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c35738c1 | 1 | /* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2002, 2003 Free Software Foundation, Inc. |
a00c95d9 | 2 | * |
73be1d9e MV |
3 | * This library is free software; you can redistribute it and/or |
4 | * modify it under the terms of the GNU Lesser General Public | |
5 | * License as published by the Free Software Foundation; either | |
6 | * version 2.1 of the License, or (at your option) any later version. | |
a00c95d9 | 7 | * |
73be1d9e | 8 | * This library is distributed in the hope that it will be useful, |
0f2d19dd | 9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
73be1d9e MV |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
11 | * Lesser General Public License for more details. | |
a00c95d9 | 12 | * |
73be1d9e MV |
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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
16 | */ | |
1bbd0b84 | 17 | |
9de87eea | 18 | #define _GNU_SOURCE |
1bbd0b84 | 19 | |
37ddcaf6 MD |
20 | /* #define DEBUGINFO */ |
21 | ||
aa54a9b0 RB |
22 | #if HAVE_CONFIG_H |
23 | # include <config.h> | |
24 | #endif | |
56495472 | 25 | |
0f2d19dd | 26 | #include <stdio.h> |
e6e2e95a | 27 | #include <errno.h> |
783e7774 | 28 | #include <string.h> |
c8a1bdc4 | 29 | #include <assert.h> |
e6e2e95a | 30 | |
d9189652 RB |
31 | #ifdef __ia64__ |
32 | #include <ucontext.h> | |
bb1180ef | 33 | extern unsigned long * __libc_ia64_register_backing_store_base; |
d9189652 RB |
34 | #endif |
35 | ||
a0599745 | 36 | #include "libguile/_scm.h" |
0a7a7445 | 37 | #include "libguile/eval.h" |
a0599745 MD |
38 | #include "libguile/stime.h" |
39 | #include "libguile/stackchk.h" | |
40 | #include "libguile/struct.h" | |
a0599745 MD |
41 | #include "libguile/smob.h" |
42 | #include "libguile/unif.h" | |
43 | #include "libguile/async.h" | |
44 | #include "libguile/ports.h" | |
45 | #include "libguile/root.h" | |
46 | #include "libguile/strings.h" | |
47 | #include "libguile/vectors.h" | |
801cb5e7 | 48 | #include "libguile/weaks.h" |
686765af | 49 | #include "libguile/hashtab.h" |
ecf470a2 | 50 | #include "libguile/tags.h" |
a0599745 | 51 | |
c8a1bdc4 | 52 | #include "libguile/private-gc.h" |
a0599745 | 53 | #include "libguile/validate.h" |
1be6b49c | 54 | #include "libguile/deprecation.h" |
a0599745 | 55 | #include "libguile/gc.h" |
9de87eea | 56 | #include "libguile/dynwind.h" |
fce59c93 | 57 | |
bc9d9bb2 | 58 | #ifdef GUILE_DEBUG_MALLOC |
a0599745 | 59 | #include "libguile/debug-malloc.h" |
bc9d9bb2 MD |
60 | #endif |
61 | ||
0f2d19dd | 62 | #ifdef HAVE_MALLOC_H |
95b88819 | 63 | #include <malloc.h> |
0f2d19dd JB |
64 | #endif |
65 | ||
66 | #ifdef HAVE_UNISTD_H | |
95b88819 | 67 | #include <unistd.h> |
0f2d19dd JB |
68 | #endif |
69 | ||
406c7d90 | 70 | |
8c494e99 | 71 | |
406c7d90 DH |
72 | unsigned int scm_gc_running_p = 0; |
73 | ||
fb50ef08 MD |
74 | /* Lock this mutex before doing lazy sweeping. |
75 | */ | |
9de87eea | 76 | scm_i_pthread_mutex_t scm_i_sweep_mutex = SCM_I_PTHREAD_RECURSIVE_MUTEX_INITIALIZER; |
fb50ef08 | 77 | |
eae33935 | 78 | /* Set this to != 0 if every cell that is accessed shall be checked: |
61045190 | 79 | */ |
eab1b259 HWN |
80 | int scm_debug_cell_accesses_p = 0; |
81 | int scm_expensive_debug_cell_accesses_p = 0; | |
406c7d90 | 82 | |
e81d98ec DH |
83 | /* Set this to 0 if no additional gc's shall be performed, otherwise set it to |
84 | * the number of cell accesses after which a gc shall be called. | |
85 | */ | |
eab1b259 | 86 | int scm_debug_cells_gc_interval = 0; |
e81d98ec | 87 | |
eab1b259 HWN |
88 | /* |
89 | Global variable, so you can switch it off at runtime by setting | |
90 | scm_i_cell_validation_already_running. | |
406c7d90 | 91 | */ |
eab1b259 HWN |
92 | int scm_i_cell_validation_already_running ; |
93 | ||
94 | #if (SCM_DEBUG_CELL_ACCESSES == 1) | |
95 | ||
96 | ||
97 | /* | |
98 | ||
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 | |
105 | periods. | |
106 | ||
107 | */ | |
406c7d90 | 108 | void |
eab1b259 | 109 | scm_i_expensive_validation_check (SCM cell) |
406c7d90 | 110 | { |
eab1b259 HWN |
111 | if (!scm_in_heap_p (cell)) |
112 | { | |
113 | fprintf (stderr, "scm_assert_cell_valid: this object does not live in the heap: %lux\n", | |
114 | (unsigned long) SCM_UNPACK (cell)); | |
115 | abort (); | |
116 | } | |
117 | ||
118 | /* If desired, perform additional garbage collections after a user | |
119 | * defined number of cell accesses. | |
120 | */ | |
121 | if (scm_debug_cells_gc_interval) | |
122 | { | |
123 | static unsigned int counter = 0; | |
61045190 | 124 | |
eab1b259 HWN |
125 | if (counter != 0) |
126 | { | |
127 | --counter; | |
128 | } | |
129 | else | |
130 | { | |
131 | counter = scm_debug_cells_gc_interval; | |
132 | scm_igc ("scm_assert_cell_valid"); | |
133 | } | |
134 | } | |
135 | } | |
136 | ||
137 | void | |
138 | scm_assert_cell_valid (SCM cell) | |
139 | { | |
140 | if (!scm_i_cell_validation_already_running && scm_debug_cell_accesses_p) | |
