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"
35 extern unsigned long * __libc_ia64_register_backing_store_base
;
38 #include "libguile/_scm.h"
39 #include "libguile/eval.h"
40 #include "libguile/stime.h"
41 #include "libguile/stackchk.h"
42 #include "libguile/struct.h"
43 #include "libguile/smob.h"
44 #include "libguile/arrays.h"
45 #include "libguile/async.h"
46 #include "libguile/ports.h"
47 #include "libguile/root.h"
48 #include "libguile/strings.h"
49 #include "libguile/vectors.h"
50 #include "libguile/hashtab.h"
51 #include "libguile/tags.h"
53 #include "libguile/private-gc.h"
54 #include "libguile/validate.h"
55 #include "libguile/deprecation.h"
56 #include "libguile/gc.h"
57 #include "libguile/dynwind.h"
59 #include "libguile/bdw-gc.h"
61 /* For GC_set_start_callback. */
62 #include <gc/gc_mark.h>
64 #ifdef GUILE_DEBUG_MALLOC
65 #include "libguile/debug-malloc.h"
72 /* Set this to != 0 if every cell that is accessed shall be checked:
74 int scm_debug_cell_accesses_p
= 0;
75 int scm_expensive_debug_cell_accesses_p
= 0;
77 /* Set this to 0 if no additional gc's shall be performed, otherwise set it to
78 * the number of cell accesses after which a gc shall be called.
80 int scm_debug_cells_gc_interval
= 0;
82 /* Hash table that keeps a reference to objects the user wants to protect from
83 garbage collection. */
84 static SCM scm_protects
;
87 #if (SCM_DEBUG_CELL_ACCESSES == 1)
92 Assert that the given object is a valid reference to a valid cell. This
93 test involves to determine whether the object is a cell pointer, whether
94 this pointer actually points into a heap segment and whether the cell
95 pointed to is not a free cell. Further, additional garbage collections may
96 get executed after a user defined number of cell accesses. This helps to
97 find places in the C code where references are dropped for extremely short
102 scm_i_expensive_validation_check (SCM cell
)
104 /* If desired, perform additional garbage collections after a user
105 * defined number of cell accesses.
107 if (scm_debug_cells_gc_interval
)
109 static unsigned int counter
= 0;
117 counter
= scm_debug_cells_gc_interval
;
123 /* Whether cell validation is already running. */
124 static int scm_i_cell_validation_already_running
= 0;
127 scm_assert_cell_valid (SCM cell
)
129 if (!scm_i_cell_validation_already_running
&& scm_debug_cell_accesses_p
)
131 scm_i_cell_validation_already_running
= 1; /* set to avoid recursion */
134 During GC, no user-code should be run, and the guile core
135 should use non-protected accessors.
137 if (scm_gc_running_p
)
141 Only scm_in_heap_p and rescanning the heap is wildly
144 if (scm_expensive_debug_cell_accesses_p
)
145 scm_i_expensive_validation_check (cell
);
147 scm_i_cell_validation_already_running
= 0; /* re-enable */
153 SCM_DEFINE (scm_set_debug_cell_accesses_x
, "set-debug-cell-accesses!", 1, 0, 0,
155 "If @var{flag} is @code{#f}, cell access checking is disabled.\n"
156 "If @var{flag} is @code{#t}, cheap cell access checking is enabled,\n"
157 "but no additional calls to garbage collection are issued.\n"
158 "If @var{flag} is a number, strict cell access checking is enabled,\n"
159 "with an additional garbage collection after the given\n"
160 "number of cell accesses.\n"
161 "This procedure only exists when the compile-time flag\n"
162 "@code{SCM_DEBUG_CELL_ACCESSES} was set to 1.")
