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 if (!SCM_I_CURRENT_THREAD
)
231 /* GC while a thread is spinning up; punt. */
234 scm_c_hook_run (&scm_before_gc_c_hook
, NULL
);
238 /* GC Statistics Keeping
240 unsigned long scm_gc_ports_collected
= 0;
241 static long gc_time_taken
= 0;
242 static long gc_start_time
= 0;
244 static unsigned long free_space_divisor
;
245 static unsigned long minimum_free_space_divisor
;
246 static double target_free_space_divisor
;
248 static unsigned long protected_obj_count
= 0;
251 SCM_SYMBOL (sym_gc_time_taken
, "gc-time-taken");
252 SCM_SYMBOL (sym_heap_size
, "heap-size");
253 SCM_SYMBOL (sym_heap_free_size
, "heap-free-size");
254 SCM_SYMBOL (sym_heap_total_allocated
, "heap-total-allocated");
255 SCM_SYMBOL (sym_heap_allocated_since_gc
, "heap-allocated-since-gc");
256 SCM_SYMBOL (sym_protected_objects
, "protected-objects");
257 SCM_SYMBOL (sym_times
, "gc-times");
260 /* {Scheme Interface to GC}
263 tag_table_to_type_alist (void *closure
, SCM key
, SCM val
, SCM acc
)
265 if (scm_is_integer (key
))
267 int c_tag
= scm_to_int (key
);
269 char const * name
= scm_i_tag_name (c_tag
);
272 key
= scm_from_locale_string (name
);
277 sprintf (s
, "tag %d", c_tag
);
278 key
= scm_from_locale_string (s
);
282 return scm_cons (scm_cons (key
, val
), acc
);
285 SCM_DEFINE (scm_gc_live_object_stats
, "gc-live-object-stats", 0, 0, 0,
287 "Return an alist of statistics of the current live objects. ")
288 #define FUNC_NAME s_scm_gc_live_object_stats
290 SCM tab
= scm_make_hash_table (scm_from_int (57));
294 = scm_internal_hash_fold (&tag_table_to_type_alist
, NULL
, SCM_EOL
, tab
);
300 extern int scm_gc_malloc_yield_percentage
;
301 SCM_DEFINE (scm_gc_stats
, "gc-stats", 0, 0, 0,
303 "Return an association list of statistics about Guile's current\n"
305 #define FUNC_NAME s_scm_gc_stats
308 GC_word heap_size
, free_bytes
, unmapped_bytes
, bytes_since_gc
, total_bytes
;
311 GC_get_heap_usage_safe (&heap_size
, &free_bytes
, &unmapped_bytes
,
312 &bytes_since_gc
, &total_bytes
);
316 scm_list_n (scm_cons (sym_gc_time_taken
, scm_from_long (gc_time_taken
)),
317 scm_cons (sym_heap_size
, scm_from_size_t (heap_size
)),
318 scm_cons (sym_heap_free_size
, scm_from_size_t (free_bytes
)),
319 scm_cons (sym_heap_total_allocated
,
320 scm_from_size_t (total_bytes
)),
321 scm_cons (sym_heap_allocated_since_gc
,
322 scm_from_size_t (bytes_since_gc
)),
323 scm_cons (sym_protected_objects
,
324 scm_from_ulong (protected_obj_count
)),
325 scm_cons (sym_times
, scm_from_size_t (gc_times
)),
333 SCM_DEFINE (scm_gc_dump
, "gc-dump", 0, 0, 0,
335 "Dump information about the garbage collector's internal data "
336 "structures and memory usage to the standard output.")
337 #define FUNC_NAME s_scm_gc_dump
341 return SCM_UNSPECIFIED
;
346 SCM_DEFINE (scm_object_address
, "object-address", 1, 0, 0,
348 "Return an integer that for the lifetime of @var{obj} is uniquely\n"
349 "returned by this function for @var{obj}")
350 #define FUNC_NAME s_scm_object_address
352 return scm_from_ulong (SCM_UNPACK (obj
));
357 SCM_DEFINE (scm_gc_disable
, "gc-disable", 0, 0, 0,
359 "Disables the garbage collector. Nested calls are permitted. "
360 "GC is re-enabled once @code{gc-enable} has been called the "
361 "same number of times @code{gc-disable} was called.")
