1 /* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2002, 2003 Free Software Foundation, Inc.
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation; either version 2, or (at your option)
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
13 * You should have received a copy of the GNU General Public License
14 * along with this software; see the file COPYING. If not, write to
15 * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
16 * Boston, MA 02111-1307 USA
18 * As a special exception, the Free Software Foundation gives permission
19 * for additional uses of the text contained in its release of GUILE.
21 * The exception is that, if you link the GUILE library with other files
22 * to produce an executable, this does not by itself cause the
23 * resulting executable to be covered by the GNU General Public License.
24 * Your use of that executable is in no way restricted on account of
25 * linking the GUILE library code into it.
27 * This exception does not however invalidate any other reasons why
28 * the executable file might be covered by the GNU General Public License.
30 * This exception applies only to the code released by the
31 * Free Software Foundation under the name GUILE. If you copy
32 * code from other Free Software Foundation releases into a copy of
33 * GUILE, as the General Public License permits, the exception does
34 * not apply to the code that you add in this way. To avoid misleading
35 * anyone as to the status of such modified files, you must delete
36 * this exception notice from them.
38 * If you write modifications of your own for GUILE, it is your choice
39 * whether to permit this exception to apply to your modifications.
40 * If you do not wish that, delete this exception notice. */
43 /* #define DEBUGINFO */
56 extern unsigned long * __libc_ia64_register_backing_store_base
;
59 #include "libguile/_scm.h"
60 #include "libguile/eval.h"
61 #include "libguile/stime.h"
62 #include "libguile/stackchk.h"
63 #include "libguile/struct.h"
64 #include "libguile/smob.h"
65 #include "libguile/unif.h"
66 #include "libguile/async.h"
67 #include "libguile/ports.h"
68 #include "libguile/root.h"
69 #include "libguile/strings.h"
70 #include "libguile/vectors.h"
71 #include "libguile/weaks.h"
72 #include "libguile/hashtab.h"
73 #include "libguile/tags.h"
75 #include "libguile/private-gc.h"
76 #include "libguile/validate.h"
77 #include "libguile/deprecation.h"
78 #include "libguile/gc.h"
80 #ifdef GUILE_DEBUG_MALLOC
81 #include "libguile/debug-malloc.h"
94 unsigned int scm_gc_running_p
= 0;
96 /* Lock this mutex before doing lazy sweeping.
98 scm_t_rec_mutex scm_i_sweep_mutex
;
100 /* Set this to != 0 if every cell that is accessed shall be checked:
102 int scm_debug_cell_accesses_p
= 0;
103 int scm_expensive_debug_cell_accesses_p
= 0;
105 /* Set this to 0 if no additional gc's shall be performed, otherwise set it to
106 * the number of cell accesses after which a gc shall be called.
108 int scm_debug_cells_gc_interval
= 0;
111 Global variable, so you can switch it off at runtime by setting
112 scm_i_cell_validation_already_running.
114 int scm_i_cell_validation_already_running
;
116 #if (SCM_DEBUG_CELL_ACCESSES == 1)
121 Assert that the given object is a valid reference to a valid cell. This
122 test involves to determine whether the object is a cell pointer, whether
123 this pointer actually points into a heap segment and whether the cell
124 pointed to is not a free cell. Further, additional garbage collections may
125 get executed after a user defined number of cell accesses. This helps to
126 find places in the C code where references are dropped for extremely short
131 scm_i_expensive_validation_check (SCM cell
)
133 if (!scm_in_heap_p (cell
))
135 fprintf (stderr
, "scm_assert_cell_valid: this object does not live in the heap: %lux\n",
136 (unsigned long) SCM_UNPACK (cell
));
140 /* If desired, perform additional garbage collections after a user
141 * defined number of cell accesses.