163 #define FUNC_NAME s_scm_set_debug_cell_accesses_x
165 if (scm_is_false (flag
))
167 scm_debug_cell_accesses_p
= 0;
169 else if (scm_is_eq (flag
, SCM_BOOL_T
))
171 scm_debug_cells_gc_interval
= 0;
172 scm_debug_cell_accesses_p
= 1;
173 scm_expensive_debug_cell_accesses_p
= 0;
177 scm_debug_cells_gc_interval
= scm_to_signed_integer (flag
, 0, INT_MAX
);
178 scm_debug_cell_accesses_p
= 1;
179 scm_expensive_debug_cell_accesses_p
= 1;
181 return SCM_UNSPECIFIED
;
186 #endif /* SCM_DEBUG_CELL_ACCESSES == 1 */
192 #ifndef HAVE_GC_GET_HEAP_USAGE_SAFE
194 GC_get_heap_usage_safe (GC_word
*pheap_size
, GC_word
*pfree_bytes
,
195 GC_word
*punmapped_bytes
, GC_word
*pbytes_since_gc
,
196 GC_word
*ptotal_bytes
)
198 *pheap_size
= GC_get_heap_size ();
199 *pfree_bytes
= GC_get_free_bytes ();
200 #ifdef HAVE_GC_GET_UNMAPPED_BYTES
201 *punmapped_bytes
= GC_get_unmapped_bytes ();
203 *punmapped_bytes
= 0;
205 *pbytes_since_gc
= GC_get_bytes_since_gc ();
206 *ptotal_bytes
= GC_get_total_bytes ();
210 #ifndef HAVE_GC_GET_FREE_SPACE_DIVISOR
212 GC_get_free_space_divisor (void)
214 return GC_free_space_divisor
;
220 scm_t_c_hook scm_before_gc_c_hook
;
221 scm_t_c_hook scm_before_mark_c_hook
;
222 scm_t_c_hook scm_before_sweep_c_hook
;
223 scm_t_c_hook scm_after_sweep_c_hook
;
224 scm_t_c_hook scm_after_gc_c_hook
;
228 run_before_gc_c_hook (void)
230 scm_c_hook_run (&scm_before_gc_c_hook
, NULL
);
234 /* GC Statistics Keeping
236 unsigned long scm_gc_ports_collected
= 0;
237 static long gc_time_taken
= 0;
238 static long gc_start_time
= 0;
240 static unsigned long free_space_divisor
;
241 static unsigned long minimum_free_space_divisor
;
242 static double target_free_space_divisor
;
244 static unsigned long protected_obj_count
= 0;
247 SCM_SYMBOL (sym_gc_time_taken
, "gc-time-taken");
248 SCM_SYMBOL (sym_heap_size
, "heap-size");
249 SCM_SYMBOL (sym_heap_free_size
, "heap-free-size");
250 SCM_SYMBOL (sym_heap_total_allocated
, "heap-total-allocated");
251 SCM_SYMBOL (sym_heap_allocated_since_gc
, "heap-allocated-since-gc");
252 SCM_SYMBOL (sym_protected_objects
, "protected-objects");
253 SCM_SYMBOL (sym_times
, "gc-times");
256 /* {Scheme Interface to GC}
259 tag_table_to_type_alist (void *closure
, SCM key
, SCM val
, SCM acc
)
261 if (scm_is_integer (key
))
263 int c_tag
= scm_to_int (key
);
265 char const * name
= scm_i_tag_name (c_tag
);
268 key
= scm_from_locale_string (name
);
273 sprintf (s
, "tag %d", c_tag
);
274 key
= scm_from_locale_string (s
);
278 return scm_cons (scm_cons (key
, val
), acc
);
281 SCM_DEFINE (scm_gc_live_object_stats
, "gc-live-object-stats", 0, 0, 0,
283 "Return an alist of statistics of the current live objects. ")
284 #define FUNC_NAME s_scm_gc_live_object_stats
286 SCM tab
= scm_make_hash_table (scm_from_int (57));
290 = scm_internal_hash_fold (&tag_table_to_type_alist
, NULL
, SCM_EOL
, tab
);
296 extern int scm_gc_malloc_yield_percentage
;
297 SCM_DEFINE (scm_gc_stats
, "gc-stats", 0, 0, 0,
299 "Return an association list of statistics about Guile's current\n"
301 #define FUNC_NAME s_scm_gc_stats
304 GC_word heap_size
, free_bytes
, unmapped_bytes
, bytes_since_gc
, total_bytes
;
307 GC_get_heap_usage_safe (&heap_size
, &free_bytes
, &unmapped_bytes
,
308 &bytes_since_gc
, &total_bytes
);
312 scm_list_n (scm_cons (sym_gc_time_taken
, scm_from_long (gc_time_taken
)),
313 scm_cons (sym_heap_size
, scm_from_size_t (heap_size
)),
314 scm_cons (sym_heap_free_size
, scm_from_size_t (free_bytes
)),
315 scm_cons (sym_heap_total_allocated
,
316 scm_from_size_t (total_bytes
)),
317 scm_cons (sym_heap_allocated_since_gc
,
318 scm_from_size_t (bytes_since_gc
)),
319 scm_cons (sym_protected_objects
,
320 scm_from_ulong (protected_obj_count
)),
321 scm_cons (sym_times
, scm_from_size_t (gc_times
)),
329 SCM_DEFINE (scm_gc_dump
, "gc-dump", 0, 0, 0,
331 "Dump information about the garbage collector's internal data "
332 "structures and memory usage to the standard output.")