362 #define FUNC_NAME s_scm_gc_disable
365 return SCM_UNSPECIFIED
;
369 SCM_DEFINE (scm_gc_enable
, "gc-enable", 0, 0, 0,
371 "Enables the garbage collector.")
372 #define FUNC_NAME s_scm_gc_enable
375 return SCM_UNSPECIFIED
;
380 SCM_DEFINE (scm_gc
, "gc", 0, 0, 0,
382 "Scans all of SCM objects and reclaims for further use those that are\n"
383 "no longer accessible.")
384 #define FUNC_NAME s_scm_gc
387 return SCM_UNSPECIFIED
;
392 scm_i_gc (const char *what
)
394 #ifndef HAVE_GC_SET_START_CALLBACK
395 run_before_gc_c_hook ();
402 /* {GC Protection Helper Functions}
407 * If within a function you need to protect one or more scheme objects from
408 * garbage collection, pass them as parameters to one of the
409 * scm_remember_upto_here* functions below. These functions don't do
410 * anything, but since the compiler does not know that they are actually
411 * no-ops, it will generate code that calls these functions with the given
412 * parameters. Therefore, you can be sure that the compiler will keep those
413 * scheme values alive (on the stack or in a register) up to the point where
414 * scm_remember_upto_here* is called. In other words, place the call to
415 * scm_remember_upto_here* _behind_ the last code in your function, that
416 * depends on the scheme object to exist.
418 * Example: We want to make sure that the string object str does not get
419 * garbage collected during the execution of 'some_function' in the code
420 * below, because otherwise the characters belonging to str would be freed and
421 * 'some_function' might access freed memory. To make sure that the compiler
422 * keeps str alive on the stack or in a register such that it is visible to
423 * the conservative gc we add the call to scm_remember_upto_here_1 _after_ the
424 * call to 'some_function'. Note that this would not be necessary if str was
425 * used anyway after the call to 'some_function'.
426 * char *chars = scm_i_string_chars (str);
427 * some_function (chars);
428 * scm_remember_upto_here_1 (str); // str will be alive up to this point.
431 /* Remove any macro versions of these while defining the functions.
432 Functions are always included in the library, for upward binary
433 compatibility and in case combinations of GCC and non-GCC are used. */
434 #undef scm_remember_upto_here_1
435 #undef scm_remember_upto_here_2
438 scm_remember_upto_here_1 (SCM obj SCM_UNUSED
)
440 /* Empty. Protects a single object from garbage collection. */
444 scm_remember_upto_here_2 (SCM obj1 SCM_UNUSED
, SCM obj2 SCM_UNUSED
)
446 /* Empty. Protects two objects from garbage collection. */
450 scm_remember_upto_here (SCM obj SCM_UNUSED
, ...)
452 /* Empty. Protects any number of objects from garbage collection. */
456 These crazy functions prevent garbage collection
457 of arguments after the first argument by
458 ensuring they remain live throughout the
459 function because they are used in the last
460 line of the code block.
461 It'd be better to have a nice compiler hint to
462 aid the conservative stack-scanning GC. --03/09/00 gjb */
464 scm_return_first (SCM elt
, ...)
470 scm_return_first_int (int i
, ...)
477 scm_permanent_object (SCM obj
)
479 return (scm_gc_protect_object (obj
));
483 /* Protect OBJ from the garbage collector. OBJ will not be freed, even if all
484 other references are dropped, until the object is unprotected by calling
485 scm_gc_unprotect_object (OBJ). Calls to scm_gc_protect/unprotect_object nest,
486 i. e. it is possible to protect the same object several times, but it is
487 necessary to unprotect the object the same number of times to actually get
488 the object unprotected. It is an error to unprotect an object more often
489 than it has been protected before. The function scm_protect_object returns
493 /* Implementation note: For every object X, there is a counter which
494 scm_gc_protect_object (X) increments and scm_gc_unprotect_object (X) decrements.