143 if (scm_debug_cells_gc_interval
)
145 static unsigned int counter
= 0;
153 counter
= scm_debug_cells_gc_interval
;
154 scm_igc ("scm_assert_cell_valid");
160 scm_assert_cell_valid (SCM cell
)
162 if (!scm_i_cell_validation_already_running
&& scm_debug_cell_accesses_p
)
164 scm_i_cell_validation_already_running
= 1; /* set to avoid recursion */
167 During GC, no user-code should be run, and the guile core
168 should use non-protected accessors.
170 if (scm_gc_running_p
)
174 Only scm_in_heap_p and rescanning the heap is wildly
177 if (scm_expensive_debug_cell_accesses_p
)
178 scm_i_expensive_validation_check (cell
);
180 if (!SCM_GC_MARK_P (cell
))
183 "scm_assert_cell_valid: this object is unmarked. \n"
184 "It has been garbage-collected in the last GC run: "
186 (unsigned long) SCM_UNPACK (cell
));
190 scm_i_cell_validation_already_running
= 0; /* re-enable */
196 SCM_DEFINE (scm_set_debug_cell_accesses_x
, "set-debug-cell-accesses!", 1, 0, 0,
198 "If @var{flag} is @code{#f}, cell access checking is disabled.\n"
199 "If @var{flag} is @code{#t}, cheap cell access checking is enabled,\n"
200 "but no additional calls to garbage collection are issued.\n"
201 "If @var{flag} is a number, strict cell access checking is enabled,\n"
202 "with an additional garbage collection after the given\n"
203 "number of cell accesses.\n"
204 "This procedure only exists when the compile-time flag\n"
205 "@code{SCM_DEBUG_CELL_ACCESSES} was set to 1.")
206 #define FUNC_NAME s_scm_set_debug_cell_accesses_x
208 if (SCM_FALSEP (flag
))
210 scm_debug_cell_accesses_p
= 0;
212 else if (SCM_EQ_P (flag
, SCM_BOOL_T
))
214 scm_debug_cells_gc_interval
= 0;
215 scm_debug_cell_accesses_p
= 1;
216 scm_expensive_debug_cell_accesses_p
= 0;
218 else if (SCM_INUMP (flag
))
220 long int f
= SCM_INUM (flag
);
222 SCM_OUT_OF_RANGE (1, flag
);
223 scm_debug_cells_gc_interval
= f
;
224 scm_debug_cell_accesses_p
= 1;
225 scm_expensive_debug_cell_accesses_p
= 1;
229 SCM_WRONG_TYPE_ARG (1, flag
);
231 return SCM_UNSPECIFIED
;
237 Provide a stub, so people can use their Scheme code on non-debug
238 versions of GUILE as well.
240 SCM_DEFINE (scm_set_debug_cell_accesses_x
, "set-debug-cell-accesses!", 1, 0, 0,
242 "This function is used to turn on checking for a debug version of GUILE. This version does not support this functionality\n")
243 #define FUNC_NAME s_scm_set_debug_cell_accesses_x
249 fprintf (stderr
, "\nWARNING: GUILE was not compiled with SCM_DEBUG_CELL_ACCESSES");
250 scm_remember_upto_here (flag
);
251 return SCM_UNSPECIFIED
;
255 #endif /* SCM_DEBUG_CELL_ACCESSES == 1 */
259 scm_t_key scm_i_freelist
;
260 scm_t_key scm_i_freelist2
;
264 * is the number of bytes of malloc allocation needed to trigger gc.
266 unsigned long scm_mtrigger
;
269 * If set, don't expand the heap. Set only during gc, during which no allocation
270 * is supposed to take place anyway.
