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;
280 SCM_SYMBOL (sym_cells_allocated
, "cells-allocated");
281 SCM_SYMBOL (sym_heap_size
, "cell-heap-size");
282 SCM_SYMBOL (sym_mallocated
, "bytes-malloced");
283 SCM_SYMBOL (sym_mtrigger
, "gc-malloc-threshold");
284 SCM_SYMBOL (sym_heap_segments
, "cell-heap-segments");
285 SCM_SYMBOL (sym_gc_time_taken
, "gc-time-taken");
286 SCM_SYMBOL (sym_gc_mark_time_taken
, "gc-mark-time-taken");
287 SCM_SYMBOL (sym_times
, "gc-times");
288 SCM_SYMBOL (sym_cells_marked
, "cells-marked");
289 SCM_SYMBOL (sym_cells_swept
, "cells-swept");
290 SCM_SYMBOL (sym_malloc_yield
, "malloc-yield");
291 SCM_SYMBOL (sym_cell_yield
, "cell-yield");
296 /* Number of calls to SCM_NEWCELL since startup. */
297 unsigned scm_newcell_count
;
298 unsigned scm_newcell2_count
;
301 /* {Scheme Interface to GC}
303 extern int scm_gc_malloc_yield_percentage
;
304 SCM_DEFINE (scm_gc_stats
, "gc-stats", 0, 0, 0,
306 "Return an association list of statistics about Guile's current\n"
308 #define FUNC_NAME s_scm_gc_stats
311 SCM heap_segs
= SCM_EOL
;
312 unsigned long int local_scm_mtrigger
;
313 unsigned long int local_scm_mallocated
;
314 unsigned long int local_scm_heap_size
;
315 int local_scm_gc_cell_yield_percentage
;
316 int local_scm_gc_malloc_yield_percentage
;
317 unsigned long int local_scm_cells_allocated
;
318 unsigned long int local_scm_gc_time_taken
;
319 unsigned long int local_scm_gc_times
;
320 unsigned long int local_scm_gc_mark_time_taken
;
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
;
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_ulong2num (bounds
[2*i
]),
367 scm_ulong2num (bounds
[2*i
+1])),
371 answer
= scm_list_n (scm_cons (sym_gc_time_taken
, scm_ulong2num (local_scm_gc_time_taken
)),
372 scm_cons (sym_cells_allocated
, scm_ulong2num (local_scm_cells_allocated
)),
373 scm_cons (sym_heap_size
, scm_ulong2num (local_scm_heap_size
)),
374 scm_cons (sym_mallocated
, scm_ulong2num (local_scm_mallocated
)),
375 scm_cons (sym_mtrigger
, scm_ulong2num (local_scm_mtrigger
)),
376 scm_cons (sym_times
, scm_ulong2num (local_scm_gc_times
)),
377 scm_cons (sym_gc_mark_time_taken
, scm_ulong2num (local_scm_gc_mark_time_taken
)),
378 scm_cons (sym_cells_marked
, scm_i_dbl2big (local_scm_gc_cells_marked
)),
379 scm_cons (sym_cells_swept
, scm_i_dbl2big (local_scm_gc_cells_swept
)),
380 scm_cons (sym_malloc_yield
, scm_long2num (local_scm_gc_malloc_yield_percentage
)),
381 scm_cons (sym_cell_yield
, scm_long2num (local_scm_gc_cell_yield_percentage
)),
382 scm_cons (sym_heap_segments
, heap_segs
),
392 gc_start_stats (const char *what SCM_UNUSED
)
394 t_before_gc
= scm_c_get_internal_run_time ();
396 scm_gc_cells_marked_acc
+= (double) scm_gc_cells_swept
397 - (double) scm_gc_cells_collected
;
398 scm_gc_cells_swept_acc
+= (double) scm_gc_cells_swept
;
400 scm_gc_cell_yield_percentage
= ( scm_gc_cells_collected
* 100 ) / SCM_HEAP_SIZE
;
402 scm_gc_cells_swept
= 0;
403 scm_gc_cells_collected_1
= scm_gc_cells_collected
;
406 CELLS SWEPT is another word for the number of cells that were
407 examined during GC. YIELD is the number that we cleaned
408 out. MARKED is the number that weren't cleaned.
