1 /* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2002, 2003, 2006, 2008, 2009, 2010, 2011 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 #include "libguile/gen-scmconfig.h"
34 extern unsigned long * __libc_ia64_register_backing_store_base
;
37 #include "libguile/_scm.h"
38 #include "libguile/eval.h"
39 #include "libguile/stime.h"
40 #include "libguile/stackchk.h"
41 #include "libguile/struct.h"
42 #include "libguile/smob.h"
43 #include "libguile/arrays.h"
44 #include "libguile/async.h"
45 #include "libguile/ports.h"
46 #include "libguile/root.h"
47 #include "libguile/strings.h"
48 #include "libguile/vectors.h"
49 #include "libguile/hashtab.h"
50 #include "libguile/tags.h"
52 #include "libguile/private-gc.h"
53 #include "libguile/validate.h"
54 #include "libguile/deprecation.h"
55 #include "libguile/gc.h"
56 #include "libguile/dynwind.h"
58 #include "libguile/bdw-gc.h"
60 /* For GC_set_start_callback. */
61 #include <gc/gc_mark.h>
63 #ifdef GUILE_DEBUG_MALLOC
64 #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 /* Hash table that keeps a reference to objects the user wants to protect from
86 garbage collection. */
87 static SCM scm_protects
;
90 #if (SCM_DEBUG_CELL_ACCESSES == 1)
95 Assert that the given object is a valid reference to a valid cell. This
96 test involves to determine whether the object is a cell pointer, whether
97 this pointer actually points into a heap segment and whether the cell
98 pointed to is not a free cell. Further, additional garbage collections may
99 get executed after a user defined number of cell accesses. This helps to
100 find places in the C code where references are dropped for extremely short
105 scm_i_expensive_validation_check (SCM cell
)
107 /* If desired, perform additional garbage collections after a user
108 * defined number of cell accesses.
110 if (scm_debug_cells_gc_interval
)
112 static unsigned int counter
= 0;
120 counter
= scm_debug_cells_gc_interval
;
126 /* Whether cell validation is already running. */
127 static int scm_i_cell_validation_already_running
= 0;
130 scm_assert_cell_valid (SCM cell
)
132 if (!scm_i_cell_validation_already_running
&& scm_debug_cell_accesses_p
)
134 scm_i_cell_validation_already_running
= 1; /* set to avoid recursion */
137 During GC, no user-code should be run, and the guile core
138 should use non-protected accessors.
140 if (scm_gc_running_p
)
144 Only scm_in_heap_p and rescanning the heap is wildly
147 if (scm_expensive_debug_cell_accesses_p
)
148 scm_i_expensive_validation_check (cell
);
150 scm_i_cell_validation_already_running
= 0; /* re-enable */
156 SCM_DEFINE (scm_set_debug_cell_accesses_x
, "set-debug-cell-accesses!", 1, 0, 0,
158 "If @var{flag} is @code{#f}, cell access checking is disabled.\n"
159 "If @var{flag} is @code{#t}, cheap cell access checking is enabled,\n"
160 "but no additional calls to garbage collection are issued.\n"
161 "If @var{flag} is a number, strict cell access checking is enabled,\n"
162 "with an additional garbage collection after the given\n"
163 "number of cell accesses.\n"
164 "This procedure only exists when the compile-time flag\n"
165 "@code{SCM_DEBUG_CELL_ACCESSES} was set to 1.")