406c7d90 | 141 | { |
eab1b259 | 142 | scm_i_cell_validation_already_running = 1; /* set to avoid recursion */ |
406c7d90 | 143 | |
c8a1bdc4 | 144 | /* |
eab1b259 HWN |
145 | During GC, no user-code should be run, and the guile core |
146 | should use non-protected accessors. | |
147 | */ | |
c8a1bdc4 | 148 | if (scm_gc_running_p) |
eab1b259 | 149 | return; |
c8a1bdc4 HWN |
150 | |
151 | /* | |
eab1b259 HWN |
152 | Only scm_in_heap_p and rescanning the heap is wildly |
153 | expensive. | |
154 | */ | |
155 | if (scm_expensive_debug_cell_accesses_p) | |
156 | scm_i_expensive_validation_check (cell); | |
c8a1bdc4 HWN |
157 | |
158 | if (!SCM_GC_MARK_P (cell)) | |
406c7d90 | 159 | { |
c8a1bdc4 HWN |
160 | fprintf (stderr, |
161 | "scm_assert_cell_valid: this object is unmarked. \n" | |
162 | "It has been garbage-collected in the last GC run: " | |
163 | "%lux\n", | |
1be6b49c | 164 | (unsigned long) SCM_UNPACK (cell)); |
406c7d90 DH |
165 | abort (); |
166 | } | |
c8a1bdc4 | 167 | |
eab1b259 | 168 | scm_i_cell_validation_already_running = 0; /* re-enable */ |
406c7d90 DH |
169 | } |
170 | } | |
171 | ||
172 | ||
eab1b259 | 173 | |
406c7d90 DH |
174 | SCM_DEFINE (scm_set_debug_cell_accesses_x, "set-debug-cell-accesses!", 1, 0, 0, |
175 | (SCM flag), | |
1e6808ea | 176 | "If @var{flag} is @code{#f}, cell access checking is disabled.\n" |
eab1b259 | 177 | "If @var{flag} is @code{#t}, cheap cell access checking is enabled,\n" |
e81d98ec | 178 | "but no additional calls to garbage collection are issued.\n" |
eab1b259 | 179 | "If @var{flag} is a number, strict cell access checking is enabled,\n" |
e81d98ec DH |
180 | "with an additional garbage collection after the given\n" |
181 | "number of cell accesses.\n" | |
1e6808ea MG |
182 | "This procedure only exists when the compile-time flag\n" |
183 | "@code{SCM_DEBUG_CELL_ACCESSES} was set to 1.") | |
406c7d90 DH |
184 | #define FUNC_NAME s_scm_set_debug_cell_accesses_x |
185 | { | |
7888309b | 186 | if (scm_is_false (flag)) |
eab1b259 HWN |
187 | { |
188 | scm_debug_cell_accesses_p = 0; | |
189 | } | |
bc36d050 | 190 | else if (scm_is_eq (flag, SCM_BOOL_T)) |
eab1b259 HWN |
191 | { |
192 | scm_debug_cells_gc_interval = 0; | |
193 | scm_debug_cell_accesses_p = 1; | |
194 | scm_expensive_debug_cell_accesses_p = 0; | |
195 | } | |
e11e83f3 | 196 | else |
eab1b259 | 197 | { |
e11e83f3 | 198 | scm_debug_cells_gc_interval = scm_to_signed_integer (flag, 0, INT_MAX); |
eab1b259 HWN |
199 | scm_debug_cell_accesses_p = 1; |
200 | scm_expensive_debug_cell_accesses_p = 1; | |
201 | } | |
406c7d90 DH |
202 | return SCM_UNSPECIFIED; |
203 | } | |
204 | #undef FUNC_NAME | |
0f2d19dd | 205 | |
ecf470a2 | 206 | |
c8a1bdc4 | 207 | #endif /* SCM_DEBUG_CELL_ACCESSES == 1 */ |
0f2d19dd JB |
208 | |
209 | \f | |
945fec60 | 210 | |
0f2d19dd JB |
211 | |
212 | /* scm_mtrigger | |
539b08a4 | 213 | * is the number of bytes of malloc allocation needed to trigger gc. |
0f2d19dd | 214 | */ |
c014a02e | 215 | unsigned long scm_mtrigger; |
0f2d19dd | 216 | |
0f2d19dd JB |
217 | /* scm_gc_heap_lock |
218 | * If set, don't expand the heap. Set only during gc, during which no allocation | |
219 | * is supposed to take place anyway. | |
220 | */ | |
221 | int scm_gc_heap_lock = 0; | |
222 | ||
223 | /* GC Blocking | |
224 | * Don't pause for collection if this is set -- just | |
225 | * expand the heap. | |
226 | */ | |
0f2d19dd JB |
227 | int scm_block_gc = 1; |
228 | ||
0f2d19dd JB |
229 | /* During collection, this accumulates objects holding |
230 | * weak references. | |
231 | */ | |
ab4bef85 | 232 | SCM scm_weak_vectors; |
0f2d19dd JB |
233 | |
234 | /* GC Statistics Keeping | |
235 | */ | |
f2893a25 | 236 | unsigned long scm_cells_allocated = 0; |
c014a02e ML |
237 | unsigned long scm_mallocated = 0; |
238 | unsigned long scm_gc_cells_collected; | |
c8a1bdc4 | 239 | unsigned long scm_gc_cells_collected_1 = 0; /* previous GC yield */ |
c014a02e ML |
240 | unsigned long scm_gc_malloc_collected; |
241 | unsigned long scm_gc_ports_collected; | |
0f2d19dd | 242 | unsigned long scm_gc_time_taken = 0; |
c014a02e | 243 | static unsigned long t_before_gc; |
c9b0d4b0 | 244 | unsigned long scm_gc_mark_time_taken = 0; |
c014a02e ML |
245 | unsigned long scm_gc_times = 0; |
246 | unsigned long scm_gc_cells_swept = 0; | |
c9b0d4b0 ML |
247 | double scm_gc_cells_marked_acc = 0.; |
248 | double scm_gc_cells_swept_acc = 0.; | |
c2cbcc57 HWN |
249 | int scm_gc_cell_yield_percentage =0; |
250 | int scm_gc_malloc_yield_percentage = 0; | |
7eec4c37 | 251 | unsigned long protected_obj_count = 0; |
c2cbcc57 | 252 | |
0f2d19dd JB |
253 | |
254 | SCM_SYMBOL (sym_cells_allocated, "cells-allocated"); | |
255 | SCM_SYMBOL (sym_heap_size, "cell-heap-size"); | |
256 | SCM_SYMBOL (sym_mallocated, "bytes-malloced"); | |
257 | SCM_SYMBOL (sym_mtrigger, "gc-malloc-threshold"); | |
258 | SCM_SYMBOL (sym_heap_segments, "cell-heap-segments"); | |
259 | SCM_SYMBOL (sym_gc_time_taken, "gc-time-taken"); | |
