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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 | ||
fb50ef08 MD |
70 | /* Lock this mutex before doing lazy sweeping. |
71 | */ | |
b17e0ac3 | 72 | scm_i_pthread_mutex_t scm_i_sweep_mutex = SCM_I_PTHREAD_MUTEX_INITIALIZER; |
fb50ef08 | 73 | |
eae33935 | 74 | /* Set this to != 0 if every cell that is accessed shall be checked: |
61045190 | 75 | */ |
eab1b259 HWN |
76 | int scm_debug_cell_accesses_p = 0; |
77 | int scm_expensive_debug_cell_accesses_p = 0; | |
406c7d90 | 78 | |
e81d98ec DH |
79 | /* Set this to 0 if no additional gc's shall be performed, otherwise set it to |
80 | * the number of cell accesses after which a gc shall be called. | |
81 | */ | |
eab1b259 | 82 | int scm_debug_cells_gc_interval = 0; |
e81d98ec | 83 | |
eab1b259 HWN |
84 | /* |
85 | Global variable, so you can switch it off at runtime by setting | |
86 | scm_i_cell_validation_already_running. | |
406c7d90 | 87 | */ |
eab1b259 HWN |
88 | int scm_i_cell_validation_already_running ; |
89 | ||
90 | #if (SCM_DEBUG_CELL_ACCESSES == 1) | |
91 | ||
92 | ||
93 | /* | |
94 | ||
95 | Assert that the given object is a valid reference to a valid cell. This | |
96 | test involves to determine whether the object is a cell pointer, whether | |
97 | this pointer actually points into a heap segment and whether the cell | |
98 | pointed to is not a free cell. Further, additional garbage collections may | |
99 | get executed after a user defined number of cell accesses. This helps to | |
100 | find places in the C code where references are dropped for extremely short | |
101 | periods. | |
102 | ||
103 | */ | |
406c7d90 | 104 | void |
eab1b259 | 105 | scm_i_expensive_validation_check (SCM cell) |
406c7d90 | 106 | { |
eab1b259 HWN |
107 | if (!scm_in_heap_p (cell)) |
108 | { | |
109 | fprintf (stderr, "scm_assert_cell_valid: this object does not live in the heap: %lux\n", | |
110 | (unsigned long) SCM_UNPACK (cell)); | |
111 | abort (); | |
112 | } | |
113 | ||
114 | /* If desired, perform additional garbage collections after a user | |
115 | * defined number of cell accesses. | |
116 | */ | |
117 | if (scm_debug_cells_gc_interval) | |
118 | { | |
119 | static unsigned int counter = 0; | |
61045190 | 120 | |
eab1b259 HWN |
121 | if (counter != 0) |
122 | { | |
123 | --counter; | |
124 | } | |
125 | else | |
126 | { | |
127 | counter = scm_debug_cells_gc_interval; | |
b17e0ac3 | 128 | scm_gc (); |
eab1b259 HWN |
129 | } |
130 | } | |
131 | } | |
132 | ||
133 | void | |
134 | scm_assert_cell_valid (SCM cell) | |
135 | { | |
136 | if (!scm_i_cell_validation_already_running && scm_debug_cell_accesses_p) | |
406c7d90 | 137 | { |
eab1b259 | 138 | scm_i_cell_validation_already_running = 1; /* set to avoid recursion */ |
406c7d90 | 139 | |
c8a1bdc4 | 140 | /* |
eab1b259 HWN |
141 | During GC, no user-code should be run, and the guile core |
142 | should use non-protected accessors. | |
143 | */ | |
c8a1bdc4 | 144 | if (scm_gc_running_p) |
eab1b259 | 145 | return; |
c8a1bdc4 HWN |
146 | |
147 | /* | |
eab1b259 HWN |
148 | Only scm_in_heap_p and rescanning the heap is wildly |
149 | expensive. | |
150 | */ | |
151 | if (scm_expensive_debug_cell_accesses_p) | |
152 | scm_i_expensive_validation_check (cell); | |
c8a1bdc4 HWN |
153 | |
154 | if (!SCM_GC_MARK_P (cell)) | |
406c7d90 | 155 | { |
c8a1bdc4 HWN |
156 | fprintf (stderr, |
157 | "scm_assert_cell_valid: this object is unmarked. \n" | |
158 | "It has been garbage-collected in the last GC run: " | |
159 | "%lux\n", | |
1be6b49c | 160 | (unsigned long) SCM_UNPACK (cell)); |
406c7d90 DH |
161 | abort (); |
162 | } | |
c8a1bdc4 | 163 | |
eab1b259 | 164 | scm_i_cell_validation_already_running = 0; /* re-enable */ |
406c7d90 DH |
165 | } |
166 | } | |
167 | ||
168 | ||
eab1b259 | 169 | |
406c7d90 DH |
170 | SCM_DEFINE (scm_set_debug_cell_accesses_x, "set-debug-cell-accesses!", 1, 0, 0, |
171 | (SCM flag), | |
1e6808ea | 172 | "If @var{flag} is @code{#f}, cell access checking is disabled.\n" |
eab1b259 | 173 | "If @var{flag} is @code{#t}, cheap cell access checking is enabled,\n" |
e81d98ec | 174 | "but no additional calls to garbage collection are issued.\n" |
eab1b259 | 175 | "If @var{flag} is a number, strict cell access checking is enabled,\n" |
e81d98ec DH |
176 | "with an additional garbage collection after the given\n" |
177 | "number of cell accesses.\n" | |
1e6808ea MG |
178 | "This procedure only exists when the compile-time flag\n" |
179 | "@code{SCM_DEBUG_CELL_ACCESSES} was set to 1.") | |
406c7d90 DH |
180 | #define FUNC_NAME s_scm_set_debug_cell_accesses_x |
181 | { | |
7888309b | 182 | if (scm_is_false (flag)) |
eab1b259 HWN |
183 | { |
184 | scm_debug_cell_accesses_p = 0; | |
185 | } | |
bc36d050 | 186 | else if (scm_is_eq (flag, SCM_BOOL_T)) |
eab1b259 HWN |
187 | { |
