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_FALSEP (flag
))
186 scm_debug_cell_accesses_p
= 0;
188 else if (SCM_EQ_P (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;
194 else if (SCM_INUMP (flag
))
196 long int f
= SCM_INUM (flag
);
198 SCM_OUT_OF_RANGE (1, flag
);
199 scm_debug_cells_gc_interval
= f
;
200 scm_debug_cell_accesses_p
= 1;
201 scm_expensive_debug_cell_accesses_p
= 1;
205 SCM_WRONG_TYPE_ARG (1, flag
);
207 return SCM_UNSPECIFIED
;
213 Provide a stub, so people can use their Scheme code on non-debug
214 versions of GUILE as well.
216 SCM_DEFINE (scm_set_debug_cell_accesses_x
, "set-debug-cell-accesses!", 1, 0, 0,
218 "This function is used to turn on checking for a debug version of GUILE. This version does not support this functionality\n")
219 #define FUNC_NAME s_scm_set_debug_cell_accesses_x
225 fprintf (stderr
, "\nWARNING: GUILE was not compiled with SCM_DEBUG_CELL_ACCESSES");
226 scm_remember_upto_here (flag
);
227 return SCM_UNSPECIFIED
;
231 #endif /* SCM_DEBUG_CELL_ACCESSES == 1 */
235 scm_t_key scm_i_freelist
;
236 scm_t_key scm_i_freelist2
;
240 * is the number of bytes of malloc allocation needed to trigger gc.
242 unsigned long scm_mtrigger
;
245 * If set, don't expand the heap. Set only during gc, during which no allocation
246 * is supposed to take place anyway.
248 int scm_gc_heap_lock
= 0;
251 * Don't pause for collection if this is set -- just
254 int scm_block_gc
= 1;
256 /* During collection, this accumulates objects holding
259 SCM scm_weak_vectors
;
261 /* GC Statistics Keeping
263 unsigned long scm_cells_allocated
= 0;
264 unsigned long scm_mallocated
= 0;
265 unsigned long scm_gc_cells_collected
;
266 unsigned long scm_gc_cells_collected_1
= 0; /* previous GC yield */
267 unsigned long scm_gc_malloc_collected
;
268 unsigned long scm_gc_ports_collected
;
269 unsigned long scm_gc_time_taken
= 0;
270 static unsigned long t_before_gc
;
271 unsigned long scm_gc_mark_time_taken
= 0;
272 unsigned long scm_gc_times
= 0;
273 unsigned long scm_gc_cells_swept
= 0;
274 double scm_gc_cells_marked_acc
= 0.;
275 double scm_gc_cells_swept_acc
= 0.;
276 int scm_gc_cell_yield_percentage
=0;
277 int scm_gc_malloc_yield_percentage
= 0;
278 unsigned long protected_obj_count
= 0;
281 SCM_SYMBOL (sym_cells_allocated
, "cells-allocated");
282 SCM_SYMBOL (sym_heap_size
, "cell-heap-size");
283 SCM_SYMBOL (sym_mallocated
, "bytes-malloced");
284 SCM_SYMBOL (sym_mtrigger
, "gc-malloc-threshold");
285 SCM_SYMBOL (sym_heap_segments
, "cell-heap-segments");
286 SCM_SYMBOL (sym_gc_time_taken
, "gc-time-taken");
287 SCM_SYMBOL (sym_gc_mark_time_taken
, "gc-mark-time-taken");
288 SCM_SYMBOL (sym_times
, "gc-times");
289 SCM_SYMBOL (sym_cells_marked
, "cells-marked");
290 SCM_SYMBOL (sym_cells_swept
, "cells-swept");
291 SCM_SYMBOL (sym_malloc_yield
, "malloc-yield");
292 SCM_SYMBOL (sym_cell_yield
, "cell-yield");
293 SCM_SYMBOL (sym_protected_objects
, "protected-objects");
298 /* Number of calls to SCM_NEWCELL since startup. */
299 unsigned scm_newcell_count
;
300 unsigned scm_newcell2_count
;
303 /* {Scheme Interface to GC}
305 extern int scm_gc_malloc_yield_percentage
;
306 SCM_DEFINE (scm_gc_stats
, "gc-stats", 0, 0, 0,
308 "Return an association list of statistics about Guile's current\n"
310 #define FUNC_NAME s_scm_gc_stats
313 SCM heap_segs
= SCM_EOL
;
314 unsigned long int local_scm_mtrigger
;
315 unsigned long int local_scm_mallocated
;
316 unsigned long int local_scm_heap_size
;
317 int local_scm_gc_cell_yield_percentage
;
318 int local_scm_gc_malloc_yield_percentage
;
319 unsigned long int local_scm_cells_allocated
;
320 unsigned long int local_scm_gc_time_taken
;
321 unsigned long int local_scm_gc_times
;
322 unsigned long int local_scm_gc_mark_time_taken
;
323 unsigned long int local_protected_obj_count
;
324 double local_scm_gc_cells_swept
;
325 double local_scm_gc_cells_marked
;
327 unsigned long *bounds
= 0;
328 int table_size
= scm_i_heap_segment_table_size
;
332 temporarily store the numbers, so as not to cause GC.
