1 /* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2002, 2003 Free Software Foundation, Inc.
3 * This library is free software; you can redistribute it and/or
4 * modify it under the terms of the GNU Lesser General Public
5 * License as published by the Free Software Foundation; either
6 * version 2.1 of the License, or (at your option) any later version.
8 * This library 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 GNU
11 * Lesser General Public License for more details.
13 * You should have received a copy of the GNU Lesser General Public
14 * License along with this library; if not, write to the Free Software
15 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 /* #define DEBUGINFO */
32 extern unsigned long * __libc_ia64_register_backing_store_base
;
35 #include "libguile/_scm.h"
36 #include "libguile/eval.h"
37 #include "libguile/stime.h"
38 #include "libguile/stackchk.h"
39 #include "libguile/struct.h"
40 #include "libguile/smob.h"
41 #include "libguile/unif.h"
42 #include "libguile/async.h"
43 #include "libguile/ports.h"
44 #include "libguile/root.h"
45 #include "libguile/strings.h"
46 #include "libguile/vectors.h"
47 #include "libguile/weaks.h"
48 #include "libguile/hashtab.h"
49 #include "libguile/tags.h"
51 #include "libguile/private-gc.h"
52 #include "libguile/validate.h"
53 #include "libguile/deprecation.h"
54 #include "libguile/gc.h"
56 #ifdef GUILE_DEBUG_MALLOC
57 #include "libguile/debug-malloc.h"
70 unsigned int scm_gc_running_p
= 0;
72 /* Lock this mutex before doing lazy sweeping.
74 scm_t_rec_mutex scm_i_sweep_mutex
;
76 /* Set this to != 0 if every cell that is accessed shall be checked:
78 int scm_debug_cell_accesses_p
= 0;
79 int scm_expensive_debug_cell_accesses_p
= 0;
81 /* Set this to 0 if no additional gc's shall be performed, otherwise set it to
82 * the number of cell accesses after which a gc shall be called.
84 int scm_debug_cells_gc_interval
= 0;
87 Global variable, so you can switch it off at runtime by setting
88 scm_i_cell_validation_already_running.
90 int scm_i_cell_validation_already_running
;
92 #if (SCM_DEBUG_CELL_ACCESSES == 1)
97 Assert that the given object is a valid reference to a valid cell. This
98 test involves to determine whether the object is a cell pointer, whether
99 this pointer actually points into a heap segment and whether the cell
100 pointed to is not a free cell. Further, additional garbage collections may
101 get executed after a user defined number of cell accesses. This helps to
102 find places in the C code where references are dropped for extremely short
107 scm_i_expensive_validation_check (SCM cell
)
109 if (!scm_in_heap_p (cell
))
111 fprintf (stderr
, "scm_assert_cell_valid: this object does not live in the heap: %lux\n",
112 (unsigned long) SCM_UNPACK (cell
));
116 /* If desired, perform additional garbage collections after a user
117 * defined number of cell accesses.
119 if (scm_debug_cells_gc_interval
)
121 static unsigned int counter
= 0;
129 counter
= scm_debug_cells_gc_interval
;
130 scm_igc ("scm_assert_cell_valid");
136 scm_assert_cell_valid (SCM cell
)
138 if (!scm_i_cell_validation_already_running
&& scm_debug_cell_accesses_p
)
140 scm_i_cell_validation_already_running
= 1; /* set to avoid recursion */
143 During GC, no user-code should be run, and the guile core
144 should use non-protected accessors.
146 if (scm_gc_running_p
)
150 Only scm_in_heap_p and rescanning the heap is wildly
153 if (scm_expensive_debug_cell_accesses_p
)
154 scm_i_expensive_validation_check (cell
);
156 if (!SCM_GC_MARK_P (cell
))
159 "scm_assert_cell_valid: this object is unmarked. \n"
160 "It has been garbage-collected in the last GC run: "
162 (unsigned long) SCM_UNPACK (cell
));
166 scm_i_cell_validation_already_running
= 0; /* re-enable */
172 SCM_DEFINE (scm_set_debug_cell_accesses_x
, "set-debug-cell-accesses!", 1, 0, 0,
174 "If @var{flag} is @code{#f}, cell access checking is disabled.\n"
175 "If @var{flag} is @code{#t}, cheap cell access checking is enabled,\n"
176 "but no additional calls to garbage collection are issued.\n"
177 "If @var{flag} is a number, strict cell access checking is enabled,\n"
178 "with an additional garbage collection after the given\n"
179 "number of cell accesses.\n"
180 "This procedure only exists when the compile-time flag\n"
181 "@code{SCM_DEBUG_CELL_ACCESSES} was set to 1.")