188 | scm_debug_cells_gc_interval = 0; | |
189 | scm_debug_cell_accesses_p = 1; | |
190 | scm_expensive_debug_cell_accesses_p = 0; | |
191 | } | |
e11e83f3 | 192 | else |
eab1b259 | 193 | { |
e11e83f3 | 194 | scm_debug_cells_gc_interval = scm_to_signed_integer (flag, 0, INT_MAX); |
eab1b259 HWN |
195 | scm_debug_cell_accesses_p = 1; |
196 | scm_expensive_debug_cell_accesses_p = 1; | |
197 | } | |
406c7d90 DH |
198 | return SCM_UNSPECIFIED; |
199 | } | |
200 | #undef FUNC_NAME | |
0f2d19dd | 201 | |
ecf470a2 | 202 | |
c8a1bdc4 | 203 | #endif /* SCM_DEBUG_CELL_ACCESSES == 1 */ |
0f2d19dd JB |
204 | |
205 | \f | |
945fec60 | 206 | |
0f2d19dd JB |
207 | |
208 | /* scm_mtrigger | |
539b08a4 | 209 | * is the number of bytes of malloc allocation needed to trigger gc. |
0f2d19dd | 210 | */ |
c014a02e | 211 | unsigned long scm_mtrigger; |
0f2d19dd | 212 | |
0f2d19dd JB |
213 | /* During collection, this accumulates objects holding |
214 | * weak references. | |
215 | */ | |
ab4bef85 | 216 | SCM scm_weak_vectors; |
0f2d19dd JB |
217 | |
218 | /* GC Statistics Keeping | |
219 | */ | |
f2893a25 | 220 | unsigned long scm_cells_allocated = 0; |
c014a02e ML |
221 | unsigned long scm_mallocated = 0; |
222 | unsigned long scm_gc_cells_collected; | |
c8a1bdc4 | 223 | unsigned long scm_gc_cells_collected_1 = 0; /* previous GC yield */ |
c014a02e ML |
224 | unsigned long scm_gc_malloc_collected; |
225 | unsigned long scm_gc_ports_collected; | |
0f2d19dd | 226 | unsigned long scm_gc_time_taken = 0; |
c014a02e | 227 | static unsigned long t_before_gc; |
c9b0d4b0 | 228 | unsigned long scm_gc_mark_time_taken = 0; |
c014a02e ML |
229 | unsigned long scm_gc_times = 0; |
230 | unsigned long scm_gc_cells_swept = 0; | |
c9b0d4b0 ML |
231 | double scm_gc_cells_marked_acc = 0.; |
232 | double scm_gc_cells_swept_acc = 0.; | |
c2cbcc57 HWN |
233 | int scm_gc_cell_yield_percentage =0; |
234 | int scm_gc_malloc_yield_percentage = 0; | |
7eec4c37 | 235 | unsigned long protected_obj_count = 0; |
c2cbcc57 | 236 | |
0f2d19dd JB |
237 | |
238 | SCM_SYMBOL (sym_cells_allocated, "cells-allocated"); | |
239 | SCM_SYMBOL (sym_heap_size, "cell-heap-size"); | |
240 | SCM_SYMBOL (sym_mallocated, "bytes-malloced"); | |
241 | SCM_SYMBOL (sym_mtrigger, "gc-malloc-threshold"); | |
242 | SCM_SYMBOL (sym_heap_segments, "cell-heap-segments"); | |
243 | SCM_SYMBOL (sym_gc_time_taken, "gc-time-taken"); | |
c9b0d4b0 | 244 | SCM_SYMBOL (sym_gc_mark_time_taken, "gc-mark-time-taken"); |
c9b0d4b0 ML |
245 | SCM_SYMBOL (sym_times, "gc-times"); |
246 | SCM_SYMBOL (sym_cells_marked, "cells-marked"); | |
247 | SCM_SYMBOL (sym_cells_swept, "cells-swept"); | |
c2cbcc57 HWN |
248 | SCM_SYMBOL (sym_malloc_yield, "malloc-yield"); |
249 | SCM_SYMBOL (sym_cell_yield, "cell-yield"); | |
7eec4c37 | 250 | SCM_SYMBOL (sym_protected_objects, "protected-objects"); |
0f2d19dd | 251 | |
bb2c57fa | 252 | |
cf2d30f6 | 253 | |
d3dd80ab | 254 | |
cf2d30f6 | 255 | /* Number of calls to SCM_NEWCELL since startup. */ |
c8a1bdc4 HWN |
256 | unsigned scm_newcell_count; |
257 | unsigned scm_newcell2_count; | |
b37fe1c5 | 258 | |
b37fe1c5 | 259 | |
0f2d19dd JB |
260 | /* {Scheme Interface to GC} |
261 | */ | |
1367aa5e HWN |
262 | static SCM |
263 | tag_table_to_type_alist (void *closure, SCM key, SCM val, SCM acc) | |
264 | { | |
265 | scm_t_bits c_tag = scm_to_int (key); | |
73a4c24e HWN |
266 | |
267 | char const * name = scm_i_tag_name (c_tag); | |
268 | if (name != NULL) | |
269 | key = scm_from_locale_string (name); | |
270 | ||
1367aa5e HWN |
271 | return scm_cons (scm_cons (key, val), acc); |
272 | } | |
273 | ||
274 | SCM_DEFINE (scm_gc_live_object_stats, "gc-live-object-stats", 0, 0, 0, | |
275 | (), | |
276 | "Return an alist of statistics of the current live objects. ") | |
277 | #define FUNC_NAME s_scm_gc_live_object_stats | |
278 | { | |
279 | SCM tab = scm_make_hash_table (scm_from_int (57)); | |
280 | scm_i_all_segments_statistics (tab); | |
281 | ||
282 | SCM alist | |
283 | = scm_internal_hash_fold (&tag_table_to_type_alist, NULL, SCM_EOL, tab); | |
284 | ||
285 | return alist; | |
286 | } | |
287 | #undef FUNC_NAME | |
288 | ||
c2cbcc57 | 289 | extern int scm_gc_malloc_yield_percentage; |
a00c95d9 | 290 | SCM_DEFINE (scm_gc_stats, "gc-stats", 0, 0, 0, |
1bbd0b84 | 291 | (), |
1e6808ea | 292 | "Return an association list of statistics about Guile's current\n" |
c8a1bdc4 | 293 | "use of storage.\n") |
1bbd0b84 | 294 | #define FUNC_NAME s_scm_gc_stats |
0f2d19dd | 295 | { |
c8a1bdc4 HWN |
296 | long i = 0; |
297 | SCM heap_segs = SCM_EOL ; | |
c014a02e ML |
298 | unsigned long int local_scm_mtrigger; |
299 | unsigned long int local_scm_mallocated; | |
300 | unsigned long int local_scm_heap_size; | |
c2cbcc57 HWN |
301 | int local_scm_gc_cell_yield_percentage; |
302 | int local_scm_gc_malloc_yield_percentage; | |