c9b0d4b0 | 260 | SCM_SYMBOL (sym_gc_mark_time_taken, "gc-mark-time-taken"); |
c9b0d4b0 ML |
261 | SCM_SYMBOL (sym_times, "gc-times"); |
262 | SCM_SYMBOL (sym_cells_marked, "cells-marked"); | |
263 | SCM_SYMBOL (sym_cells_swept, "cells-swept"); | |
c2cbcc57 HWN |
264 | SCM_SYMBOL (sym_malloc_yield, "malloc-yield"); |
265 | SCM_SYMBOL (sym_cell_yield, "cell-yield"); | |
7eec4c37 | 266 | SCM_SYMBOL (sym_protected_objects, "protected-objects"); |
0f2d19dd | 267 | |
bb2c57fa | 268 | |
cf2d30f6 | 269 | |
d3dd80ab | 270 | |
cf2d30f6 | 271 | /* Number of calls to SCM_NEWCELL since startup. */ |
c8a1bdc4 HWN |
272 | unsigned scm_newcell_count; |
273 | unsigned scm_newcell2_count; | |
b37fe1c5 | 274 | |
b37fe1c5 | 275 | |
0f2d19dd JB |
276 | /* {Scheme Interface to GC} |
277 | */ | |
1367aa5e HWN |
278 | static SCM |
279 | tag_table_to_type_alist (void *closure, SCM key, SCM val, SCM acc) | |
280 | { | |
281 | scm_t_bits c_tag = scm_to_int (key); | |
73a4c24e HWN |
282 | |
283 | char const * name = scm_i_tag_name (c_tag); | |
284 | if (name != NULL) | |
285 | key = scm_from_locale_string (name); | |
286 | ||
1367aa5e HWN |
287 | return scm_cons (scm_cons (key, val), acc); |
288 | } | |
289 | ||
290 | SCM_DEFINE (scm_gc_live_object_stats, "gc-live-object-stats", 0, 0, 0, | |
291 | (), | |
292 | "Return an alist of statistics of the current live objects. ") | |
293 | #define FUNC_NAME s_scm_gc_live_object_stats | |
294 | { | |
295 | SCM tab = scm_make_hash_table (scm_from_int (57)); | |
296 | scm_i_all_segments_statistics (tab); | |
297 | ||
298 | SCM alist | |
299 | = scm_internal_hash_fold (&tag_table_to_type_alist, NULL, SCM_EOL, tab); | |
300 | ||
301 | return alist; | |
302 | } | |
303 | #undef FUNC_NAME | |
304 | ||
c2cbcc57 | 305 | extern int scm_gc_malloc_yield_percentage; |
a00c95d9 | 306 | SCM_DEFINE (scm_gc_stats, "gc-stats", 0, 0, 0, |
1bbd0b84 | 307 | (), |
1e6808ea | 308 | "Return an association list of statistics about Guile's current\n" |
c8a1bdc4 | 309 | "use of storage.\n") |
1bbd0b84 | 310 | #define FUNC_NAME s_scm_gc_stats |
0f2d19dd | 311 | { |
c8a1bdc4 HWN |
312 | long i = 0; |
313 | SCM heap_segs = SCM_EOL ; | |
c014a02e ML |
314 | unsigned long int local_scm_mtrigger; |
315 | unsigned long int local_scm_mallocated; | |
316 | unsigned long int local_scm_heap_size; | |
c2cbcc57 HWN |
317 | int local_scm_gc_cell_yield_percentage; |
318 | int local_scm_gc_malloc_yield_percentage; | |
f2893a25 | 319 | unsigned long int local_scm_cells_allocated; |
c014a02e ML |
320 | unsigned long int local_scm_gc_time_taken; |
321 | unsigned long int local_scm_gc_times; | |
322 | unsigned long int local_scm_gc_mark_time_taken; | |
7eec4c37 | 323 | unsigned long int local_protected_obj_count; |
c9b0d4b0 ML |
324 | double local_scm_gc_cells_swept; |
325 | double local_scm_gc_cells_marked; | |
0f2d19dd | 326 | SCM answer; |
c8a1bdc4 HWN |
327 | unsigned long *bounds = 0; |
328 | int table_size = scm_i_heap_segment_table_size; | |
9de87eea | 329 | SCM_CRITICAL_SECTION_START; |
939794ce | 330 | |
c8a1bdc4 HWN |
331 | /* |
332 | temporarily store the numbers, so as not to cause GC. | |
7febb4a2 | 333 | */ |
c8a1bdc4 HWN |
334 | |
335 | bounds = malloc (sizeof (int) * table_size * 2); | |
336 | if (!bounds) | |
337 | abort(); | |
338 | for (i = table_size; i--; ) | |
339 | { | |
340 | bounds[2*i] = (unsigned long)scm_i_heap_segment_table[i]->bounds[0]; | |
341 | bounds[2*i+1] = (unsigned long)scm_i_heap_segment_table[i]->bounds[1]; | |
342 | } | |
0f2d19dd | 343 | |
4c9419ac | 344 | |
c8a1bdc4 HWN |
345 | /* Below, we cons to produce the resulting list. We want a snapshot of |
346 | * the heap situation before consing. | |
347 | */ | |
348 | local_scm_mtrigger = scm_mtrigger; | |
349 | local_scm_mallocated = scm_mallocated; | |
350 | local_scm_heap_size = SCM_HEAP_SIZE; | |
539b08a4 | 351 | |
c8a1bdc4 HWN |
352 | local_scm_cells_allocated = scm_cells_allocated; |
353 | ||
354 | local_scm_gc_time_taken = scm_gc_time_taken; | |
355 | local_scm_gc_mark_time_taken = scm_gc_mark_time_taken; | |
356 | local_scm_gc_times = scm_gc_times; | |
c2cbcc57 HWN |
357 | local_scm_gc_malloc_yield_percentage = scm_gc_malloc_yield_percentage; |
358 | local_scm_gc_cell_yield_percentage= scm_gc_cell_yield_percentage; | |
7eec4c37 | 359 | local_protected_obj_count = protected_obj_count; |
c2cbcc57 HWN |
360 | local_scm_gc_cells_swept = |
361 | (double) scm_gc_cells_swept_acc | |
362 | + (double) scm_gc_cells_swept; | |
c8a1bdc4 HWN |
363 | local_scm_gc_cells_marked = scm_gc_cells_marked_acc |
364 | +(double) scm_gc_cells_swept | |
365 | -(double) scm_gc_cells_collected; | |
0f2d19dd | 366 | |
c8a1bdc4 HWN |
367 | for (i = table_size; i--;) |
368 | { | |
b9bd8526 MV |
369 | heap_segs = scm_cons (scm_cons (scm_from_ulong (bounds[2*i]), |
370 | scm_from_ulong (bounds[2*i+1])), | |
c8a1bdc4 HWN |
371 | heap_segs); |
372 | } | |
373 | ||
b9bd8526 MV |
374 | answer = |
375 | scm_list_n (scm_cons (sym_gc_time_taken, | |
