1 /* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2002, 2003, 2006, 2008, 2009, 2010, 2011, 2012 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 License
5 * as published by the Free Software Foundation; either version 3 of
6 * the License, or (at your option) any later version.
8 * This library is distributed in the hope that it will be useful, but
9 * 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., 51 Franklin Street, Fifth Floor, Boston, MA
19 /* #define DEBUGINFO */
25 #define SCM_BUILDING_DEPRECATED_CODE
27 #include "libguile/gen-scmconfig.h"
37 extern unsigned long * __libc_ia64_register_backing_store_base
;
40 #include "libguile/_scm.h"
41 #include "libguile/eval.h"
42 #include "libguile/stime.h"
43 #include "libguile/stackchk.h"
44 #include "libguile/struct.h"
45 #include "libguile/smob.h"
46 #include "libguile/arrays.h"
47 #include "libguile/async.h"
48 #include "libguile/ports.h"
49 #include "libguile/root.h"
50 #include "libguile/strings.h"
51 #include "libguile/vectors.h"
52 #include "libguile/weaks.h"
53 #include "libguile/hashtab.h"
54 #include "libguile/tags.h"
56 #include "libguile/private-gc.h"
57 #include "libguile/validate.h"
58 #include "libguile/deprecation.h"
59 #include "libguile/gc.h"
60 #include "libguile/dynwind.h"
62 #include "libguile/bdw-gc.h"
64 /* For GC_set_start_callback. */
65 #include <gc/gc_mark.h>
67 #ifdef GUILE_DEBUG_MALLOC
68 #include "libguile/debug-malloc.h"
75 /* Set this to != 0 if every cell that is accessed shall be checked:
77 int scm_debug_cell_accesses_p
= 0;
78 int scm_expensive_debug_cell_accesses_p
= 0;
80 /* Set this to 0 if no additional gc's shall be performed, otherwise set it to
81 * the number of cell accesses after which a gc shall be called.
83 int scm_debug_cells_gc_interval
= 0;
85 #if SCM_ENABLE_DEPRECATED == 1
86 /* Hash table that keeps a reference to objects the user wants to protect from
87 garbage collection. It could arguably be private but applications have come
88 to rely on it (e.g., Lilypond 2.13.9). */
91 static SCM scm_protects
;
94 #if (SCM_DEBUG_CELL_ACCESSES == 1)
99 Assert that the given object is a valid reference to a valid cell. This
100 test involves to determine whether the object is a cell pointer, whether
101 this pointer actually points into a heap segment and whether the cell
102 pointed to is not a free cell. Further, additional garbage collections may
103 get executed after a user defined number of cell accesses. This helps to
104 find places in the C code where references are dropped for extremely short
109 scm_i_expensive_validation_check (SCM cell
)
111 /* If desired, perform additional garbage collections after a user
112 * defined number of cell accesses.
114 if (scm_debug_cells_gc_interval
)
116 static unsigned int counter
= 0;
124 counter
= scm_debug_cells_gc_interval
;
130 /* Whether cell validation is already running. */
131 static int scm_i_cell_validation_already_running
= 0;
134 scm_assert_cell_valid (SCM cell
)
136 if (!scm_i_cell_validation_already_running
&& scm_debug_cell_accesses_p
)
138 scm_i_cell_validation_already_running
= 1; /* set to avoid recursion */
141 During GC, no user-code should be run, and the guile core
142 should use non-protected accessors.