500 scm_gc_protect_object (SCM obj
)
504 /* This critical section barrier will be replaced by a mutex. */
505 /* njrev: Indeed; if my comment above is correct, there is the same
506 critsec/mutex inconsistency here. */
507 SCM_CRITICAL_SECTION_START
;
509 handle
= scm_hashq_create_handle_x (scm_protects
, obj
, scm_from_int (0));
510 SCM_SETCDR (handle
, scm_sum (SCM_CDR (handle
), scm_from_int (1)));
512 protected_obj_count
++;
514 SCM_CRITICAL_SECTION_END
;
520 /* Remove any protection for OBJ established by a prior call to
521 scm_protect_object. This function returns OBJ.
523 See scm_protect_object for more information. */
525 scm_gc_unprotect_object (SCM obj
)
529 /* This critical section barrier will be replaced by a mutex. */
530 /* njrev: and again. */
531 SCM_CRITICAL_SECTION_START
;
533 if (scm_gc_running_p
)
535 fprintf (stderr
, "scm_unprotect_object called during GC.\n");
539 handle
= scm_hashq_get_handle (scm_protects
, obj
);
541 if (scm_is_false (handle
))
543 fprintf (stderr
, "scm_unprotect_object called on unprotected object\n");
548 SCM count
= scm_difference (SCM_CDR (handle
), scm_from_int (1));
549 if (scm_is_eq (count
, scm_from_int (0)))
550 scm_hashq_remove_x (scm_protects
, obj
);
552 SCM_SETCDR (handle
, count
);
554 protected_obj_count
--;
556 SCM_CRITICAL_SECTION_END
;
562 scm_gc_register_root (SCM
*p
)
568 scm_gc_unregister_root (SCM
*p
)
574 scm_gc_register_roots (SCM
*b
, unsigned long n
)
577 for (; p
< b
+ n
; ++p
)
578 scm_gc_register_root (p
);
582 scm_gc_unregister_roots (SCM
*b
, unsigned long n
)
585 for (; p
< b
+ n
; ++p
)
586 scm_gc_unregister_root (p
);
593 MOVE THIS FUNCTION. IT DOES NOT HAVE ANYTHING TODO WITH GC.
596 /* Get an integer from an environment variable. */
598 scm_getenv_int (const char *var
, int def
)
601 char *val
= getenv (var
);
605 res
= strtol (val
, &end
, 10);
612 scm_storage_prehistory ()
614 GC_all_interior_pointers
= 0;
615 free_space_divisor
= scm_getenv_int ("GC_FREE_SPACE_DIVISOR", 3);
616 minimum_free_space_divisor
= free_space_divisor
;
617 target_free_space_divisor
= free_space_divisor
;
618 GC_set_free_space_divisor (free_space_divisor
);
622 #if (! ((defined GC_VERSION_MAJOR) && (GC_VERSION_MAJOR >= 7))) \
623 && (defined SCM_I_GSC_USE_PTHREAD_THREADS)
624 /* When using GC 6.8, this call is required to initialize thread-local
625 freelists (shouldn't be necessary with GC 7.0). */
629 GC_expand_hp (SCM_DEFAULT_INIT_HEAP_SIZE_2
);
631 /* We only need to register a displacement for those types for which the
632 higher bits of the type tag are used to store a pointer (that is, a
633 pointer to an 8-octet aligned region). For `scm_tc3_struct', this is
634 handled in `scm_alloc_struct ()'. */
635 GC_REGISTER_DISPLACEMENT (scm_tc3_cons
);
636 /* GC_REGISTER_DISPLACEMENT (scm_tc3_unused); */
639 if (!GC_is_visible (&scm_protects
))
642 scm_c_hook_init (&scm_before_gc_c_hook
, 0, SCM_C_HOOK_NORMAL
);
643 scm_c_hook_init (&scm_before_mark_c_hook
, 0, SCM_C_HOOK_NORMAL
);
644 scm_c_hook_init (&scm_before_sweep_c_hook
, 0, SCM_C_HOOK_NORMAL
);
645 scm_c_hook_init (&scm_after_sweep_c_hook
, 0, SCM_C_HOOK_NORMAL
);
646 scm_c_hook_init (&scm_after_gc_c_hook
, 0, SCM_C_HOOK_NORMAL
);
649 scm_i_pthread_mutex_t scm_i_gc_admin_mutex
= SCM_I_PTHREAD_MUTEX_INITIALIZER
;
652 scm_init_gc_protect_object ()
654 scm_protects
= scm_c_make_hash_table (31);
657 /* We can't have a cleanup handler since we have no thread to run it
664 on_exit (cleanup
, 0);
673 SCM scm_after_gc_hook
;
675 static SCM after_gc_async_cell
;
677 /* The function after_gc_async_thunk causes the execution of the
678 * after-gc-hook. It is run after the gc, as soon as the asynchronous
679 * events are handled by the evaluator.