376 | scm_from_ulong (local_scm_gc_time_taken)), | |
377 | scm_cons (sym_cells_allocated, | |
378 | scm_from_ulong (local_scm_cells_allocated)), | |
379 | scm_cons (sym_heap_size, | |
380 | scm_from_ulong (local_scm_heap_size)), | |
381 | scm_cons (sym_mallocated, | |
382 | scm_from_ulong (local_scm_mallocated)), | |
383 | scm_cons (sym_mtrigger, | |
384 | scm_from_ulong (local_scm_mtrigger)), | |
385 | scm_cons (sym_times, | |
386 | scm_from_ulong (local_scm_gc_times)), | |
387 | scm_cons (sym_gc_mark_time_taken, | |
388 | scm_from_ulong (local_scm_gc_mark_time_taken)), | |
389 | scm_cons (sym_cells_marked, | |
390 | scm_from_double (local_scm_gc_cells_marked)), | |
391 | scm_cons (sym_cells_swept, | |
392 | scm_from_double (local_scm_gc_cells_swept)), | |
393 | scm_cons (sym_malloc_yield, | |
394 | scm_from_long(local_scm_gc_malloc_yield_percentage)), | |
395 | scm_cons (sym_cell_yield, | |
396 | scm_from_long (local_scm_gc_cell_yield_percentage)), | |
397 | scm_cons (sym_protected_objects, | |
398 | scm_from_ulong (local_protected_obj_count)), | |
399 | scm_cons (sym_heap_segments, heap_segs), | |
400 | SCM_UNDEFINED); | |
9de87eea | 401 | SCM_CRITICAL_SECTION_END; |
c8a1bdc4 HWN |
402 | |
403 | free (bounds); | |
404 | return answer; | |
0f2d19dd | 405 | } |
c8a1bdc4 | 406 | #undef FUNC_NAME |
0f2d19dd | 407 | |
c8a1bdc4 HWN |
408 | static void |
409 | gc_start_stats (const char *what SCM_UNUSED) | |
e4a7824f | 410 | { |
c8a1bdc4 | 411 | t_before_gc = scm_c_get_internal_run_time (); |
539b08a4 | 412 | |
c8a1bdc4 HWN |
413 | scm_gc_cells_marked_acc += (double) scm_gc_cells_swept |
414 | - (double) scm_gc_cells_collected; | |
c2cbcc57 | 415 | scm_gc_cells_swept_acc += (double) scm_gc_cells_swept; |
e4a7824f | 416 | |
c2cbcc57 HWN |
417 | scm_gc_cell_yield_percentage = ( scm_gc_cells_collected * 100 ) / SCM_HEAP_SIZE; |
418 | ||
c8a1bdc4 HWN |
419 | scm_gc_cells_swept = 0; |
420 | scm_gc_cells_collected_1 = scm_gc_cells_collected; | |
539b08a4 | 421 | |
c8a1bdc4 HWN |
422 | /* |
423 | CELLS SWEPT is another word for the number of cells that were | |
424 | examined during GC. YIELD is the number that we cleaned | |
425 | out. MARKED is the number that weren't cleaned. | |
426 | */ | |
427 | scm_gc_cells_collected = 0; | |
428 | scm_gc_malloc_collected = 0; | |
429 | scm_gc_ports_collected = 0; | |
e4a7824f | 430 | } |
acf4331f | 431 | |
c8a1bdc4 HWN |
432 | static void |
433 | gc_end_stats () | |
0f2d19dd | 434 | { |
c8a1bdc4 HWN |
435 | unsigned long t = scm_c_get_internal_run_time (); |
436 | scm_gc_time_taken += (t - t_before_gc); | |
539b08a4 | 437 | |
c8a1bdc4 | 438 | ++scm_gc_times; |
0f2d19dd | 439 | } |
acf4331f | 440 | |
0f2d19dd | 441 | |
c8a1bdc4 HWN |
442 | SCM_DEFINE (scm_object_address, "object-address", 1, 0, 0, |
443 | (SCM obj), | |
444 | "Return an integer that for the lifetime of @var{obj} is uniquely\n" | |
445 | "returned by this function for @var{obj}") | |
446 | #define FUNC_NAME s_scm_object_address | |
c68296f8 | 447 | { |
b9bd8526 | 448 | return scm_from_ulong (SCM_UNPACK (obj)); |
c68296f8 | 449 | } |
c8a1bdc4 | 450 | #undef FUNC_NAME |
c68296f8 | 451 | |
1be6b49c | 452 | |
c8a1bdc4 HWN |
453 | SCM_DEFINE (scm_gc, "gc", 0, 0, 0, |
454 | (), | |
455 | "Scans all of SCM objects and reclaims for further use those that are\n" | |
456 | "no longer accessible.") | |
457 | #define FUNC_NAME s_scm_gc | |
458 | { | |
c8a1bdc4 | 459 | scm_igc ("call"); |
c8a1bdc4 | 460 | return SCM_UNSPECIFIED; |
9d47a1e6 | 461 | } |
c8a1bdc4 | 462 | #undef FUNC_NAME |
9d47a1e6 | 463 | |
c68296f8 MV |
464 | |
465 | \f | |
0f2d19dd | 466 | |
c8a1bdc4 HWN |
467 | /* When we get POSIX threads support, the master will be global and |
468 | * common while the freelist will be individual for each thread. | |
0f2d19dd JB |
469 | */ |
470 | ||
c8a1bdc4 HWN |
471 | SCM |
472 | scm_gc_for_newcell (scm_t_cell_type_statistics *freelist, SCM *free_cells) | |
0f2d19dd | 473 | { |
c8a1bdc4 HWN |
474 | SCM cell; |
475 | ||
9de87eea | 476 | scm_i_scm_pthread_mutex_lock (&scm_i_sweep_mutex); |
9bc4701c | 477 | |
c8a1bdc4 HWN |
478 | *free_cells = scm_i_sweep_some_segments (freelist); |
479 | if (*free_cells == SCM_EOL && scm_i_gc_grow_heap_p (freelist)) | |
480 | { | |
481 | freelist->heap_segment_idx = scm_i_get_new_heap_segment (freelist, abort_on_error); | |
482 | *free_cells = scm_i_sweep_some_segments (freelist); | |
483 | } | |
acb0a19c | 484 | |
c8a1bdc4 HWN |
485 | if (*free_cells == SCM_EOL && !scm_block_gc) |
486 | { | |
487 | /* | |
488 | with the advent of lazy sweep, GC yield is only know just | |
489 | before doing the GC. | |
490 | */ | |
491 | scm_i_adjust_min_yield (freelist); | |
492 | ||
493 | /* | |
494 | out of fresh cells. Try to get some new ones. | |
495 | */ | |
0f2d19dd | 496 | |
c8a1bdc4 | 497 | scm_igc ("cells"); |
a00c95d9 | 498 | |
c8a1bdc4 HWN |
499 | *free_cells = scm_i_sweep_some_segments (freelist); |
500 | } | |
501 | ||
502 | if (*free_cells == SCM_EOL) | |
503 | { | |
504 | /* | |
