1 /* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2002, 2003, 2006,
2 * 2008, 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc.
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public License
6 * as published by the Free Software Foundation; either version 3 of
7 * the License, or (at your option) any later version.
9 * This library is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with this library; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
20 /* #define DEBUGINFO */
26 #include "libguile/gen-scmconfig.h"
36 extern unsigned long * __libc_ia64_register_backing_store_base
;
39 #include "libguile/_scm.h"
40 #include "libguile/eval.h"
41 #include "libguile/stime.h"
42 #include "libguile/stackchk.h"
43 #include "libguile/struct.h"
44 #include "libguile/smob.h"
45 #include "libguile/arrays.h"
46 #include "libguile/async.h"
47 #include "libguile/ports.h"
48 #include "libguile/root.h"
49 #include "libguile/simpos.h"
50 #include "libguile/strings.h"
51 #include "libguile/vectors.h"
52 #include "libguile/hashtab.h"
53 #include "libguile/tags.h"
55 #include "libguile/validate.h"
56 #include "libguile/deprecation.h"
57 #include "libguile/gc.h"
58 #include "libguile/dynwind.h"
60 #include "libguile/bdw-gc.h"
62 /* For GC_set_start_callback. */
63 #include <gc/gc_mark.h>
65 #ifdef GUILE_DEBUG_MALLOC
66 #include "libguile/debug-malloc.h"
73 /* Size in bytes of the initial heap. This should be about the size of
74 result of 'guile -c "(display (assq-ref (gc-stats)
75 'heap-total-allocated))"'. */
77 #define DEFAULT_INITIAL_HEAP_SIZE (128 * 1024 * SIZEOF_SCM_T_BITS)
79 /* Set this to != 0 if every cell that is accessed shall be checked:
81 int scm_debug_cell_accesses_p
= 0;
82 int scm_expensive_debug_cell_accesses_p
= 0;
84 /* Set this to 0 if no additional gc's shall be performed, otherwise set it to
85 * the number of cell accesses after which a gc shall be called.
87 int scm_debug_cells_gc_interval
= 0;
89 /* Hash table that keeps a reference to objects the user wants to protect from
90 garbage collection. */
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 */
198 scm_t_c_hook scm_before_gc_c_hook
;
199 scm_t_c_hook scm_before_mark_c_hook
;
200 scm_t_c_hook scm_before_sweep_c_hook
;
201 scm_t_c_hook scm_after_sweep_c_hook
;
202 scm_t_c_hook scm_after_gc_c_hook
;
206 run_before_gc_c_hook (void)
208 if (!SCM_I_CURRENT_THREAD
)
209 /* GC while a thread is spinning up; punt. */
212 scm_c_hook_run (&scm_before_gc_c_hook
, NULL
);
216 /* GC Statistics Keeping
218 unsigned long scm_gc_ports_collected
= 0;
219 static long gc_time_taken
= 0;
220 static long gc_start_time
= 0;
222 static unsigned long free_space_divisor
;
223 static unsigned long minimum_free_space_divisor
;
224 static double target_free_space_divisor
;
226 static unsigned long protected_obj_count
= 0;
229 SCM_SYMBOL (sym_gc_time_taken
, "gc-time-taken");
230 SCM_SYMBOL (sym_heap_size
, "heap-size");
231 SCM_SYMBOL (sym_heap_free_size
, "heap-free-size");
232 SCM_SYMBOL (sym_heap_total_allocated
, "heap-total-allocated");
233 SCM_SYMBOL (sym_heap_allocated_since_gc
, "heap-allocated-since-gc");
234 SCM_SYMBOL (sym_protected_objects
, "protected-objects");
235 SCM_SYMBOL (sym_times
, "gc-times");
238 /* {Scheme Interface to GC}
240 static char const * scm_i_tag_name (scm_t_bits tag
);
242 tag_table_to_type_alist (void *closure
, SCM key
, SCM val
, SCM acc
)
244 if (scm_is_integer (key
))
246 int c_tag
= scm_to_int (key
);
248 char const * name
= scm_i_tag_name (c_tag
);
251 key
