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}
280 tag_table_to_type_alist (void *closure
, SCM key
, SCM val
, SCM acc
)
282 scm_t_bits c_tag
= scm_to_int (key
);
283 key
= scm_from_locale_string (scm_i_tag_name (c_tag
));
284 return scm_cons (scm_cons (key
, val
), acc
);
287 SCM_DEFINE (scm_gc_live_object_stats
, "gc-live-object-stats", 0, 0, 0,
289 "Return an alist of statistics of the current live objects. ")
290 #define FUNC_NAME s_scm_gc_live_object_stats
292 SCM tab
= scm_make_hash_table (scm_from_int (57));
293 scm_i_all_segments_statistics (tab
);
296 = scm_internal_hash_fold (&tag_table_to_type_alist
, NULL
, SCM_EOL
, tab
);
302 extern int scm_gc_malloc_yield_percentage
;
303 SCM_DEFINE (scm_gc_stats
, "gc-stats", 0, 0, 0,
305 "Return an association list of statistics about Guile's current\n"
307 #define FUNC_NAME s_scm_gc_stats
310 SCM heap_segs
= SCM_EOL
;
311 unsigned long int local_scm_mtrigger
;
312 unsigned long int local_scm_mallocated
;
313 unsigned long int local_scm_heap_size
;
314 int local_scm_gc_cell_yield_percentage
;
315 int local_scm_gc_malloc_yield_percentage
;
316 unsigned long int local_scm_cells_allocated
;
317 unsigned long int local_scm_gc_time_taken
;
318 unsigned long int local_scm_gc_times
;
319 unsigned long int local_scm_gc_mark_time_taken
;
320 unsigned long int local_protected_obj_count
;
321 double local_scm_gc_cells_swept
;
322 double local_scm_gc_cells_marked
;
324 unsigned long *bounds
= 0;
325 int table_size
= scm_i_heap_segment_table_size
;
329 temporarily store the numbers, so as not to cause GC.
332 bounds
= malloc (sizeof (int) * table_size
* 2);
335 for (i
= table_size
; i
--; )
337 bounds
[2*i
] = (unsigned long)scm_i_heap_segment_table
[i
]->bounds
[0];
338 bounds
[2*i
+1] = (unsigned long)scm_i_heap_segment_table
[i
]->bounds
[1];
342 /* Below, we cons to produce the resulting list. We want a snapshot of
343 * the heap situation before consing.
345 local_scm_mtrigger
= scm_mtrigger
;
346 local_scm_mallocated
= scm_mallocated
;
347 local_scm_heap_size
= SCM_HEAP_SIZE
;
349 local_scm_cells_allocated
= scm_cells_allocated
;
351 local_scm_gc_time_taken
= scm_gc_time_taken
;
352 local_scm_gc_mark_time_taken
= scm_gc_mark_time_taken
;
353 local_scm_gc_times
= scm_gc_times
;
354 local_scm_gc_malloc_yield_percentage
= scm_gc_malloc_yield_percentage
;
355 local_scm_gc_cell_yield_percentage
= scm_gc_cell_yield_percentage
;
356 local_protected_obj_count
= protected_obj_count
;
357 local_scm_gc_cells_swept
=
358 (double) scm_gc_cells_swept_acc
359 + (double) scm_gc_cells_swept
;
360 local_scm_gc_cells_marked
= scm_gc_cells_marked_acc
361 +(double) scm_gc_cells_swept
362 -(double) scm_gc_cells_collected
;
364 for (i
= table_size
; i
--;)
366 heap_segs
= scm_cons (scm_cons (scm_from_ulong (bounds
[2*i
]),
367 scm_from_ulong (bounds
[2*i
+1])),
372 scm_list_n (scm_cons (sym_gc_time_taken
,
373 scm_from_ulong (local_scm_gc_time_taken
)),
374 scm_cons (sym_cells_allocated
,
375 scm_from_ulong (local_scm_cells_allocated