166 #define FUNC_NAME s_scm_set_debug_cell_accesses_x
168 if (scm_is_false (flag
))
170 scm_debug_cell_accesses_p
= 0;
172 else if (scm_is_eq (flag
, SCM_BOOL_T
))
174 scm_debug_cells_gc_interval
= 0;
175 scm_debug_cell_accesses_p
= 1;
176 scm_expensive_debug_cell_accesses_p
= 0;
180 scm_debug_cells_gc_interval
= scm_to_signed_integer (flag
, 0, INT_MAX
);
181 scm_debug_cell_accesses_p
= 1;
182 scm_expensive_debug_cell_accesses_p
= 1;
184 return SCM_UNSPECIFIED
;
189 #endif /* SCM_DEBUG_CELL_ACCESSES == 1 */
195 #ifndef HAVE_GC_GET_HEAP_USAGE_SAFE
197 GC_get_heap_usage_safe (GC_word
*pheap_size
, GC_word
*pfree_bytes
,
198 GC_word
*punmapped_bytes
, GC_word
*pbytes_since_gc
,
199 GC_word
*ptotal_bytes
)
201 *pheap_size
= GC_get_heap_size ();
202 *pfree_bytes
= GC_get_free_bytes ();
203 #ifdef HAVE_GC_GET_UNMAPPED_BYTES
204 *punmapped_bytes
= GC_get_unmapped_bytes ();
206 *punmapped_bytes
= 0;
208 *pbytes_since_gc
= GC_get_bytes_since_gc ();
209 *ptotal_bytes
= GC_get_total_bytes ();
213 #ifndef HAVE_GC_GET_FREE_SPACE_DIVISOR
215 GC_get_free_space_divisor (void)
217 return GC_free_space_divisor
;
223 scm_t_c_hook scm_before_gc_c_hook
;
224 scm_t_c_hook scm_before_mark_c_hook
;
225 scm_t_c_hook scm_before_sweep_c_hook
;
226 scm_t_c_hook scm_after_sweep_c_hook
;
227 scm_t_c_hook scm_after_gc_c_hook
;
231 run_before_gc_c_hook (void)
233 scm_c_hook_run (&scm_before_gc_c_hook
, NULL
);
237 /* GC Statistics Keeping
239 unsigned long scm_gc_ports_collected
= 0;
240 static long gc_time_taken
= 0;
241 static long gc_start_time
= 0;
243 static unsigned long free_space_divisor
;
244 static unsigned long minimum_free_space_divisor
;
245 static double target_free_space_divisor
;
247 static unsigned long protected_obj_count
= 0;
250 SCM_SYMBOL (sym_gc_time_taken
, "gc-time-taken");
251 SCM_SYMBOL (sym_heap_size
, "heap-size");
252 SCM_SYMBOL (sym_heap_free_size
, "heap-free-size");
253 SCM_SYMBOL (sym_heap_total_allocated
, "heap-total-allocated");
254 SCM_SYMBOL (sym_heap_allocated_since_gc
, "heap-allocated-since-gc");
255 SCM_SYMBOL (sym_protected_objects
, "protected-objects");
256 SCM_SYMBOL (sym_times
, "gc-times");
259 /* {Scheme Interface to GC}
262 tag_table_to_type_alist (void *closure
, SCM key
, SCM val
, SCM acc
)
264 if (scm_is_integer (key
))
266 int c_tag
= scm_to_int (key
);
268 char const * name
= scm_i_tag_name (c_tag
);
271 key
= scm_from_locale_string (name
);
276 sprintf (s
, "tag %d", c_tag
);
277 key
= scm_from_locale_string (s
);
281 return scm_cons (scm_cons (key
, val
), acc
);
284 SCM_DEFINE (scm_gc_live_object_stats
, "gc-live-object-stats", 0, 0, 0,
286 "Return an alist of statistics of the current live objects. ")
287 #define FUNC_NAME s_scm_gc_live_object_stats
289 SCM tab
= scm_make_hash_table (scm_from_int (57));
293 = scm_internal_hash_fold (&tag_table_to_type_alist
, NULL
, SCM_EOL
, tab
);
299 extern int scm_gc_malloc_yield_percentage
;
300 SCM_DEFINE (scm_gc_stats
, "gc-stats", 0, 0, 0,
302 "Return an association list of statistics about Guile's current\n"
304 #define FUNC_NAME s_scm_gc_stats
307 GC_word heap_size
, free_bytes
, unmapped_bytes
, bytes_since_gc
, total_bytes
;
310 GC_get_heap_usage_safe (&heap_size
, &free_bytes
, &unmapped_bytes
,
311 &bytes_since_gc
, &total_bytes
);
315 scm_list_n (scm_cons (sym_gc_time_taken
, scm_from_long (gc_time_taken
)),
316 scm_cons (sym_heap_size
, scm_from_size_t (heap_size
)),
317 scm_cons (sym_heap_free_size
, scm_from_size_t (free_bytes
)),
318 scm_cons (sym_heap_total_allocated
,
319 scm_from_size_t (total_bytes
)),
320 scm_cons (sym_heap_allocated_since_gc
,
321 scm_from_size_t (bytes_since_gc
)),
322 scm_cons (sym_protected_objects
,
323 scm_from_ulong (protected_obj_count
)),
324 scm_cons (sym_times
, scm_from_size_t (gc_times
)),
332 SCM_DEFINE (scm_gc_dump
, "gc-dump", 0, 0, 0,
334 "Dump information about the garbage collector's internal data "
335 "structures and memory usage to the standard output.")