f2893a25 | 303 | unsigned long int local_scm_cells_allocated; |
c014a02e ML |
304 | unsigned long int local_scm_gc_time_taken; |
305 | unsigned long int local_scm_gc_times; | |
306 | unsigned long int local_scm_gc_mark_time_taken; | |
7eec4c37 | 307 | unsigned long int local_protected_obj_count; |
c9b0d4b0 ML |
308 | double local_scm_gc_cells_swept; |
309 | double local_scm_gc_cells_marked; | |
0f2d19dd | 310 | SCM answer; |
c8a1bdc4 HWN |
311 | unsigned long *bounds = 0; |
312 | int table_size = scm_i_heap_segment_table_size; | |
9de87eea | 313 | SCM_CRITICAL_SECTION_START; |
939794ce | 314 | |
c8a1bdc4 HWN |
315 | /* |
316 | temporarily store the numbers, so as not to cause GC. | |
7febb4a2 | 317 | */ |
c8a1bdc4 HWN |
318 | |
319 | bounds = malloc (sizeof (int) * table_size * 2); | |
320 | if (!bounds) | |
321 | abort(); | |
322 | for (i = table_size; i--; ) | |
323 | { | |
324 | bounds[2*i] = (unsigned long)scm_i_heap_segment_table[i]->bounds[0]; | |
325 | bounds[2*i+1] = (unsigned long)scm_i_heap_segment_table[i]->bounds[1]; | |
326 | } | |
0f2d19dd | 327 | |
4c9419ac | 328 | |
c8a1bdc4 HWN |
329 | /* Below, we cons to produce the resulting list. We want a snapshot of |
330 | * the heap situation before consing. | |
331 | */ | |
332 | local_scm_mtrigger = scm_mtrigger; | |
333 | local_scm_mallocated = scm_mallocated; | |
334 | local_scm_heap_size = SCM_HEAP_SIZE; | |
539b08a4 | 335 | |
c8a1bdc4 HWN |
336 | local_scm_cells_allocated = scm_cells_allocated; |
337 | ||
338 | local_scm_gc_time_taken = scm_gc_time_taken; | |
339 | local_scm_gc_mark_time_taken = scm_gc_mark_time_taken; | |
340 | local_scm_gc_times = scm_gc_times; | |
c2cbcc57 HWN |
341 | local_scm_gc_malloc_yield_percentage = scm_gc_malloc_yield_percentage; |
342 | local_scm_gc_cell_yield_percentage= scm_gc_cell_yield_percentage; | |
7eec4c37 | 343 | local_protected_obj_count = protected_obj_count; |
c2cbcc57 HWN |
344 | local_scm_gc_cells_swept = |
345 | (double) scm_gc_cells_swept_acc | |
346 | + (double) scm_gc_cells_swept; | |
c8a1bdc4 HWN |
347 | local_scm_gc_cells_marked = scm_gc_cells_marked_acc |
348 | +(double) scm_gc_cells_swept | |
349 | -(double) scm_gc_cells_collected; | |
0f2d19dd | 350 | |
c8a1bdc4 HWN |
351 | for (i = table_size; i--;) |
352 | { | |
b9bd8526 MV |
353 | heap_segs = scm_cons (scm_cons (scm_from_ulong (bounds[2*i]), |
354 | scm_from_ulong (bounds[2*i+1])), | |
c8a1bdc4 HWN |
355 | heap_segs); |
356 | } | |
33b320ae NJ |
357 | /* njrev: can any of these scm_cons's or scm_list_n signal a memory |
358 | error? If so we need a frame here. */ | |
b9bd8526 MV |
359 | answer = |
360 | scm_list_n (scm_cons (sym_gc_time_taken, | |
361 | scm_from_ulong (local_scm_gc_time_taken)), | |
362 | scm_cons (sym_cells_allocated, | |
363 | scm_from_ulong (local_scm_cells_allocated)), | |
364 | scm_cons (sym_heap_size, | |
365 | scm_from_ulong (local_scm_heap_size)), | |
366 | scm_cons (sym_mallocated, | |
367 | scm_from_ulong (local_scm_mallocated)), | |
368 | scm_cons (sym_mtrigger, | |
369 | scm_from_ulong (local_scm_mtrigger)), | |
370 | scm_cons (sym_times, | |
371 | scm_from_ulong (local_scm_gc_times)), | |
372 | scm_cons (sym_gc_mark_time_taken, | |
373 | scm_from_ulong (local_scm_gc_mark_time_taken)), | |
374 | scm_cons (sym_cells_marked, | |
375 | scm_from_double (local_scm_gc_cells_marked)), | |
376 | scm_cons (sym_cells_swept, | |
377 | scm_from_double (local_scm_gc_cells_swept)), | |
378 | scm_cons (sym_malloc_yield, | |
379 | scm_from_long(local_scm_gc_malloc_yield_percentage)), | |
380 | scm_cons (sym_cell_yield, | |
381 | scm_from_long (local_scm_gc_cell_yield_percentage)), | |
382 | scm_cons (sym_protected_objects, | |
383 | scm_from_ulong (local_protected_obj_count)), | |
384 | scm_cons (sym_heap_segments, heap_segs), | |
385 | SCM_UNDEFINED); | |
9de87eea | 386 | SCM_CRITICAL_SECTION_END; |
c8a1bdc4 HWN |
387 | |
388 | free (bounds); | |
389 | return answer; | |
0f2d19dd | 390 | } |
c8a1bdc4 | 391 | #undef FUNC_NAME |
0f2d19dd | 392 | |
c8a1bdc4 HWN |
393 | static void |
394 | gc_start_stats (const char *what SCM_UNUSED) | |
e4a7824f | 395 | { |
c8a1bdc4 | 396 | t_before_gc = scm_c_get_internal_run_time (); |
539b08a4 | 397 | |
c8a1bdc4 HWN |
398 | scm_gc_cells_marked_acc += (double) scm_gc_cells_swept |
399 | - (double) scm_gc_cells_collected; | |
c2cbcc57 | 400 | scm_gc_cells_swept_acc += (double) scm_gc_cells_swept; |
e4a7824f | 401 | |
c2cbcc57 HWN |
402 | scm_gc_cell_yield_percentage = ( scm_gc_cells_collected * 100 ) / SCM_HEAP_SIZE; |
403 | ||
c8a1bdc4 HWN |
404 | scm_gc_cells_swept = 0; |
405 | scm_gc_cells_collected_1 = scm_gc_cells_collected; | |
539b08a4 | 406 | |
c8a1bdc4 HWN |
407 | /* |
408 | CELLS SWEPT is another word for the number of cells that were | |
409 | examined during GC. YIELD is the number that we cleaned | |