144 if (scm_gc_running_p
)
148 Only scm_in_heap_p and rescanning the heap is wildly
151 if (scm_expensive_debug_cell_accesses_p
)
152 scm_i_expensive_validation_check (cell
);
154 scm_i_cell_validation_already_running
= 0; /* re-enable */
160 SCM_DEFINE (scm_set_debug_cell_accesses_x
, "set-debug-cell-accesses!", 1, 0, 0,
162 "If @var{flag} is @code{#f}, cell access checking is disabled.\n"
163 "If @var{flag} is @code{#t}, cheap cell access checking is enabled,\n"
164 "but no additional calls to garbage collection are issued.\n"
165 "If @var{flag} is a number, strict cell access checking is enabled,\n"
166 "with an additional garbage collection after the given\n"
167 "number of cell accesses.\n"
168 "This procedure only exists when the compile-time flag\n"
169 "@code{SCM_DEBUG_CELL_ACCESSES} was set to 1.")
170 #define FUNC_NAME s_scm_set_debug_cell_accesses_x
172 if (scm_is_false (flag
))
174 scm_debug_cell_accesses_p
= 0;
176 else if (scm_is_eq (flag
, SCM_BOOL_T
))
178 scm_debug_cells_gc_interval
= 0;
179 scm_debug_cell_accesses_p
= 1;
180 scm_expensive_debug_cell_accesses_p
= 0;
184 scm_debug_cells_gc_interval
= scm_to_signed_integer (flag
, 0, INT_MAX
);
185 scm_debug_cell_accesses_p
= 1;
186 scm_expensive_debug_cell_accesses_p
= 1;
188 return SCM_UNSPECIFIED
;
193 #endif /* SCM_DEBUG_CELL_ACCESSES == 1 */
199 #ifndef HAVE_GC_GET_HEAP_USAGE_SAFE
201 GC_get_heap_usage_safe (GC_word
*pheap_size
, GC_word
*pfree_bytes
,
202 GC_word
*punmapped_bytes
, GC_word
*pbytes_since_gc
,
203 GC_word
*ptotal_bytes
)
205 *pheap_size
= GC_get_heap_size ();
206 *pfree_bytes
= GC_get_free_bytes ();
207 #ifdef HAVE_GC_GET_UNMAPPED_BYTES
208 *punmapped_bytes
= GC_get_unmapped_bytes ();
210 *punmapped_bytes
= 0;
212 *pbytes_since_gc
= GC_get_bytes_since_gc ();
213 *ptotal_bytes
= GC_get_total_bytes ();
217 #ifndef HAVE_GC_GET_FREE_SPACE_DIVISOR
219 GC_get_free_space_divisor (void)
221 return GC_free_space_divisor
;
227 scm_t_c_hook scm_before_gc_c_hook
;
228 scm_t_c_hook scm_before_mark_c_hook
;
229 scm_t_c_hook scm_before_sweep_c_hook
;
230 scm_t_c_hook scm_after_sweep_c_hook
;
231 scm_t_c_hook scm_after_gc_c_hook
;
235 run_before_gc_c_hook (void)
237 if (!SCM_I_CURRENT_THREAD
)
238 /* GC while a thread is spinning up; punt. */
241 scm_c_hook_run (&scm_before_gc_c_hook
, NULL
);
245 /* GC Statistics Keeping
247 unsigned long scm_gc_ports_collected
= 0;
248 static long gc_time_taken
= 0;
249 static long gc_start_time
= 0;
251 static unsigned long free_space_divisor
;
252 static unsigned long minimum_free_space_divisor
;
253 static double target_free_space_divisor
;
255 static unsigned long protected_obj_count
= 0;
258 SCM_SYMBOL (sym_gc_time_taken
, "gc-time-taken");
259 SCM_SYMBOL (sym_heap_size
, "heap-size");
260 SCM_SYMBOL (sym_heap_free_size
, "heap-free-size");
261 SCM_SYMBOL (sym_heap_total_allocated
, "heap-total-allocated");
262 SCM_SYMBOL (sym_heap_allocated_since_gc