505 | failed getting new cells. Get new juice or die. | |
506 | */ | |
507 | freelist->heap_segment_idx = scm_i_get_new_heap_segment (freelist, abort_on_error); | |
508 | *free_cells = scm_i_sweep_some_segments (freelist); | |
509 | } | |
510 | ||
511 | if (*free_cells == SCM_EOL) | |
512 | abort (); | |
0f2d19dd | 513 | |
c8a1bdc4 | 514 | cell = *free_cells; |
0f2d19dd | 515 | |
c8a1bdc4 | 516 | *free_cells = SCM_FREE_CELL_CDR (cell); |
eab1b259 | 517 | |
9de87eea | 518 | scm_i_pthread_mutex_unlock (&scm_i_sweep_mutex); |
eab1b259 | 519 | |
c8a1bdc4 HWN |
520 | return cell; |
521 | } | |
4a4c9785 | 522 | |
4a4c9785 | 523 | |
c8a1bdc4 HWN |
524 | scm_t_c_hook scm_before_gc_c_hook; |
525 | scm_t_c_hook scm_before_mark_c_hook; | |
526 | scm_t_c_hook scm_before_sweep_c_hook; | |
527 | scm_t_c_hook scm_after_sweep_c_hook; | |
528 | scm_t_c_hook scm_after_gc_c_hook; | |
4a4c9785 | 529 | |
c8a1bdc4 HWN |
530 | void |
531 | scm_igc (const char *what) | |
532 | { | |
9de87eea MV |
533 | if (scm_block_gc) |
534 | return; | |
535 | ||
536 | scm_i_scm_pthread_mutex_lock (&scm_i_sweep_mutex); | |
537 | ||
538 | /* During the critical section, only the current thread may run. */ | |
539 | scm_i_thread_put_to_sleep (); | |
540 | ||
c8a1bdc4 HWN |
541 | ++scm_gc_running_p; |
542 | scm_c_hook_run (&scm_before_gc_c_hook, 0); | |
a00c95d9 | 543 | |
c8a1bdc4 HWN |
544 | #ifdef DEBUGINFO |
545 | fprintf (stderr,"gc reason %s\n", what); | |
546 | ||
547 | fprintf (stderr, | |
d2e53ed6 | 548 | scm_is_null (*SCM_FREELIST_LOC (scm_i_freelist)) |
c8a1bdc4 | 549 | ? "*" |
d2e53ed6 | 550 | : (scm_is_null (*SCM_FREELIST_LOC (scm_i_freelist2)) ? "o" : "m")); |
c8a1bdc4 | 551 | #endif |
4c48ba06 | 552 | |
c8a1bdc4 | 553 | gc_start_stats (what); |
a00c95d9 | 554 | |
1367aa5e HWN |
555 | |
556 | ||
c8a1bdc4 HWN |
557 | if (scm_gc_heap_lock) |
558 | /* We've invoked the collector while a GC is already in progress. | |
559 | That should never happen. */ | |
560 | abort (); | |
a00c95d9 | 561 | |
1367aa5e HWN |
562 | /* |
563 | Set freelists to NULL so scm_cons() always triggers gc, causing | |
564 | the above abort() to be triggered. | |
565 | */ | |
566 | *SCM_FREELIST_LOC (scm_i_freelist) = SCM_EOL; | |
567 | *SCM_FREELIST_LOC (scm_i_freelist2) = SCM_EOL; | |
568 | ||
c8a1bdc4 | 569 | ++scm_gc_heap_lock; |
a00c95d9 | 570 | |
c8a1bdc4 HWN |
571 | /* |
572 | Let's finish the sweep. The conservative GC might point into the | |
573 | garbage, and marking that would create a mess. | |
574 | */ | |
575 | scm_i_sweep_all_segments("GC"); | |
576 | if (scm_mallocated < scm_i_deprecated_memory_return) | |
b6efc951 | 577 | { |
c8a1bdc4 HWN |
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. */ | |
583 | fprintf (stderr, | |
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"); | |
b6efc951 DH |
587 | abort (); |
588 | } | |
c8a1bdc4 | 589 | scm_mallocated -= scm_i_deprecated_memory_return; |
0f2d19dd | 590 | |
c8a1bdc4 HWN |
591 | |
592 | ||
593 | scm_c_hook_run (&scm_before_mark_c_hook, 0); | |
b6efc951 | 594 | |
c8a1bdc4 HWN |
595 | scm_mark_all (); |
596 | ||
c2cbcc57 | 597 | scm_gc_mark_time_taken += (scm_c_get_internal_run_time () - t_before_gc); |
c8a1bdc4 HWN |
598 | |
599 | scm_c_hook_run (&scm_before_sweep_c_hook, 0); | |
600 | ||
601 | /* | |
602 | Moved this lock upwards so that we can alloc new heap at the end of a sweep. | |
0f2d19dd | 603 | |
c8a1bdc4 | 604 | DOCME: why should the heap be locked anyway? |
0f2d19dd | 605 | */ |
c8a1bdc4 | 606 | --scm_gc_heap_lock; |
a00c95d9 | 607 | |
c8a1bdc4 | 608 | scm_gc_sweep (); |
0f2d19dd | 609 | |
ffd72400 HWN |
610 | |
611 | /* | |
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. | |
c35738c1 MD |
614 | |
615 | MDJ 030219 <djurfeldt@nada.kth.se>: No, probably not. The | |
616 | original meaning implied at least two things: that it would be | |
617 | called when | |
618 | ||
619 | 1. the freelist is re-initialized (no evaluation possible, though) | |
620 | ||
621 | and | |
622 | ||
623 | 2. the heap is "fresh" | |
624 | (it is well-defined what data is used and what is not) | |
625 | ||
626 | Neither of these conditions would hold just before the mark phase. | |
627 | ||
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. | |
ffd72400 | 633 | */ |
c8a1bdc4 HWN |
634 | scm_c_hook_run (&scm_after_sweep_c_hook, 0); |
635 | gc_end_stats (); | |
636 | ||
9de87eea | 637 | --scm_gc_running_p; |
fb50ef08 | 638 | scm_i_thread_wake_up (); |
ffd72400 HWN |
639 | |
640 | /* | |
641 | See above. | |
642 | */ | |
9de87eea | 643 | scm_i_pthread_mutex_unlock (&scm_i_sweep_mutex); |
07b99edb | 644 | scm_c_hook_run (&scm_after_gc_c_hook, 0); |
a00c95d9 | 645 | |
eab1b259 HWN |
646 | /* |
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. | |
650 | */ | |
651 | } | |
0f2d19dd | 652 | |
0f2d19dd JB |
653 | \f |
654 | /* {GC Protection Helper Functions} | |
655 | */ | |
656 | ||
657 | ||
5d2b97cd DH |
658 | /* |
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 | |