182 #define FUNC_NAME s_scm_set_debug_cell_accesses_x
184 if (scm_is_false (flag
))
186 scm_debug_cell_accesses_p
= 0;
188 else if (scm_is_eq (flag
, SCM_BOOL_T
))
190 scm_debug_cells_gc_interval
= 0;
191 scm_debug_cell_accesses_p
= 1;
192 scm_expensive_debug_cell_accesses_p
= 0;
196 scm_debug_cells_gc_interval
= scm_to_signed_integer (flag
, 0, INT_MAX
);
197 scm_debug_cell_accesses_p
= 1;
198 scm_expensive_debug_cell_accesses_p
= 1;
200 return SCM_UNSPECIFIED
;
205 #endif /* SCM_DEBUG_CELL_ACCESSES == 1 */
209 scm_t_key scm_i_freelist
;
210 scm_t_key scm_i_freelist2
;
214 * is the number of bytes of malloc allocation needed to trigger gc.
216 unsigned long scm_mtrigger
;
219 * If set, don't expand the heap. Set only during gc, during which no allocation
220 * is supposed to take place anyway.
222 int scm_gc_heap_lock
= 0;
225 * Don't pause for collection if this is set -- just
228 int scm_block_gc
= 1;
230 /* During collection, this accumulates objects holding
233 SCM scm_weak_vectors
;
235 /* GC Statistics Keeping
237 unsigned long scm_cells_allocated
= 0;
238 unsigned long scm_mallocated
= 0;
239 unsigned long scm_gc_cells_collected
;
240 unsigned long scm_gc_cells_collected_1
= 0; /* previous GC yield */
241 unsigned long scm_gc_malloc_collected
;
242 unsigned long scm_gc_ports_collected
;
243 unsigned long scm_gc_time_taken
= 0;
244 static unsigned long t_before_gc
;
245 unsigned long scm_gc_mark_time_taken
= 0;
246 unsigned long scm_gc_times
= 0;
247 unsigned long scm_gc_cells_swept
= 0;
248 double scm_gc_cells_marked_acc
= 0.;
249 double scm_gc_cells_swept_acc
= 0.;
250 int scm_gc_cell_yield_percentage
=0;
251 int scm_gc_malloc_yield_percentage
= 0;
252 unsigned long protected_obj_count
= 0;
255 SCM_SYMBOL (sym_cells_allocated
, "cells-allocated");
256 SCM_SYMBOL (sym_heap_size
, "cell-heap-size");
257 SCM_SYMBOL (sym_mallocated
, "bytes-malloced");
258 SCM_SYMBOL (sym_mtrigger
, "gc-malloc-threshold");
259 SCM_SYMBOL (sym_heap_segments
, "cell-heap-segments");
260 SCM_SYMBOL (sym_gc_time_taken
, "gc-time-taken");
261 SCM_SYMBOL (sym_gc_mark_time_taken
, "gc-mark-time-taken");
262 SCM_SYMBOL (sym_times
, "gc-times");
263 SCM_SYMBOL (sym_cells_marked
, "cells-marked");
264 SCM_SYMBOL (sym_cells_swept
, "cells-swept");
265 SCM_SYMBOL (sym_malloc_yield
, "malloc-yield");
266 SCM_SYMBOL (sym_cell_yield
, "cell-yield");
267 SCM_SYMBOL (sym_protected_objects
, "protected-objects");
272 /* Number of calls to SCM_NEWCELL since startup. */
273 unsigned scm_newcell_count
;
274 unsigned scm_newcell2_count
;
277 /* {Scheme Interface to GC}
279 extern int scm_gc_malloc_yield_percentage
;
280 SCM_DEFINE (scm_gc_stats
, "gc-stats", 0, 0, 0,
282 "Return an association list of statistics about Guile's current\n"
284 #define FUNC_NAME s_scm_gc_stats
287 SCM heap_segs
= SCM_EOL
;
288 unsigned long int local_scm_mtrigger
;
289 unsigned long int local_scm_mallocated
;
290 unsigned long int local_scm_heap_size
;
291 int local_scm_gc_cell_yield_percentage
;
292 int local_scm_gc_malloc_yield_percentage
;
293 unsigned long int local_scm_cells_allocated
;
294 unsigned long int local_scm_gc_time_taken
;
295 unsigned long int local_scm_gc_times
;
296 unsigned long int local_scm_gc_mark_time_taken
;
297 unsigned long int local_protected_obj_count
;
298 double local_scm_gc_cells_swept
;
299 double local_scm_gc_cells_marked
;
301 unsigned long *bounds
= 0;
302 int table_size
= scm_i_heap_segment_table_size
;
306 temporarily store the numbers, so as not to cause GC.