410 | out. MARKED is the number that weren't cleaned. | |
411 | */ | |
412 | scm_gc_cells_collected = 0; | |
413 | scm_gc_malloc_collected = 0; | |
414 | scm_gc_ports_collected = 0; | |
e4a7824f | 415 | } |
acf4331f | 416 | |
c8a1bdc4 HWN |
417 | static void |
418 | gc_end_stats () | |
0f2d19dd | 419 | { |
c8a1bdc4 HWN |
420 | unsigned long t = scm_c_get_internal_run_time (); |
421 | scm_gc_time_taken += (t - t_before_gc); | |
539b08a4 | 422 | |
c8a1bdc4 | 423 | ++scm_gc_times; |
0f2d19dd | 424 | } |
acf4331f | 425 | |
0f2d19dd | 426 | |
c8a1bdc4 HWN |
427 | SCM_DEFINE (scm_object_address, "object-address", 1, 0, 0, |
428 | (SCM obj), | |
429 | "Return an integer that for the lifetime of @var{obj} is uniquely\n" | |
430 | "returned by this function for @var{obj}") | |
431 | #define FUNC_NAME s_scm_object_address | |
c68296f8 | 432 | { |
b9bd8526 | 433 | return scm_from_ulong (SCM_UNPACK (obj)); |
c68296f8 | 434 | } |
c8a1bdc4 | 435 | #undef FUNC_NAME |
c68296f8 | 436 | |
1be6b49c | 437 | |
c8a1bdc4 HWN |
438 | SCM_DEFINE (scm_gc, "gc", 0, 0, 0, |
439 | (), | |
440 | "Scans all of SCM objects and reclaims for further use those that are\n" | |
441 | "no longer accessible.") | |
442 | #define FUNC_NAME s_scm_gc | |
443 | { | |
b17e0ac3 MV |
444 | scm_i_scm_pthread_mutex_lock (&scm_i_sweep_mutex); |
445 | scm_gc_running_p = 1; | |
446 | scm_i_gc ("call"); | |
33b320ae NJ |
447 | /* njrev: It looks as though other places, e.g. scm_realloc, |
448 | can call scm_i_gc without acquiring the sweep mutex. Does this | |
449 | matter? Also scm_i_gc (or its descendants) touch the | |
450 | scm_sys_protects, which are protected in some cases | |
451 | (e.g. scm_permobjs above in scm_gc_stats) by a critical section, | |
452 | not by the sweep mutex. Shouldn't all the GC-relevant objects be | |
453 | protected in the same way? */ | |
b17e0ac3 MV |
454 | scm_gc_running_p = 0; |
455 | scm_i_pthread_mutex_unlock (&scm_i_sweep_mutex); | |
456 | scm_c_hook_run (&scm_after_gc_c_hook, 0); | |
c8a1bdc4 | 457 | return SCM_UNSPECIFIED; |
9d47a1e6 | 458 | } |
c8a1bdc4 | 459 | #undef FUNC_NAME |
9d47a1e6 | 460 | |
c68296f8 MV |
461 | |
462 | \f | |
0f2d19dd | 463 | |
b17e0ac3 MV |
464 | /* The master is global and common while the freelist will be |
465 | * individual for each thread. | |
0f2d19dd JB |
466 | */ |
467 | ||
c8a1bdc4 HWN |
468 | SCM |
469 | scm_gc_for_newcell (scm_t_cell_type_statistics *freelist, SCM *free_cells) | |
0f2d19dd | 470 | { |
c8a1bdc4 | 471 | SCM cell; |
b17e0ac3 | 472 | int did_gc = 0; |
c8a1bdc4 | 473 | |
9de87eea | 474 | scm_i_scm_pthread_mutex_lock (&scm_i_sweep_mutex); |
b17e0ac3 | 475 | scm_gc_running_p = 1; |
9bc4701c | 476 | |
c8a1bdc4 HWN |
477 | *free_cells = scm_i_sweep_some_segments (freelist); |
478 | if (*free_cells == SCM_EOL && scm_i_gc_grow_heap_p (freelist)) | |
479 | { | |
480 | freelist->heap_segment_idx = scm_i_get_new_heap_segment (freelist, abort_on_error); | |
481 | *free_cells = scm_i_sweep_some_segments (freelist); | |
482 | } | |
acb0a19c | 483 | |
b17e0ac3 | 484 | if (*free_cells == SCM_EOL) |
c8a1bdc4 HWN |
485 | { |
486 | /* | |
b17e0ac3 | 487 | with the advent of lazy sweep, GC yield is only known just |
c8a1bdc4 HWN |
488 | before doing the GC. |
489 | */ | |
490 | scm_i_adjust_min_yield (freelist); | |
491 | ||
492 | /* | |
493 | out of fresh cells. Try to get some new ones. | |
494 | */ | |
0f2d19dd | 495 | |
b17e0ac3 MV |
496 | did_gc = 1; |
497 | scm_i_gc ("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 | |
b17e0ac3 | 518 | scm_gc_running_p = 0; |
9de87eea | 519 | scm_i_pthread_mutex_unlock (&scm_i_sweep_mutex); |
eab1b259 | 520 | |
b17e0ac3 MV |
521 | if (did_gc) |
522 | scm_c_hook_run (&scm_after_gc_c_hook, 0); | |
523 | ||
c8a1bdc4 HWN |
524 | return cell; |
525 | } | |
4a4c9785 | 526 | |
4a4c9785 | 527 | |
c8a1bdc4 HWN |
528 | scm_t_c_hook scm_before_gc_c_hook; |
529 | scm_t_c_hook scm_before_mark_c_hook; | |
530 | scm_t_c_hook scm_before_sweep_c_hook; | |
531 | scm_t_c_hook scm_after_sweep_c_hook; | |
532 | scm_t_c_hook scm_after_gc_c_hook; | |
4a4c9785 | 533 | |
b17e0ac3 MV |
534 | /* Must be called while holding scm_i_sweep_mutex. |
535 | */ | |
536 | ||
c8a1bdc4 | 537 | void |
b17e0ac3 | 538 | scm_i_gc (const char *what) |
c8a1bdc4 | 539 | { |
9de87eea MV |
540 | scm_i_thread_put_to_sleep (); |
541 | ||
c8a1bdc4 | 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 | Set freelists to NULL so scm_cons() always triggers gc, causing | |
b17e0ac3 | 557 | the assertion above to fail. |
1367aa5e HWN |
558 | */ |
559 | *SCM_FREELIST_LOC (scm_i_freelist) = SCM_EOL; | |
560 | *SCM_FREELIST_LOC (scm_i_freelist2) = SCM_EOL; | |
561 | ||
c8a1bdc4 HWN |
562 | /* |
563 | Let's finish the sweep. The conservative GC might point into the | |
564 | garbage, and marking that would create a mess. | |
565 | */ | |