335 bounds
= malloc (sizeof (int) * table_size
* 2);
338 for (i
= table_size
; i
--; )
340 bounds
[2*i
] = (unsigned long)scm_i_heap_segment_table
[i
]->bounds
[0];
341 bounds
[2*i
+1] = (unsigned long)scm_i_heap_segment_table
[i
]->bounds
[1];
345 /* Below, we cons to produce the resulting list. We want a snapshot of
346 * the heap situation before consing.
348 local_scm_mtrigger
= scm_mtrigger
;
349 local_scm_mallocated
= scm_mallocated
;
350 local_scm_heap_size
= SCM_HEAP_SIZE
;
352 local_scm_cells_allocated
= scm_cells_allocated
;
354 local_scm_gc_time_taken
= scm_gc_time_taken
;
355 local_scm_gc_mark_time_taken
= scm_gc_mark_time_taken
;
356 local_scm_gc_times
= scm_gc_times
;
357 local_scm_gc_malloc_yield_percentage
= scm_gc_malloc_yield_percentage
;
358 local_scm_gc_cell_yield_percentage
= scm_gc_cell_yield_percentage
;
359 local_protected_obj_count
= protected_obj_count
;
360 local_scm_gc_cells_swept
=
361 (double) scm_gc_cells_swept_acc
362 + (double) scm_gc_cells_swept
;
363 local_scm_gc_cells_marked
= scm_gc_cells_marked_acc
364 +(double) scm_gc_cells_swept
365 -(double) scm_gc_cells_collected
;
367 for (i
= table_size
; i
--;)
369 heap_segs
= scm_cons (scm_cons (scm_ulong2num (bounds
[2*i
]),
370 scm_ulong2num (bounds
[2*i
+1])),
374 answer
= scm_list_n (scm_cons (sym_gc_time_taken
, scm_ulong2num (local_scm_gc_time_taken
)),
375 scm_cons (sym_cells_allocated
, scm_ulong2num (local_scm_cells_allocated
)),
376 scm_cons (sym_heap_size
, scm_ulong2num (local_scm_heap_size
)),
377 scm_cons (sym_mallocated
, scm_ulong2num (local_scm_mallocated
)),
378 scm_cons (sym_mtrigger
, scm_ulong2num (local_scm_mtrigger
)),
379 scm_cons (sym_times
, scm_ulong2num (local_scm_gc_times
)),
380 scm_cons (sym_gc_mark_time_taken
, scm_ulong2num (local_scm_gc_mark_time_taken
)),
381 scm_cons (sym_cells_marked
, scm_i_dbl2big (local_scm_gc_cells_marked
)),
382 scm_cons (sym_cells_swept
, scm_i_dbl2big (local_scm_gc_cells_swept
)),
383 scm_cons (sym_malloc_yield
, scm_long2num (local_scm_gc_malloc_yield_percentage
)),
384 scm_cons (sym_cell_yield
, scm_long2num (local_scm_gc_cell_yield_percentage
)),
385 scm_cons (sym_protected_objects
, scm_ulong2num (local_protected_obj_count
)),
386 scm_cons (sym_heap_segments
, heap_segs
),
396 gc_start_stats (const char *what SCM_UNUSED
)
398 t_before_gc
= scm_c_get_internal_run_time ();
400 scm_gc_cells_marked_acc
+= (double) scm_gc_cells_swept
401 - (double) scm_gc_cells_collected
;
402 scm_gc_cells_swept_acc
+= (double) scm_gc_cells_swept
;
404 scm_gc_cell_yield_percentage
= ( scm_gc_cells_collected
* 100 ) / SCM_HEAP_SIZE
;
406 scm_gc_cells_swept
= 0;
407 scm_gc_cells_collected_1
= scm_gc_cells_collected
;
410 CELLS SWEPT is another word for the number of cells that were
411 examined during GC. YIELD is the number that we cleaned
412 out. MARKED is the number that weren't cleaned.