, "heap-allocated-since-gc");
263 SCM_SYMBOL (sym_protected_objects
, "protected-objects");
264 SCM_SYMBOL (sym_times
, "gc-times");
267 /* {Scheme Interface to GC}
270 tag_table_to_type_alist (void *closure
, SCM key
, SCM val
, SCM acc
)
272 if (scm_is_integer (key
))
274 int c_tag
= scm_to_int (key
);
276 char const * name
= scm_i_tag_name (c_tag
);
279 key
= scm_from_locale_string (name
);
284 sprintf (s
, "tag %d", c_tag
);
285 key
= scm_from_locale_string (s
);
289 return scm_cons (scm_cons (key
, val
), acc
);
292 SCM_DEFINE (scm_gc_live_object_stats
, "gc-live-object-stats", 0, 0, 0,
294 "Return an alist of statistics of the current live objects. ")
295 #define FUNC_NAME s_scm_gc_live_object_stats
297 SCM tab
= scm_make_hash_table (scm_from_int (57));
301 = scm_internal_hash_fold (&tag_table_to_type_alist
, NULL
, SCM_EOL
, tab
);
307 extern int scm_gc_malloc_yield_percentage
;
308 SCM_DEFINE (scm_gc_stats
, "gc-stats", 0, 0, 0,
310 "Return an association list of statistics about Guile's current\n"
312 #define FUNC_NAME s_scm_gc_stats
315 GC_word heap_size
, free_bytes
, unmapped_bytes
, bytes_since_gc
, total_bytes
;
318 GC_get_heap_usage_safe (&heap_size
, &free_bytes
, &unmapped_bytes
,
319 &bytes_since_gc
, &total_bytes
);
323 scm_list_n (scm_cons (sym_gc_time_taken
, scm_from_long (gc_time_taken
)),
324 scm_cons (sym_heap_size
, scm_from_size_t (heap_size
)),
325 scm_cons (sym_heap_free_size
, scm_from_size_t (free_bytes
)),
326 scm_cons (sym_heap_total_allocated
,
327 scm_from_size_t (total_bytes
)),
328 scm_cons (sym_heap_allocated_since_gc
,
329 scm_from_size_t (bytes_since_gc
)),
330 scm_cons (sym_protected_objects
,
331 scm_from_ulong (protected_obj_count
)),
332 scm_cons (sym_times
, scm_from_size_t (gc_times
)),
340 SCM_DEFINE (scm_gc_dump
, "gc-dump", 0, 0, 0,
342 "Dump information about the garbage collector's internal data "
343 "structures and memory usage to the standard output.")
344 #define FUNC_NAME s_scm_gc_dump
348 return SCM_UNSPECIFIED
;
353 SCM_DEFINE (scm_object_address
, "object-address", 1, 0, 0,
355 "Return an integer that for the lifetime of @var{obj} is uniquely\n"
356 "returned by this function for @var{obj}")
357 #define FUNC_NAME s_scm_object_address
359 return scm_from_ulong (SCM_UNPACK (obj
));
364 SCM_DEFINE (scm_gc_disable
, "gc-disable", 0, 0, 0,
366 "Disables the garbage collector. Nested calls are permitted. "
367 "GC is re-enabled once @code{gc-enable} has been called the "
368 "same number of times @code{gc-disable} was called.")
369 #define FUNC_NAME s_scm_gc_disable
372 return SCM_UNSPECIFIED
;
376 SCM_DEFINE (scm_gc_enable
, "gc-enable", 0, 0, 0,
378 "Enables the garbage collector.")
379 #define FUNC_NAME s_scm_gc_enable
382 return SCM_UNSPECIFIED
;
387 SCM_DEFINE (scm_gc
, "gc", 0, 0, 0,
389 "Scans all of SCM objects and reclaims for further use those that are\n"
390 "no longer accessible.")