333 #define FUNC_NAME s_scm_gc_dump
337 return SCM_UNSPECIFIED
;
342 SCM_DEFINE (scm_object_address
, "object-address", 1, 0, 0,
344 "Return an integer that for the lifetime of @var{obj} is uniquely\n"
345 "returned by this function for @var{obj}")
346 #define FUNC_NAME s_scm_object_address
348 return scm_from_ulong (SCM_UNPACK (obj
));
353 SCM_DEFINE (scm_gc_disable
, "gc-disable", 0, 0, 0,
355 "Disables the garbage collector. Nested calls are permitted. "
356 "GC is re-enabled once @code{gc-enable} has been called the "
357 "same number of times @code{gc-disable} was called.")
358 #define FUNC_NAME s_scm_gc_disable
361 return SCM_UNSPECIFIED
;
365 SCM_DEFINE (scm_gc_enable
, "gc-enable", 0, 0, 0,
367 "Enables the garbage collector.")
368 #define FUNC_NAME s_scm_gc_enable
371 return SCM_UNSPECIFIED
;
376 SCM_DEFINE (scm_gc
, "gc", 0, 0, 0,
378 "Scans all of SCM objects and reclaims for further use those that are\n"
379 "no longer accessible.")
380 #define FUNC_NAME s_scm_gc
383 return SCM_UNSPECIFIED
;
388 scm_i_gc (const char *what
)
390 #ifndef HAVE_GC_SET_START_CALLBACK
391 run_before_gc_c_hook ();
398 /* {GC Protection Helper Functions}
403 * If within a function you need to protect one or more scheme objects from
404 * garbage collection, pass them as parameters to one of the
405 * scm_remember_upto_here* functions below. These functions don't do
406 * anything, but since the compiler does not know that they are actually
407 * no-ops, it will generate code that calls these functions with the given
408 * parameters. Therefore, you can be sure that the compiler will keep those
409 * scheme values alive (on the stack or in a register) up to the point where
410 * scm_remember_upto_here* is called. In other words, place the call to
411 * scm_remember_upto_here* _behind_ the last code in your function, that
412 * depends on the scheme object to exist.
414 * Example: We want to make sure that the string object str does not get
415 * garbage collected during the execution of 'some_function' in the code
416 * below, because otherwise the characters belonging to str would be freed and
417 * 'some_function' might access freed memory. To make sure that the compiler
418 * keeps str alive on the stack or in a register such that it is visible to
419 * the conservative gc we add the call to scm_remember_upto_here_1 _after_ the
420 * call to 'some_function'. Note that this would not be necessary if str was
421 * used anyway after the call to 'some_function'.
422 * char *chars = scm_i_string_chars (str);
423 * some_function (chars);
424 * scm_remember_upto_here_1 (str); // str will be alive up to this point.
427 /* Remove any macro versions of these while defining the functions.
428 Functions are always included in the library, for upward binary
429 compatibility and in case combinations of GCC and non-GCC are used. */
430 #undef scm_remember_upto_here_1
431 #undef scm_remember_upto_here_2
434 scm_remember_upto_here_1 (SCM obj SCM_UNUSED
)
436 /* Empty. Protects a single object from garbage collection. */
440 scm_remember_upto_here_2 (SCM obj1 SCM_UNUSED
, SCM obj2 SCM_UNUSED
)
442 /* Empty. Protects two objects from garbage collection. */
446 scm_remember_upto_here (SCM obj SCM_UNUSED
, ...)