682 after_gc_async_thunk (void)
684 /* Fun, no? Hook-run *and* run-hook? */
685 scm_c_hook_run (&scm_after_gc_c_hook
, NULL
);
686 scm_c_run_hook (scm_after_gc_hook
, SCM_EOL
);
687 return SCM_UNSPECIFIED
;
691 /* The function queue_after_gc_hook is run by the scm_before_gc_c_hook
692 * at the end of the garbage collection. The only purpose of this
693 * function is to mark the after_gc_async (which will eventually lead to
694 * the execution of the after_gc_async_thunk).
697 queue_after_gc_hook (void * hook_data SCM_UNUSED
,
698 void *fn_data SCM_UNUSED
,
699 void *data SCM_UNUSED
)
701 /* If cell access debugging is enabled, the user may choose to perform
702 * additional garbage collections after an arbitrary number of cell
703 * accesses. We don't want the scheme level after-gc-hook to be performed
704 * for each of these garbage collections for the following reason: The
705 * execution of the after-gc-hook causes cell accesses itself. Thus, if the
706 * after-gc-hook was performed with every gc, and if the gc was performed
707 * after a very small number of cell accesses, then the number of cell
708 * accesses during the execution of the after-gc-hook will suffice to cause
709 * the execution of the next gc. Then, guile would keep executing the
710 * after-gc-hook over and over again, and would never come to do other
713 * To overcome this problem, if cell access debugging with additional
714 * garbage collections is enabled, the after-gc-hook is never run by the
715 * garbage collecter. When running guile with cell access debugging and the
716 * execution of the after-gc-hook is desired, then it is necessary to run
717 * the hook explicitly from the user code. This has the effect, that from
718 * the scheme level point of view it seems that garbage collection is
719 * performed with a much lower frequency than it actually is. Obviously,
720 * this will not work for code that depends on a fixed one to one
721 * relationship between the execution counts of the C level garbage
722 * collection hooks and the execution count of the scheme level
726 #if (SCM_DEBUG_CELL_ACCESSES == 1)
727 if (scm_debug_cells_gc_interval
== 0)
730 scm_i_thread
*t
= SCM_I_CURRENT_THREAD
;
732 if (scm_is_false (SCM_CDR (after_gc_async_cell
)))
734 SCM_SETCDR (after_gc_async_cell
, t
->active_asyncs
);
735 t
->active_asyncs
= after_gc_async_cell
;
736 t
->pending_asyncs
= 1;
746 start_gc_timer (void * hook_data SCM_UNUSED
,
747 void *fn_data SCM_UNUSED
,
748 void *data SCM_UNUSED
)
751 gc_start_time
= scm_c_get_internal_run_time ();
757 accumulate_gc_timer (void * hook_data SCM_UNUSED
,
758 void *fn_data SCM_UNUSED
,
759 void *data SCM_UNUSED
)
763 long now
= scm_c_get_internal_run_time ();
764 gc_time_taken
+= now
- gc_start_time
;
771 /* Return some idea of the memory footprint of a process, in bytes.