391 #define FUNC_NAME s_scm_gc
394 /* If you're calling scm_gc(), you probably want synchronous
396 GC_invoke_finalizers ();
397 return SCM_UNSPECIFIED
;
402 scm_i_gc (const char *what
)
404 #ifndef HAVE_GC_SET_START_CALLBACK
405 run_before_gc_c_hook ();
412 /* {GC Protection Helper Functions}
417 * If within a function you need to protect one or more scheme objects from
418 * garbage collection, pass them as parameters to one of the
419 * scm_remember_upto_here* functions below. These functions don't do
420 * anything, but since the compiler does not know that they are actually
421 * no-ops, it will generate code that calls these functions with the given
422 * parameters. Therefore, you can be sure that the compiler will keep those
423 * scheme values alive (on the stack or in a register) up to the point where
424 * scm_remember_upto_here* is called. In other words, place the call to
425 * scm_remember_upto_here* _behind_ the last code in your function, that
426 * depends on the scheme object to exist.
428 * Example: We want to make sure that the string object str does not get
429 * garbage collected during the execution of 'some_function' in the code
430 * below, because otherwise the characters belonging to str would be freed and
431 * 'some_function' might access freed memory. To make sure that the compiler
432 * keeps str alive on the stack or in a register such that it is visible to
433 * the conservative gc we add the call to scm_remember_upto_here_1 _after_ the
434 * call to 'some_function'. Note that this would not be necessary if str was
435 * used anyway after the call to 'some_function'.
436 * char *chars = scm_i_string_chars (str);
437 * some_function (chars);
438 * scm_remember_upto_here_1 (str); // str will be alive up to this point.
441 /* Remove any macro versions of these while defining the functions.
442 Functions are always included in the library, for upward binary
443 compatibility and in case combinations of GCC and non-GCC are used. */
444 #undef scm_remember_upto_here_1
445 #undef scm_remember_upto_here_2
448 scm_remember_upto_here_1 (SCM obj SCM_UNUSED
)
450 /* Empty. Protects a single object from garbage collection. */
454 scm_remember_upto_here_2 (SCM obj1 SCM_UNUSED
, SCM obj2 SCM_UNUSED
)
456 /* Empty. Protects two objects from garbage collection. */
460 scm_remember_upto_here (SCM obj SCM_UNUSED
, ...)
462 /* Empty. Protects any number of objects from garbage collection. */
466 These crazy functions prevent garbage collection
467 of arguments after the first argument by
468 ensuring they remain live throughout the
469 function because they are used in the last
470 line of the code block.
471 It'd be better to have a nice compiler hint to
472 aid the conservative stack-scanning GC. --03/09/00 gjb */
474 scm_return_first (SCM elt
, ...)
480 scm_return_first_int (int i
, ...)
487 scm_permanent_object (SCM obj
)
489 return (scm_gc_protect_object (obj
));
493 /* Protect OBJ from the garbage collector. OBJ will not be freed, even if all
494 other references are dropped, until the object is unprotected by calling
495 scm_gc_unprotect_object (OBJ). Calls to scm_gc_protect/unprotect_object nest,
496 i. e. it is possible to protect the same object several times, but it is
497 necessary to unprotect the object the same number of times to actually get
498 the object unprotected. It is an error to unprotect an object more often
499 than it has been protected before. The function scm_protect_object returns
503 /* Implementation note: For every object X, there is a counter which
504 scm_gc_protect_object (X) increments and scm_gc_unprotect_object (X) decrements.
510 scm_gc_protect_object (SCM obj
)
514 /* This critical section barrier will be replaced by a mutex. */
515 /* njrev: Indeed; if my comment above is correct, there is the same
516 critsec/mutex inconsistency here. */
517 SCM_CRITICAL_SECTION_START
;
519 handle
= scm_hashq_create_handle_x (scm_protects
, obj
, scm_from_int (0));
520 SCM_SETCDR (handle
, scm_sum (SCM_CDR (handle
), scm_from_int (1)));
522 protected_obj_count
++;
524 SCM_CRITICAL_SECTION_END
;
530 /* Remove any protection for OBJ established by a prior call to
531 scm_protect_object. This function returns OBJ.