592996c9 | 667 | * scm_remember_upto_here* _behind_ the last code in your function, that |
5d2b97cd DH |
668 | * depends on the scheme object to exist. |
669 | * | |
8c494e99 DH |
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 | |
5d2b97cd DH |
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'. | |
eb01cb64 | 678 | * char *chars = scm_i_string_chars (str); |
5d2b97cd DH |
679 | * some_function (chars); |
680 | * scm_remember_upto_here_1 (str); // str will be alive up to this point. | |
681 | */ | |
682 | ||
9e1569bd KR |
683 | /* Remove any macro versions of these while defining the functions. |
684 | Functions are always included in the library, for upward binary | |
685 | compatibility and in case combinations of GCC and non-GCC are used. */ | |
686 | #undef scm_remember_upto_here_1 | |
687 | #undef scm_remember_upto_here_2 | |
688 | ||
5d2b97cd | 689 | void |
e81d98ec | 690 | scm_remember_upto_here_1 (SCM obj SCM_UNUSED) |
5d2b97cd DH |
691 | { |
692 | /* Empty. Protects a single object from garbage collection. */ | |
693 | } | |
694 | ||
695 | void | |
e81d98ec | 696 | scm_remember_upto_here_2 (SCM obj1 SCM_UNUSED, SCM obj2 SCM_UNUSED) |
5d2b97cd DH |
697 | { |
698 | /* Empty. Protects two objects from garbage collection. */ | |
699 | } | |
700 | ||
701 | void | |
e81d98ec | 702 | scm_remember_upto_here (SCM obj SCM_UNUSED, ...) |
5d2b97cd DH |
703 | { |
704 | /* Empty. Protects any number of objects from garbage collection. */ | |
705 | } | |
706 | ||
c209c88e | 707 | /* |
41b0806d GB |
708 | These crazy functions prevent garbage collection |
709 | of arguments after the first argument by | |
710 | ensuring they remain live throughout the | |
711 | function because they are used in the last | |
712 | line of the code block. | |
713 | It'd be better to have a nice compiler hint to | |
714 | aid the conservative stack-scanning GC. --03/09/00 gjb */ | |
0f2d19dd JB |
715 | SCM |
716 | scm_return_first (SCM elt, ...) | |
0f2d19dd JB |
717 | { |
718 | return elt; | |
719 | } | |
720 | ||
41b0806d GB |
721 | int |
722 | scm_return_first_int (int i, ...) | |
723 | { | |
724 | return i; | |
725 | } | |
726 | ||
0f2d19dd | 727 | |
0f2d19dd | 728 | SCM |
6e8d25a6 | 729 | scm_permanent_object (SCM obj) |
0f2d19dd | 730 | { |
9de87eea MV |
731 | SCM cell = scm_cons (obj, SCM_EOL); |
732 | SCM_CRITICAL_SECTION_START; | |
733 | SCM_SETCDR (cell, scm_permobjs); | |
734 | scm_permobjs = cell; | |
735 | SCM_CRITICAL_SECTION_END; | |
0f2d19dd JB |
736 | return obj; |
737 | } | |
738 | ||
739 | ||
7bd4fbe2 MD |
740 | /* Protect OBJ from the garbage collector. OBJ will not be freed, even if all |
741 | other references are dropped, until the object is unprotected by calling | |
6b1b030e | 742 | scm_gc_unprotect_object (OBJ). Calls to scm_gc_protect/unprotect_object nest, |
7bd4fbe2 MD |
743 | i. e. it is possible to protect the same object several times, but it is |
744 | necessary to unprotect the object the same number of times to actually get | |
745 | the object unprotected. It is an error to unprotect an object more often | |
746 | than it has been protected before. The function scm_protect_object returns | |
747 | OBJ. | |
748 | */ | |
749 | ||
750 | /* Implementation note: For every object X, there is a counter which | |
6b1b030e | 751 | scm_gc_protect_object(X) increments and scm_gc_unprotect_object(X) decrements. |
7bd4fbe2 | 752 | */ |
686765af | 753 | |
7eec4c37 HWN |
754 | |
755 | ||
ef290276 | 756 | SCM |
6b1b030e | 757 | scm_gc_protect_object (SCM obj) |
ef290276 | 758 | { |
686765af | 759 | SCM handle; |
9d47a1e6 | 760 | |
686765af | 761 | /* This critical section barrier will be replaced by a mutex. */ |
9de87eea | 762 | SCM_CRITICAL_SECTION_START; |
9d47a1e6 | 763 | |
e11e83f3 MV |
764 | handle = scm_hashq_create_handle_x (scm_protects, obj, scm_from_int (0)); |
765 | SCM_SETCDR (handle, scm_sum (SCM_CDR (handle), scm_from_int (1))); | |
9d47a1e6 | 766 | |
7eec4c37 HWN |
767 | protected_obj_count ++; |
768 | ||
9de87eea | 769 | SCM_CRITICAL_SECTION_END; |
9d47a1e6 | 770 | |
ef290276 JB |
771 | return obj; |
772 | } | |
773 | ||
774 | ||
775 | /* Remove any protection for OBJ established by a prior call to | |
dab7f566 | 776 | scm_protect_object. This function returns OBJ. |
ef290276 | 777 | |
dab7f566 | 778 | See scm_protect_object for more information. */ |
ef290276 | 779 | SCM |
6b1b030e | 780 | scm_gc_unprotect_object (SCM obj) |
ef290276 | 781 | { |
686765af | 782 | SCM handle; |
9d47a1e6 | 783 | |
686765af | 784 | /* This critical section barrier will be replaced by a mutex. */ |
9de87eea | 785 | SCM_CRITICAL_SECTION_START; |
9d47a1e6 | 786 | |
0ff7e3ff HWN |
787 | if (scm_gc_running_p) |
788 | { | |
789 | fprintf (stderr, "scm_unprotect_object called during GC.\n"); | |
790 | abort (); | |
791 | } | |
792 | ||
686765af | 793 | handle = scm_hashq_get_handle (scm_protects, obj); |
9d47a1e6 | 794 | |
7888309b | 795 | if (scm_is_false (handle)) |
686765af | 796 | { |
0f0f0899 MD |