566 | scm_i_sweep_all_segments("GC"); | |
567 | if (scm_mallocated < scm_i_deprecated_memory_return) | |
b6efc951 | 568 | { |
c8a1bdc4 HWN |
569 | /* The byte count of allocated objects has underflowed. This is |
570 | probably because you forgot to report the sizes of objects you | |
571 | have allocated, by calling scm_done_malloc or some such. When | |
572 | the GC freed them, it subtracted their size from | |
573 | scm_mallocated, which underflowed. */ | |
574 | fprintf (stderr, | |
575 | "scm_gc_sweep: Byte count of allocated objects has underflowed.\n" | |
576 | "This is probably because the GC hasn't been correctly informed\n" | |
577 | "about object sizes\n"); | |
b6efc951 DH |
578 | abort (); |
579 | } | |
c8a1bdc4 | 580 | scm_mallocated -= scm_i_deprecated_memory_return; |
0f2d19dd | 581 | |
c8a1bdc4 | 582 | |
b17e0ac3 | 583 | /* Mark */ |
b6efc951 | 584 | |
b17e0ac3 | 585 | scm_c_hook_run (&scm_before_mark_c_hook, 0); |
c8a1bdc4 | 586 | scm_mark_all (); |
c2cbcc57 | 587 | scm_gc_mark_time_taken += (scm_c_get_internal_run_time () - t_before_gc); |
c8a1bdc4 | 588 | |
b17e0ac3 | 589 | /* Sweep |
ffd72400 | 590 | |
b17e0ac3 MV |
591 | TODO: the after_sweep hook should probably be moved to just before |
592 | the mark, since that's where the sweep is finished in lazy | |
593 | sweeping. | |
c35738c1 MD |
594 | |
595 | MDJ 030219 <djurfeldt@nada.kth.se>: No, probably not. The | |
596 | original meaning implied at least two things: that it would be | |
597 | called when | |
598 | ||
599 | 1. the freelist is re-initialized (no evaluation possible, though) | |
600 | ||
601 | and | |
602 | ||
603 | 2. the heap is "fresh" | |
604 | (it is well-defined what data is used and what is not) | |
605 | ||
606 | Neither of these conditions would hold just before the mark phase. | |
607 | ||
608 | Of course, the lazy sweeping has muddled the distinction between | |
609 | scm_before_sweep_c_hook and scm_after_sweep_c_hook, but even if | |
610 | there were no difference, it would still be useful to have two | |
611 | distinct classes of hook functions since this can prevent some | |
612 | bad interference when several modules adds gc hooks. | |
ffd72400 | 613 | */ |
b17e0ac3 MV |
614 | |
615 | scm_c_hook_run (&scm_before_sweep_c_hook, 0); | |
616 | scm_gc_sweep (); | |
c8a1bdc4 | 617 | scm_c_hook_run (&scm_after_sweep_c_hook, 0); |
b17e0ac3 | 618 | |
c8a1bdc4 HWN |
619 | gc_end_stats (); |
620 | ||
fb50ef08 | 621 | scm_i_thread_wake_up (); |
ffd72400 | 622 | |
eab1b259 HWN |
623 | /* |
624 | For debugging purposes, you could do | |
625 | scm_i_sweep_all_segments("debug"), but then the remains of the | |
626 | cell aren't left to analyse. | |
627 | */ | |
628 | } | |
0f2d19dd | 629 | |
0f2d19dd JB |
630 | \f |
631 | /* {GC Protection Helper Functions} | |
632 | */ | |
633 | ||
634 | ||
5d2b97cd DH |
635 | /* |
636 | * If within a function you need to protect one or more scheme objects from | |
637 | * garbage collection, pass them as parameters to one of the | |
638 | * scm_remember_upto_here* functions below. These functions don't do | |
639 | * anything, but since the compiler does not know that they are actually | |
640 | * no-ops, it will generate code that calls these functions with the given | |
641 | * parameters. Therefore, you can be sure that the compiler will keep those | |
642 | * scheme values alive (on the stack or in a register) up to the point where | |
643 | * scm_remember_upto_here* is called. In other words, place the call to | |
592996c9 | 644 | * scm_remember_upto_here* _behind_ the last code in your function, that |
5d2b97cd DH |
645 | * depends on the scheme object to exist. |
646 | * | |
8c494e99 DH |
647 | * Example: We want to make sure that the string object str does not get |
648 | * garbage collected during the execution of 'some_function' in the code | |
649 | * below, because otherwise the characters belonging to str would be freed and | |
5d2b97cd DH |
650 | * 'some_function' might access freed memory. To make sure that the compiler |
651 | * keeps str alive on the stack or in a register such that it is visible to | |
652 | * the conservative gc we add the call to scm_remember_upto_here_1 _after_ the | |
653 | * call to 'some_function'. Note that this would not be necessary if str was | |
654 | * used anyway after the call to 'some_function'. | |
eb01cb64 | 655 | * char *chars = scm_i_string_chars (str); |
5d2b97cd DH |
656 | * some_function (chars); |
657 | * scm_remember_upto_here_1 (str); // str will be alive up to this point. | |
658 | */ | |
659 | ||
9e1569bd KR |
660 | /* Remove any macro versions of these while defining the functions. |
661 | Functions are always included in the library, for upward binary | |
662 | compatibility and in case combinations of GCC and non-GCC are used. */ | |
663 | #undef scm_remember_upto_here_1 | |