)),
376 scm_cons (sym_heap_size
,
377 scm_from_ulong (local_scm_heap_size
)),
378 scm_cons (sym_mallocated
,
379 scm_from_ulong (local_scm_mallocated
)),
380 scm_cons (sym_mtrigger
,
381 scm_from_ulong (local_scm_mtrigger
)),
383 scm_from_ulong (local_scm_gc_times
)),
384 scm_cons (sym_gc_mark_time_taken
,
385 scm_from_ulong (local_scm_gc_mark_time_taken
)),
386 scm_cons (sym_cells_marked
,
387 scm_from_double (local_scm_gc_cells_marked
)),
388 scm_cons (sym_cells_swept
,
389 scm_from_double (local_scm_gc_cells_swept
)),
390 scm_cons (sym_malloc_yield
,
391 scm_from_long(local_scm_gc_malloc_yield_percentage
)),
392 scm_cons (sym_cell_yield
,
393 scm_from_long (local_scm_gc_cell_yield_percentage
)),
394 scm_cons (sym_protected_objects
,
395 scm_from_ulong (local_protected_obj_count
)),
396 scm_cons (sym_heap_segments
, heap_segs
),
406 gc_start_stats (const char *what SCM_UNUSED
)
408 t_before_gc
= scm_c_get_internal_run_time ();
410 scm_gc_cells_marked_acc
+= (double) scm_gc_cells_swept
411 - (double) scm_gc_cells_collected
;
412 scm_gc_cells_swept_acc
+= (double) scm_gc_cells_swept
;
414 scm_gc_cell_yield_percentage
= ( scm_gc_cells_collected
* 100 ) / SCM_HEAP_SIZE
;
416 scm_gc_cells_swept
= 0;
417 scm_gc_cells_collected_1
= scm_gc_cells_collected
;
420 CELLS SWEPT is another word for the number of cells that were
421 examined during GC. YIELD is the number that we cleaned
422 out. MARKED is the number that weren't cleaned.
424 scm_gc_cells_collected
= 0;
425 scm_gc_malloc_collected
= 0;
426 scm_gc_ports_collected
= 0;
432 unsigned long t
= scm_c_get_internal_run_time ();
433 scm_gc_time_taken
+= (t
- t_before_gc
);
439 SCM_DEFINE (scm_object_address
, "object-address", 1, 0, 0,
441 "Return an integer that for the lifetime of @var{obj} is uniquely\n"
442 "returned by this function for @var{obj}")
443 #define FUNC_NAME s_scm_object_address
445 return scm_from_ulong (SCM_UNPACK (obj
));
450 SCM_DEFINE (scm_gc
, "gc", 0, 0, 0,
452 "Scans all of SCM objects and reclaims for further use those that are\n"
453 "no longer accessible.")
454 #define FUNC_NAME s_scm_gc
457 return SCM_UNSPECIFIED
;
464 /* When we get POSIX threads support, the master will be global and
465 * common while the freelist will be individual for each thread.
469 scm_gc_for_newcell (scm_t_cell_type_statistics
*freelist
, SCM
*free_cells
)
473 scm_rec_mutex_lock (&scm_i_sweep_mutex
);
475 *free_cells
= scm_i_sweep_some_segments (freelist
);
476 if (*free_cells
== SCM_EOL
&& scm_i_gc_grow_heap_p (freelist
))
478 freelist
->heap_segment_idx
= scm_i_get_new_heap_segment (freelist
, abort_on_error
);
479 *free_cells
= scm_i_sweep_some_segments (freelist
);
482 if (*free_cells
== SCM_EOL
&& !scm_block_gc
)
485 with the advent of lazy sweep, GC yield is only know just
488 scm_i_adjust_min_yield (freelist
);
491 out of fresh cells. Try to get some new ones.
496 *free_cells
= scm_i_sweep_some_segments (freelist
);
499 if (*free_cells
== SCM_EOL
)
502 failed getting new cells. Get new juice or die.