772 Currently only works on Linux systems. */
774 get_image_size (void)
776 unsigned long size
, resident
, share
;
779 FILE *fp
= fopen ("/proc/self/statm", "r");
781 if (fp
&& fscanf (fp
, "%lu %lu %lu", &size
, &resident
, &share
) == 3)
782 ret
= resident
* 4096;
790 /* These are discussed later. */
791 static size_t bytes_until_gc
;
792 static scm_i_pthread_mutex_t bytes_until_gc_lock
= SCM_I_PTHREAD_MUTEX_INITIALIZER
;
794 /* Make GC run more frequently when the process image size is growing,
795 measured against the number of bytes allocated through the GC.
797 If Guile is allocating at a GC-managed heap size H, libgc will tend
798 to limit the process image size to H*N. But if at the same time the
799 user program is mallocating at a rate M bytes per GC-allocated byte,
800 then the process stabilizes at H*N*M -- assuming that collecting data
801 will result in malloc'd data being freed. It doesn't take a very
802 large M for this to be a bad situation. To limit the image size,
803 Guile should GC more often -- the bigger the M, the more often.
805 Numeric functions that produce bigger and bigger integers are
806 pessimal, because M is an increasing function of time. Here is an
807 example of such a function:
809 (define (factorial n)
813 (fac (1- n) (* n acc))))
816 It is possible for a process to grow for reasons that will not be
817 solved by faster GC. In that case M will be estimated as
818 artificially high for a while, and so GC will happen more often on
819 the Guile side. But when it stabilizes, Guile can ease back the GC
822 The key is to measure process image growth, not mallocation rate.
823 For maximum effectiveness, Guile reacts quickly to process growth,
824 and exponentially backs down when the process stops growing.
826 See http://thread.gmane.org/gmane.lisp.guile.devel/12552/focus=12936
827 for further discussion.
830 adjust_gc_frequency (void * hook_data SCM_UNUSED
,
831 void *fn_data SCM_UNUSED
,
832 void *data SCM_UNUSED
)
834 static size_t prev_image_size
= 0;
835 static size_t prev_bytes_alloced
= 0;
837 size_t bytes_alloced
;
839 scm_i_pthread_mutex_lock (&bytes_until_gc_lock
);
840 bytes_until_gc
= GC_get_heap_size ();
841 scm_i_pthread_mutex_unlock (&bytes_until_gc_lock
);
843 image_size
= get_image_size ();
844 bytes_alloced
= GC_get_total_bytes ();
846 #define HEURISTICS_DEBUG 0
849 fprintf (stderr
, "prev image / alloced: %lu / %lu\n", prev_image_size
, prev_bytes_alloced
);
850 fprintf (stderr
, " image / alloced: %lu / %lu\n", image_size
, bytes_alloced
);
851 fprintf (stderr
, "divisor %lu / %f\n", free_space_divisor
, target_free_space_divisor
);
854 if (prev_image_size
&& bytes_alloced
!= prev_bytes_alloced
)
856 double growth_rate
, new_target_free_space_divisor
;
857 double decay_factor
= 0.5;
858 double hysteresis
= 0.1;
860 growth_rate
= ((double) image_size
- prev_image_size
)
861 / ((double)bytes_alloced
- prev_bytes_alloced
);
864 fprintf (stderr
, "growth rate %f\n", growth_rate
);
867 new_target_free_space_divisor
= minimum_free_space_divisor
;
870 new_target_free_space_divisor
*= 1.0 + growth_rate
;
873 fprintf (stderr
, "new divisor %f\n", new_target_free_space_divisor
);
876 if (new_target_free_space_divisor
< target_free_space_divisor
)
878 target_free_space_divisor
=
879 (decay_factor
* target_free_space_divisor
880 + (1.0 - decay_factor
) * new_target_free_space_divisor
);
883 target_free_space_divisor
= new_target_free_space_divisor
;
886 fprintf (stderr
, "new target divisor %f\n", target_free_space_divisor
);
889 if (free_space_divisor
+ 0.5 + hysteresis
< target_free_space_divisor
890 || free_space_divisor
- 0.5 - hysteresis
> target_free_space_divisor
)
892 free_space_divisor
= lround (target_free_space_divisor
);
894 fprintf (stderr
, "new divisor %lu\n", free_space_divisor
);
896 GC_set_free_space_divisor (free_space_divisor
);
900 prev_image_size
= image_size
;
901 prev_bytes_alloced
= bytes_alloced
;
906 /* The adjust_gc_frequency routine handles transients in the process
907 image size. It can't handle instense non-GC-managed steady-state
908 allocation though, as it decays the FSD at steady-state down to its
911 The only real way to handle continuous, high non-GC allocation is to
912 let the GC know about it. This routine can handle non-GC allocation
913 rates that are similar in size to the GC-managed heap size.