= scm_from_locale_string (name
);
256 sprintf (s
, "tag %d", c_tag
);
257 key
= scm_from_locale_string (s
);
261 return scm_cons (scm_cons (key
, val
), acc
);
264 SCM_DEFINE (scm_gc_live_object_stats
, "gc-live-object-stats", 0, 0, 0,
266 "Return an alist of statistics of the current live objects. ")
267 #define FUNC_NAME s_scm_gc_live_object_stats
269 SCM tab
= scm_make_hash_table (scm_from_int (57));
273 = scm_internal_hash_fold (&tag_table_to_type_alist
, NULL
, SCM_EOL
, tab
);
279 extern int scm_gc_malloc_yield_percentage
;
280 SCM_DEFINE (scm_gc_stats
, "gc-stats", 0, 0, 0,
282 "Return an association list of statistics about Guile's current\n"
284 #define FUNC_NAME s_scm_gc_stats
287 GC_word heap_size
, free_bytes
, unmapped_bytes
, bytes_since_gc
, total_bytes
;
290 GC_get_heap_usage_safe (&heap_size
, &free_bytes
, &unmapped_bytes
,
291 &bytes_since_gc
, &total_bytes
);
292 gc_times
= GC_get_gc_no ();
295 scm_list_n (scm_cons (sym_gc_time_taken
, scm_from_long (gc_time_taken
)),
296 scm_cons (sym_heap_size
, scm_from_size_t (heap_size
)),
297 scm_cons (sym_heap_free_size
, scm_from_size_t (free_bytes
)),
298 scm_cons (sym_heap_total_allocated
,
299 scm_from_size_t (total_bytes
)),
300 scm_cons (sym_heap_allocated_since_gc
,
301 scm_from_size_t (bytes_since_gc
)),
302 scm_cons (sym_protected_objects
,
303 scm_from_ulong (protected_obj_count
)),
304 scm_cons (sym_times
, scm_from_size_t (gc_times
)),
312 SCM_DEFINE (scm_gc_dump
, "gc-dump", 0, 0, 0,
314 "Dump information about the garbage collector's internal data "
315 "structures and memory usage to the standard output.")
316 #define FUNC_NAME s_scm_gc_dump
320 return SCM_UNSPECIFIED
;
325 SCM_DEFINE (scm_object_address
, "object-address", 1, 0, 0,
327 "Return an integer that for the lifetime of @var{obj} is uniquely\n"
328 "returned by this function for @var{obj}")
329 #define FUNC_NAME s_scm_object_address
331 return scm_from_ulong (SCM_UNPACK (obj
));
336 SCM_DEFINE (scm_gc_disable
, "gc-disable", 0, 0, 0,
338 "Disables the garbage collector. Nested calls are permitted. "
339 "GC is re-enabled once @code{gc-enable} has been called the "
340 "same number of times @code{gc-disable} was called.")
341 #define FUNC_NAME s_scm_gc_disable
344 return SCM_UNSPECIFIED
;
348 SCM_DEFINE (scm_gc_enable
, "gc-enable", 0, 0, 0,
350 "Enables the garbage collector.")
351 #define FUNC_NAME s_scm_gc_enable
354 return SCM_UNSPECIFIED
;
359 SCM_DEFINE (scm_gc
, "gc", 0, 0, 0,
361 "Scans all of SCM objects and reclaims for further use those that are\n"
362 "no longer accessible.")
363 #define FUNC_NAME s_scm_gc
366 /* If you're calling scm_gc(), you probably want synchronous
368 GC_invoke_finalizers ();
369 return SCM_UNSPECIFIED
;
374 scm_i_gc (const char *what
)
381 /* {GC Protection Helper Functions}
386 * If within a function you need to protect one or more scheme objects from
387 * garbage collection, pass them as parameters to one of the
388 * scm_remember_upto_here* functions below. These functions don't do
389 * anything, but since the compiler does not know that they are actually
390 * no-ops, it will generate code that calls these functions with the given
391 * parameters. Therefore, you can be sure that the compiler will keep those
392 * scheme values alive (on the stack or in a register) up to the point where
393 * scm_remember_upto_here* is called. In other words, place the call to
394 * scm_remember_upto_here* _behind_ the last code in your function, that
395 * depends on the scheme object to exist.