414 scm_gc_cells_collected
= 0;
415 scm_gc_malloc_collected
= 0;
416 scm_gc_ports_collected
= 0;
422 unsigned long t
= scm_c_get_internal_run_time ();
423 scm_gc_time_taken
+= (t
- t_before_gc
);
429 SCM_DEFINE (scm_object_address
, "object-address", 1, 0, 0,
431 "Return an integer that for the lifetime of @var{obj} is uniquely\n"
432 "returned by this function for @var{obj}")
433 #define FUNC_NAME s_scm_object_address
435 return scm_ulong2num ((unsigned long) SCM_UNPACK (obj
));
440 SCM_DEFINE (scm_gc
, "gc", 0, 0, 0,
442 "Scans all of SCM objects and reclaims for further use those that are\n"
443 "no longer accessible.")
444 #define FUNC_NAME s_scm_gc
447 return SCM_UNSPECIFIED
;
454 /* When we get POSIX threads support, the master will be global and
455 * common while the freelist will be individual for each thread.
459 scm_gc_for_newcell (scm_t_cell_type_statistics
*freelist
, SCM
*free_cells
)
463 scm_rec_mutex_lock (&scm_i_sweep_mutex
);
465 *free_cells
= scm_i_sweep_some_segments (freelist
);
466 if (*free_cells
== SCM_EOL
&& scm_i_gc_grow_heap_p (freelist
))
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
&& !scm_block_gc
)
475 with the advent of lazy sweep, GC yield is only know just
478 scm_i_adjust_min_yield (freelist
);
481 out of fresh cells. Try to get some new ones.
486 *free_cells
= scm_i_sweep_some_segments (freelist
);
489 if (*free_cells
== SCM_EOL
)
492 failed getting new cells. Get new juice or die.
494 freelist
->heap_segment_idx
= scm_i_get_new_heap_segment (freelist
, abort_on_error
);
495 *free_cells
= scm_i_sweep_some_segments (freelist
);
498 if (*free_cells
== SCM_EOL
)
503 *free_cells
= SCM_FREE_CELL_CDR (cell
);
505 scm_rec_mutex_unlock (&scm_i_sweep_mutex
);
511 scm_t_c_hook scm_before_gc_c_hook
;
512 scm_t_c_hook scm_before_mark_c_hook
;
513 scm_t_c_hook scm_before_sweep_c_hook
;
514 scm_t_c_hook scm_after_sweep_c_hook
;
515 scm_t_c_hook scm_after_gc_c_hook
;
518 scm_igc (const char *what
)
520 scm_rec_mutex_lock (&scm_i_sweep_mutex
);
522 scm_c_hook_run (&scm_before_gc_c_hook
, 0);
525 fprintf (stderr
,"gc reason %s\n", what
);
528 SCM_NULLP (*SCM_FREELIST_LOC (scm_i_freelist
))
530 : (SCM_NULLP (*SCM_FREELIST_LOC (scm_i_freelist2
)) ? "o" : "m"));
533 /* During the critical section, only the current thread may run. */
534 scm_i_thread_put_to_sleep ();
536 if (!scm_root
|| !scm_stack_base
|| scm_block_gc
)
542 gc_start_stats (what
);
544 if (scm_gc_heap_lock
)
545 /* We've invoked the collector while a GC is already in progress.
546 That should never happen. */
552 Let's finish the sweep. The conservative GC might point into the
553 garbage, and marking that would create a mess.
555 scm_i_sweep_all_segments("GC");
556 if (scm_mallocated
< scm_i_deprecated_memory_return
)
558 /* The byte count of allocated objects has underflowed. This is
559 probably because you forgot to report the sizes of objects you
560 have allocated, by calling scm_done_malloc or some such. When
561 the GC freed them, it subtracted their size from
562 scm_mallocated, which underflowed. */
564 "scm_gc_sweep: Byte count of allocated objects has underflowed.\n"
565 "This is probably because the GC hasn't been correctly informed\n"
566 "about object sizes\n");
569 scm_mallocated
-= scm_i_deprecated_memory_return
;
573 scm_c_hook_run (&scm_before_mark_c_hook
, 0);
577 scm_gc_mark_time_taken
+= (scm_c_get_internal_run_time () - t_before_gc
);
579 scm_c_hook_run (&scm_before_sweep_c_hook
, 0);
582 Moved this lock upwards so that we can alloc new heap at the end of a sweep.
584 DOCME: why should the heap be locked anyway?
592 TODO: this hook should probably be moved to just before the mark,
593 since that's where the sweep is finished in lazy sweeping.