504 freelist
->heap_segment_idx
= scm_i_get_new_heap_segment (freelist
, abort_on_error
);
505 *free_cells
= scm_i_sweep_some_segments (freelist
);
508 if (*free_cells
== SCM_EOL
)
513 *free_cells
= SCM_FREE_CELL_CDR (cell
);
515 scm_rec_mutex_unlock (&scm_i_sweep_mutex
);
521 scm_t_c_hook scm_before_gc_c_hook
;
522 scm_t_c_hook scm_before_mark_c_hook
;
523 scm_t_c_hook scm_before_sweep_c_hook
;
524 scm_t_c_hook scm_after_sweep_c_hook
;
525 scm_t_c_hook scm_after_gc_c_hook
;
528 scm_igc (const char *what
)
530 scm_rec_mutex_lock (&scm_i_sweep_mutex
);
532 scm_c_hook_run (&scm_before_gc_c_hook
, 0);
535 fprintf (stderr
,"gc reason %s\n", what
);
538 scm_is_null (*SCM_FREELIST_LOC (scm_i_freelist
))
540 : (scm_is_null (*SCM_FREELIST_LOC (scm_i_freelist2
)) ? "o" : "m"));
543 /* During the critical section, only the current thread may run. */
544 scm_i_thread_put_to_sleep ();
546 if (!scm_root
|| !scm_stack_base
|| scm_block_gc
)
552 gc_start_stats (what
);
556 if (scm_gc_heap_lock
)
557 /* We've invoked the collector while a GC is already in progress.
558 That should never happen. */
562 Set freelists to NULL so scm_cons() always triggers gc, causing
563 the above abort() to be triggered.
565 *SCM_FREELIST_LOC (scm_i_freelist
) = SCM_EOL
;
566 *SCM_FREELIST_LOC (scm_i_freelist2
) = SCM_EOL
;
571 Let's finish the sweep. The conservative GC might point into the
572 garbage, and marking that would create a mess.
574 scm_i_sweep_all_segments("GC");
575 if (scm_mallocated
< scm_i_deprecated_memory_return
)
577 /* The byte count of allocated objects has underflowed. This is
578 probably because you forgot to report the sizes of objects you
579 have allocated, by calling scm_done_malloc or some such. When
580 the GC freed them, it subtracted their size from
581 scm_mallocated, which underflowed. */
583 "scm_gc_sweep: Byte count of allocated objects has underflowed.\n"
584 "This is probably because the GC hasn't been correctly informed\n"
585 "about object sizes\n");
588 scm_mallocated
-= scm_i_deprecated_memory_return
;
592 scm_c_hook_run (&scm_before_mark_c_hook
, 0);
596 scm_gc_mark_time_taken
+= (scm_c_get_internal_run_time () - t_before_gc
);
598 scm_c_hook_run (&scm_before_sweep_c_hook
, 0);
601 Moved this lock upwards so that we can alloc new heap at the end of a sweep.
603 DOCME: why should the heap be locked anyway?
611 TODO: this hook should probably be moved to just before the mark,
612 since that's where the sweep is finished in lazy sweeping.
614 MDJ 030219 <djurfeldt@nada.kth.se>: No, probably not. The
615 original meaning implied at least two things: that it would be
618 1. the freelist is re-initialized (no evaluation possible, though)
622 2. the heap is "fresh"
623 (it is well-defined what data is used and what is not)
625 Neither of these conditions would hold just before the mark phase.
627 Of course, the lazy sweeping has muddled the distinction between
628 scm_before_sweep_c_hook and scm_after_sweep_c_hook, but even if
629 there were no difference, it would still be useful to have two
630 distinct classes of hook functions since this can prevent some
631 bad interference when several modules adds gc hooks.
633 scm_c_hook_run (&scm_after_sweep_c_hook
, 0);
636 scm_i_thread_wake_up ();
642 scm_c_hook_run (&scm_after_gc_c_hook
, 0);
643 scm_rec_mutex_unlock (&scm_i_sweep_mutex
);
646 For debugging purposes, you could do
647 scm_i_sweep_all_segments("debug"), but then the remains of the
648 cell aren't left to analyse.