272 int scm_gc_heap_lock
= 0;
275 * Don't pause for collection if this is set -- just
278 int scm_block_gc
= 1;
280 /* During collection, this accumulates objects holding
283 SCM scm_weak_vectors
;
285 /* GC Statistics Keeping
287 unsigned long scm_cells_allocated
= 0;
288 unsigned long scm_mallocated
= 0;
289 unsigned long scm_gc_cells_collected
;
290 unsigned long scm_gc_cells_collected_1
= 0; /* previous GC yield */
291 unsigned long scm_gc_malloc_collected
;
292 unsigned long scm_gc_ports_collected
;
293 unsigned long scm_gc_time_taken
= 0;
294 static unsigned long t_before_gc
;
295 unsigned long scm_gc_mark_time_taken
= 0;
296 unsigned long scm_gc_times
= 0;
297 unsigned long scm_gc_cells_swept
= 0;
298 double scm_gc_cells_marked_acc
= 0.;
299 double scm_gc_cells_swept_acc
= 0.;
300 int scm_gc_cell_yield_percentage
=0;
301 int scm_gc_malloc_yield_percentage
= 0;
304 SCM_SYMBOL (sym_cells_allocated
, "cells-allocated");
305 SCM_SYMBOL (sym_heap_size
, "cell-heap-size");
306 SCM_SYMBOL (sym_mallocated
, "bytes-malloced");
307 SCM_SYMBOL (sym_mtrigger
, "gc-malloc-threshold");
308 SCM_SYMBOL (sym_heap_segments
, "cell-heap-segments");
309 SCM_SYMBOL (sym_gc_time_taken
, "gc-time-taken");
310 SCM_SYMBOL (sym_gc_mark_time_taken
, "gc-mark-time-taken");
311 SCM_SYMBOL (sym_times
, "gc-times");
312 SCM_SYMBOL (sym_cells_marked
, "cells-marked");
313 SCM_SYMBOL (sym_cells_swept
, "cells-swept");
314 SCM_SYMBOL (sym_malloc_yield
, "malloc-yield");
315 SCM_SYMBOL (sym_cell_yield
, "cell-yield");
320 /* Number of calls to SCM_NEWCELL since startup. */
321 unsigned scm_newcell_count
;
322 unsigned scm_newcell2_count
;
325 /* {Scheme Interface to GC}
327 extern int scm_gc_malloc_yield_percentage
;
328 SCM_DEFINE (scm_gc_stats
, "gc-stats", 0, 0, 0,
330 "Return an association list of statistics about Guile's current\n"
332 #define FUNC_NAME s_scm_gc_stats
335 SCM heap_segs
= SCM_EOL
;
336 unsigned long int local_scm_mtrigger
;
337 unsigned long int local_scm_mallocated
;
338 unsigned long int local_scm_heap_size
;
339 int local_scm_gc_cell_yield_percentage
;
340 int local_scm_gc_malloc_yield_percentage
;
341 unsigned long int local_scm_cells_allocated
;
342 unsigned long int local_scm_gc_time_taken
;
343 unsigned long int local_scm_gc_times
;
344 unsigned long int local_scm_gc_mark_time_taken
;
345 double local_scm_gc_cells_swept
;
346 double local_scm_gc_cells_marked
;
348 unsigned long *bounds
= 0;
349 int table_size
= scm_i_heap_segment_table_size
;
353 temporarily store the numbers, so as not to cause GC.
356 bounds
= malloc (sizeof (int) * table_size
* 2);
359 for (i
= table_size
; i
--; )
361 bounds
[2*i
] = (unsigned long)scm_i_heap_segment_table
[i
]->bounds
[0];
362 bounds
[2*i
+1] = (unsigned long)scm_i_heap_segment_table
[i
]->bounds
[1];
366 /* Below, we cons to produce the resulting list. We want a snapshot of
367 * the heap situation before consing.