533 See scm_protect_object for more information. */
535 scm_gc_unprotect_object (SCM obj
)
539 /* This critical section barrier will be replaced by a mutex. */
540 /* njrev: and again. */
541 SCM_CRITICAL_SECTION_START
;
543 if (scm_gc_running_p
)
545 fprintf (stderr
, "scm_unprotect_object called during GC.\n");
549 handle
= scm_hashq_get_handle (scm_protects
, obj
);
551 if (scm_is_false (handle
))
553 fprintf (stderr
, "scm_unprotect_object called on unprotected object\n");
558 SCM count
= scm_difference (SCM_CDR (handle
), scm_from_int (1));
559 if (scm_is_eq (count
, scm_from_int (0)))
560 scm_hashq_remove_x (scm_protects
, obj
);
562 SCM_SETCDR (handle
, count
);
564 protected_obj_count
--;
566 SCM_CRITICAL_SECTION_END
;
572 scm_gc_register_root (SCM
*p
)
578 scm_gc_unregister_root (SCM
*p
)
584 scm_gc_register_roots (SCM
*b
, unsigned long n
)
587 for (; p
< b
+ n
; ++p
)
588 scm_gc_register_root (p
);
592 scm_gc_unregister_roots (SCM
*b
, unsigned long n
)
595 for (; p
< b
+ n
; ++p
)
596 scm_gc_unregister_root (p
);
603 MOVE THIS FUNCTION. IT DOES NOT HAVE ANYTHING TODO WITH GC.
606 /* Get an integer from an environment variable. */
608 scm_getenv_int (const char *var
, int def
)
611 char *val
= getenv (var
);
615 res
= strtol (val
, &end
, 10);
621 #ifndef HAVE_GC_SET_FINALIZE_ON_DEMAND
623 GC_set_finalize_on_demand (int foo
)
625 GC_finalize_on_demand
= foo
;
630 scm_storage_prehistory ()
632 GC_all_interior_pointers
= 0;
633 free_space_divisor
= scm_getenv_int ("GC_FREE_SPACE_DIVISOR", 3);
634 minimum_free_space_divisor
= free_space_divisor
;
635 target_free_space_divisor
= free_space_divisor
;
636 GC_set_free_space_divisor (free_space_divisor
);
637 GC_set_finalize_on_demand (1);
641 #if (! ((defined GC_VERSION_MAJOR) && (GC_VERSION_MAJOR >= 7))) \
642 && (defined SCM_I_GSC_USE_PTHREAD_THREADS)
643 /* When using GC 6.8, this call is required to initialize thread-local
644 freelists (shouldn't be necessary with GC 7.0). */
648 GC_expand_hp (SCM_DEFAULT_INIT_HEAP_SIZE_2
);
650 /* We only need to register a displacement for those types for which the
651 higher bits of the type tag are used to store a pointer (that is, a
652 pointer to an 8-octet aligned region). For `scm_tc3_struct', this is
653 handled in `scm_alloc_struct ()'. */
654 GC_REGISTER_DISPLACEMENT (scm_tc3_cons
);
655 /* GC_REGISTER_DISPLACEMENT (scm_tc3_unused); */
658 if (!GC_is_visible (&scm_protects
))
661 scm_c_hook_init (&scm_before_gc_c_hook
, 0, SCM_C_HOOK_NORMAL
);
662 scm_c_hook_init (&scm_before_mark_c_hook
, 0, SCM_C_HOOK_NORMAL
);
663 scm_c_hook_init (&scm_before_sweep_c_hook
, 0, SCM_C_HOOK_NORMAL
);
664 scm_c_hook_init (&scm_after_sweep_c_hook
, 0, SCM_C_HOOK_NORMAL
);
665 scm_c_hook_init (&scm_after_gc_c_hook
, 0, SCM_C_HOOK_NORMAL
);
668 scm_i_pthread_mutex_t scm_i_gc_admin_mutex
= SCM_I_PTHREAD_MUTEX_INITIALIZER
;
671 scm_init_gc_protect_object ()
673 scm_protects
= scm_c_make_hash_table (31);
676 /* We can't have a cleanup handler since we have no thread to run it
683 on_exit (cleanup
, 0);
692 SCM scm_after_gc_hook
;
694 static SCM after_gc_async_cell
;
696 /* The function after_gc_async_thunk causes the execution of the
697 * after-gc-hook. It is run after the gc, as soon as the asynchronous
698 * events are handled by the evaluator.