309 bounds
= malloc (sizeof (int) * table_size
* 2);
312 for (i
= table_size
; i
--; )
314 bounds
[2*i
] = (unsigned long)scm_i_heap_segment_table
[i
]->bounds
[0];
315 bounds
[2*i
+1] = (unsigned long)scm_i_heap_segment_table
[i
]->bounds
[1];
319 /* Below, we cons to produce the resulting list. We want a snapshot of
320 * the heap situation before consing.
322 local_scm_mtrigger
= scm_mtrigger
;
323 local_scm_mallocated
= scm_mallocated
;
324 local_scm_heap_size
= SCM_HEAP_SIZE
;
326 local_scm_cells_allocated
= scm_cells_allocated
;
328 local_scm_gc_time_taken
= scm_gc_time_taken
;
329 local_scm_gc_mark_time_taken
= scm_gc_mark_time_taken
;
330 local_scm_gc_times
= scm_gc_times
;
331 local_scm_gc_malloc_yield_percentage
= scm_gc_malloc_yield_percentage
;
332 local_scm_gc_cell_yield_percentage
= scm_gc_cell_yield_percentage
;
333 local_protected_obj_count
= protected_obj_count
;
334 local_scm_gc_cells_swept
=
335 (double) scm_gc_cells_swept_acc
336 + (double) scm_gc_cells_swept
;
337 local_scm_gc_cells_marked
= scm_gc_cells_marked_acc
338 +(double) scm_gc_cells_swept
339 -(double) scm_gc_cells_collected
;
341 for (i
= table_size
; i
--;)
343 heap_segs
= scm_cons (scm_cons (scm_ulong2num (bounds
[2*i
]),
344 scm_ulong2num (bounds
[2*i
+1])),
348 answer
= scm_list_n (scm_cons (sym_gc_time_taken
, scm_ulong2num (local_scm_gc_time_taken
)),
349 scm_cons (sym_cells_allocated
, scm_ulong2num (local_scm_cells_allocated
)),
350 scm_cons (sym_heap_size
, scm_ulong2num (local_scm_heap_size
)),
351 scm_cons (sym_mallocated
, scm_ulong2num (local_scm_mallocated
)),
352 scm_cons (sym_mtrigger
, scm_ulong2num (local_scm_mtrigger
)),
353 scm_cons (sym_times
, scm_ulong2num (local_scm_gc_times
)),
354 scm_cons (sym_gc_mark_time_taken
, scm_ulong2num (local_scm_gc_mark_time_taken
)),
355 scm_cons (sym_cells_marked
, scm_i_dbl2big (local_scm_gc_cells_marked
)),
356 scm_cons (sym_cells_swept
, scm_i_dbl2big (local_scm_gc_cells_swept
)),
357 scm_cons (sym_malloc_yield
, scm_long2num (local_scm_gc_malloc_yield_percentage
)),
358 scm_cons (sym_cell_yield
, scm_long2num (local_scm_gc_cell_yield_percentage
)),
359 scm_cons (sym_protected_objects
, scm_ulong2num (local_protected_obj_count
)),
360 scm_cons (sym_heap_segments
, heap_segs
),
370 gc_start_stats (const char *what SCM_UNUSED
)
372 t_before_gc
= scm_c_get_internal_run_time ();
374 scm_gc_cells_marked_acc
+= (double) scm_gc_cells_swept
375 - (double) scm_gc_cells_collected
;
376 scm_gc_cells_swept_acc
+= (double) scm_gc_cells_swept
;
378 scm_gc_cell_yield_percentage
= ( scm_gc_cells_collected
* 100 ) / SCM_HEAP_SIZE
;
380 scm_gc_cells_swept
= 0;
381 scm_gc_cells_collected_1
= scm_gc_cells_collected
;
384 CELLS SWEPT is another word for the number of cells that were
385 examined during GC. YIELD is the number that we cleaned
386 out. MARKED is the number that weren't cleaned.