595 MDJ 030219 <djurfeldt@nada.kth.se>: No, probably not. The
596 original meaning implied at least two things: that it would be
599 1. the freelist is re-initialized (no evaluation possible, though)
603 2. the heap is "fresh"
604 (it is well-defined what data is used and what is not)
606 Neither of these conditions would hold just before the mark phase.
608 Of course, the lazy sweeping has muddled the distinction between
609 scm_before_sweep_c_hook and scm_after_sweep_c_hook, but even if
610 there were no difference, it would still be useful to have two
611 distinct classes of hook functions since this can prevent some
612 bad interference when several modules adds gc hooks.
614 scm_c_hook_run (&scm_after_sweep_c_hook
, 0);
617 scm_i_thread_wake_up ();
622 scm_c_hook_run (&scm_after_gc_c_hook
, 0);
624 scm_rec_mutex_unlock (&scm_i_sweep_mutex
);
627 For debugging purposes, you could do
628 scm_i_sweep_all_segments("debug"), but then the remains of the
629 cell aren't left to analyse.
634 /* {GC Protection Helper Functions}
639 * If within a function you need to protect one or more scheme objects from
640 * garbage collection, pass them as parameters to one of the
641 * scm_remember_upto_here* functions below. These functions don't do
642 * anything, but since the compiler does not know that they are actually
643 * no-ops, it will generate code that calls these functions with the given
644 * parameters. Therefore, you can be sure that the compiler will keep those
645 * scheme values alive (on the stack or in a register) up to the point where
646 * scm_remember_upto_here* is called. In other words, place the call to
647 * scm_remember_upto_here* _behind_ the last code in your function, that
648 * depends on the scheme object to exist.
650 * Example: We want to make sure that the string object str does not get
651 * garbage collected during the execution of 'some_function' in the code
652 * below, because otherwise the characters belonging to str would be freed and
653 * 'some_function' might access freed memory. To make sure that the compiler
654 * keeps str alive on the stack or in a register such that it is visible to
655 * the conservative gc we add the call to scm_remember_upto_here_1 _after_ the
656 * call to 'some_function'. Note that this would not be necessary if str was
657 * used anyway after the call to 'some_function'.
658 * char *chars = SCM_STRING_CHARS (str);
659 * some_function (chars);
660 * scm_remember_upto_here_1 (str); // str will be alive up to this point.
663 /* Remove any macro versions of these while defining the functions.
664 Functions are always included in the library, for upward binary
665 compatibility and in case combinations of GCC and non-GCC are used. */
666 #undef scm_remember_upto_here_1
667 #undef scm_remember_upto_here_2
670 scm_remember_upto_here_1 (SCM obj SCM_UNUSED
)
672 /* Empty. Protects a single object from garbage collection. */
676 scm_remember_upto_here_2 (SCM obj1 SCM_UNUSED
, SCM obj2 SCM_UNUSED
)
678 /* Empty. Protects two objects from garbage collection. */
682 scm_remember_upto_here (SCM obj SCM_UNUSED
, ...)
684 /* Empty. Protects any number of objects from garbage collection. */
688 These crazy functions prevent garbage collection
689 of arguments after the first argument by
690 ensuring they remain live throughout the
691 function because they are used in the last
692 line of the code block.
693 It'd be better to have a nice compiler hint to
694 aid the conservative stack-scanning GC. --03/09/00 gjb */
696 scm_return_first (SCM elt
, ...)
702 scm_return_first_int (int i
, ...)