701 after_gc_async_thunk (void)
703 /* Fun, no? Hook-run *and* run-hook? */
704 scm_c_hook_run (&scm_after_gc_c_hook
, NULL
);
705 scm_c_run_hook (scm_after_gc_hook
, SCM_EOL
);
706 return SCM_UNSPECIFIED
;
710 /* The function queue_after_gc_hook is run by the scm_before_gc_c_hook
711 * at the end of the garbage collection. The only purpose of this
712 * function is to mark the after_gc_async (which will eventually lead to
713 * the execution of the after_gc_async_thunk).
716 queue_after_gc_hook (void * hook_data SCM_UNUSED
,
717 void *fn_data SCM_UNUSED
,
718 void *data SCM_UNUSED
)
720 /* If cell access debugging is enabled, the user may choose to perform
721 * additional garbage collections after an arbitrary number of cell
722 * accesses. We don't want the scheme level after-gc-hook to be performed
723 * for each of these garbage collections for the following reason: The
724 * execution of the after-gc-hook causes cell accesses itself. Thus, if the
725 * after-gc-hook was performed with every gc, and if the gc was performed
726 * after a very small number of cell accesses, then the number of cell
727 * accesses during the execution of the after-gc-hook will suffice to cause
728 * the execution of the next gc. Then, guile would keep executing the
729 * after-gc-hook over and over again, and would never come to do other
732 * To overcome this problem, if cell access debugging with additional
733 * garbage collections is enabled, the after-gc-hook is never run by the
734 * garbage collecter. When running guile with cell access debugging and the
735 * execution of the after-gc-hook is desired, then it is necessary to run
736 * the hook explicitly from the user code. This has the effect, that from
737 * the scheme level point of view it seems that garbage collection is
738 * performed with a much lower frequency than it actually is. Obviously,
739 * this will not work for code that depends on a fixed one to one
740 * relationship between the execution counts of the C level garbage
741 * collection hooks and the execution count of the scheme level
745 #if (SCM_DEBUG_CELL_ACCESSES == 1)
746 if (scm_debug_cells_gc_interval
== 0)
749 scm_i_thread
*t
= SCM_I_CURRENT_THREAD
;
751 if (scm_is_false (SCM_CDR (after_gc_async_cell
)))
753 SCM_SETCDR (after_gc_async_cell
, t
->active_asyncs
);
754 t
->active_asyncs
= after_gc_async_cell
;
755 t
->pending_asyncs
= 1;
765 start_gc_timer (void * hook_data SCM_UNUSED
,
766 void *fn_data SCM_UNUSED
,
767 void *data SCM_UNUSED
)
770 gc_start_time
= scm_c_get_internal_run_time ();
776 accumulate_gc_timer (void * hook_data SCM_UNUSED
,
777 void *fn_data SCM_UNUSED
,
778 void *data SCM_UNUSED
)
782 long now
= scm_c_get_internal_run_time ();
783 gc_time_taken
+= now
- gc_start_time
;
790 /* Return some idea of the memory footprint of a process, in bytes.