410 scm_gc_cells_collected
= 0;
411 scm_gc_malloc_collected
= 0;
412 scm_gc_ports_collected
= 0;
418 unsigned long t
= scm_c_get_internal_run_time ();
419 scm_gc_time_taken
+= (t
- t_before_gc
);
425 SCM_DEFINE (scm_object_address
, "object-address", 1, 0, 0,
427 "Return an integer that for the lifetime of @var{obj} is uniquely\n"
428 "returned by this function for @var{obj}")
429 #define FUNC_NAME s_scm_object_address
431 return scm_ulong2num ((unsigned long) SCM_UNPACK (obj
));
436 SCM_DEFINE (scm_gc
, "gc", 0, 0, 0,
438 "Scans all of SCM objects and reclaims for further use those that are\n"
439 "no longer accessible.")
440 #define FUNC_NAME s_scm_gc
443 return SCM_UNSPECIFIED
;
450 /* When we get POSIX threads support, the master will be global and
451 * common while the freelist will be individual for each thread.
455 scm_gc_for_newcell (scm_t_cell_type_statistics
*freelist
, SCM
*free_cells
)
459 scm_rec_mutex_lock (&scm_i_sweep_mutex
);
461 *free_cells
= scm_i_sweep_some_segments (freelist
);
462 if (*free_cells
== SCM_EOL
&& scm_i_gc_grow_heap_p (freelist
))
464 freelist
->heap_segment_idx
= scm_i_get_new_heap_segment (freelist
, abort_on_error
);
465 *free_cells
= scm_i_sweep_some_segments (freelist
);
468 if (*free_cells
== SCM_EOL
&& !scm_block_gc
)
471 with the advent of lazy sweep, GC yield is only know just
474 scm_i_adjust_min_yield (freelist
);
477 out of fresh cells. Try to get some new ones.
482 *free_cells
= scm_i_sweep_some_segments (freelist
);
485 if (*free_cells
== SCM_EOL
)
488 failed getting new cells. Get new juice or die.
490 freelist
->heap_segment_idx
= scm_i_get_new_heap_segment (freelist
, abort_on_error
);
491 *free_cells
= scm_i_sweep_some_segments (freelist
);
494 if (*free_cells
== SCM_EOL
)
499 *free_cells
= SCM_FREE_CELL_CDR (cell
);
501 scm_rec_mutex_unlock (&scm_i_sweep_mutex
);
507 scm_t_c_hook scm_before_gc_c_hook
;
508 scm_t_c_hook scm_before_mark_c_hook
;
509 scm_t_c_hook scm_before_sweep_c_hook
;
510 scm_t_c_hook scm_after_sweep_c_hook
;
511 scm_t_c_hook scm_after_gc_c_hook
;
514 scm_igc (const char *what
)
516 scm_rec_mutex_lock (&scm_i_sweep_mutex
);
518 scm_c_hook_run (&scm_before_gc_c_hook
, 0);
521 fprintf (stderr
,"gc reason %s\n", what
);
524 SCM_NULLP (*SCM_FREELIST_LOC (scm_i_freelist
))
526 : (SCM_NULLP (*SCM_FREELIST_LOC (scm_i_freelist2
)) ? "o" : "m"));
529 /* During the critical section, only the current thread may run. */
530 scm_i_thread_put_to_sleep ();
532 if (!scm_root
|| !scm_stack_base
|| scm_block_gc
)
538 gc_start_stats (what
);
540 if (scm_gc_heap_lock
)
541 /* We've invoked the collector while a GC is already in progress.
542 That should never happen. */
548 Let's finish the sweep. The conservative GC might point into the
549 garbage, and marking that would create a mess.