653 /* {GC Protection Helper Functions}
658 * If within a function you need to protect one or more scheme objects from
659 * garbage collection, pass them as parameters to one of the
660 * scm_remember_upto_here* functions below. These functions don't do
661 * anything, but since the compiler does not know that they are actually
662 * no-ops, it will generate code that calls these functions with the given
663 * parameters. Therefore, you can be sure that the compiler will keep those
664 * scheme values alive (on the stack or in a register) up to the point where
665 * scm_remember_upto_here* is called. In other words, place the call to
666 * scm_remember_upto_here* _behind_ the last code in your function, that
667 * depends on the scheme object to exist.
669 * Example: We want to make sure that the string object str does not get
670 * garbage collected during the execution of 'some_function' in the code
671 * below, because otherwise the characters belonging to str would be freed and
672 * 'some_function' might access freed memory. To make sure that the compiler
673 * keeps str alive on the stack or in a register such that it is visible to
674 * the conservative gc we add the call to scm_remember_upto_here_1 _after_ the
675 * call to 'some_function'. Note that this would not be necessary if str was
676 * used anyway after the call to 'some_function'.
677 * char *chars = scm_i_string_chars (str);
678 * some_function (chars);
679 * scm_remember_upto_here_1 (str); // str will be alive up to this point.
682 /* Remove any macro versions of these while defining the functions.
683 Functions are always included in the library, for upward binary
684 compatibility and in case combinations of GCC and non-GCC are used. */
685 #undef scm_remember_upto_here_1
686 #undef scm_remember_upto_here_2
689 scm_remember_upto_here_1 (SCM obj SCM_UNUSED
)
691 /* Empty. Protects a single object from garbage collection. */
695 scm_remember_upto_here_2 (SCM obj1 SCM_UNUSED
, SCM obj2 SCM_UNUSED
)
697 /* Empty. Protects two objects from garbage collection. */
701 scm_remember_upto_here (SCM obj SCM_UNUSED
, ...)
703 /* Empty. Protects any number of objects from garbage collection. */
707 These crazy functions prevent garbage collection
708 of arguments after the first argument by
709 ensuring they remain live throughout the
710 function because they are used in the last
711 line of the code block.
712 It'd be better to have a nice compiler hint to
713 aid the conservative stack-scanning GC. --03/09/00 gjb */
715 scm_return_first (SCM elt
, ...)
721 scm_return_first_int (int i
, ...)
728 scm_permanent_object (SCM obj
)
731 scm_permobjs
= scm_cons (obj
, scm_permobjs
);
737 /* Protect OBJ from the garbage collector. OBJ will not be freed, even if all
738 other references are dropped, until the object is unprotected by calling
739 scm_gc_unprotect_object (OBJ). Calls to scm_gc_protect/unprotect_object nest,
740 i. e. it is possible to protect the same object several times, but it is
741 necessary to unprotect the object the same number of times to actually get
742 the object unprotected. It is an error to unprotect an object more often
743 than it has been protected before. The function scm_protect_object returns
747 /* Implementation note: For every object X, there is a counter which
748 scm_gc_protect_object(X) increments and scm_gc_unprotect_object(X) decrements.
754 scm_gc_protect_object (SCM obj
)
758 /* This critical section barrier will be replaced by a mutex. */
761 handle
= scm_hashq_create_handle_x (scm_protects
, obj
, scm_from_int (0));
762 SCM_SETCDR (handle
, scm_sum (SCM_CDR (handle
), scm_from_int (1)));
764 protected_obj_count
++;
772 /* Remove any protection for OBJ established by a prior call to
773 scm_protect_object. This function returns OBJ.