797 | fprintf (stderr, "scm_unprotect_object called on unprotected object\n"); |
798 | abort (); | |
686765af | 799 | } |
6a199940 DH |
800 | else |
801 | { | |
e11e83f3 | 802 | SCM count = scm_difference (SCM_CDR (handle), scm_from_int (1)); |
bc36d050 | 803 | if (scm_is_eq (count, scm_from_int (0))) |
6a199940 DH |
804 | scm_hashq_remove_x (scm_protects, obj); |
805 | else | |
1be6b49c | 806 | SCM_SETCDR (handle, count); |
6a199940 | 807 | } |
7eec4c37 | 808 | protected_obj_count --; |
686765af | 809 | |
9de87eea | 810 | SCM_CRITICAL_SECTION_END; |
ef290276 JB |
811 | |
812 | return obj; | |
813 | } | |
814 | ||
6b1b030e ML |
815 | void |
816 | scm_gc_register_root (SCM *p) | |
817 | { | |
818 | SCM handle; | |
b9bd8526 | 819 | SCM key = scm_from_ulong ((unsigned long) p); |
eae33935 | 820 | |
6b1b030e | 821 | /* This critical section barrier will be replaced by a mutex. */ |
9de87eea | 822 | SCM_CRITICAL_SECTION_START; |
6b1b030e | 823 | |
e11e83f3 MV |
824 | handle = scm_hashv_create_handle_x (scm_gc_registered_roots, key, |
825 | scm_from_int (0)); | |
826 | SCM_SETCDR (handle, scm_sum (SCM_CDR (handle), scm_from_int (1))); | |
6b1b030e | 827 | |
9de87eea | 828 | SCM_CRITICAL_SECTION_END; |
6b1b030e ML |
829 | } |
830 | ||
831 | void | |
832 | scm_gc_unregister_root (SCM *p) | |
833 | { | |
834 | SCM handle; | |
b9bd8526 | 835 | SCM key = scm_from_ulong ((unsigned long) p); |
6b1b030e ML |
836 | |
837 | /* This critical section barrier will be replaced by a mutex. */ | |
9de87eea | 838 | SCM_CRITICAL_SECTION_START; |
6b1b030e ML |
839 | |
840 | handle = scm_hashv_get_handle (scm_gc_registered_roots, key); | |
841 | ||
7888309b | 842 | if (scm_is_false (handle)) |
6b1b030e ML |
843 | { |
844 | fprintf (stderr, "scm_gc_unregister_root called on unregistered root\n"); | |
845 | abort (); | |
846 | } | |
847 | else | |
848 | { | |
e11e83f3 | 849 | SCM count = scm_difference (SCM_CDR (handle), scm_from_int (1)); |
bc36d050 | 850 | if (scm_is_eq (count, scm_from_int (0))) |
6b1b030e ML |
851 | scm_hashv_remove_x (scm_gc_registered_roots, key); |
852 | else | |
853 | SCM_SETCDR (handle, count); | |
854 | } | |
855 | ||
9de87eea | 856 | SCM_CRITICAL_SECTION_END; |
6b1b030e ML |
857 | } |
858 | ||
859 | void | |
860 | scm_gc_register_roots (SCM *b, unsigned long n) | |
861 | { | |
862 | SCM *p = b; | |
863 | for (; p < b + n; ++p) | |
864 | scm_gc_register_root (p); | |
865 | } | |
866 | ||
867 | void | |
868 | scm_gc_unregister_roots (SCM *b, unsigned long n) | |
869 | { | |
870 | SCM *p = b; | |
871 | for (; p < b + n; ++p) | |
872 | scm_gc_unregister_root (p); | |
873 | } | |
874 | ||
04a98cff | 875 | int scm_i_terminating; |
c45acc34 | 876 | |
0f2d19dd | 877 | \f |
a00c95d9 | 878 | |
4c48ba06 | 879 | |
c8a1bdc4 HWN |
880 | /* |
881 | MOVE THIS FUNCTION. IT DOES NOT HAVE ANYTHING TODO WITH GC. | |
882 | */ | |
85db4a2c DH |
883 | |
884 | /* Get an integer from an environment variable. */ | |
c8a1bdc4 HWN |
885 | int |
886 | scm_getenv_int (const char *var, int def) | |
85db4a2c | 887 | { |
c8a1bdc4 HWN |
888 | char *end = 0; |
889 | char *val = getenv (var); | |
890 | long res = def; | |
85db4a2c DH |
891 | if (!val) |
892 | return def; | |
893 | res = strtol (val, &end, 10); | |
894 | if (end == val) | |
895 | return def; | |
896 | return res; | |
897 | } | |
898 | ||
c35738c1 MD |
899 | void |
900 | scm_storage_prehistory () | |
901 | { | |
902 | scm_c_hook_init (&scm_before_gc_c_hook, 0, SCM_C_HOOK_NORMAL); | |
903 | scm_c_hook_init (&scm_before_mark_c_hook, 0, SCM_C_HOOK_NORMAL); | |
904 | scm_c_hook_init (&scm_before_sweep_c_hook, 0, SCM_C_HOOK_NORMAL); | |
905 | scm_c_hook_init (&scm_after_sweep_c_hook, 0, SCM_C_HOOK_NORMAL); | |
906 | scm_c_hook_init (&scm_after_gc_c_hook, 0, SCM_C_HOOK_NORMAL); | |
907 | } | |
85db4a2c | 908 | |
9de87eea | 909 | scm_i_pthread_mutex_t scm_i_gc_admin_mutex = SCM_I_PTHREAD_MUTEX_INITIALIZER; |
eb01cb64 | 910 | |
4a4c9785 | 911 | int |
85db4a2c | 912 | scm_init_storage () |
0f2d19dd | 913 | { |
1be6b49c | 914 | size_t j; |
0f2d19dd JB |
915 | |
916 | j = SCM_NUM_PROTECTS; | |
917 | while (j) | |
918 | scm_sys_protects[--j] = SCM_BOOL_F; | |
919 | scm_block_gc = 1; | |
4a4c9785 | 920 | |
c8a1bdc4 HWN |
921 | scm_gc_init_freelist(); |
922 | scm_gc_init_malloc (); | |
0f2d19dd JB |
923 | |
924 | j = SCM_HEAP_SEG_SIZE; | |
d6884e63 | 925 | |
c8a1bdc4 | 926 | |
0f2d19dd | 927 | /* Initialise the list of ports. */ |
67329a9e HWN |
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) | |
0f2d19dd JB |
931 | return 1; |
932 | ||
9de87eea MV |
933 | #if 0 |
934 | /* We can't have a cleanup handler since we have no thread to run it | |
935 | in. */ | |
936 | ||
a18bcd0e | 937 | #ifdef HAVE_ATEXIT |
c45acc34 | 938 | atexit (cleanup); |
e52ceaac MD |
939 | #else |
940 | #ifdef HAVE_ON_EXIT | |
941 | on_exit (cleanup, 0); | |
942 | #endif | |
9de87eea MV |
943 | #endif |
944 | ||
a18bcd0e | 945 | #endif |
0f2d19dd | 946 | |
82c76fd3 | 947 | scm_stand_in_procs = scm_c_make_hash_table (257); |