791 Currently only works on Linux systems. */
793 get_image_size (void)
795 unsigned long size
, resident
, share
;
798 FILE *fp
= fopen ("/proc/self/statm", "r");
800 if (fp
&& fscanf (fp
, "%lu %lu %lu", &size
, &resident
, &share
) == 3)
801 ret
= resident
* 4096;
809 /* These are discussed later. */
810 static size_t bytes_until_gc
;
811 static scm_i_pthread_mutex_t bytes_until_gc_lock
= SCM_I_PTHREAD_MUTEX_INITIALIZER
;
813 /* Make GC run more frequently when the process image size is growing,
814 measured against the number of bytes allocated through the GC.
816 If Guile is allocating at a GC-managed heap size H, libgc will tend
817 to limit the process image size to H*N. But if at the same time the
818 user program is mallocating at a rate M bytes per GC-allocated byte,
819 then the process stabilizes at H*N*M -- assuming that collecting data
820 will result in malloc'd data being freed. It doesn't take a very
821 large M for this to be a bad situation. To limit the image size,
822 Guile should GC more often -- the bigger the M, the more often.
824 Numeric functions that produce bigger and bigger integers are
825 pessimal, because M is an increasing function of time. Here is an
826 example of such a function:
828 (define (factorial n)
832 (fac (1- n) (* n acc))))
835 It is possible for a process to grow for reasons that will not be
836 solved by faster GC. In that case M will be estimated as
837 artificially high for a while, and so GC will happen more often on
838 the Guile side. But when it stabilizes, Guile can ease back the GC
841 The key is to measure process image growth, not mallocation rate.
842 For maximum effectiveness, Guile reacts quickly to process growth,
843 and exponentially backs down when the process stops growing.
845 See http://thread.gmane.org/gmane.lisp.guile.devel/12552/focus=12936
846 for further discussion.
849 adjust_gc_frequency (void * hook_data SCM_UNUSED
,
850 void *fn_data SCM_UNUSED
,
851 void *data SCM_UNUSED
)
853 static size_t prev_image_size
= 0;
854 static size_t prev_bytes_alloced
= 0;
856 size_t bytes_alloced
;
858 scm_i_pthread_mutex_lock (&bytes_until_gc_lock
);
859 bytes_until_gc
= GC_get_heap_size ();
860 scm_i_pthread_mutex_unlock (&bytes_until_gc_lock
);
862 image_size
= get_image_size ();
863 bytes_alloced
= GC_get_total_bytes ();
865 #define HEURISTICS_DEBUG 0
868 fprintf (stderr
, "prev image / alloced: %lu / %lu\n", prev_image_size
, prev_bytes_alloced
);
869 fprintf (stderr
, " image / alloced: %lu / %lu\n", image_size
, bytes_alloced
);
870 fprintf (stderr
, "divisor %lu / %f\n", free_space_divisor
, target_free_space_divisor
);
873 if (prev_image_size
&& bytes_alloced
!= prev_bytes_alloced
)
875 double growth_rate
, new_target_free_space_divisor
;
876 double decay_factor
= 0.5;
877 double hysteresis
= 0.1;
879 growth_rate
= ((double) image_size
- prev_image_size
)
880 / ((double)bytes_alloced
- prev_bytes_alloced
);
883 fprintf (stderr
, "growth rate %f\n", growth_rate
);
886 new_target_free_space_divisor
= minimum_free_space_divisor
;
889 new_target_free_space_divisor
*= 1.0 + growth_rate
;
892 fprintf (stderr
, "new divisor %f\n", new_target_free_space_divisor
);
895 if (new_target_free_space_divisor
< target_free_space_divisor
)
897 target_free_space_divisor
=
898 (decay_factor
* target_free_space_divisor
899 + (1.0 - decay_factor
) * new_target_free_space_divisor
);
902 target_free_space_divisor
= new_target_free_space_divisor
;
905 fprintf (stderr
, "new target divisor %f\n", target_free_space_divisor
);
908 if (free_space_divisor
+ 0.5 + hysteresis
< target_free_space_divisor
909 || free_space_divisor
- 0.5 - hysteresis
> target_free_space_divisor
)
911 free_space_divisor
= lround (target_free_space_divisor
);
913 fprintf (stderr
, "new divisor %lu\n", free_space_divisor
);
915 GC_set_free_space_divisor (free_space_divisor
);
919 prev_image_size
= image_size
;
920 prev_bytes_alloced
= bytes_alloced
;
925 /* The adjust_gc_frequency routine handles transients in the process
926 image size. It can't handle instense non-GC-managed steady-state
927 allocation though, as it decays the FSD at steady-state down to its
930 The only real way to handle continuous, high non-GC allocation is to
931 let the GC know about it. This routine can handle non-GC allocation
932 rates that are similar in size to the GC-managed heap size.