388 scm_gc_cells_collected
= 0;
389 scm_gc_malloc_collected
= 0;
390 scm_gc_ports_collected
= 0;
396 unsigned long t
= scm_c_get_internal_run_time ();
397 scm_gc_time_taken
+= (t
- t_before_gc
);
403 SCM_DEFINE (scm_object_address
, "object-address", 1, 0, 0,
405 "Return an integer that for the lifetime of @var{obj} is uniquely\n"
406 "returned by this function for @var{obj}")
407 #define FUNC_NAME s_scm_object_address
409 return scm_ulong2num ((unsigned long) SCM_UNPACK (obj
));
414 SCM_DEFINE (scm_gc
, "gc", 0, 0, 0,
416 "Scans all of SCM objects and reclaims for further use those that are\n"
417 "no longer accessible.")
418 #define FUNC_NAME s_scm_gc
421 return SCM_UNSPECIFIED
;
428 /* When we get POSIX threads support, the master will be global and
429 * common while the freelist will be individual for each thread.
433 scm_gc_for_newcell (scm_t_cell_type_statistics
*freelist
, SCM
*free_cells
)
437 scm_rec_mutex_lock (&scm_i_sweep_mutex
);
439 *free_cells
= scm_i_sweep_some_segments (freelist
);
440 if (*free_cells
== SCM_EOL
&& scm_i_gc_grow_heap_p (freelist
))
442 freelist
->heap_segment_idx
= scm_i_get_new_heap_segment (freelist
, abort_on_error
);
443 *free_cells
= scm_i_sweep_some_segments (freelist
);
446 if (*free_cells
== SCM_EOL
&& !scm_block_gc
)
449 with the advent of lazy sweep, GC yield is only know just
452 scm_i_adjust_min_yield (freelist
);
455 out of fresh cells. Try to get some new ones.
460 *free_cells
= scm_i_sweep_some_segments (freelist
);
463 if (*free_cells
== SCM_EOL
)
466 failed getting new cells. Get new juice or die.
468 freelist
->heap_segment_idx
= scm_i_get_new_heap_segment (freelist
, abort_on_error
);
469 *free_cells
= scm_i_sweep_some_segments (freelist
);
472 if (*free_cells
== SCM_EOL
)
477 *free_cells
= SCM_FREE_CELL_CDR (cell
);
479 scm_rec_mutex_unlock (&scm_i_sweep_mutex
);
485 scm_t_c_hook scm_before_gc_c_hook
;
486 scm_t_c_hook scm_before_mark_c_hook
;
487 scm_t_c_hook scm_before_sweep_c_hook
;
488 scm_t_c_hook scm_after_sweep_c_hook
;
489 scm_t_c_hook scm_after_gc_c_hook
;
492 scm_igc (const char *what
)
494 scm_rec_mutex_lock (&scm_i_sweep_mutex
);
496 scm_c_hook_run (&scm_before_gc_c_hook
, 0);
499 fprintf (stderr
,"gc reason %s\n", what
);
502 SCM_NULLP (*SCM_FREELIST_LOC (scm_i_freelist
))
504 : (SCM_NULLP (*SCM_FREELIST_LOC (scm_i_freelist2
)) ? "o" : "m"));
507 /* During the critical section, only the current thread may run. */
508 scm_i_thread_put_to_sleep ();
510 if (!scm_root
|| !scm_stack_base
|| scm_block_gc
)
516 gc_start_stats (what
);
518 if (scm_gc_heap_lock
)
519 /* We've invoked the collector while a GC is already in progress.
520 That should never happen. */
526 Let's finish the sweep. The conservative GC might point into the
527 garbage, and marking that would create a mess.