775 See scm_protect_object for more information. */
777 scm_gc_unprotect_object (SCM obj
)
781 /* This critical section barrier will be replaced by a mutex. */
784 if (scm_gc_running_p
)
786 fprintf (stderr
, "scm_unprotect_object called during GC.\n");
790 handle
= scm_hashq_get_handle (scm_protects
, obj
);
792 if (scm_is_false (handle
))
794 fprintf (stderr
, "scm_unprotect_object called on unprotected object\n");
799 SCM count
= scm_difference (SCM_CDR (handle
), scm_from_int (1));
800 if (scm_is_eq (count
, scm_from_int (0)))
801 scm_hashq_remove_x (scm_protects
, obj
);
803 SCM_SETCDR (handle
, count
);
805 protected_obj_count
--;
813 scm_gc_register_root (SCM
*p
)
816 SCM key
= scm_from_ulong ((unsigned long) p
);
818 /* This critical section barrier will be replaced by a mutex. */
821 handle
= scm_hashv_create_handle_x (scm_gc_registered_roots
, key
,
823 SCM_SETCDR (handle
, scm_sum (SCM_CDR (handle
), scm_from_int (1)));
829 scm_gc_unregister_root (SCM
*p
)
832 SCM key
= scm_from_ulong ((unsigned long) p
);
834 /* This critical section barrier will be replaced by a mutex. */
837 handle
= scm_hashv_get_handle (scm_gc_registered_roots
, key
);
839 if (scm_is_false (handle
))
841 fprintf (stderr
, "scm_gc_unregister_root called on unregistered root\n");
846 SCM count
= scm_difference (SCM_CDR (handle
), scm_from_int (1));
847 if (scm_is_eq (count
, scm_from_int (0)))
848 scm_hashv_remove_x (scm_gc_registered_roots
, key
);
850 SCM_SETCDR (handle
, count
);
857 scm_gc_register_roots (SCM
*b
, unsigned long n
)
860 for (; p
< b
+ n
; ++p
)
861 scm_gc_register_root (p
);
865 scm_gc_unregister_roots (SCM
*b
, unsigned long n
)
868 for (; p
< b
+ n
; ++p
)
869 scm_gc_unregister_root (p
);
872 int scm_i_terminating
;
874 /* called on process termination. */
880 extern int on_exit (void (*procp
) (), int arg
);
883 cleanup (int status
, void *arg
)
885 #error Dont know how to setup a cleanup handler on your system.
889 scm_i_terminating
= 1;
890 scm_flush_all_ports ();
897 MOVE THIS FUNCTION. IT DOES NOT HAVE ANYTHING TODO WITH GC.
900 /* Get an integer from an environment variable. */
902 scm_getenv_int (const char *var
, int def
)
905 char *val
= getenv (var
);
909 res
= strtol (val
, &end
, 10);
916 scm_storage_prehistory ()
918 scm_c_hook_init (&scm_before_gc_c_hook
, 0, SCM_C_HOOK_NORMAL
);
919 scm_c_hook_init (&scm_before_mark_c_hook
, 0, SCM_C_HOOK_NORMAL
);
920 scm_c_hook_init (&scm_before_sweep_c_hook
, 0, SCM_C_HOOK_NORMAL
);
921 scm_c_hook_init (&scm_after_sweep_c_hook
, 0, SCM_C_HOOK_NORMAL
);
922 scm_c_hook_init (&scm_after_gc_c_hook
, 0, SCM_C_HOOK_NORMAL
);
925 scm_t_mutex scm_i_gc_admin_mutex
;
932 /* Fixme: Should use mutexattr from the low-level API. */
933 scm_rec_mutex_init (&scm_i_sweep_mutex
, &scm_i_plugin_rec_mutex
);
935 scm_i_plugin_mutex_init (&scm_i_gc_admin_mutex
, &scm_i_plugin_mutex
);
937 j
= SCM_NUM_PROTECTS
;
939 scm_sys_protects
[--j
] = SCM_BOOL_F
;
942 scm_gc_init_freelist();
943 scm_gc_init_malloc ();
945 j
= SCM_HEAP_SEG_SIZE
;
948 /* Initialise the list of ports. */
949 scm_i_port_table
= (scm_t_port
**)
950 malloc (sizeof (scm_t_port
*) * scm_i_port_table_room
);
951 if (!scm_i_port_table
)
958 on_exit (cleanup
, 0);
962 scm_stand_in_procs
= scm_c_make_hash_table (257);
963 scm_permobjs
= SCM_EOL
;