709 scm_permanent_object (SCM obj
)
712 scm_permobjs
= scm_cons (obj
, scm_permobjs
);
718 /* Protect OBJ from the garbage collector. OBJ will not be freed, even if all
719 other references are dropped, until the object is unprotected by calling
720 scm_gc_unprotect_object (OBJ). Calls to scm_gc_protect/unprotect_object nest,
721 i. e. it is possible to protect the same object several times, but it is
722 necessary to unprotect the object the same number of times to actually get
723 the object unprotected. It is an error to unprotect an object more often
724 than it has been protected before. The function scm_protect_object returns
728 /* Implementation note: For every object X, there is a counter which
729 scm_gc_protect_object(X) increments and scm_gc_unprotect_object(X) decrements.
735 scm_gc_protect_object (SCM obj
)
739 /* This critical section barrier will be replaced by a mutex. */
742 handle
= scm_hashq_create_handle_x (scm_protects
, obj
, SCM_MAKINUM (0));
743 SCM_SETCDR (handle
, scm_sum (SCM_CDR (handle
), SCM_MAKINUM (1)));
745 protected_obj_count
++;
753 /* Remove any protection for OBJ established by a prior call to
754 scm_protect_object. This function returns OBJ.
756 See scm_protect_object for more information. */
758 scm_gc_unprotect_object (SCM obj
)
762 /* This critical section barrier will be replaced by a mutex. */
765 handle
= scm_hashq_get_handle (scm_protects
, obj
);
767 if (SCM_FALSEP (handle
))
769 fprintf (stderr
, "scm_unprotect_object called on unprotected object\n");
774 SCM count
= scm_difference (SCM_CDR (handle
), SCM_MAKINUM (1));
775 if (SCM_EQ_P (count
, SCM_MAKINUM (0)))
776 scm_hashq_remove_x (scm_protects
, obj
);
778 SCM_SETCDR (handle
, count
);
780 protected_obj_count
--;
788 scm_gc_register_root (SCM
*p
)
791 SCM key
= scm_long2num ((long) p
);
793 /* This critical section barrier will be replaced by a mutex. */
796 handle
= scm_hashv_create_handle_x (scm_gc_registered_roots
, key
, SCM_MAKINUM (0));
797 SCM_SETCDR (handle
, scm_sum (SCM_CDR (handle
), SCM_MAKINUM (1)));
803 scm_gc_unregister_root (SCM
*p
)
806 SCM key
= scm_long2num ((long) p
);
808 /* This critical section barrier will be replaced by a mutex. */
811 handle
= scm_hashv_get_handle (scm_gc_registered_roots
, key
);
813 if (SCM_FALSEP (handle
))
815 fprintf (stderr
, "scm_gc_unregister_root called on unregistered root\n");
820 SCM count
= scm_difference (SCM_CDR (handle
), SCM_MAKINUM (1));
821 if (SCM_EQ_P (count
, SCM_MAKINUM (0)))
822 scm_hashv_remove_x (scm_gc_registered_roots
, key
);
824 SCM_SETCDR (handle
, count
);
831 scm_gc_register_roots (SCM
*b
, unsigned long n
)
834 for (; p
< b
+ n
; ++p
)
835 scm_gc_register_root (p
);
839 scm_gc_unregister_roots (SCM
*b
, unsigned long n
)
842 for (; p
< b
+ n
; ++p
)
843 scm_gc_unregister_root (p
);
846 int scm_i_terminating
;
848 /* called on process termination. */
854 extern int on_exit (void (*procp
) (), int arg
);
857 cleanup (int status
, void *arg
)
859 #error Dont know how to setup a cleanup handler on your system.
863 scm_i_terminating
= 1;
864 scm_flush_all_ports ();