448 /* Empty. Protects any number of objects from garbage collection. */
452 These crazy functions prevent garbage collection
453 of arguments after the first argument by
454 ensuring they remain live throughout the
455 function because they are used in the last
456 line of the code block.
457 It'd be better to have a nice compiler hint to
458 aid the conservative stack-scanning GC. --03/09/00 gjb */
460 scm_return_first (SCM elt
, ...)
466 scm_return_first_int (int i
, ...)
473 scm_permanent_object (SCM obj
)
475 return (scm_gc_protect_object (obj
));
479 /* Protect OBJ from the garbage collector. OBJ will not be freed, even if all
480 other references are dropped, until the object is unprotected by calling
481 scm_gc_unprotect_object (OBJ). Calls to scm_gc_protect/unprotect_object nest,
482 i. e. it is possible to protect the same object several times, but it is
483 necessary to unprotect the object the same number of times to actually get
484 the object unprotected. It is an error to unprotect an object more often
485 than it has been protected before. The function scm_protect_object returns
489 /* Implementation note: For every object X, there is a counter which
490 scm_gc_protect_object (X) increments and scm_gc_unprotect_object (X) decrements.
496 scm_gc_protect_object (SCM obj
)
500 /* This critical section barrier will be replaced by a mutex. */
501 /* njrev: Indeed; if my comment above is correct, there is the same
502 critsec/mutex inconsistency here. */
503 SCM_CRITICAL_SECTION_START
;
505 handle
= scm_hashq_create_handle_x (scm_protects
, obj
, scm_from_int (0));
506 SCM_SETCDR (handle
, scm_sum (SCM_CDR (handle
), scm_from_int (1)));
508 protected_obj_count
++;
510 SCM_CRITICAL_SECTION_END
;
516 /* Remove any protection for OBJ established by a prior call to
517 scm_protect_object. This function returns OBJ.
519 See scm_protect_object for more information. */
521 scm_gc_unprotect_object (SCM obj
)
525 /* This critical section barrier will be replaced by a mutex. */
526 /* njrev: and again. */
527 SCM_CRITICAL_SECTION_START
;
529 if (scm_gc_running_p
)
531 fprintf (stderr
, "scm_unprotect_object called during GC.\n");
535 handle
= scm_hashq_get_handle (scm_protects
, obj
);
537 if (scm_is_false (handle
))
539 fprintf (stderr
, "scm_unprotect_object called on unprotected object\n");
544 SCM count
= scm_difference (SCM_CDR (handle
), scm_from_int (1));
545 if (scm_is_eq (count
, scm_from_int (0)))
546 scm_hashq_remove_x (scm_protects
, obj
);
548 SCM_SETCDR (handle
, count
);
550 protected_obj_count
--;
552 SCM_CRITICAL_SECTION_END
;
558 scm_gc_register_root (SCM
*p
)
564 scm_gc_unregister_root (SCM
*p
)
570 scm_gc_register_roots (SCM
*b
, unsigned long n
)
573 for (; p
< b
+ n
; ++p
)
574 scm_gc_register_root (p
);
578 scm_gc_unregister_roots (SCM
*b
, unsigned long n
)
581 for (; p
< b
+ n
; ++p
)
582 scm_gc_unregister_root (p
);