0f2d19dd | 948 | scm_permobjs = SCM_EOL; |
00ffa0e7 | 949 | scm_protects = scm_c_make_hash_table (31); |
6b1b030e | 950 | scm_gc_registered_roots = scm_c_make_hash_table (31); |
d6884e63 | 951 | |
0f2d19dd JB |
952 | return 0; |
953 | } | |
939794ce | 954 | |
0f2d19dd JB |
955 | \f |
956 | ||
939794ce DH |
957 | SCM scm_after_gc_hook; |
958 | ||
939794ce DH |
959 | static SCM gc_async; |
960 | ||
939794ce DH |
961 | /* The function gc_async_thunk causes the execution of the after-gc-hook. It |
962 | * is run after the gc, as soon as the asynchronous events are handled by the | |
963 | * evaluator. | |
964 | */ | |
965 | static SCM | |
966 | gc_async_thunk (void) | |
967 | { | |
968 | scm_c_run_hook (scm_after_gc_hook, SCM_EOL); | |
939794ce DH |
969 | return SCM_UNSPECIFIED; |
970 | } | |
971 | ||
972 | ||
973 | /* The function mark_gc_async is run by the scm_after_gc_c_hook at the end of | |
974 | * the garbage collection. The only purpose of this function is to mark the | |
975 | * gc_async (which will eventually lead to the execution of the | |
976 | * gc_async_thunk). | |
977 | */ | |
978 | static void * | |
e81d98ec DH |
979 | mark_gc_async (void * hook_data SCM_UNUSED, |
980 | void *func_data SCM_UNUSED, | |
981 | void *data SCM_UNUSED) | |
982 | { | |
983 | /* If cell access debugging is enabled, the user may choose to perform | |
984 | * additional garbage collections after an arbitrary number of cell | |
985 | * accesses. We don't want the scheme level after-gc-hook to be performed | |
986 | * for each of these garbage collections for the following reason: The | |
987 | * execution of the after-gc-hook causes cell accesses itself. Thus, if the | |
988 | * after-gc-hook was performed with every gc, and if the gc was performed | |
989 | * after a very small number of cell accesses, then the number of cell | |
990 | * accesses during the execution of the after-gc-hook will suffice to cause | |
991 | * the execution of the next gc. Then, guile would keep executing the | |
992 | * after-gc-hook over and over again, and would never come to do other | |
993 | * things. | |
eae33935 | 994 | * |
e81d98ec DH |
995 | * To overcome this problem, if cell access debugging with additional |
996 | * garbage collections is enabled, the after-gc-hook is never run by the | |
997 | * garbage collecter. When running guile with cell access debugging and the | |
998 | * execution of the after-gc-hook is desired, then it is necessary to run | |
999 | * the hook explicitly from the user code. This has the effect, that from | |
1000 | * the scheme level point of view it seems that garbage collection is | |
1001 | * performed with a much lower frequency than it actually is. Obviously, | |
1002 | * this will not work for code that depends on a fixed one to one | |
1003 | * relationship between the execution counts of the C level garbage | |
1004 | * collection hooks and the execution count of the scheme level | |
1005 | * after-gc-hook. | |
1006 | */ | |
9de87eea | 1007 | |
e81d98ec | 1008 | #if (SCM_DEBUG_CELL_ACCESSES == 1) |
eab1b259 | 1009 | if (scm_debug_cells_gc_interval == 0) |
e81d98ec DH |
1010 | scm_system_async_mark (gc_async); |
1011 | #else | |
939794ce | 1012 | scm_system_async_mark (gc_async); |
e81d98ec DH |
1013 | #endif |
1014 | ||
939794ce DH |
1015 | return NULL; |
1016 | } | |
1017 | ||
0f2d19dd JB |
1018 | void |
1019 | scm_init_gc () | |
0f2d19dd | 1020 | { |
c8a1bdc4 | 1021 | scm_gc_init_mark (); |
d678e25c | 1022 | |
fde50407 ML |
1023 | scm_after_gc_hook = scm_permanent_object (scm_make_hook (SCM_INUM0)); |
1024 | scm_c_define ("after-gc-hook", scm_after_gc_hook); | |
939794ce | 1025 | |
2592c4c7 MV |
1026 | gc_async = scm_c_make_subr ("%gc-thunk", scm_tc7_subr_0, |
1027 | gc_async_thunk); | |
939794ce DH |
1028 | |
1029 | scm_c_hook_add (&scm_after_gc_c_hook, mark_gc_async, NULL, 0); | |
1030 | ||
a0599745 | 1031 | #include "libguile/gc.x" |
0f2d19dd | 1032 | } |
89e00824 | 1033 | |
c8a1bdc4 HWN |
1034 | |
1035 | void | |
1036 | scm_gc_sweep (void) | |
1037 | #define FUNC_NAME "scm_gc_sweep" | |
1038 | { | |
1039 | scm_i_deprecated_memory_return = 0; | |
1040 | ||
1041 | scm_i_gc_sweep_freelist_reset (&scm_i_master_freelist); | |
1042 | scm_i_gc_sweep_freelist_reset (&scm_i_master_freelist2); | |
1043 | ||
1044 | /* | |
1045 | NOTHING HERE: LAZY SWEEPING ! | |
1046 | */ | |
1047 | scm_i_reset_segments (); | |
1048 | ||
1049 | /* When we move to POSIX threads private freelists should probably | |
1050 | be GC-protected instead. */ | |
9bc4701c MD |
1051 | *SCM_FREELIST_LOC (scm_i_freelist) = SCM_EOL; |
1052 | *SCM_FREELIST_LOC (scm_i_freelist2) = SCM_EOL; | |
392d2833 MD |
1053 | |
1054 | /* Invalidate the freelists of other threads. */ | |
1055 | scm_i_thread_invalidate_freelists (); | |
c8a1bdc4 HWN |
1056 | } |
1057 | ||
1058 | #undef FUNC_NAME | |
1059 | ||
1060 | ||
56495472 | 1061 | |
89e00824 ML |
1062 | /* |
1063 | Local Variables: | |
1064 | c-file-style: "gnu" | |
1065 | End: | |
1066 | */ |