936 scm_gc_register_allocation (size_t size
)
938 scm_i_pthread_mutex_lock (&bytes_until_gc_lock
);
939 if (bytes_until_gc
- size
> bytes_until_gc
)
941 bytes_until_gc
= GC_get_heap_size ();
942 scm_i_pthread_mutex_unlock (&bytes_until_gc_lock
);
947 bytes_until_gc
-= size
;
948 scm_i_pthread_mutex_unlock (&bytes_until_gc_lock
);
956 scm_i_tag_name (scm_t_bits tag
)
958 switch (tag
& 0x7f) /* 7 bits */
962 case scm_tcs_cons_imcar
:
963 return "cons (immediate car)";
964 case scm_tcs_cons_nimcar
:
965 return "cons (non-immediate car)";
966 case scm_tc7_pointer
:
968 case scm_tc7_hashtable
:
972 case scm_tc7_dynamic_state
:
973 return "dynamic state";
976 case scm_tc7_objcode
:
980 case scm_tc7_vm_cont
:
981 return "vm continuation";
983 return "weak vector";
995 case scm_tc16_complex
:
996 return "complex number";
998 case scm_tc16_fraction
:
1003 case scm_tc7_string
:
1006 case scm_tc7_stringbuf
:
1007 return "string buffer";
1009 case scm_tc7_symbol
:
1012 case scm_tc7_variable
:
1020 int k
= 0xff & (tag
>> 8);
1021 return (scm_smobs
[k
].name
);
1035 /* `GC_INIT ()' was invoked in `scm_storage_prehistory ()'. */
1037 scm_after_gc_hook
= scm_make_hook (SCM_INUM0
);
1038 scm_c_define ("after-gc-hook", scm_after_gc_hook
);
1040 /* When the async is to run, the cdr of the gc_async pair gets set to
1041 the asyncs queue of the current thread. */
1042 after_gc_async_cell
= scm_cons (scm_c_make_gsubr ("%after-gc-thunk", 0, 0, 0,
1043 after_gc_async_thunk
),
1046 scm_c_hook_add (&scm_before_gc_c_hook
, queue_after_gc_hook
, NULL
, 0);
1047 scm_c_hook_add (&scm_before_gc_c_hook
, start_gc_timer
, NULL
, 0);
1048 scm_c_hook_add (&scm_after_gc_c_hook
, accumulate_gc_timer
, NULL
, 0);
1050 #if HAVE_GC_GET_HEAP_USAGE_SAFE
1051 /* GC_get_heap_usage does not take a lock, and so can run in the GC
1053 scm_c_hook_add (&scm_before_gc_c_hook
, adjust_gc_frequency
, NULL
, 0);
1055 /* GC_get_heap_usage might take a lock (and did from 7.2alpha1 to
1056 7.2alpha7), so call it in the after_gc_hook. */
1057 scm_c_hook_add (&scm_after_gc_c_hook
, adjust_gc_frequency
, NULL
, 0);
1060 #ifdef HAVE_GC_SET_START_CALLBACK
1061 GC_set_start_callback (run_before_gc_c_hook
);
1064 #include "libguile/gc.x"
1070 #define FUNC_NAME "scm_gc_sweep"
1073 fprintf (stderr
, "%s: doing nothing\n", FUNC_NAME
);