589 MOVE THIS FUNCTION. IT DOES NOT HAVE ANYTHING TODO WITH GC.
592 /* Get an integer from an environment variable. */
594 scm_getenv_int (const char *var
, int def
)
597 char *val
= getenv (var
);
601 res
= strtol (val
, &end
, 10);
608 scm_storage_prehistory ()
610 GC_all_interior_pointers
= 0;
611 free_space_divisor
= scm_getenv_int ("GC_FREE_SPACE_DIVISOR", 3);
612 minimum_free_space_divisor
= free_space_divisor
;
613 target_free_space_divisor
= free_space_divisor
;
614 GC_set_free_space_divisor (free_space_divisor
);
618 #if (! ((defined GC_VERSION_MAJOR) && (GC_VERSION_MAJOR >= 7))) \
619 && (defined SCM_I_GSC_USE_PTHREAD_THREADS)
620 /* When using GC 6.8, this call is required to initialize thread-local
621 freelists (shouldn't be necessary with GC 7.0). */
625 GC_expand_hp (SCM_DEFAULT_INIT_HEAP_SIZE_2
);
627 /* We only need to register a displacement for those types for which the
628 higher bits of the type tag are used to store a pointer (that is, a
629 pointer to an 8-octet aligned region). For `scm_tc3_struct', this is
630 handled in `scm_alloc_struct ()'. */
631 GC_REGISTER_DISPLACEMENT (scm_tc3_cons
);
632 /* GC_REGISTER_DISPLACEMENT (scm_tc3_unused); */
635 if (!GC_is_visible (&scm_protects
))
638 scm_c_hook_init (&scm_before_gc_c_hook
, 0, SCM_C_HOOK_NORMAL
);
639 scm_c_hook_init (&scm_before_mark_c_hook
, 0, SCM_C_HOOK_NORMAL
);
640 scm_c_hook_init (&scm_before_sweep_c_hook
, 0, SCM_C_HOOK_NORMAL
);
641 scm_c_hook_init (&scm_after_sweep_c_hook
, 0, SCM_C_HOOK_NORMAL
);
642 scm_c_hook_init (&scm_after_gc_c_hook
, 0, SCM_C_HOOK_NORMAL
);
645 scm_i_pthread_mutex_t scm_i_gc_admin_mutex
= SCM_I_PTHREAD_MUTEX_INITIALIZER
;
648 scm_init_gc_protect_object ()
650 scm_protects
= scm_c_make_hash_table (31);
653 /* We can't have a cleanup handler since we have no thread to run it
660 on_exit (cleanup
, 0);
669 SCM scm_after_gc_hook
;
671 static SCM after_gc_async_cell
;
673 /* The function after_gc_async_thunk causes the execution of the
674 * after-gc-hook. It is run after the gc, as soon as the asynchronous
675 * events are handled by the evaluator.
678 after_gc_async_thunk (void)
680 /* Fun, no? Hook-run *and* run-hook? */
681 scm_c_hook_run (&scm_after_gc_c_hook
, NULL
);
682 scm_c_run_hook (scm_after_gc_hook
, SCM_EOL
);
683 return SCM_UNSPECIFIED
;
687 /* The function queue_after_gc_hook is run by the scm_before_gc_c_hook
688 * at the end of the garbage collection. The only purpose of this
689 * function is to mark the after_gc_async (which will eventually lead to
690 * the execution of the after_gc_async_thunk).
693 queue_after_gc_hook (void * hook_data SCM_UNUSED
,
694 void *fn_data SCM_UNUSED
,
695 void *data SCM_UNUSED
)
697 /* If cell access debugging is enabled, the user may choose to perform
698 * additional garbage collections after an arbitrary number of cell
699 * accesses. We don't want the scheme level after-gc-hook to be performed
700 * for each of these garbage collections for the following reason: The
701 * execution of the after-gc-hook causes cell accesses itself. Thus, if the
702 * after-gc-hook was performed with every gc, and if the gc was performed
703 * after a very small number of cell accesses, then the number of cell
704 * accesses during the execution of the after-gc-hook will suffice to cause
705 * the execution of the next gc. Then, guile would keep executing the
706 * after-gc-hook over and over again, and would never come to do other
709 * To overcome this problem, if cell access debugging with additional
710 * garbage collections is enabled, the after-gc-hook is never run by the
711 * garbage collecter. When running guile with cell access debugging and the
712 * execution of the after-gc-hook is desired, then it is necessary to run
713 * the hook explicitly from the user code. This has the effect, that from
714 * the scheme level point of view it seems that garbage collection is
715 * performed with a much lower frequency than it actually is. Obviously,
716 * this will not work for code that depends on a fixed one to one
717 * relationship between the execution counts of the C level garbage
718 * collection hooks and the execution count of the scheme level
722 #if (SCM_DEBUG_CELL_ACCESSES == 1)
723 if (scm_debug_cells_gc_interval
== 0)
726 scm_i_thread
*t
= SCM_I_CURRENT_THREAD
;
728 if (scm_is_false (SCM_CDR (after_gc_async_cell
)))
730 SCM_SETCDR (after_gc_async_cell
, t
->active_asyncs
);
731 t
->active_asyncs
= after_gc_async_cell
;
732 t
->pending_asyncs
= 1;
742 start_gc_timer (void * hook_data SCM_UNUSED
,
743 void *fn_data SCM_UNUSED
,
744 void *data SCM_UNUSED
)
747 gc_start_time
= scm_c_get_internal_run_time ();
753 accumulate_gc_timer (void * hook_data SCM_UNUSED
,
754 void *fn_data SCM_UNUSED
,
755 void *data SCM_UNUSED
)
759 long now
= scm_c_get_internal_run_time ();
760 gc_time_taken
+= now
- gc_start_time
;
767 /* Return some idea of the memory footprint of a process, in bytes.