964 scm_protects
= scm_c_make_hash_table (31);
965 scm_gc_registered_roots
= scm_c_make_hash_table (31);
972 SCM scm_after_gc_hook
;
976 /* The function gc_async_thunk causes the execution of the after-gc-hook. It
977 * is run after the gc, as soon as the asynchronous events are handled by the
981 gc_async_thunk (void)
983 scm_c_run_hook (scm_after_gc_hook
, SCM_EOL
);
984 return SCM_UNSPECIFIED
;
988 /* The function mark_gc_async is run by the scm_after_gc_c_hook at the end of
989 * the garbage collection. The only purpose of this function is to mark the
990 * gc_async (which will eventually lead to the execution of the
994 mark_gc_async (void * hook_data SCM_UNUSED
,
995 void *func_data SCM_UNUSED
,
996 void *data SCM_UNUSED
)
998 /* If cell access debugging is enabled, the user may choose to perform
999 * additional garbage collections after an arbitrary number of cell
1000 * accesses. We don't want the scheme level after-gc-hook to be performed
1001 * for each of these garbage collections for the following reason: The
1002 * execution of the after-gc-hook causes cell accesses itself. Thus, if the
1003 * after-gc-hook was performed with every gc, and if the gc was performed
1004 * after a very small number of cell accesses, then the number of cell
1005 * accesses during the execution of the after-gc-hook will suffice to cause
1006 * the execution of the next gc. Then, guile would keep executing the
1007 * after-gc-hook over and over again, and would never come to do other
1010 * To overcome this problem, if cell access debugging with additional
1011 * garbage collections is enabled, the after-gc-hook is never run by the
1012 * garbage collecter. When running guile with cell access debugging and the
1013 * execution of the after-gc-hook is desired, then it is necessary to run
1014 * the hook explicitly from the user code. This has the effect, that from
1015 * the scheme level point of view it seems that garbage collection is
1016 * performed with a much lower frequency than it actually is. Obviously,
1017 * this will not work for code that depends on a fixed one to one
1018 * relationship between the execution counts of the C level garbage
1019 * collection hooks and the execution count of the scheme level
1022 #if (SCM_DEBUG_CELL_ACCESSES == 1)
1023 if (scm_debug_cells_gc_interval
== 0)
1024 scm_system_async_mark (gc_async
);
1026 scm_system_async_mark (gc_async
);
1035 scm_gc_init_mark ();
1037 scm_after_gc_hook
= scm_permanent_object (scm_make_hook (SCM_INUM0
));
1038 scm_c_define ("after-gc-hook", scm_after_gc_hook
);
1040 gc_async
= scm_c_make_subr ("%gc-thunk", scm_tc7_subr_0
,
1043 scm_c_hook_add (&scm_after_gc_c_hook
, mark_gc_async
, NULL
, 0);
1045 #include "libguile/gc.x"
1051 #define FUNC_NAME "scm_gc_sweep"
1053 scm_i_deprecated_memory_return
= 0;
1055 scm_i_gc_sweep_freelist_reset (&scm_i_master_freelist
);
1056 scm_i_gc_sweep_freelist_reset (&scm_i_master_freelist2
);
1059 NOTHING HERE: LAZY SWEEPING !
1061 scm_i_reset_segments ();
1063 /* When we move to POSIX threads private freelists should probably
1064 be GC-protected instead. */
1065 *SCM_FREELIST_LOC (scm_i_freelist
) = SCM_EOL
;
1066 *SCM_FREELIST_LOC (scm_i_freelist2
) = SCM_EOL
;
1068 /* Invalidate the freelists of other threads. */
1069 scm_i_thread_invalidate_freelists ();