369 local_scm_mtrigger
= scm_mtrigger
;
370 local_scm_mallocated
= scm_mallocated
;
371 local_scm_heap_size
= SCM_HEAP_SIZE
;
373 local_scm_cells_allocated
= scm_cells_allocated
;
375 local_scm_gc_time_taken
= scm_gc_time_taken
;
376 local_scm_gc_mark_time_taken
= scm_gc_mark_time_taken
;
377 local_scm_gc_times
= scm_gc_times
;
378 local_scm_gc_malloc_yield_percentage
= scm_gc_malloc_yield_percentage
;
379 local_scm_gc_cell_yield_percentage
= scm_gc_cell_yield_percentage
;
381 local_scm_gc_cells_swept
=
382 (double) scm_gc_cells_swept_acc
383 + (double) scm_gc_cells_swept
;
384 local_scm_gc_cells_marked
= scm_gc_cells_marked_acc
385 +(double) scm_gc_cells_swept
386 -(double) scm_gc_cells_collected
;
388 for (i
= table_size
; i
--;)
390 heap_segs
= scm_cons (scm_cons (scm_ulong2num (bounds
[2*i
]),
391 scm_ulong2num (bounds
[2*i
+1])),
395 answer
= scm_list_n (scm_cons (sym_gc_time_taken
, scm_ulong2num (local_scm_gc_time_taken
)),
396 scm_cons (sym_cells_allocated
, scm_ulong2num (local_scm_cells_allocated
)),
397 scm_cons (sym_heap_size
, scm_ulong2num (local_scm_heap_size
)),
398 scm_cons (sym_mallocated
, scm_ulong2num (local_scm_mallocated
)),
399 scm_cons (sym_mtrigger
, scm_ulong2num (local_scm_mtrigger
)),
400 scm_cons (sym_times
, scm_ulong2num (local_scm_gc_times
)),
401 scm_cons (sym_gc_mark_time_taken
, scm_ulong2num (local_scm_gc_mark_time_taken
)),
402 scm_cons (sym_cells_marked
, scm_i_dbl2big (local_scm_gc_cells_marked
)),
403 scm_cons (sym_cells_swept
, scm_i_dbl2big (local_scm_gc_cells_swept
)),
404 scm_cons (sym_malloc_yield
, scm_long2num (local_scm_gc_malloc_yield_percentage
)),
405 scm_cons (sym_cell_yield
, scm_long2num (local_scm_gc_cell_yield_percentage
)),
406 scm_cons (sym_heap_segments
, heap_segs
),
416 gc_start_stats (const char *what SCM_UNUSED
)
418 t_before_gc
= scm_c_get_internal_run_time ();
420 scm_gc_cells_marked_acc
+= (double) scm_gc_cells_swept
421 - (double) scm_gc_cells_collected
;
422 scm_gc_cells_swept_acc
+= (double) scm_gc_cells_swept
;
424 scm_gc_cell_yield_percentage
= ( scm_gc_cells_collected
* 100 ) / SCM_HEAP_SIZE
;
426 scm_gc_cells_swept
= 0;
427 scm_gc_cells_collected_1
= scm_gc_cells_collected
;
430 CELLS SWEPT is another word for the number of cells that were
431 examined during GC. YIELD is the number that we cleaned
432 out. MARKED is the number that weren't cleaned.
434 scm_gc_cells_collected
= 0;
435 scm_gc_malloc_collected
= 0;
436 scm_gc_ports_collected
= 0;
442 unsigned long t
= scm_c_get_internal_run_time ();
443 scm_gc_time_taken
+= (t
- t_before_gc
);
449 SCM_DEFINE (scm_object_address
, "object-address", 1, 0, 0,
451 "Return an integer that for the lifetime of @var{obj} is uniquely\n"
452 "returned by this function for @var{obj}")
453 #define FUNC_NAME s_scm_object_address
455 return scm_ulong2num ((unsigned long) SCM_UNPACK (obj
));
460 SCM_DEFINE (scm_gc
, "gc", 0, 0, 0,
462 "Scans all of SCM objects and reclaims for further use those that are\n"
463 "no longer accessible.")
464 #define FUNC_NAME s_scm_gc
467 return SCM_UNSPECIFIED
;
474 /* When we get POSIX threads support, the master will be global and
475 * common while the freelist will be individual for each thread.