664 | #undef scm_remember_upto_here_2 | |
665 | ||
5d2b97cd | 666 | void |
e81d98ec | 667 | scm_remember_upto_here_1 (SCM obj SCM_UNUSED) |
5d2b97cd DH |
668 | { |
669 | /* Empty. Protects a single object from garbage collection. */ | |
670 | } | |
671 | ||
672 | void | |
e81d98ec | 673 | scm_remember_upto_here_2 (SCM obj1 SCM_UNUSED, SCM obj2 SCM_UNUSED) |
5d2b97cd DH |
674 | { |
675 | /* Empty. Protects two objects from garbage collection. */ | |
676 | } | |
677 | ||
678 | void | |
e81d98ec | 679 | scm_remember_upto_here (SCM obj SCM_UNUSED, ...) |
5d2b97cd DH |
680 | { |
681 | /* Empty. Protects any number of objects from garbage collection. */ | |
682 | } | |
683 | ||
c209c88e | 684 | /* |
41b0806d GB |
685 | These crazy functions prevent garbage collection |
686 | of arguments after the first argument by | |
687 | ensuring they remain live throughout the | |
688 | function because they are used in the last | |
689 | line of the code block. | |
690 | It'd be better to have a nice compiler hint to | |
691 | aid the conservative stack-scanning GC. --03/09/00 gjb */ | |
0f2d19dd JB |
692 | SCM |
693 | scm_return_first (SCM elt, ...) | |
0f2d19dd JB |
694 | { |
695 | return elt; | |
696 | } | |
697 | ||
41b0806d GB |
698 | int |
699 | scm_return_first_int (int i, ...) | |
700 | { | |
701 | return i; | |
702 | } | |
703 | ||
0f2d19dd | 704 | |
0f2d19dd | 705 | SCM |
6e8d25a6 | 706 | scm_permanent_object (SCM obj) |
0f2d19dd | 707 | { |
9de87eea MV |
708 | SCM cell = scm_cons (obj, SCM_EOL); |
709 | SCM_CRITICAL_SECTION_START; | |
710 | SCM_SETCDR (cell, scm_permobjs); | |
711 | scm_permobjs = cell; | |
712 | SCM_CRITICAL_SECTION_END; | |
0f2d19dd JB |
713 | return obj; |
714 | } | |
715 | ||
716 | ||
7bd4fbe2 MD |
717 | /* Protect OBJ from the garbage collector. OBJ will not be freed, even if all |
718 | other references are dropped, until the object is unprotected by calling | |
6b1b030e | 719 | scm_gc_unprotect_object (OBJ). Calls to scm_gc_protect/unprotect_object nest, |
7bd4fbe2 MD |
720 | i. e. it is possible to protect the same object several times, but it is |
721 | necessary to unprotect the object the same number of times to actually get | |
722 | the object unprotected. It is an error to unprotect an object more often | |
723 | than it has been protected before. The function scm_protect_object returns | |
724 | OBJ. | |
725 | */ | |
726 | ||
727 | /* Implementation note: For every object X, there is a counter which | |
6b1b030e | 728 | scm_gc_protect_object(X) increments and scm_gc_unprotect_object(X) decrements. |
7bd4fbe2 | 729 | */ |
686765af | 730 | |
7eec4c37 HWN |
731 | |
732 | ||
ef290276 | 733 | SCM |
6b1b030e | 734 | scm_gc_protect_object (SCM obj) |
ef290276 | 735 | { |
686765af | 736 | SCM handle; |
9d47a1e6 | 737 | |
686765af | 738 | /* This critical section barrier will be replaced by a mutex. */ |
33b320ae NJ |
739 | /* njrev: Indeed; if my comment above is correct, there is the same |
740 | critsec/mutex inconsistency here. */ | |
9de87eea | 741 | SCM_CRITICAL_SECTION_START; |
9d47a1e6 | 742 | |
e11e83f3 MV |
743 | handle = scm_hashq_create_handle_x (scm_protects, obj, scm_from_int (0)); |
744 | SCM_SETCDR (handle, scm_sum (SCM_CDR (handle), scm_from_int (1))); | |
9d47a1e6 | 745 | |
7eec4c37 HWN |
746 | protected_obj_count ++; |
747 | ||
9de87eea | 748 | SCM_CRITICAL_SECTION_END; |
9d47a1e6 | 749 | |
ef290276 JB |
750 | return obj; |
751 | } | |
752 | ||
753 | ||
754 | /* Remove any protection for OBJ established by a prior call to | |
dab7f566 | 755 | scm_protect_object. This function returns OBJ. |
ef290276 | 756 | |
dab7f566 | 757 | See scm_protect_object for more information. */ |
ef290276 | 758 | SCM |
6b1b030e | 759 | scm_gc_unprotect_object (SCM obj) |
ef290276 | 760 | { |
686765af | 761 | SCM handle; |
9d47a1e6 | 762 | |
686765af | 763 | /* This critical section barrier will be replaced by a mutex. */ |
33b320ae | 764 | /* njrev: and again. */ |
9de87eea | 765 | SCM_CRITICAL_SECTION_START; |
9d47a1e6 | 766 | |
0ff7e3ff HWN |
767 | if (scm_gc_running_p) |
768 | { | |
769 | fprintf (stderr, "scm_unprotect_object called during GC.\n"); | |
770 | abort (); | |
771 | } | |
b17e0ac3 | 772 | |
686765af | 773 | handle = scm_hashq_get_handle (scm_protects, obj); |
9d47a1e6 | 774 | |
7888309b | 775 | if (scm_is_false (handle)) |
686765af | 776 | { |
0f0f0899 MD |
777 | fprintf (stderr, "scm_unprotect_object called on unprotected object\n"); |
778 | abort (); | |
686765af | 779 | } |
6a199940 DH |
780 | else |
781 | { | |
e11e83f3 | 782 | SCM count = scm_difference (SCM_CDR (handle), scm_from_int (1)); |
bc36d050 | 783 | if (scm_is_eq (count, scm_from_int (0))) |
6a199940 DH |
784 | scm_hashq_remove_x (scm_protects, obj); |
785 | else | |
1be6b49c | 786 | SCM_SETCDR (handle, count); |
6a199940 | 787 | } |