397 * Example: We want to make sure that the string object str does not get
398 * garbage collected during the execution of 'some_function' in the code
399 * below, because otherwise the characters belonging to str would be freed and
400 * 'some_function' might access freed memory. To make sure that the compiler
401 * keeps str alive on the stack or in a register such that it is visible to
402 * the conservative gc we add the call to scm_remember_upto_here_1 _after_ the
403 * call to 'some_function'. Note that this would not be necessary if str was
404 * used anyway after the call to 'some_function'.
405 * char *chars = scm_i_string_chars (str);
406 * some_function (chars);
407 * scm_remember_upto_here_1 (str); // str will be alive up to this point.
410 /* Remove any macro versions of these while defining the functions.
411 Functions are always included in the library, for upward binary
412 compatibility and in case combinations of GCC and non-GCC are used. */
413 #undef scm_remember_upto_here_1
414 #undef scm_remember_upto_here_2
417 scm_remember_upto_here_1 (SCM obj SCM_UNUSED
)
419 /* Empty. Protects a single object from garbage collection. */
423 scm_remember_upto_here_2 (SCM obj1 SCM_UNUSED
, SCM obj2 SCM_UNUSED
)
425 /* Empty. Protects two objects from garbage collection. */
429 scm_remember_upto_here (SCM obj SCM_UNUSED
, ...)
431 /* Empty. Protects any number of objects from garbage collection. */
435 These crazy functions prevent garbage collection
436 of arguments after the first argument by
437 ensuring they remain live throughout the
438 function because they are used in the last
439 line of the code block.
440 It'd be better to have a nice compiler hint to
441 aid the conservative stack-scanning GC. --03/09/00 gjb */
443 scm_return_first (SCM elt
, ...)
449 scm_return_first_int (int i
, ...)
456 scm_permanent_object (SCM obj
)
458 return (scm_gc_protect_object (obj
));
462 /* Protect OBJ from the garbage collector. OBJ will not be freed, even if all
463 other references are dropped, until the object is unprotected by calling
464 scm_gc_unprotect_object (OBJ). Calls to scm_gc_protect/unprotect_object nest,
465 i. e. it is possible to protect the same object several times, but it is
466 necessary to unprotect the object the same number of times to actually get
467 the object unprotected. It is an error to unprotect an object more often
468 than it has been protected before. The function scm_protect_object returns
472 /* Implementation note: For every object X, there is a counter which
473 scm_gc_protect_object (X) increments and scm_gc_unprotect_object (X) decrements.
479 scm_gc_protect_object (SCM obj
)
483 /* This critical section barrier will be replaced by a mutex. */
484 /* njrev: Indeed; if my comment above is correct, there is the same
485 critsec/mutex inconsistency here. */
486 SCM_CRITICAL_SECTION_START
;
488 handle
= scm_hashq_create_handle_x (scm_protects
, obj
, scm_from_int (0));
489 SCM_SETCDR (handle
, scm_sum (SCM_CDR (handle
), scm_from_int (1)));
491 protected_obj_count
++;
493 SCM_CRITICAL_SECTION_END
;
499 /* Remove any protection for OBJ established by a prior call to
500 scm_protect_object. This function returns OBJ.
502 See scm_protect_object for more information. */
504 scm_gc_unprotect_object (SCM obj
)
508 /* This critical section barrier will be replaced by a mutex. */
509 /* njrev: and again. */
510 SCM_CRITICAL_SECTION_START
;
512 if (scm_gc_running_p
)
514 fprintf (stderr
, "scm_unprotect_object called during GC.\n");
518 handle
= scm_hashq_get_handle (scm_protects
, obj
);
520 if (scm_is_false (handle
))
522 fprintf (stderr
, "scm_unprotect_object called on unprotected object\n");
527 SCM count
= scm_difference (SCM_CDR (handle
), scm_from_int (1));
528 if (scm_is_eq (count
, scm_from_int (0)))
529 scm_hashq_remove_x (scm_protects
, obj
);
531 SCM_SETCDR (handle
, count
);
533 protected_obj_count
--;
535 SCM_CRITICAL_SECTION_END
;
541 scm_gc_register_root (SCM
*p
)
547 scm_gc_unregister_root (SCM
*p
)
553 scm_gc_register_roots (SCM
*b
, unsigned long n
)
556 for (; p
< b
+ n
; ++p
)
557 scm_gc_register_root (p
);
561 scm_gc_unregister_roots (SCM
*b
, unsigned long n
)
564 for (; p
< b
+ n
; ++p
)
565 scm_gc_unregister_root (p
);
572 scm_storage_prehistory ()
574 GC_set_all_interior_pointers (0);
576 free_space_divisor
= scm_getenv_int ("GC_FREE_SPACE_DIVISOR", 3);