336 #define FUNC_NAME s_scm_gc_dump
340 return SCM_UNSPECIFIED
;
345 SCM_DEFINE (scm_object_address
, "object-address", 1, 0, 0,
347 "Return an integer that for the lifetime of @var{obj} is uniquely\n"
348 "returned by this function for @var{obj}")
349 #define FUNC_NAME s_scm_object_address
351 return scm_from_ulong (SCM_UNPACK (obj
));
356 SCM_DEFINE (scm_gc_disable
, "gc-disable", 0, 0, 0,
358 "Disables the garbage collector. Nested calls are permitted. "
359 "GC is re-enabled once @code{gc-enable} has been called the "
360 "same number of times @code{gc-disable} was called.")
361 #define FUNC_NAME s_scm_gc_disable
364 return SCM_UNSPECIFIED
;
368 SCM_DEFINE (scm_gc_enable
, "gc-enable", 0, 0, 0,
370 "Enables the garbage collector.")
371 #define FUNC_NAME s_scm_gc_enable
374 return SCM_UNSPECIFIED
;
379 SCM_DEFINE (scm_gc
, "gc", 0, 0, 0,
381 "Scans all of SCM objects and reclaims for further use those that are\n"
382 "no longer accessible.")
383 #define FUNC_NAME s_scm_gc
386 return SCM_UNSPECIFIED
;
391 scm_i_gc (const char *what
)
393 #ifndef HAVE_GC_SET_START_CALLBACK
394 run_before_gc_c_hook ();
401 /* {GC Protection Helper Functions}
406 * If within a function you need to protect one or more scheme objects from
407 * garbage collection, pass them as parameters to one of the
408 * scm_remember_upto_here* functions below. These functions don't do
409 * anything, but since the compiler does not know that they are actually
410 * no-ops, it will generate code that calls these functions with the given
411 * parameters. Therefore, you can be sure that the compiler will keep those
412 * scheme values alive (on the stack or in a register) up to the point where
413 * scm_remember_upto_here* is called. In other words, place the call to
414 * scm_remember_upto_here* _behind_ the last code in your function, that
415 * depends on the scheme object to exist.
417 * Example: We want to make sure that the string object str does not get
418 * garbage collected during the execution of 'some_function' in the code
419 * below, because otherwise the characters belonging to str would be freed and
420 * 'some_function' might access freed memory. To make sure that the compiler
421 * keeps str alive on the stack or in a register such that it is visible to
422 * the conservative gc we add the call to scm_remember_upto_here_1 _after_ the
423 * call to 'some_function'. Note that this would not be necessary if str was
424 * used anyway after the call to 'some_function'.
425 * char *chars = scm_i_string_chars (str);
426 * some_function (chars);
427 * scm_remember_upto_here_1 (str); // str will be alive up to this point.
430 /* Remove any macro versions of these while defining the functions.
431 Functions are always included in the library, for upward binary
432 compatibility and in case combinations of GCC and non-GCC are used. */
433 #undef scm_remember_upto_here_1
434 #undef scm_remember_upto_here_2
437 scm_remember_upto_here_1 (SCM obj SCM_UNUSED
)
439 /* Empty. Protects a single object from garbage collection. */
443 scm_remember_upto_here_2 (SCM obj1 SCM_UNUSED
, SCM obj2 SCM_UNUSED
)
445 /* Empty. Protects two objects from garbage collection. */
449 scm_remember_upto_here (SCM obj SCM_UNUSED
, ...)
451 /* Empty. Protects any number of objects from garbage collection. */
455 These crazy functions prevent garbage collection
456 of arguments after the first argument by
457 ensuring they remain live throughout the
458 function because they are used in the last
459 line of the code block.