551 scm_i_sweep_all_segments("GC");
552 if (scm_mallocated
< scm_i_deprecated_memory_return
)
554 /* The byte count of allocated objects has underflowed. This is
555 probably because you forgot to report the sizes of objects you
556 have allocated, by calling scm_done_malloc or some such. When
557 the GC freed them, it subtracted their size from
558 scm_mallocated, which underflowed. */
560 "scm_gc_sweep: Byte count of allocated objects has underflowed.\n"
561 "This is probably because the GC hasn't been correctly informed\n"
562 "about object sizes\n");
565 scm_mallocated
-= scm_i_deprecated_memory_return
;
569 scm_c_hook_run (&scm_before_mark_c_hook
, 0);
573 scm_gc_mark_time_taken
+= (scm_c_get_internal_run_time () - t_before_gc
);
575 scm_c_hook_run (&scm_before_sweep_c_hook
, 0);
578 Moved this lock upwards so that we can alloc new heap at the end of a sweep.
580 DOCME: why should the heap be locked anyway?
588 TODO: this hook should probably be moved to just before the mark,
589 since that's where the sweep is finished in lazy sweeping.
591 MDJ 030219 <djurfeldt@nada.kth.se>: No, probably not. The
592 original meaning implied at least two things: that it would be
595 1. the freelist is re-initialized (no evaluation possible, though)
599 2. the heap is "fresh"
600 (it is well-defined what data is used and what is not)
602 Neither of these conditions would hold just before the mark phase.
604 Of course, the lazy sweeping has muddled the distinction between
605 scm_before_sweep_c_hook and scm_after_sweep_c_hook, but even if
606 there were no difference, it would still be useful to have two
607 distinct classes of hook functions since this can prevent some
608 bad interference when several modules adds gc hooks.
610 scm_c_hook_run (&scm_after_sweep_c_hook
, 0);
613 scm_i_thread_wake_up ();
618 scm_c_hook_run (&scm_after_gc_c_hook
, 0);
620 scm_rec_mutex_unlock (&scm_i_sweep_mutex
);
623 For debugging purposes, you could do
624 scm_i_sweep_all_segments("debug"), but then the remains of the
625 cell aren't left to analyse.
630 /* {GC Protection Helper Functions}
635 * If within a function you need to protect one or more scheme objects from
636 * garbage collection, pass them as parameters to one of the
637 * scm_remember_upto_here* functions below. These functions don't do
638 * anything, but since the compiler does not know that they are actually
639 * no-ops, it will generate code that calls these functions with the given
640 * parameters. Therefore, you can be sure that the compiler will keep those
641 * scheme values alive (on the stack or in a register) up to the point where
642 * scm_remember_upto_here* is called. In other words, place the call to
643 * scm_remember_upto_here* _behind_ the last code in your function, that
644 * depends on the scheme object to exist.
646 * Example: We want to make sure that the string object str does not get
647 * garbage collected during the execution of 'some_function' in the code
648 * below, because otherwise the characters belonging to str would be freed and
649 * 'some_function' might access freed memory. To make sure that the compiler
650 * keeps str alive on the stack or in a register such that it is visible to
651 * the conservative gc we add the call to scm_remember_upto_here_1 _after_ the
652 * call to 'some_function'. Note that this would not be necessary if str was
653 * used anyway after the call to 'some_function'.
654 * char *chars = SCM_STRING_CHARS (str);
655 * some_function (chars);
656 * scm_remember_upto_here_1 (str); // str will be alive up to this point.
660 scm_remember_upto_here_1 (SCM obj SCM_UNUSED
)
662 /* Empty. Protects a single object from garbage collection. */
666 scm_remember_upto_here_2 (SCM obj1 SCM_UNUSED
, SCM obj2 SCM_UNUSED
)
668 /* Empty. Protects two objects from garbage collection. */
672 scm_remember_upto_here (SCM obj SCM_UNUSED
, ...)
674 /* Empty. Protects any number of objects from garbage collection. */
678 These crazy functions prevent garbage collection
679 of arguments after the first argument by
680 ensuring they remain live throughout the
681 function because they are used in the last
682 line of the code block.
683 It'd be better to have a nice compiler hint to
684 aid the conservative stack-scanning GC. --03/09/00 gjb */
686 scm_return_first (SCM elt
, ...)
692 scm_return_first_int (int i
, ...)
699 scm_permanent_object (SCM obj
)
702 scm_permobjs
= scm_cons (obj
, scm_permobjs
);
708 /* Protect OBJ from the garbage collector. OBJ will not be freed, even if all
709 other references are dropped, until the object is unprotected by calling
710 scm_gc_unprotect_object (OBJ). Calls to scm_gc_protect/unprotect_object nest,
711 i. e. it is possible to protect the same object several times, but it is
712 necessary to unprotect the object the same number of times to actually get
713 the object unprotected. It is an error to unprotect an object more often
714 than it has been protected before. The function scm_protect_object returns
718 /* Implementation note: For every object X, there is a counter which
719 scm_gc_protect_object(X) increments and scm_gc_unprotect_object(X) decrements.