577 minimum_free_space_divisor
= free_space_divisor
;
578 target_free_space_divisor
= free_space_divisor
;
579 GC_set_free_space_divisor (free_space_divisor
);
580 GC_set_finalize_on_demand (1);
584 GC_expand_hp (DEFAULT_INITIAL_HEAP_SIZE
);
586 /* We only need to register a displacement for those types for which the
587 higher bits of the type tag are used to store a pointer (that is, a
588 pointer to an 8-octet aligned region). For `scm_tc3_struct', this is
589 handled in `scm_alloc_struct ()'. */
590 GC_REGISTER_DISPLACEMENT (scm_tc3_cons
);
591 /* GC_REGISTER_DISPLACEMENT (scm_tc3_unused); */
594 if (!GC_is_visible (&scm_protects
))
597 scm_c_hook_init (&scm_before_gc_c_hook
, 0, SCM_C_HOOK_NORMAL
);
598 scm_c_hook_init (&scm_before_mark_c_hook
, 0, SCM_C_HOOK_NORMAL
);
599 scm_c_hook_init (&scm_before_sweep_c_hook
, 0, SCM_C_HOOK_NORMAL
);
600 scm_c_hook_init (&scm_after_sweep_c_hook
, 0, SCM_C_HOOK_NORMAL
);
601 scm_c_hook_init (&scm_after_gc_c_hook
, 0, SCM_C_HOOK_NORMAL
);
604 scm_i_pthread_mutex_t scm_i_gc_admin_mutex
= SCM_I_PTHREAD_MUTEX_INITIALIZER
;
607 scm_init_gc_protect_object ()
609 scm_protects
= scm_c_make_hash_table (31);
612 /* We can't have a cleanup handler since we have no thread to run it
619 on_exit (cleanup
, 0);
628 SCM scm_after_gc_hook
;
630 static SCM after_gc_async_cell
;
632 /* The function after_gc_async_thunk causes the execution of the
633 * after-gc-hook. It is run after the gc, as soon as the asynchronous
634 * events are handled by the evaluator.
637 after_gc_async_thunk (void)
639 /* Fun, no? Hook-run *and* run-hook? */
640 scm_c_hook_run (&scm_after_gc_c_hook
, NULL
);
641 scm_c_run_hook (scm_after_gc_hook
, SCM_EOL
);
642 return SCM_UNSPECIFIED
;
646 /* The function queue_after_gc_hook is run by the scm_before_gc_c_hook
647 * at the end of the garbage collection. The only purpose of this
648 * function is to mark the after_gc_async (which will eventually lead to
649 * the execution of the after_gc_async_thunk).
652 queue_after_gc_hook (void * hook_data SCM_UNUSED
,
653 void *fn_data SCM_UNUSED
,
654 void *data SCM_UNUSED
)
656 /* If cell access debugging is enabled, the user may choose to perform
657 * additional garbage collections after an arbitrary number of cell
658 * accesses. We don't want the scheme level after-gc-hook to be performed
659 * for each of these garbage collections for the following reason: The
660 * execution of the after-gc-hook causes cell accesses itself. Thus, if the
661 * after-gc-hook was performed with every gc, and if the gc was performed
662 * after a very small number of cell accesses, then the number of cell
663 * accesses during the execution of the after-gc-hook will suffice to cause
664 * the execution of the next gc. Then, guile would keep executing the
665 * after-gc-hook over and over again, and would never come to do other
668 * To overcome this problem, if cell access debugging with additional
669 * garbage collections is enabled, the after-gc-hook is never run by the
670 * garbage collecter. When running guile with cell access debugging and the
671 * execution of the after-gc-hook is desired, then it is necessary to run
672 * the hook explicitly from the user code. This has the effect, that from
673 * the scheme level point of view it seems that garbage collection is
674 * performed with a much lower frequency than it actually is. Obviously,
675 * this will not work for code that depends on a fixed one to one
676 * relationship between the execution counts of the C level garbage
677 * collection hooks and the execution count of the scheme level
681 #if (SCM_DEBUG_CELL_ACCESSES == 1)
682 if (scm_debug_cells_gc_interval
== 0)
685 scm_i_thread
*t
= SCM_I_CURRENT_THREAD
;
687 if (scm_is_false (SCM_CDR (after_gc_async_cell
)))
689 SCM_SETCDR (after_gc_async_cell
, t
->active_asyncs
);
690 t
->active_asyncs
= after_gc_async_cell
;
691 t
->pending_asyncs
= 1;
701 start_gc_timer (void * hook_data SCM_UNUSED
,
702 void *fn_data SCM_UNUSED
,
703 void *data SCM_UNUSED
)
706 gc_start_time
= scm_c_get_internal_run_time ();
712 accumulate_gc_timer (void * hook_data SCM_UNUSED
,
713 void *fn_data SCM_UNUSED
,
714 void *data SCM_UNUSED
)
718 long now
= scm_c_get_internal_run_time ();
719 gc_time_taken
+= now
- gc_start_time
;
726 /* Return some idea of the memory footprint of a process, in bytes.