460 It'd be better to have a nice compiler hint to
461 aid the conservative stack-scanning GC. --03/09/00 gjb */
463 scm_return_first (SCM elt
, ...)
469 scm_return_first_int (int i
, ...)
476 scm_permanent_object (SCM obj
)
478 return (scm_gc_protect_object (obj
));
482 /* Protect OBJ from the garbage collector. OBJ will not be freed, even if all
483 other references are dropped, until the object is unprotected by calling
484 scm_gc_unprotect_object (OBJ). Calls to scm_gc_protect/unprotect_object nest,
485 i. e. it is possible to protect the same object several times, but it is
486 necessary to unprotect the object the same number of times to actually get
487 the object unprotected. It is an error to unprotect an object more often
488 than it has been protected before. The function scm_protect_object returns
492 /* Implementation note: For every object X, there is a counter which
493 scm_gc_protect_object (X) increments and scm_gc_unprotect_object (X) decrements.
499 scm_gc_protect_object (SCM obj
)
503 /* This critical section barrier will be replaced by a mutex. */
504 /* njrev: Indeed; if my comment above is correct, there is the same
505 critsec/mutex inconsistency here. */
506 SCM_CRITICAL_SECTION_START
;
508 handle
= scm_hashq_create_handle_x (scm_protects
, obj
, scm_from_int (0));
509 SCM_SETCDR (handle
, scm_sum (SCM_CDR (handle
), scm_from_int (1)));
511 protected_obj_count
++;
513 SCM_CRITICAL_SECTION_END
;
519 /* Remove any protection for OBJ established by a prior call to
520 scm_protect_object. This function returns OBJ.
522 See scm_protect_object for more information. */
524 scm_gc_unprotect_object (SCM obj
)
528 /* This critical section barrier will be replaced by a mutex. */
529 /* njrev: and again. */
530 SCM_CRITICAL_SECTION_START
;
532 if (scm_gc_running_p
)
534 fprintf (stderr
, "scm_unprotect_object called during GC.\n");
538 handle
= scm_hashq_get_handle (scm_protects
, obj
);
540 if (scm_is_false (handle
))
542 fprintf (stderr
, "scm_unprotect_object called on unprotected object\n");
547 SCM count
= scm_difference (SCM_CDR (handle
), scm_from_int (1));
548 if (scm_is_eq (count
, scm_from_int (0)))
549 scm_hashq_remove_x (scm_protects
, obj
);
551 SCM_SETCDR (handle
, count
);
553 protected_obj_count
--;
555 SCM_CRITICAL_SECTION_END
;
561 scm_gc_register_root (SCM
*p
)
567 scm_gc_unregister_root (SCM
*p
)
573 scm_gc_register_roots (SCM
*b
, unsigned long n
)
576 for (; p
< b
+ n
; ++p
)
577 scm_gc_register_root (p
);
581 scm_gc_unregister_roots (SCM
*b
, unsigned long n
)
584 for (; p
< b
+ n
; ++p
)
585 scm_gc_unregister_root (p
);