529 scm_i_sweep_all_segments("GC");
530 if (scm_mallocated
< scm_i_deprecated_memory_return
)
532 /* The byte count of allocated objects has underflowed. This is
533 probably because you forgot to report the sizes of objects you
534 have allocated, by calling scm_done_malloc or some such. When
535 the GC freed them, it subtracted their size from
536 scm_mallocated, which underflowed. */
538 "scm_gc_sweep: Byte count of allocated objects has underflowed.\n"
539 "This is probably because the GC hasn't been correctly informed\n"
540 "about object sizes\n");
543 scm_mallocated
-= scm_i_deprecated_memory_return
;
547 scm_c_hook_run (&scm_before_mark_c_hook
, 0);
551 scm_gc_mark_time_taken
+= (scm_c_get_internal_run_time () - t_before_gc
);
553 scm_c_hook_run (&scm_before_sweep_c_hook
, 0);
556 Moved this lock upwards so that we can alloc new heap at the end of a sweep.
558 DOCME: why should the heap be locked anyway?
566 TODO: this hook should probably be moved to just before the mark,
567 since that's where the sweep is finished in lazy sweeping.
569 MDJ 030219 <djurfeldt@nada.kth.se>: No, probably not. The
570 original meaning implied at least two things: that it would be
573 1. the freelist is re-initialized (no evaluation possible, though)
577 2. the heap is "fresh"
578 (it is well-defined what data is used and what is not)
580 Neither of these conditions would hold just before the mark phase.
582 Of course, the lazy sweeping has muddled the distinction between
583 scm_before_sweep_c_hook and scm_after_sweep_c_hook, but even if
584 there were no difference, it would still be useful to have two
585 distinct classes of hook functions since this can prevent some
586 bad interference when several modules adds gc hooks.
588 scm_c_hook_run (&scm_after_sweep_c_hook
, 0);
591 scm_i_thread_wake_up ();
596 scm_c_hook_run (&scm_after_gc_c_hook
, 0);
598 scm_rec_mutex_unlock (&scm_i_sweep_mutex
);
601 For debugging purposes, you could do
602 scm_i_sweep_all_segments("debug"), but then the remains of the
603 cell aren't left to analyse.
608 /* {GC Protection Helper Functions}
613 * If within a function you need to protect one or more scheme objects from
614 * garbage collection, pass them as parameters to one of the
615 * scm_remember_upto_here* functions below. These functions don't do
616 * anything, but since the compiler does not know that they are actually
617 * no-ops, it will generate code that calls these functions with the given
618 * parameters. Therefore, you can be sure that the compiler will keep those
619 * scheme values alive (on the stack or in a register) up to the point where
620 * scm_remember_upto_here* is called. In other words, place the call to
621 * scm_remember_upto_here* _behind_ the last code in your function, that
622 * depends on the scheme object to exist.
624 * Example: We want to make sure that the string object str does not get
625 * garbage collected during the execution of 'some_function' in the code
626 * below, because otherwise the characters belonging to str would be freed and
627 * 'some_function' might access freed memory. To make sure that the compiler
628 * keeps str alive on the stack or in a register such that it is visible to
629 * the conservative gc we add the call to scm_remember_upto_here_1 _after_ the
630 * call to 'some_function'. Note that this would not be necessary if str was
631 * used anyway after the call to 'some_function'.
632 * char *chars = SCM_STRING_CHARS (str);
633 * some_function (chars);
634 * scm_remember_upto_here_1 (str); // str will be alive up to this point.
637 /* Remove any macro versions of these while defining the functions.
638 Functions are always included in the library, for upward binary
639 compatibility and in case combinations of GCC and non-GCC are used. */
640 #undef scm_remember_upto_here_1
641 #undef scm_remember_upto_here_2
644 scm_remember_upto_here_1 (SCM obj SCM_UNUSED
)
646 /* Empty. Protects a single object from garbage collection. */
650 scm_remember_upto_here_2 (SCM obj1 SCM_UNUSED
, SCM obj2 SCM_UNUSED
)
652 /* Empty. Protects two objects from garbage collection. */
656 scm_remember_upto_here (SCM obj SCM_UNUSED
, ...)
658 /* Empty. Protects any number of objects from garbage collection. */
662 These crazy functions prevent garbage collection
663 of arguments after the first argument by
664 ensuring they remain live throughout the
665 function because they are used in the last
666 line of the code block.
667 It'd be better to have a nice compiler hint to
668 aid the conservative stack-scanning GC. --03/09/00 gjb */
670 scm_return_first (SCM elt
, ...)
676 scm_return_first_int (int i
, ...)