768 Currently only works on Linux systems. */
770 get_image_size (void)
772 unsigned long size
, resident
, share
;
775 FILE *fp
= fopen ("/proc/self/statm", "r");
777 if (fp
&& fscanf (fp
, "%lu %lu %lu", &size
, &resident
, &share
) == 3)
778 ret
= resident
* 4096;
786 /* These are discussed later. */
787 static size_t bytes_until_gc
;
788 static scm_i_pthread_mutex_t bytes_until_gc_lock
= SCM_I_PTHREAD_MUTEX_INITIALIZER
;
790 /* Make GC run more frequently when the process image size is growing,
791 measured against the number of bytes allocated through the GC.
793 If Guile is allocating at a GC-managed heap size H, libgc will tend
794 to limit the process image size to H*N. But if at the same time the
795 user program is mallocating at a rate M bytes per GC-allocated byte,
796 then the process stabilizes at H*N*M -- assuming that collecting data
797 will result in malloc'd data being freed. It doesn't take a very
798 large M for this to be a bad situation. To limit the image size,
799 Guile should GC more often -- the bigger the M, the more often.
801 Numeric functions that produce bigger and bigger integers are
802 pessimal, because M is an increasing function of time. Here is an
803 example of such a function:
805 (define (factorial n)
809 (fac (1- n) (* n acc))))
812 It is possible for a process to grow for reasons that will not be
813 solved by faster GC. In that case M will be estimated as
814 artificially high for a while, and so GC will happen more often on
815 the Guile side. But when it stabilizes, Guile can ease back the GC
818 The key is to measure process image growth, not mallocation rate.
819 For maximum effectiveness, Guile reacts quickly to process growth,
820 and exponentially backs down when the process stops growing.
822 See http://thread.gmane.org/gmane.lisp.guile.devel/12552/focus=12936
823 for further discussion.
826 adjust_gc_frequency (void * hook_data SCM_UNUSED
,
827 void *fn_data SCM_UNUSED
,
828 void *data SCM_UNUSED
)
830 static size_t prev_image_size
= 0;
831 static size_t prev_bytes_alloced
= 0;
833 size_t bytes_alloced
;
835 scm_i_pthread_mutex_lock (&bytes_until_gc_lock
);
836 bytes_until_gc
= GC_get_heap_size ();
837 scm_i_pthread_mutex_unlock (&bytes_until_gc_lock
);
839 image_size
= get_image_size ();
840 bytes_alloced
= GC_get_total_bytes ();
842 #define HEURISTICS_DEBUG 0
845 fprintf (stderr
, "prev image / alloced: %lu / %lu\n", prev_image_size
, prev_bytes_alloced
);
846 fprintf (stderr
, " image / alloced: %lu / %lu\n", image_size
, bytes_alloced
);
847 fprintf (stderr
, "divisor %lu / %f\n", free_space_divisor
, target_free_space_divisor
);
850 if (prev_image_size
&& bytes_alloced
!= prev_bytes_alloced
)
852 double growth_rate
, new_target_free_space_divisor
;
853 double decay_factor
= 0.5;
854 double hysteresis
= 0.1;
856 growth_rate
= ((double) image_size
- prev_image_size
)
857 / ((double)bytes_alloced
- prev_bytes_alloced
);
860 fprintf (stderr
, "growth rate %f\n", growth_rate
);
863 new_target_free_space_divisor
= minimum_free_space_divisor
;
866 new_target_free_space_divisor
*= 1.0 + growth_rate
;
869 fprintf (stderr
, "new divisor %f\n", new_target_free_space_divisor
);
872 if (new_target_free_space_divisor
< target_free_space_divisor
)
874 target_free_space_divisor
=
875 (decay_factor
* target_free_space_divisor
876 + (1.0 - decay_factor
) * new_target_free_space_divisor
);
879 target_free_space_divisor
= new_target_free_space_divisor
;
882 fprintf (stderr
, "new target divisor %f\n", target_free_space_divisor
);
885 if (free_space_divisor
+ 0.5 + hysteresis
< target_free_space_divisor
886 || free_space_divisor
- 0.5 - hysteresis
> target_free_space_divisor
)
888 free_space_divisor
= lround (target_free_space_divisor
);
890 fprintf (stderr
, "new divisor %lu\n", free_space_divisor
);
892 GC_set_free_space_divisor (free_space_divisor
);
896 prev_image_size
= image_size
;
897 prev_bytes_alloced
= bytes_alloced
;
902 /* The adjust_gc_frequency routine handles transients in the process
903 image size. It can't handle instense non-GC-managed steady-state
904 allocation though, as it decays the FSD at steady-state down to its
907 The only real way to handle continuous, high non-GC allocation is to
908 let the GC know about it. This routine can handle non-GC allocation
909 rates that are similar in size to the GC-managed heap size.