592 MOVE THIS FUNCTION. IT DOES NOT HAVE ANYTHING TODO WITH GC.
595 /* Get an integer from an environment variable. */
597 scm_getenv_int (const char *var
, int def
)
600 char *val
= getenv (var
);
604 res
= strtol (val
, &end
, 10);
611 scm_storage_prehistory ()
613 GC_all_interior_pointers
= 0;
614 free_space_divisor
= scm_getenv_int ("GC_FREE_SPACE_DIVISOR", 3);
615 minimum_free_space_divisor
= free_space_divisor
;
616 target_free_space_divisor
= free_space_divisor
;
617 GC_set_free_space_divisor (free_space_divisor
);
621 #if (! ((defined GC_VERSION_MAJOR) && (GC_VERSION_MAJOR >= 7))) \
622 && (defined SCM_I_GSC_USE_PTHREAD_THREADS)
623 /* When using GC 6.8, this call is required to initialize thread-local
624 freelists (shouldn't be necessary with GC 7.0). */
628 GC_expand_hp (SCM_DEFAULT_INIT_HEAP_SIZE_2
);
630 /* We only need to register a displacement for those types for which the
631 higher bits of the type tag are used to store a pointer (that is, a
632 pointer to an 8-octet aligned region). For `scm_tc3_struct', this is
633 handled in `scm_alloc_struct ()'. */
634 GC_REGISTER_DISPLACEMENT (scm_tc3_cons
);
635 /* GC_REGISTER_DISPLACEMENT (scm_tc3_unused); */
638 if (!GC_is_visible (&scm_protects
))
641 scm_c_hook_init (&scm_before_gc_c_hook
, 0, SCM_C_HOOK_NORMAL
);
642 scm_c_hook_init (&scm_before_mark_c_hook
, 0, SCM_C_HOOK_NORMAL
);
643 scm_c_hook_init (&scm_before_sweep_c_hook
, 0, SCM_C_HOOK_NORMAL
);
644 scm_c_hook_init (&scm_after_sweep_c_hook
, 0, SCM_C_HOOK_NORMAL
);
645 scm_c_hook_init (&scm_after_gc_c_hook
, 0, SCM_C_HOOK_NORMAL
);
648 scm_i_pthread_mutex_t scm_i_gc_admin_mutex
= SCM_I_PTHREAD_MUTEX_INITIALIZER
;
651 scm_init_gc_protect_object ()
653 scm_protects
= scm_c_make_hash_table (31);
656 /* We can't have a cleanup handler since we have no thread to run it
663 on_exit (cleanup
, 0);
672 SCM scm_after_gc_hook
;
674 static SCM after_gc_async_cell
;
676 /* The function after_gc_async_thunk causes the execution of the
677 * after-gc-hook. It is run after the gc, as soon as the asynchronous
678 * events are handled by the evaluator.
681 after_gc_async_thunk (void)
683 /* Fun, no? Hook-run *and* run-hook? */
684 scm_c_hook_run (&scm_after_gc_c_hook
, NULL
);
685 scm_c_run_hook (scm_after_gc_hook
, SCM_EOL
);
686 return SCM_UNSPECIFIED
;
690 /* The function queue_after_gc_hook is run by the scm_before_gc_c_hook
691 * at the end of the garbage collection. The only purpose of this
692 * function is to mark the after_gc_async (which will eventually lead to
693 * the execution of the after_gc_async_thunk).
696 queue_after_gc_hook (void * hook_data SCM_UNUSED
,
697 void *fn_data SCM_UNUSED
,
698 void *data SCM_UNUSED
)
700 /* If cell access debugging is enabled, the user may choose to perform
701 * additional garbage collections after an arbitrary number of cell
702 * accesses. We don't want the scheme level after-gc-hook to be performed
703 * for each of these garbage collections for the following reason: The
704 * execution of the after-gc-hook causes cell accesses itself. Thus, if the
705 * after-gc-hook was performed with every gc, and if the gc was performed
706 * after a very small number of cell accesses, then the number of cell
707 * accesses during the execution of the after-gc-hook will suffice to cause
708 * the execution of the next gc. Then, guile would keep executing the
709 * after-gc-hook over and over again, and would never come to do other
712 * To overcome this problem, if cell access debugging with additional
713 * garbage collections is enabled, the after-gc-hook is never run by the
714 * garbage collecter. When running guile with cell access debugging and the
715 * execution of the after-gc-hook is desired, then it is necessary to run
716 * the hook explicitly from the user code. This has the effect, that from
717 * the scheme level point of view it seems that garbage collection is
718 * performed with a much lower frequency than it actually is. Obviously,
719 * this will not work for code that depends on a fixed one to one
720 * relationship between the execution counts of the C level garbage
721 * collection hooks and the execution count of the scheme level
725 #if (SCM_DEBUG_CELL_ACCESSES == 1)
726 if (scm_debug_cells_gc_interval
== 0)
729 scm_i_thread
*t
= SCM_I_CURRENT_THREAD
;
731 if (scm_is_false (SCM_CDR (after_gc_async_cell
)))
733 SCM_SETCDR (after_gc_async_cell
, t
->active_asyncs
);
734 t
->active_asyncs
= after_gc_async_cell
;
735 t
->pending_asyncs
= 1;
745 start_gc_timer (void * hook_data SCM_UNUSED
,
746 void *fn_data SCM_UNUSED
,
747 void *data SCM_UNUSED
)
750 gc_start_time
= scm_c_get_internal_run_time ();
756 accumulate_gc_timer (void * hook_data SCM_UNUSED
,
757 void *fn_data SCM_UNUSED
,
758 void *data SCM_UNUSED
)
762 long now
= scm_c_get_internal_run_time ();
763 gc_time_taken
+= now
- gc_start_time
;
770 /* Return some idea of the memory footprint of a process, in bytes.