479 scm_gc_for_newcell (scm_t_cell_type_statistics
*freelist
, SCM
*free_cells
)
483 scm_rec_mutex_lock (&scm_i_sweep_mutex
);
485 *free_cells
= scm_i_sweep_some_segments (freelist
);
486 if (*free_cells
== SCM_EOL
&& scm_i_gc_grow_heap_p (freelist
))
488 freelist
->heap_segment_idx
= scm_i_get_new_heap_segment (freelist
, abort_on_error
);
489 *free_cells
= scm_i_sweep_some_segments (freelist
);
492 if (*free_cells
== SCM_EOL
&& !scm_block_gc
)
495 with the advent of lazy sweep, GC yield is only know just
498 scm_i_adjust_min_yield (freelist
);
501 out of fresh cells. Try to get some new ones.
506 *free_cells
= scm_i_sweep_some_segments (freelist
);
509 if (*free_cells
== SCM_EOL
)
512 failed getting new cells. Get new juice or die.
514 freelist
->heap_segment_idx
= scm_i_get_new_heap_segment (freelist
, abort_on_error
);
515 *free_cells
= scm_i_sweep_some_segments (freelist
);
518 if (*free_cells
== SCM_EOL
)
523 *free_cells
= SCM_FREE_CELL_CDR (cell
);
525 scm_rec_mutex_unlock (&scm_i_sweep_mutex
);
531 scm_t_c_hook scm_before_gc_c_hook
;
532 scm_t_c_hook scm_before_mark_c_hook
;
533 scm_t_c_hook scm_before_sweep_c_hook
;
534 scm_t_c_hook scm_after_sweep_c_hook
;
535 scm_t_c_hook scm_after_gc_c_hook
;
538 scm_igc (const char *what
)
540 scm_rec_mutex_lock (&scm_i_sweep_mutex
);
542 scm_c_hook_run (&scm_before_gc_c_hook
, 0);
545 fprintf (stderr
,"gc reason %s\n", what
);
548 SCM_NULLP (*SCM_FREELIST_LOC (scm_i_freelist
))
550 : (SCM_NULLP (*SCM_FREELIST_LOC (scm_i_freelist2
)) ? "o" : "m"));
553 /* During the critical section, only the current thread may run. */
554 scm_i_thread_put_to_sleep ();
556 if (!scm_root
|| !scm_stack_base
|| scm_block_gc
)
562 gc_start_stats (what
);
564 if (scm_gc_heap_lock
)
565 /* We've invoked the collector while a GC is already in progress.
566 That should never happen. */
572 Let's finish the sweep. The conservative GC might point into the
573 garbage, and marking that would create a mess.
575 scm_i_sweep_all_segments("GC");
576 if (scm_mallocated
< scm_i_deprecated_memory_return
)
578 /* The byte count of allocated objects has underflowed. This is
579 probably because you forgot to report the sizes of objects you
580 have allocated, by calling scm_done_malloc or some such. When
581 the GC freed them, it subtracted their size from
582 scm_mallocated, which underflowed. */
584 "scm_gc_sweep: Byte count of allocated objects has underflowed.\n"
585 "This is probably because the GC hasn't been correctly informed\n"
586 "about object sizes\n");
589 scm_mallocated
-= scm_i_deprecated_memory_return
;
593 scm_c_hook_run (&scm_before_mark_c_hook
, 0);
597 scm_gc_mark_time_taken
+= (scm_c_get_internal_run_time () - t_before_gc
);
599 scm_c_hook_run (&scm_before_sweep_c_hook
, 0);
602 Moved this lock upwards so that we can alloc new heap at the end of a sweep.
604 DOCME: why should the heap be locked anyway?
612 TODO: this hook should probably be moved to just before the mark,
613 since that's where the sweep is finished in lazy sweeping.
615 MDJ 030219 <djurfeldt@nada.kth.se>: No, probably not. The
616 original meaning implied at least two things: that it would be
619 1. the freelist is re-initialized (no evaluation possible, though)
623 2. the heap is "fresh"
624 (it is well-defined what data is used and what is not)
626 Neither of these conditions would hold just before the mark phase.
628 Of course, the lazy sweeping has muddled the distinction between
629 scm_before_sweep_c_hook and scm_after_sweep_c_hook, but even if
630 there were no difference, it would still be useful to have two
631 distinct classes of hook functions since this can prevent some
632 bad interference when several modules adds gc hooks.