683 scm_permanent_object (SCM obj
)
686 scm_permobjs
= scm_cons (obj
, scm_permobjs
);
692 /* Protect OBJ from the garbage collector. OBJ will not be freed, even if all
693 other references are dropped, until the object is unprotected by calling
694 scm_gc_unprotect_object (OBJ). Calls to scm_gc_protect/unprotect_object nest,
695 i. e. it is possible to protect the same object several times, but it is
696 necessary to unprotect the object the same number of times to actually get
697 the object unprotected. It is an error to unprotect an object more often
698 than it has been protected before. The function scm_protect_object returns
702 /* Implementation note: For every object X, there is a counter which
703 scm_gc_protect_object(X) increments and scm_gc_unprotect_object(X) decrements.
709 scm_gc_protect_object (SCM obj
)
713 /* This critical section barrier will be replaced by a mutex. */
716 handle
= scm_hashq_create_handle_x (scm_protects
, obj
, scm_from_int (0));
717 SCM_SETCDR (handle
, scm_sum (SCM_CDR (handle
), scm_from_int (1)));
719 protected_obj_count
++;
727 /* Remove any protection for OBJ established by a prior call to
728 scm_protect_object. This function returns OBJ.
730 See scm_protect_object for more information. */
732 scm_gc_unprotect_object (SCM obj
)
736 /* This critical section barrier will be replaced by a mutex. */
739 handle
= scm_hashq_get_handle (scm_protects
, obj
);
741 if (scm_is_false (handle
))
743 fprintf (stderr
, "scm_unprotect_object called on unprotected object\n");
748 SCM count
= scm_difference (SCM_CDR (handle
), scm_from_int (1));
749 if (scm_is_eq (count
, scm_from_int (0)))
750 scm_hashq_remove_x (scm_protects
, obj
);
752 SCM_SETCDR (handle
, count
);
754 protected_obj_count
--;
762 scm_gc_register_root (SCM
*p
)
765 SCM key
= scm_long2num ((long) p
);
767 /* This critical section barrier will be replaced by a mutex. */
770 handle
= scm_hashv_create_handle_x (scm_gc_registered_roots
, key
,
772 SCM_SETCDR (handle
, scm_sum (SCM_CDR (handle
), scm_from_int (1)));
778 scm_gc_unregister_root (SCM
*p
)
781 SCM key
= scm_long2num ((long) p
);
783 /* This critical section barrier will be replaced by a mutex. */
786 handle
= scm_hashv_get_handle (scm_gc_registered_roots
, key
);
788 if (scm_is_false (handle
))
790 fprintf (stderr
, "scm_gc_unregister_root called on unregistered root\n");
795 SCM count
= scm_difference (SCM_CDR (handle
), scm_from_int (1));
796 if (scm_is_eq (count
, scm_from_int (0)))
797 scm_hashv_remove_x (scm_gc_registered_roots
, key
);
799 SCM_SETCDR (handle
, count
);
806 scm_gc_register_roots (SCM
*b
, unsigned long n
)
809 for (; p
< b
+ n
; ++p
)
810 scm_gc_register_root (p
);
814 scm_gc_unregister_roots (SCM
*b
, unsigned long n
)
817 for (; p
< b
+ n
; ++p
)
818 scm_gc_unregister_root (p
);
821 int scm_i_terminating
;
823 /* called on process termination. */
829 extern int on_exit (void (*procp
) (), int arg
);
832 cleanup (int status
, void *arg
)
834 #error Dont know how to setup a cleanup handler on your system.
838 scm_i_terminating
= 1;
839 scm_flush_all_ports ();