727 Currently only works on Linux systems. */
729 get_image_size (void)
731 unsigned long size
, resident
, share
;
734 FILE *fp
= fopen ("/proc/self/statm", "r");
736 if (fp
&& fscanf (fp
, "%lu %lu %lu", &size
, &resident
, &share
) == 3)
737 ret
= resident
* 4096;
745 /* These are discussed later. */
746 static size_t bytes_until_gc
;
747 static scm_i_pthread_mutex_t bytes_until_gc_lock
= SCM_I_PTHREAD_MUTEX_INITIALIZER
;
749 /* Make GC run more frequently when the process image size is growing,
750 measured against the number of bytes allocated through the GC.
752 If Guile is allocating at a GC-managed heap size H, libgc will tend
753 to limit the process image size to H*N. But if at the same time the
754 user program is mallocating at a rate M bytes per GC-allocated byte,
755 then the process stabilizes at H*N*M -- assuming that collecting data
756 will result in malloc'd data being freed. It doesn't take a very
757 large M for this to be a bad situation. To limit the image size,
758 Guile should GC more often -- the bigger the M, the more often.
760 Numeric functions that produce bigger and bigger integers are
761 pessimal, because M is an increasing function of time. Here is an
762 example of such a function:
764 (define (factorial n)
768 (fac (1- n) (* n acc))))
771 It is possible for a process to grow for reasons that will not be
772 solved by faster GC. In that case M will be estimated as
773 artificially high for a while, and so GC will happen more often on
774 the Guile side. But when it stabilizes, Guile can ease back the GC
777 The key is to measure process image growth, not mallocation rate.
778 For maximum effectiveness, Guile reacts quickly to process growth,
779 and exponentially backs down when the process stops growing.
781 See http://thread.gmane.org/gmane.lisp.guile.devel/12552/focus=12936
782 for further discussion.
785 adjust_gc_frequency (void * hook_data SCM_UNUSED
,
786 void *fn_data SCM_UNUSED
,
787 void *data SCM_UNUSED
)
789 static size_t prev_image_size
= 0;
790 static size_t prev_bytes_alloced
= 0;
792 size_t bytes_alloced
;
794 scm_i_pthread_mutex_lock (&bytes_until_gc_lock
);
795 bytes_until_gc
= GC_get_heap_size ();
796 scm_i_pthread_mutex_unlock (&bytes_until_gc_lock
);
798 image_size
= get_image_size ();
799 bytes_alloced
= GC_get_total_bytes ();
801 #define HEURISTICS_DEBUG 0
804 fprintf (stderr
, "prev image / alloced: %lu / %lu\n", prev_image_size
, prev_bytes_alloced
);
805 fprintf (stderr
, " image / alloced: %lu / %lu\n", image_size
, bytes_alloced
);
806 fprintf (stderr
, "divisor %lu / %f\n", free_space_divisor
, target_free_space_divisor
);
809 if (prev_image_size
&& bytes_alloced
!= prev_bytes_alloced
)
811 double growth_rate
, new_target_free_space_divisor
;
812 double decay_factor
= 0.5;
813 double hysteresis
= 0.1;
815 growth_rate
= ((double) image_size
- prev_image_size
)
816 / ((double)bytes_alloced
- prev_bytes_alloced
);
819 fprintf (stderr
, "growth rate %f\n", growth_rate
);
822 new_target_free_space_divisor
= minimum_free_space_divisor
;
825 new_target_free_space_divisor
*= 1.0 + growth_rate
;
828 fprintf (stderr
, "new divisor %f\n", new_target_free_space_divisor
