976 * relationship between the execution counts of the C level garbage
977 * collection hooks and the execution count of the scheme level
980 #if (SCM_DEBUG_CELL_ACCESSES == 1)
981 if (scm_debug_cells_gc_interval
== 0)
982 scm_system_async_mark (gc_async
);
984 scm_system_async_mark (gc_async
);
995 scm_after_gc_hook
= scm_permanent_object (scm_make_hook (SCM_INUM0
));
996 scm_c_define ("after-gc-hook", scm_after_gc_hook
);
998 gc_async
= scm_c_make_subr ("%gc-thunk", scm_tc7_subr_0
,
1001 scm_c_hook_add (&scm_after_gc_c_hook
, mark_gc_async
, NULL
, 0);
1003 #include "libguile/gc.x"
1009 #define FUNC_NAME "scm_gc_sweep"
1011 scm_i_deprecated_memory_return
= 0;
1013 scm_i_gc_sweep_freelist_reset (&scm_i_master_freelist
);
1014 scm_i_gc_sweep_freelist_reset (&scm_i_master_freelist2
);
1017 NOTHING HERE: LAZY SWEEPING !
1019 scm_i_reset_segments ();
1021 /* When we move to POSIX threads private freelists should probably
1022 be GC-protected instead. */
1023 *SCM_FREELIST_LOC (scm_i_freelist
) = SCM_EOL
;
1024 *SCM_FREELIST_LOC (scm_i_freelist2
) = SCM_EOL
;
1026 /* Invalidate the freelists of other threads. */
1027 scm_i_thread_invalidate_freelists ();