917 scm_gc_register_allocation (size_t size
)
919 scm_i_pthread_mutex_lock (&bytes_until_gc_lock
);
920 if (bytes_until_gc
- size
> bytes_until_gc
)
922 bytes_until_gc
= GC_get_heap_size ();
923 scm_i_pthread_mutex_unlock (&bytes_until_gc_lock
);
928 bytes_until_gc
-= size
;
929 scm_i_pthread_mutex_unlock (&bytes_until_gc_lock
);
937 scm_i_tag_name (scm_t_bits tag
)
939 switch (tag
& 0x7f) /* 7 bits */
943 case scm_tcs_cons_imcar
:
944 return "cons (immediate car)";
945 case scm_tcs_cons_nimcar
:
946 return "cons (non-immediate car)";
947 case scm_tc7_pointer
:
949 case scm_tc7_hashtable
:
951 case scm_tc7_weak_set
:
953 case scm_tc7_weak_table
:
957 case scm_tc7_dynamic_state
:
958 return "dynamic state";
961 case scm_tc7_objcode
:
965 case scm_tc7_vm_cont
:
966 return "vm continuation";
968 return "weak vector";
980 case scm_tc16_complex
:
981 return "complex number";
983 case scm_tc16_fraction
:
991 case scm_tc7_stringbuf
:
992 return "string buffer";
997 case scm_tc7_variable
:
1005 int k
= 0xff & (tag
>> 8);
1006 return (scm_smobs
[k
].name
);
1020 /* `GC_INIT ()' was invoked in `scm_storage_prehistory ()'. */
1022 scm_after_gc_hook
= scm_make_hook (SCM_INUM0
);
1023 scm_c_define ("after-gc-hook", scm_after_gc_hook
);
1025 /* When the async is to run, the cdr of the gc_async pair gets set to
1026 the asyncs queue of the current thread. */
1027 after_gc_async_cell
= scm_cons (scm_c_make_gsubr ("%after-gc-thunk", 0, 0, 0,
1028 after_gc_async_thunk
),
1031 scm_c_hook_add (&scm_before_gc_c_hook
, queue_after_gc_hook
, NULL
, 0);
1032 scm_c_hook_add (&scm_before_gc_c_hook
, start_gc_timer
, NULL
, 0);
1033 scm_c_hook_add (&scm_after_gc_c_hook
, accumulate_gc_timer
, NULL
, 0);
1035 #if HAVE_GC_GET_HEAP_USAGE_SAFE
1036 /* GC_get_heap_usage does not take a lock, and so can run in the GC
1038 scm_c_hook_add (&scm_before_gc_c_hook
, adjust_gc_frequency
, NULL
, 0);
1040 /* GC_get_heap_usage might take a lock (and did from 7.2alpha1 to
1041 7.2alpha7), so call it in the after_gc_hook. */
1042 scm_c_hook_add (&scm_after_gc_c_hook
, adjust_gc_frequency
, NULL
, 0);
1045 #ifdef HAVE_GC_SET_START_CALLBACK
1046 GC_set_start_callback (run_before_gc_c_hook
);
1049 #include "libguile/gc.x"
1055 #define FUNC_NAME "scm_gc_sweep"
1058 fprintf (stderr
, "%s: doing nothing\n", FUNC_NAME
);