);
831 if (new_target_free_space_divisor
< target_free_space_divisor
)
833 target_free_space_divisor
=
834 (decay_factor
* target_free_space_divisor
835 + (1.0 - decay_factor
) * new_target_free_space_divisor
);
838 target_free_space_divisor
= new_target_free_space_divisor
;
841 fprintf (stderr
, "new target divisor %f\n", target_free_space_divisor
);
844 if (free_space_divisor
+ 0.5 + hysteresis
< target_free_space_divisor
845 || free_space_divisor
- 0.5 - hysteresis
> target_free_space_divisor
)
847 free_space_divisor
= lround (target_free_space_divisor
);
849 fprintf (stderr
, "new divisor %lu\n", free_space_divisor
);
851 GC_set_free_space_divisor (free_space_divisor
);
855 prev_image_size
= image_size
;
856 prev_bytes_alloced
= bytes_alloced
;
861 /* The adjust_gc_frequency routine handles transients in the process
862 image size. It can't handle instense non-GC-managed steady-state
863 allocation though, as it decays the FSD at steady-state down to its
866 The only real way to handle continuous, high non-GC allocation is to
867 let the GC know about it. This routine can handle non-GC allocation
868 rates that are similar in size to the GC-managed heap size.
872 scm_gc_register_allocation (size_t size
)
874 scm_i_pthread_mutex_lock (&bytes_until_gc_lock
);
875 if (bytes_until_gc
- size
> bytes_until_gc
)
877 bytes_until_gc
= GC_get_heap_size ();
878 scm_i_pthread_mutex_unlock (&bytes_until_gc_lock
);
883 bytes_until_gc
-= size
;
884 scm_i_pthread_mutex_unlock (&bytes_until_gc_lock
);
892 scm_i_tag_name (scm_t_bits tag
)
894 switch (tag
& 0x7f) /* 7 bits */
898 case scm_tcs_cons_imcar
:
899 return "cons (immediate car)";
900 case scm_tcs_cons_nimcar
:
901 return "cons (non-immediate car)";
902 case scm_tc7_pointer
:
904 case scm_tc7_hashtable
:
906 case scm_tc7_weak_set
:
908 case scm_tc7_weak_table
:
912 case scm_tc7_dynamic_state
:
913 return "dynamic state";
916 case scm_tc7_vm_cont
:
917 return "vm continuation";
919 return "weak vector";
931 case scm_tc16_complex
:
932 return "complex number";
934 case scm_tc16_fraction
:
942 case scm_tc7_stringbuf
:
943 return "string buffer";
948 case scm_tc7_variable
:
956 int k
= 0xff & (tag
>> 8);
957 return (scm_smobs
[k
].name
);
971 /* `GC_INIT ()' was invoked in `scm_storage_prehistory ()'. */
973 scm_after_gc_hook
= scm_make_hook (SCM_INUM0
);
974 scm_c_define ("after-gc-hook", scm_after_gc_hook
);
976 /* When the async is to run, the cdr of the gc_async pair gets set to
977 the asyncs queue of the current thread. */
978 after_gc_async_cell
= scm_cons (scm_c_make_gsubr ("%after-gc-thunk", 0, 0, 0,
979 after_gc_async_thunk
),
982 scm_c_hook_add (&scm_before_gc_c_hook
, queue_after_gc_hook
, NULL
, 0);
983 scm_c_hook_add (&scm_before_gc_c_hook
, start_gc_timer
, NULL
, 0);
984 scm_c_hook_add (&scm_after_gc_c_hook
, accumulate_gc_timer
, NULL
, 0);
986 /* GC_get_heap_usage does not take a lock, and so can run in the GC
988 scm_c_hook_add (&scm_before_gc_c_hook
, adjust_gc_frequency
, NULL
, 0);
990 GC_set_start_callback (run_before_gc_c_hook
);
992 #include "libguile/gc.x"
998 #define FUNC_NAME "scm_gc_sweep"
1001 fprintf (stderr
, "%s: doing nothing\n", FUNC_NAME
);