871 MOVE THIS FUNCTION. IT DOES NOT HAVE ANYTHING TODO WITH GC.
874 /* Get an integer from an environment variable. */
876 scm_getenv_int (const char *var
, int def
)
879 char *val
= getenv (var
);
883 res
= strtol (val
, &end
, 10);
890 scm_storage_prehistory ()
892 scm_c_hook_init (&scm_before_gc_c_hook
, 0, SCM_C_HOOK_NORMAL
);
893 scm_c_hook_init (&scm_before_mark_c_hook
, 0, SCM_C_HOOK_NORMAL
);
894 scm_c_hook_init (&scm_before_sweep_c_hook
, 0, SCM_C_HOOK_NORMAL
);
895 scm_c_hook_init (&scm_after_sweep_c_hook
, 0, SCM_C_HOOK_NORMAL
);
896 scm_c_hook_init (&scm_after_gc_c_hook
, 0, SCM_C_HOOK_NORMAL
);
904 /* Fixme: Should use mutexattr from the low-level API. */
905 scm_rec_mutex_init (&scm_i_sweep_mutex
, &scm_i_plugin_rec_mutex
);
907 j
= SCM_NUM_PROTECTS
;
909 scm_sys_protects
[--j
] = SCM_BOOL_F
;
912 scm_gc_init_freelist();
913 scm_gc_init_malloc ();
915 j
= SCM_HEAP_SEG_SIZE
;
918 /* Initialise the list of ports. */
919 scm_i_port_table
= (scm_t_port
**)
920 malloc (sizeof (scm_t_port
*) * scm_i_port_table_room
);
921 if (!scm_i_port_table
)
928 on_exit (cleanup
, 0);
932 scm_stand_in_procs
= SCM_EOL
;
933 scm_permobjs
= SCM_EOL
;
934 scm_protects
= scm_c_make_hash_table (31);
935 scm_gc_registered_roots
= scm_c_make_hash_table (31);
942 SCM scm_after_gc_hook
;
946 /* The function gc_async_thunk causes the execution of the after-gc-hook. It
947 * is run after the gc, as soon as the asynchronous events are handled by the
951 gc_async_thunk (void)
953 scm_c_run_hook (scm_after_gc_hook
, SCM_EOL
);
954 return SCM_UNSPECIFIED
;
958 /* The function mark_gc_async is run by the scm_after_gc_c_hook at the end of
959 * the garbage collection. The only purpose of this function is to mark the
960 * gc_async (which will eventually lead to the execution of the
964 mark_gc_async (void * hook_data SCM_UNUSED
,
965 void *func_data SCM_UNUSED
,
966 void *data SCM_UNUSED
)
968 /* If cell access debugging is enabled, the user may choose to perform
969 * additional garbage collections after an arbitrary number of cell
970 * accesses. We don't want the scheme level after-gc-hook to be performed
971 * for each of these garbage collections for the following reason: The
972 * execution of the after-gc-hook causes cell accesses itself. Thus, if the
973 * after-gc-hook was performed with every gc, and if the gc was performed
974 * after a very small number of cell accesses, then the number of cell
975 * accesses during the execution of the after-gc-hook will suffice to cause
976 * the execution of the next gc. Then, guile would keep executing the
977 * after-gc-hook over and over again, and would never come to do other
980 * To overcome this problem, if cell access debugging with additional
981 * garbage collections is enabled, the after-gc-hook is never run by the
982 * garbage collecter. When running guile with cell access debugging and the
983 * execution of the after-gc-hook is desired, then it is necessary to run
984 * the hook explicitly from the user code. This has the effect, that from
985 * the scheme level point of view it seems that garbage collection is
986 * performed with a much lower frequency than it actually is. Obviously,
987 * this will not work for code that depends on a fixed one to one
988 * relationship between the execution counts of the C level garbage
989 * collection hooks and the execution count of the scheme level
992 #if (SCM_DEBUG_CELL_ACCESSES == 1)
993 if (scm_debug_cells_gc_interval
== 0)
994 scm_system_async_mark (gc_async
);
996 scm_system_async_mark (gc_async
);
1005 scm_gc_init_mark ();
1007 scm_after_gc_hook
= scm_permanent_object (scm_make_hook (SCM_INUM0
));
1008 scm_c_define ("after-gc-hook", scm_after_gc_hook
);
1010 gc_async
= scm_c_make_subr ("%gc-thunk", scm_tc7_subr_0
,
1013 scm_c_hook_add (&scm_after_gc_c_hook
, mark_gc_async
, NULL
, 0);
1015 #include "libguile/gc.x"
1021 #define FUNC_NAME "scm_gc_sweep"
1023 scm_i_deprecated_memory_return
= 0;
1025 scm_i_gc_sweep_freelist_reset (&scm_i_master_freelist
);
1026 scm_i_gc_sweep_freelist_reset (&scm_i_master_freelist2
);
1029 NOTHING HERE: LAZY SWEEPING !
1031 scm_i_reset_segments ();
1033 /* When we move to POSIX threads private freelists should probably
1034 be GC-protected instead. */
1035 *SCM_FREELIST_LOC (scm_i_freelist
) = SCM_EOL
;
1036 *SCM_FREELIST_LOC (scm_i_freelist2
) = SCM_EOL
;
1038 /* Invalidate the freelists of other threads. */
1039 scm_i_thread_invalidate_freelists ();