7eec4c37 | 788 | protected_obj_count --; |
686765af | 789 | |
9de87eea | 790 | SCM_CRITICAL_SECTION_END; |
ef290276 JB |
791 | |
792 | return obj; | |
793 | } | |
794 | ||
6b1b030e ML |
795 | void |
796 | scm_gc_register_root (SCM *p) | |
797 | { | |
798 | SCM handle; | |
b9bd8526 | 799 | SCM key = scm_from_ulong ((unsigned long) p); |
eae33935 | 800 | |
6b1b030e | 801 | /* This critical section barrier will be replaced by a mutex. */ |
33b320ae | 802 | /* njrev: and again. */ |
9de87eea | 803 | SCM_CRITICAL_SECTION_START; |
6b1b030e | 804 | |
e11e83f3 MV |
805 | handle = scm_hashv_create_handle_x (scm_gc_registered_roots, key, |
806 | scm_from_int (0)); | |
33b320ae | 807 | /* njrev: note also that the above can probably signal an error */ |
e11e83f3 | 808 | SCM_SETCDR (handle, scm_sum (SCM_CDR (handle), scm_from_int (1))); |
6b1b030e | 809 | |
9de87eea | 810 | SCM_CRITICAL_SECTION_END; |
6b1b030e ML |
811 | } |
812 | ||
813 | void | |
814 | scm_gc_unregister_root (SCM *p) | |
815 | { | |
816 | SCM handle; | |
b9bd8526 | 817 | SCM key = scm_from_ulong ((unsigned long) p); |
6b1b030e ML |
818 | |
819 | /* This critical section barrier will be replaced by a mutex. */ | |
33b320ae | 820 | /* njrev: and again. */ |
9de87eea | 821 | SCM_CRITICAL_SECTION_START; |
6b1b030e ML |
822 | |
823 | handle = scm_hashv_get_handle (scm_gc_registered_roots, key); | |
824 | ||
7888309b | 825 | if (scm_is_false (handle)) |
6b1b030e ML |
826 | { |
827 | fprintf (stderr, "scm_gc_unregister_root called on unregistered root\n"); | |
828 | abort (); | |
829 | } | |
830 | else | |
831 | { | |
e11e83f3 | 832 | SCM count = scm_difference (SCM_CDR (handle), scm_from_int (1)); |
bc36d050 | 833 | if (scm_is_eq (count, scm_from_int (0))) |
6b1b030e ML |
834 | scm_hashv_remove_x (scm_gc_registered_roots, key); |
835 | else | |
836 | SCM_SETCDR (handle, count); | |
837 | } | |
838 | ||
9de87eea | 839 | SCM_CRITICAL_SECTION_END; |
6b1b030e ML |
840 | } |
841 | ||
842 | void | |
843 | scm_gc_register_roots (SCM *b, unsigned long n) | |
844 | { | |
845 | SCM *p = b; | |
846 | for (; p < b + n; ++p) | |
847 | scm_gc_register_root (p); | |
848 | } | |
849 | ||
850 | void | |
851 | scm_gc_unregister_roots (SCM *b, unsigned long n) | |
852 | { | |
853 | SCM *p = b; | |
854 | for (; p < b + n; ++p) | |
855 | scm_gc_unregister_root (p); | |
856 | } | |
857 | ||
04a98cff | 858 | int scm_i_terminating; |
c45acc34 | 859 | |
0f2d19dd | 860 | \f |
a00c95d9 | 861 | |
4c48ba06 | 862 | |
c8a1bdc4 HWN |
863 | /* |
864 | MOVE THIS FUNCTION. IT DOES NOT HAVE ANYTHING TODO WITH GC. | |
865 | */ | |
85db4a2c DH |
866 | |
867 | /* Get an integer from an environment variable. */ | |
c8a1bdc4 HWN |
868 | int |
869 | scm_getenv_int (const char *var, int def) | |
85db4a2c | 870 | { |
c8a1bdc4 HWN |
871 | char *end = 0; |
872 | char *val = getenv (var); | |
873 | long res = def; | |
85db4a2c DH |
874 | if (!val) |
875 | return def; | |
876 | res = strtol (val, &end, 10); | |
877 | if (end == val) | |
878 | return def; | |
879 | return res; | |
880 | } | |
881 | ||
c35738c1 MD |
882 | void |
883 | scm_storage_prehistory () | |
884 | { | |
885 | scm_c_hook_init (&scm_before_gc_c_hook, 0, SCM_C_HOOK_NORMAL); | |
886 | scm_c_hook_init (&scm_before_mark_c_hook, 0, SCM_C_HOOK_NORMAL); | |
887 | scm_c_hook_init (&scm_before_sweep_c_hook, 0, SCM_C_HOOK_NORMAL); | |
888 | scm_c_hook_init (&scm_after_sweep_c_hook, 0, SCM_C_HOOK_NORMAL); | |
889 | scm_c_hook_init (&scm_after_gc_c_hook, 0, SCM_C_HOOK_NORMAL); | |
890 | } | |
85db4a2c | 891 | |
9de87eea | 892 | scm_i_pthread_mutex_t scm_i_gc_admin_mutex = SCM_I_PTHREAD_MUTEX_INITIALIZER; |
eb01cb64 | 893 | |
4a4c9785 | 894 | int |
85db4a2c | 895 | scm_init_storage () |
0f2d19dd | 896 | { |
1be6b49c | 897 | size_t j; |
0f2d19dd JB |
898 | |
899 | j = SCM_NUM_PROTECTS; | |
900 | while (j) | |
901 | scm_sys_protects[--j] = SCM_BOOL_F; | |
4a4c9785 | 902 | |
c8a1bdc4 HWN |
903 | scm_gc_init_freelist(); |
904 | scm_gc_init_malloc (); | |
0f2d19dd JB |
905 | |
906 | j = SCM_HEAP_SEG_SIZE; | |
d6884e63 | 907 | |
c8a1bdc4 | 908 | |
0f2d19dd | 909 | /* Initialise the list of ports. */ |
67329a9e HWN |
910 | scm_i_port_table = (scm_t_port **) |
911 | malloc (sizeof (scm_t_port *) * scm_i_port_table_room); | |
912 | if (!scm_i_port_table) | |
0f2d19dd JB |
913 | return 1; |
914 | ||
9de87eea MV |
915 | #if 0 |
916 | /* We can't have a cleanup handler since we have no thread to run it | |
917 | in. */ | |
918 | ||
a18bcd0e | 919 | #ifdef HAVE_ATEXIT |
c45acc34 | 920 | atexit (cleanup); |
e52ceaac MD |
921 | #else |
922 | #ifdef HAVE_ON_EXIT | |
923 | on_exit (cleanup, 0); | |
924 | #endif | |
9de87eea MV |
925 | #endif |
926 | ||
a18bcd0e | 927 | #endif |
0f2d19dd | 928 | |
82c76fd3 | 929 | scm_stand_in_procs = scm_c_make_hash_table (257); |
0f2d19dd | 930 | scm_permobjs = SCM_EOL; |