846 MOVE THIS FUNCTION. IT DOES NOT HAVE ANYTHING TODO WITH GC.
849 /* Get an integer from an environment variable. */
851 scm_getenv_int (const char *var
, int def
)
854 char *val
= getenv (var
);
858 res
= strtol (val
, &end
, 10);
865 scm_storage_prehistory ()
867 scm_c_hook_init (&scm_before_gc_c_hook
, 0, SCM_C_HOOK_NORMAL
);
868 scm_c_hook_init (&scm_before_mark_c_hook
, 0, SCM_C_HOOK_NORMAL
);
869 scm_c_hook_init (&scm_before_sweep_c_hook
, 0, SCM_C_HOOK_NORMAL
);
870 scm_c_hook_init (&scm_after_sweep_c_hook
, 0, SCM_C_HOOK_NORMAL
);
871 scm_c_hook_init (&scm_after_gc_c_hook
, 0, SCM_C_HOOK_NORMAL
);
879 /* Fixme: Should use mutexattr from the low-level API. */
880 scm_rec_mutex_init (&scm_i_sweep_mutex
, &scm_i_plugin_rec_mutex
);
882 j
= SCM_NUM_PROTECTS
;
884 scm_sys_protects
[--j
] = SCM_BOOL_F
;
887 scm_gc_init_freelist();
888 scm_gc_init_malloc ();
890 j
= SCM_HEAP_SEG_SIZE
;
893 /* Initialise the list of ports. */
894 scm_i_port_table
= (scm_t_port
**)
895 malloc (sizeof (scm_t_port
*) * scm_i_port_table_room
);
896 if (!scm_i_port_table
)
903 on_exit (cleanup
, 0);
907 scm_stand_in_procs
= SCM_EOL
;
908 scm_permobjs
= SCM_EOL
;
909 scm_protects
= scm_c_make_hash_table (31);
910 scm_gc_registered_roots
= scm_c_make_hash_table (31);
917 SCM scm_after_gc_hook
;
921 /* The function gc_async_thunk causes the execution of the after-gc-hook. It
922 * is run after the gc, as soon as the asynchronous events are handled by the
926 gc_async_thunk (void)
928 scm_c_run_hook (scm_after_gc_hook
, SCM_EOL
);
929 return SCM_UNSPECIFIED
;
933 /* The function mark_gc_async is run by the scm_after_gc_c_hook at the end of
934 * the garbage collection. The only purpose of this function is to mark the
935 * gc_async (which will eventually lead to the execution of the
939 mark_gc_async (void * hook_data SCM_UNUSED
,
940 void *func_data SCM_UNUSED
,
941 void *data SCM_UNUSED
)
943 /* If cell access debugging is enabled, the user may choose to perform
944 * additional garbage collections after an arbitrary number of cell
945 * accesses. We don't want the scheme level after-gc-hook to be performed
946 * for each of these garbage collections for the following reason: The
947 * execution of the after-gc-hook causes cell accesses itself. Thus, if the
948 * after-gc-hook was performed with every gc, and if the gc was performed
949 * after a very small number of cell accesses, then the number of cell
950 * accesses during the execution of the after-gc-hook will suffice to cause
951 * the execution of the next gc. Then, guile would keep executing the
952 * after-gc-hook over and over again, and would never come to do other
955 * To overcome this problem, if cell access debugging with additional
956 * garbage collections is enabled, the after-gc-hook is never run by the
957 * garbage collecter. When running guile with cell access debugging and the
958 * execution of the after-gc-hook is desired, then it is necessary to run
959 * the hook explicitly from the user code. This has the effect, that from
960 * the scheme level point of view it seems that garbage collection is
961 * performed with a much lower frequency than it actually is. Obviously,
962 * this will not work for code that depends on a fixed one to one
963 * relationship between the execution counts of the C level garbage
964 * collection hooks and the execution count of the scheme level
967 #if (SCM_DEBUG_CELL_ACCESSES == 1)
968 if (scm_debug_cells_gc_interval
== 0)
969 scm_system_async_mark (gc_async
);
971 scm_system_async_mark (gc_async
);
982 scm_after_gc_hook
= scm_permanent_object (scm_make_hook (SCM_INUM0
));
983 scm_c_define ("after-gc-hook", scm_after_gc_hook
);
985 gc_async
= scm_c_make_subr ("%gc-thunk", scm_tc7_subr_0
,
988 scm_c_hook_add (&scm_after_gc_c_hook
, mark_gc_async
, NULL
, 0);
990 #include "libguile/gc.x"
996 #define FUNC_NAME "scm_gc_sweep"
998 scm_i_deprecated_memory_return
= 0;
1000 scm_i_gc_sweep_freelist_reset (&scm_i_master_freelist
);
1001 scm_i_gc_sweep_freelist_reset (&scm_i_master_freelist2
);
1004 NOTHING HERE: LAZY SWEEPING !
1006 scm_i_reset_segments ();
1008 /* When we move to POSIX threads private freelists should probably
1009 be GC-protected instead. */
1010 *SCM_FREELIST_LOC (scm_i_freelist
) = SCM_EOL
;
1011 *SCM_FREELIST_LOC (scm_i_freelist2
) = SCM_EOL
;
1013 /* Invalidate the freelists of other threads. */
1014 scm_i_thread_invalidate_freelists ();