634 scm_c_hook_run (&scm_after_sweep_c_hook
, 0);
637 scm_i_thread_wake_up ();
642 scm_c_hook_run (&scm_after_gc_c_hook
, 0);
644 scm_rec_mutex_unlock (&scm_i_sweep_mutex
);
647 For debugging purposes, you could do
648 scm_i_sweep_all_segments("debug"), but then the remains of the
649 cell aren't left to analyse.
654 /* {GC Protection Helper Functions}
659 * If within a function you need to protect one or more scheme objects from
660 * garbage collection, pass them as parameters to one of the
661 * scm_remember_upto_here* functions below. These functions don't do
662 * anything, but since the compiler does not know that they are actually
663 * no-ops, it will generate code that calls these functions with the given
664 * parameters. Therefore, you can be sure that the compiler will keep those
665 * scheme values alive (on the stack or in a register) up to the point where
666 * scm_remember_upto_here* is called. In other words, place the call to
667 * scm_remember_upto_here* _behind_ the last code in your function, that
668 * depends on the scheme object to exist.
670 * Example: We want to make sure that the string object str does not get
671 * garbage collected during the execution of 'some_function' in the code
672 * below, because otherwise the characters belonging to str would be freed and
673 * 'some_function' might access freed memory. To make sure that the compiler
674 * keeps str alive on the stack or in a register such that it is visible to
675 * the conservative gc we add the call to scm_remember_upto_here_1 _after_ the
676 * call to 'some_function'. Note that this would not be necessary if str was
677 * used anyway after the call to 'some_function'.
678 * char *chars = SCM_STRING_CHARS (str);
679 * some_function (chars);
680 * scm_remember_upto_here_1 (str); // str will be alive up to this point.
684 scm_remember_upto_here_1 (SCM obj SCM_UNUSED
)
686 /* Empty. Protects a single object from garbage collection. */
690 scm_remember_upto_here_2 (SCM obj1 SCM_UNUSED
, SCM obj2 SCM_UNUSED
)
692 /* Empty. Protects two objects from garbage collection. */
696 scm_remember_upto_here (SCM obj SCM_UNUSED
, ...)
698 /* Empty. Protects any number of objects from garbage collection. */
702 These crazy functions prevent garbage collection
703 of arguments after the first argument by
704 ensuring they remain live throughout the
705 function because they are used in the last
706 line of the code block.
707 It'd be better to have a nice compiler hint to
708 aid the conservative stack-scanning GC. --03/09/00 gjb */
710 scm_return_first (SCM elt
, ...)
716 scm_return_first_int (int i
, ...)
723 scm_permanent_object (SCM obj
)
726 scm_permobjs
= scm_cons (obj
, scm_permobjs
);
732 /* Protect OBJ from the garbage collector. OBJ will not be freed, even if all
733 other references are dropped, until the object is unprotected by calling
734 scm_gc_unprotect_object (OBJ). Calls to scm_gc_protect/unprotect_object nest,
735 i. e. it is possible to protect the same object several times, but it is
736 necessary to unprotect the object the same number of times to actually get
737 the object unprotected. It is an error to unprotect an object more often
738 than it has been protected before. The function scm_protect_object returns
742 /* Implementation note: For every object X, there is a counter which
743 scm_gc_protect_object(X) increments and scm_gc_unprotect_object(X) decrements.
747 scm_gc_protect_object (SCM obj
)
751 /* This critical section barrier will be replaced by a mutex. */
754 handle
= scm_hashq_create_handle_x (scm_protects
, obj
, SCM_MAKINUM (0));
755 SCM_SETCDR (handle
, scm_sum (SCM_CDR (handle
), SCM_MAKINUM (1)));
763 /* Remove any protection for OBJ established by a prior call to
764 scm_protect_object. This function returns OBJ.