723 scm_gc_protect_object (SCM obj
)
727 /* This critical section barrier will be replaced by a mutex. */
730 handle
= scm_hashq_create_handle_x (scm_protects
, obj
, SCM_MAKINUM (0));
731 SCM_SETCDR (handle
, scm_sum (SCM_CDR (handle
), SCM_MAKINUM (1)));
739 /* Remove any protection for OBJ established by a prior call to
740 scm_protect_object. This function returns OBJ.
742 See scm_protect_object for more information. */
744 scm_gc_unprotect_object (SCM obj
)
748 /* This critical section barrier will be replaced by a mutex. */
751 handle
= scm_hashq_get_handle (scm_protects
, obj
);
753 if (SCM_FALSEP (handle
))
755 fprintf (stderr
, "scm_unprotect_object called on unprotected object\n");
760 SCM count
= scm_difference (SCM_CDR (handle
), SCM_MAKINUM (1));
761 if (SCM_EQ_P (count
, SCM_MAKINUM (0)))
762 scm_hashq_remove_x (scm_protects
, obj
);
764 SCM_SETCDR (handle
, count
);
773 scm_gc_register_root (SCM
*p
)
776 SCM key
= scm_long2num ((long) p
);
778 /* This critical section barrier will be replaced by a mutex. */
781 handle
= scm_hashv_create_handle_x (scm_gc_registered_roots
, key
, SCM_MAKINUM (0));
782 SCM_SETCDR (handle
, scm_sum (SCM_CDR (handle
), SCM_MAKINUM (1)));
788 scm_gc_unregister_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_get_handle (scm_gc_registered_roots
, key
);
798 if (SCM_FALSEP (handle
))
800 fprintf (stderr
, "scm_gc_unregister_root called on unregistered root\n");
805 SCM count
= scm_difference (SCM_CDR (handle
), SCM_MAKINUM (1));
806 if (SCM_EQ_P (count
, SCM_MAKINUM (0)))
807 scm_hashv_remove_x (scm_gc_registered_roots
, key
);
809 SCM_SETCDR (handle
, count
);
816 scm_gc_register_roots (SCM
*b
, unsigned long n
)
819 for (; p
< b
+ n
; ++p
)
820 scm_gc_register_root (p
);
824 scm_gc_unregister_roots (SCM
*b
, unsigned long n
)
827 for (; p
< b
+ n
; ++p
)
828 scm_gc_unregister_root (p
);
831 int scm_i_terminating
;
833 /* called on process termination. */
839 extern int on_exit (void (*procp
) (), int arg
);
842 cleanup (int status
, void *arg
)
844 #error Dont know how to setup a cleanup handler on your system.
848 scm_i_terminating
= 1;
849 scm_flush_all_ports ();