00ffa0e7 | 931 | scm_protects = scm_c_make_hash_table (31); |
6b1b030e | 932 | scm_gc_registered_roots = scm_c_make_hash_table (31); |
d6884e63 | 933 | |
0f2d19dd JB |
934 | return 0; |
935 | } | |
939794ce | 936 | |
0f2d19dd JB |
937 | \f |
938 | ||
939794ce DH |
939 | SCM scm_after_gc_hook; |
940 | ||
939794ce DH |
941 | static SCM gc_async; |
942 | ||
939794ce DH |
943 | /* The function gc_async_thunk causes the execution of the after-gc-hook. It |
944 | * is run after the gc, as soon as the asynchronous events are handled by the | |
945 | * evaluator. | |
946 | */ | |
947 | static SCM | |
948 | gc_async_thunk (void) | |
949 | { | |
950 | scm_c_run_hook (scm_after_gc_hook, SCM_EOL); | |
939794ce DH |
951 | return SCM_UNSPECIFIED; |
952 | } | |
953 | ||
954 | ||
955 | /* The function mark_gc_async is run by the scm_after_gc_c_hook at the end of | |
956 | * the garbage collection. The only purpose of this function is to mark the | |
957 | * gc_async (which will eventually lead to the execution of the | |
958 | * gc_async_thunk). | |
959 | */ | |
960 | static void * | |
e81d98ec DH |
961 | mark_gc_async (void * hook_data SCM_UNUSED, |
962 | void *func_data SCM_UNUSED, | |
963 | void *data SCM_UNUSED) | |
964 | { | |
965 | /* If cell access debugging is enabled, the user may choose to perform | |
966 | * additional garbage collections after an arbitrary number of cell | |
967 | * accesses. We don't want the scheme level after-gc-hook to be performed | |
968 | * for each of these garbage collections for the following reason: The | |
969 | * execution of the after-gc-hook causes cell accesses itself. Thus, if the | |
970 | * after-gc-hook was performed with every gc, and if the gc was performed | |
971 | * after a very small number of cell accesses, then the number of cell | |
972 | * accesses during the execution of the after-gc-hook will suffice to cause | |
973 | * the execution of the next gc. Then, guile would keep executing the | |
974 | * after-gc-hook over and over again, and would never come to do other | |
975 | * things. | |
eae33935 | 976 | * |
e81d98ec DH |
977 | * To overcome this problem, if cell access debugging with additional |
978 | * garbage collections is enabled, the after-gc-hook is never run by the | |
979 | * garbage collecter. When running guile with cell access debugging and the | |
980 | * execution of the after-gc-hook is desired, then it is necessary to run | |
981 | * the hook explicitly from the user code. This has the effect, that from | |
982 | * the scheme level point of view it seems that garbage collection is | |
983 | * performed with a much lower frequency than it actually is. Obviously, | |
984 | * this will not work for code that depends on a fixed one to one | |
985 | * relationship between the execution counts of the C level garbage | |
986 | * collection hooks and the execution count of the scheme level | |
987 | * after-gc-hook. | |
988 | */ | |
9de87eea | 989 | |
e81d98ec | 990 | #if (SCM_DEBUG_CELL_ACCESSES == 1) |
eab1b259 | 991 | if (scm_debug_cells_gc_interval == 0) |
e81d98ec DH |
992 | scm_system_async_mark (gc_async); |
993 | #else | |
939794ce | 994 | scm_system_async_mark (gc_async); |
e81d98ec DH |
995 | #endif |
996 | ||
939794ce DH |
997 | return NULL; |
998 | } | |
999 | ||
0f2d19dd JB |
1000 | void |
1001 | scm_init_gc () | |
0f2d19dd | 1002 | { |
c8a1bdc4 | 1003 | scm_gc_init_mark (); |
d678e25c | 1004 | |
fde50407 ML |
1005 | scm_after_gc_hook = scm_permanent_object (scm_make_hook (SCM_INUM0)); |
1006 | scm_c_define ("after-gc-hook", scm_after_gc_hook); | |
939794ce | 1007 | |
2592c4c7 MV |
1008 | gc_async = scm_c_make_subr ("%gc-thunk", scm_tc7_subr_0, |
1009 | gc_async_thunk); | |
939794ce DH |
1010 | |
1011 | scm_c_hook_add (&scm_after_gc_c_hook, mark_gc_async, NULL, 0); | |
1012 | ||
a0599745 | 1013 | #include "libguile/gc.x" |
0f2d19dd | 1014 | } |
89e00824 | 1015 | |
c8a1bdc4 HWN |
1016 | |
1017 | void | |
1018 | scm_gc_sweep (void) | |
1019 | #define FUNC_NAME "scm_gc_sweep" | |
1020 | { | |
1021 | scm_i_deprecated_memory_return = 0; | |
1022 | ||
1023 | scm_i_gc_sweep_freelist_reset (&scm_i_master_freelist); | |
1024 | scm_i_gc_sweep_freelist_reset (&scm_i_master_freelist2); | |
1025 | ||
1026 | /* | |
1027 | NOTHING HERE: LAZY SWEEPING ! | |
1028 | */ | |
1029 | scm_i_reset_segments (); | |
1030 | ||
9bc4701c MD |
1031 | *SCM_FREELIST_LOC (scm_i_freelist) = SCM_EOL; |
1032 | *SCM_FREELIST_LOC (scm_i_freelist2) = SCM_EOL; | |
392d2833 MD |
1033 | |
1034 | /* Invalidate the freelists of other threads. */ | |
1035 | scm_i_thread_invalidate_freelists (); | |
c8a1bdc4 HWN |
1036 | } |
1037 | ||
1038 | #undef FUNC_NAME | |
1039 | ||
1040 | ||
56495472 | 1041 | |
89e00824 ML |
1042 | /* |
1043 | Local Variables: | |
1044 | c-file-style: "gnu" | |
1045 | End: | |
1046 | */ |