766 See scm_protect_object for more information. */
768 scm_gc_unprotect_object (SCM obj
)
772 /* This critical section barrier will be replaced by a mutex. */
775 handle
= scm_hashq_get_handle (scm_protects
, obj
);
777 if (SCM_FALSEP (handle
))
779 fprintf (stderr
, "scm_unprotect_object called on unprotected object\n");
784 SCM count
= scm_difference (SCM_CDR (handle
), SCM_MAKINUM (1));
785 if (SCM_EQ_P (count
, SCM_MAKINUM (0)))
786 scm_hashq_remove_x (scm_protects
, obj
);
788 SCM_SETCDR (handle
, count
);
797 scm_gc_register_root (SCM
*p
)
800 SCM key
= scm_long2num ((long) p
);
802 /* This critical section barrier will be replaced by a mutex. */
805 handle
= scm_hashv_create_handle_x (scm_gc_registered_roots
, key
, SCM_MAKINUM (0));
806 SCM_SETCDR (handle
, scm_sum (SCM_CDR (handle
), SCM_MAKINUM (1)));
812 scm_gc_unregister_root (SCM
*p
)
815 SCM key
= scm_long2num ((long) p
);
817 /* This critical section barrier will be replaced by a mutex. */
820 handle
= scm_hashv_get_handle (scm_gc_registered_roots
, key
);
822 if (SCM_FALSEP (handle
))
824 fprintf (stderr
, "scm_gc_unregister_root called on unregistered root\n");
829 SCM count
= scm_difference (SCM_CDR (handle
), SCM_MAKINUM (1));
830 if (SCM_EQ_P (count
, SCM_MAKINUM (0)))
831 scm_hashv_remove_x (scm_gc_registered_roots
, key
);
833 SCM_SETCDR (handle
, count
);
840 scm_gc_register_roots (SCM
*b
, unsigned long n
)
843 for (; p
< b
+ n
; ++p
)
844 scm_gc_register_root (p
);
848 scm_gc_unregister_roots (SCM
*b
, unsigned long n
)
851 for (; p
< b
+ n
; ++p
)
852 scm_gc_unregister_root (p
);
855 int scm_i_terminating
;
857 /* called on process termination. */
863 extern int on_exit (void (*procp
) (), int arg
);
866 cleanup (int status
, void *arg
)
868 #error Dont know how to setup a cleanup handler on your system.
872 scm_i_terminating
= 1;
873 scm_flush_all_ports ();
880 MOVE THIS FUNCTION. IT DOES NOT HAVE ANYTHING TODO WITH GC.
883 /* Get an integer from an environment variable. */
885 scm_getenv_int (const char *var
, int def
)
888 char *val
= getenv (var
);
892 res
= strtol (val
, &end
, 10);
899 scm_storage_prehistory ()
901 scm_c_hook_init (&scm_before_gc_c_hook
, 0, SCM_C_HOOK_NORMAL
);
902 scm_c_hook_init (&scm_before_mark_c_hook
, 0, SCM_C_HOOK_NORMAL
);
903 scm_c_hook_init (&scm_before_sweep_c_hook
, 0, SCM_C_HOOK_NORMAL
);
904 scm_c_hook_init (&scm_after_sweep_c_hook
, 0, SCM_C_HOOK_NORMAL
);
905 scm_c_hook_init (&scm_after_gc_c_hook
, 0, SCM_C_HOOK_NORMAL
);
913 /* Fixme: Should use mutexattr from the low-level API. */
914 scm_rec_mutex_init (&scm_i_sweep_mutex
, &scm_i_plugin_rec_mutex
);
916 j
= SCM_NUM_PROTECTS
;
918 scm_sys_protects
[--j
] = SCM_BOOL_F
;
921 scm_gc_init_freelist();
922 scm_gc_init_malloc ();
924 j
= SCM_HEAP_SEG_SIZE
;
927 /* Initialise the list of ports. */
928 scm_i_port_table
= (scm_t_port
**)
929 malloc (sizeof (scm_t_port
*) * scm_i_port_table_room
);
930 if (!scm_i_port_table
)
937 on_exit (cleanup
, 0);
941 scm_stand_in_procs
= SCM_EOL
;
942 scm_permobjs
= SCM_EOL
;
943 scm_protects
= scm_c_make_hash_table (31);
944 scm_gc_registered_roots
= scm_c_make_hash_table (31);
951 SCM scm_after_gc_hook
;