771 Currently only works on Linux systems. */
773 get_image_size (void)
775 unsigned long size
, resident
, share
;
778 FILE *fp
= fopen ("/proc/self/statm", "r");
780 if (fp
&& fscanf (fp
, "%lu %lu %lu", &size
, &resident
, &share
) == 3)
781 ret
= resident
* 4096;
789 /* These are discussed later. */
790 static size_t bytes_until_gc
;
791 static scm_i_pthread_mutex_t bytes_until_gc_lock
= SCM_I_PTHREAD_MUTEX_INITIALIZER
;
793 /* Make GC run more frequently when the process image size is growing,
794 measured against the number of bytes allocated through the GC.
796 If Guile is allocating at a GC-managed heap size H, libgc will tend
797 to limit the process image size to H*N. But if at the same time the
798 user program is mallocating at a rate M bytes per GC-allocated byte,
799 then the process stabilizes at H*N*M -- assuming that collecting data
800 will result in malloc'd data being freed. It doesn't take a very
801 large M for this to be a bad situation. To limit the image size,
802 Guile should GC more often -- the bigger the M, the more often.
804 Numeric functions that produce bigger and bigger integers are
805 pessimal, because M is an increasing function of time. Here is an
806 example of such a function:
808 (define (factorial n)
812 (fac (1- n) (* n acc))))
815 It is possible for a process to grow for reasons that will not be
816 solved by faster GC. In that case M will be estimated as
817 artificially high for a while, and so GC will happen more often on
818 the Guile side. But when it stabilizes, Guile can ease back the GC
821 The key is to measure process image growth, not mallocation rate.
822 For maximum effectiveness, Guile reacts quickly to process growth,
823 and exponentially backs down when the process stops growing.
825 See http://thread.gmane.org/gmane.lisp.guile.devel/12552/focus=12936
826 for further discussion.
829 adjust_gc_frequency (void * hook_data SCM_UNUSED
,
830 void *fn_data SCM_UNUSED
,
831 void *data SCM_UNUSED
)
833 static size_t prev_image_size
= 0;
834 static size_t prev_bytes_alloced
= 0;
836 size_t bytes_alloced
;
838 scm_i_pthread_mutex_lock (&bytes_until_gc_lock
);
839 bytes_until_gc
= GC_get_heap_size ();
840 scm_i_pthread_mutex_unlock (&bytes_until_gc_lock
);
842 image_size
= get_image_size ();
843 bytes_alloced
= GC_get_total_bytes ();
845 #define HEURISTICS_DEBUG 0
848 fprintf (stderr
, "prev image / alloced: %lu / %lu\n", prev_image_size
, prev_bytes_alloced
);
849 fprintf (stderr
, " image / alloced: %lu / %lu\n", image_size
, bytes_alloced
);
850 fprintf (stderr
, "divisor %lu / %f\n", free_space_divisor
, target_free_space_divisor
);
853 if (prev_image_size
&& bytes_alloced
!= prev_bytes_alloced
)
855 double growth_rate
, new_target_free_space_divisor
;
856 double decay_factor
= 0.5;
857 double hysteresis
= 0.1;
859 growth_rate
= ((double) image_size
- prev_image_size
)
860 / ((double)bytes_alloced
- prev_bytes_alloced
);
863 fprintf (stderr
, "growth rate %f\n", growth_rate
);
866 new_target_free_space_divisor
= minimum_free_space_divisor
;
869 new_target_free_space_divisor
*= 1.0 + growth_rate
;
872 fprintf (stderr
, "new divisor %f\n", new_target_free_space_divisor
);
875 if (new_target_free_space_divisor
< target_free_space_divisor
)
877 target_free_space_divisor
=
878 (decay_factor
* target_free_space_divisor
879 + (1.0 - decay_factor
) * new_target_free_space_divisor
);
882 target_free_space_divisor
= new_target_free_space_divisor
;
885 fprintf (stderr
, "new target divisor %f\n", target_free_space_divisor
);
888 if (free_space_divisor
+ 0.5 + hysteresis
< target_free_space_divisor
889 || free_space_divisor
- 0.5 - hysteresis
> target_free_space_divisor
)
891 free_space_divisor
= lround (target_free_space_divisor
);
893 fprintf (stderr
, "new divisor %lu\n", free_space_divisor
);
895 GC_set_free_space_divisor (free_space_divisor
);
899 prev_image_size
= image_size
;
900 prev_bytes_alloced
= bytes_alloced
;
905 /* The adjust_gc_frequency routine handles transients in the process
906 image size. It can't handle instense non-GC-managed steady-state
907 allocation though, as it decays the FSD at steady-state down to its
910 The only real way to handle continuous, high non-GC allocation is to
911 let the GC know about it. This routine can handle non-GC allocation
912 rates that are similar in size to the GC-managed heap size.