913 scm_gc_register_allocation (size_t size
)
915 scm_i_pthread_mutex_lock (&bytes_until_gc_lock
);
916 if (bytes_until_gc
- size
> bytes_until_gc
)
918 bytes_until_gc
= GC_get_heap_size ();
919 scm_i_pthread_mutex_unlock (&bytes_until_gc_lock
);
924 bytes_until_gc
-= size
;
925 scm_i_pthread_mutex_unlock (&bytes_until_gc_lock
);
933 scm_i_tag_name (scm_t_bits tag
)
935 switch (tag
& 0x7f) /* 7 bits */
939 case scm_tcs_cons_imcar
:
940 return "cons (immediate car)";
941 case scm_tcs_cons_nimcar
:
942 return "cons (non-immediate car)";
943 case scm_tc7_pointer
:
945 case scm_tc7_hashtable
:
947 case scm_tc7_weak_set
:
949 case scm_tc7_weak_table
:
953 case scm_tc7_dynamic_state
:
954 return "dynamic state";
957 case scm_tc7_objcode
:
961 case scm_tc7_vm_cont
:
962 return "vm continuation";
964 return "weak vector";
976 case scm_tc16_complex
:
977 return "complex number";
979 case scm_tc16_fraction
:
987 case scm_tc7_stringbuf
:
988 return "string buffer";
993 case scm_tc7_variable
:
1001 int k
= 0xff & (tag
>> 8);
1002 return (scm_smobs
[k
].name
);
1016 /* `GC_INIT ()' was invoked in `scm_storage_prehistory ()'. */
1018 scm_after_gc_hook
= scm_make_hook (SCM_INUM0
);
1019 scm_c_define ("after-gc-hook", scm_after_gc_hook
);
1021 /* When the async is to run, the cdr of the gc_async pair gets set to
1022 the asyncs queue of the current thread. */
1023 after_gc_async_cell
= scm_cons (scm_c_make_gsubr ("%after-gc-thunk", 0, 0, 0,
1024 after_gc_async_thunk
),
1027 scm_c_hook_add (&scm_before_gc_c_hook
, queue_after_gc_hook
, NULL
, 0);
1028 scm_c_hook_add (&scm_before_gc_c_hook
, start_gc_timer
, NULL
, 0);
1029 scm_c_hook_add (&scm_after_gc_c_hook
, accumulate_gc_timer
, NULL
, 0);
1031 #if HAVE_GC_GET_HEAP_USAGE_SAFE
1032 /* GC_get_heap_usage does not take a lock, and so can run in the GC
1034 scm_c_hook_add (&scm_before_gc_c_hook
, adjust_gc_frequency
, NULL
, 0);
1036 /* GC_get_heap_usage might take a lock (and did from 7.2alpha1 to
1037 7.2alpha7), so call it in the after_gc_hook. */
1038 scm_c_hook_add (&scm_after_gc_c_hook
, adjust_gc_frequency
, NULL
, 0);
1041 #ifdef HAVE_GC_SET_START_CALLBACK
1042 GC_set_start_callback (run_before_gc_c_hook
);
1045 #include "libguile/gc.x"
1051 #define FUNC_NAME "scm_gc_sweep"
1054 fprintf (stderr
, "%s: doing nothing\n", FUNC_NAME
);