856 MOVE THIS FUNCTION. IT DOES NOT HAVE ANYTHING TODO WITH GC.
859 /* Get an integer from an environment variable. */
861 scm_getenv_int (const char *var
, int def
)
864 char *val
= getenv (var
);
868 res
= strtol (val
, &end
, 10);
875 scm_storage_prehistory ()
877 scm_c_hook_init (&scm_before_gc_c_hook
, 0, SCM_C_HOOK_NORMAL
);
878 scm_c_hook_init (&scm_before_mark_c_hook
, 0, SCM_C_HOOK_NORMAL
);
879 scm_c_hook_init (&scm_before_sweep_c_hook
, 0, SCM_C_HOOK_NORMAL
);
880 scm_c_hook_init (&scm_after_sweep_c_hook
, 0, SCM_C_HOOK_NORMAL
);
881 scm_c_hook_init (&scm_after_gc_c_hook
, 0, SCM_C_HOOK_NORMAL
);
889 /* Fixme: Should use mutexattr from the low-level API. */
890 scm_rec_mutex_init (&scm_i_sweep_mutex
, &scm_i_plugin_rec_mutex
);
892 j
= SCM_NUM_PROTECTS
;
894 scm_sys_protects
[--j
] = SCM_BOOL_F
;
897 scm_gc_init_freelist();
898 scm_gc_init_malloc ();
900 j
= SCM_HEAP_SEG_SIZE
;
903 /* Initialise the list of ports. */
904 scm_i_port_table
= (scm_t_port
**)
905 malloc (sizeof (scm_t_port
*) * scm_i_port_table_room
);
906 if (!scm_i_port_table
)
913 on_exit (cleanup
, 0);
917 scm_stand_in_procs
= SCM_EOL
;
918 scm_permobjs
= SCM_EOL
;
919 scm_protects
= scm_c_make_hash_table (31);
920 scm_gc_registered_roots
= scm_c_make_hash_table (31);
927 SCM scm_after_gc_hook
;
931 /* The function gc_async_thunk causes the execution of the after-gc-hook. It
932 * is run after the gc, as soon as the asynchronous events are handled by the
936 gc_async_thunk (void)
938 scm_c_run_hook (scm_after_gc_hook
, SCM_EOL
);
939 return SCM_UNSPECIFIED
;
943 /* The function mark_gc_async is run by the scm_after_gc_c_hook at the end of
944 * the garbage collection. The only purpose of this function is to mark the
945 * gc_async (which will eventually lead to the execution of the
949 mark_gc_async (void * hook_data SCM_UNUSED
,
950 void *func_data SCM_UNUSED
,
951 void *data SCM_UNUSED
)
953 /* If cell access debugging is enabled, the user may choose to perform
954 * additional garbage collections after an arbitrary number of cell
955 * accesses. We don't want the scheme level after-gc-hook to be performed
956 * for each of these garbage collections for the following reason: The
957 * execution of the after-gc-hook causes cell accesses itself. Thus, if the
958 * after-gc-hook was performed with every gc, and if the gc was performed
959 * after a very small number of cell accesses, then the number of cell
960 * accesses during the execution of the after-gc-hook will suffice to cause
961 * the execution of the next gc. Then, guile would keep executing the
962 * after-gc-hook over and over again, and would never come to do other
965 * To overcome this problem, if cell access debugging with additional
966 * garbage collections is enabled, the after-gc-hook is never run by the
967 * garbage collecter. When running guile with cell access debugging and the
968 * execution of the after-gc-hook is desired, then it is necessary to run
969 * the hook explicitly from the user code. This has the effect, that from
970 * the scheme level point of view it seems that garbage collection is
971 * performed with a much lower frequency than it actually is. Obviously,
972 * this will not work for code that depends on a fixed one to one
973 * relationship between the execution counts of the C level garbage
974 * collection hooks and the execution count of the scheme level
977 #if (SCM_DEBUG_CELL_ACCESSES == 1)
978 if (scm_debug_cells_gc_interval
== 0)
979 scm_system_async_mark (gc_async
);
981 scm_system_async_mark (gc_async
);
992 scm_after_gc_hook
= scm_permanent_object (scm_make_hook (SCM_INUM0
));
993 scm_c_define ("after-gc-hook", scm_after_gc_hook
);
995 gc_async
= scm_c_make_subr ("%gc-thunk", scm_tc7_subr_0
,
998 scm_c_hook_add (&scm_after_gc_c_hook
, mark_gc_async
, NULL
, 0);
1000 #include "libguile/gc.x"
1006 #define FUNC_NAME "scm_gc_sweep"
1008 scm_i_deprecated_memory_return
= 0;
1010 scm_i_gc_sweep_freelist_reset (&scm_i_master_freelist
);
1011 scm_i_gc_sweep_freelist_reset (&scm_i_master_freelist2
);
1014 NOTHING HERE: LAZY SWEEPING !
1016 scm_i_reset_segments ();
1018 /* When we move to POSIX threads private freelists should probably
1019 be GC-protected instead. */
1020 *SCM_FREELIST_LOC (scm_i_freelist
) = SCM_EOL
;
1021 *SCM_FREELIST_LOC (scm_i_freelist2
) = SCM_EOL
;
1023 /* Invalidate the freelists of other threads. */
1024 scm_i_thread_invalidate_freelists ();