916 scm_gc_register_allocation (size_t size
)
918 scm_i_pthread_mutex_lock (&bytes_until_gc_lock
);
919 if (bytes_until_gc
- size
> bytes_until_gc
)
921 bytes_until_gc
= GC_get_heap_size ();
922 scm_i_pthread_mutex_unlock (&bytes_until_gc_lock
);
927 bytes_until_gc
-= size
;
928 scm_i_pthread_mutex_unlock (&bytes_until_gc_lock
);
936 scm_i_tag_name (scm_t_bits tag
)
938 switch (tag
& 0x7f) /* 7 bits */
942 case scm_tcs_cons_imcar
:
943 return "cons (immediate car)";
944 case scm_tcs_cons_nimcar
:
945 return "cons (non-immediate car)";
946 case scm_tc7_pointer
:
948 case scm_tc7_hashtable
:
950 case scm_tc7_weak_set
:
952 case scm_tc7_weak_table
:
956 case scm_tc7_dynamic_state
:
957 return "dynamic state";
960 case scm_tc7_objcode
:
964 case scm_tc7_vm_cont
:
965 return "vm continuation";
967 return "weak vector";
979 case scm_tc16_complex
:
980 return "complex number";
982 case scm_tc16_fraction
:
990 case scm_tc7_stringbuf
:
991 return "string buffer";
996 case scm_tc7_variable
:
1004 int k
= 0xff & (tag
>> 8);
1005 return (scm_smobs
[k
].name
);
1019 /* `GC_INIT ()' was invoked in `scm_storage_prehistory ()'. */
1021 scm_after_gc_hook
= scm_make_hook (SCM_INUM0
);
1022 scm_c_define ("after-gc-hook", scm_after_gc_hook
);
1024 /* When the async is to run, the cdr of the gc_async pair gets set to
1025 the asyncs queue of the current thread. */
1026 after_gc_async_cell
= scm_cons (scm_c_make_gsubr ("%after-gc-thunk", 0, 0, 0,
1027 after_gc_async_thunk
),
1030 scm_c_hook_add (&scm_before_gc_c_hook
, queue_after_gc_hook
, NULL
, 0);
1031 scm_c_hook_add (&scm_before_gc_c_hook
, start_gc_timer
, NULL
, 0);
1032 scm_c_hook_add (&scm_after_gc_c_hook
, accumulate_gc_timer
, NULL
, 0);
1034 #if HAVE_GC_GET_HEAP_USAGE_SAFE
1035 /* GC_get_heap_usage does not take a lock, and so can run in the GC
1037 scm_c_hook_add (&scm_before_gc_c_hook
, adjust_gc_frequency
, NULL
, 0);
1039 /* GC_get_heap_usage might take a lock (and did from 7.2alpha1 to
1040 7.2alpha7), so call it in the after_gc_hook. */
1041 scm_c_hook_add (&scm_after_gc_c_hook
, adjust_gc_frequency
, NULL
, 0);
1044 #ifdef HAVE_GC_SET_START_CALLBACK
1045 GC_set_start_callback (run_before_gc_c_hook
);
1048 #include "libguile/gc.x"
1054 #define FUNC_NAME "scm_gc_sweep"
1057 fprintf (stderr
, "%s: doing nothing\n", FUNC_NAME
);