955 /* The function gc_async_thunk causes the execution of the after-gc-hook. It
956 * is run after the gc, as soon as the asynchronous events are handled by the
960 gc_async_thunk (void)
962 scm_c_run_hook (scm_after_gc_hook
, SCM_EOL
);
963 return SCM_UNSPECIFIED
;
967 /* The function mark_gc_async is run by the scm_after_gc_c_hook at the end of
968 * the garbage collection. The only purpose of this function is to mark the
969 * gc_async (which will eventually lead to the execution of the
973 mark_gc_async (void * hook_data SCM_UNUSED
,
974 void *func_data SCM_UNUSED
,
975 void *data SCM_UNUSED
)
977 /* If cell access debugging is enabled, the user may choose to perform
978 * additional garbage collections after an arbitrary number of cell
979 * accesses. We don't want the scheme level after-gc-hook to be performed
980 * for each of these garbage collections for the following reason: The
981 * execution of the after-gc-hook causes cell accesses itself. Thus, if the
982 * after-gc-hook was performed with every gc, and if the gc was performed
983 * after a very small number of cell accesses, then the number of cell
984 * accesses during the execution of the after-gc-hook will suffice to cause
985 * the execution of the next gc. Then, guile would keep executing the
986 * after-gc-hook over and over again, and would never come to do other
989 * To overcome this problem, if cell access debugging with additional
990 * garbage collections is enabled, the after-gc-hook is never run by the
991 * garbage collecter. When running guile with cell access debugging and the
992 * execution of the after-gc-hook is desired, then it is necessary to run
993 * the hook explicitly from the user code. This has the effect, that from
994 * the scheme level point of view it seems that garbage collection is
995 * performed with a much lower frequency than it actually is. Obviously,
996 * this will not work for code that depends on a fixed one to one
997 * relationship between the execution counts of the C level garbage
998 * collection hooks and the execution count of the scheme level
1001 #if (SCM_DEBUG_CELL_ACCESSES == 1)
1002 if (scm_debug_cells_gc_interval
== 0)
1003 scm_system_async_mark (gc_async
);
1005 scm_system_async_mark (gc_async
);
1014 scm_gc_init_mark ();
1016 scm_after_gc_hook
= scm_permanent_object (scm_make_hook (SCM_INUM0
));
1017 scm_c_define ("after-gc-hook", scm_after_gc_hook
);
1019 gc_async
= scm_c_make_subr ("%gc-thunk", scm_tc7_subr_0
,
1022 scm_c_hook_add (&scm_after_gc_c_hook
, mark_gc_async
, NULL
, 0);
1024 #include "libguile/gc.x"
1030 #define FUNC_NAME "scm_gc_sweep"
1032 scm_i_deprecated_memory_return
= 0;
1034 scm_i_gc_sweep_freelist_reset (&scm_i_master_freelist
);
1035 scm_i_gc_sweep_freelist_reset (&scm_i_master_freelist2
);
1038 NOTHING HERE: LAZY SWEEPING !
1040 scm_i_reset_segments ();
1042 /* When we move to POSIX threads private freelists should probably
1043 be GC-protected instead. */
1044 *SCM_FREELIST_LOC (scm_i_freelist
) = SCM_EOL
;
1045 *SCM_FREELIST_LOC (scm_i_freelist2
) = SCM_EOL
;
1047 /* Invalidate the freelists of other threads. */
1048 scm_i_thread_invalidate_freelists ();