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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 | |
92205699 | 15 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
73be1d9e | 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)); | |
b01532af NJ |
280 | SCM alist; |
281 | ||
1367aa5e HWN |
282 | scm_i_all_segments_statistics (tab); |
283 | ||
b01532af | 284 | alist |
1367aa5e HWN |
285 | = scm_internal_hash_fold (&tag_table_to_type_alist, NULL, SCM_EOL, tab); |
286 | ||
287 | return alist; | |
288 | } | |
289 | #undef FUNC_NAME | |
290 | ||
c2cbcc57 | 291 | extern int scm_gc_malloc_yield_percentage; |
a00c95d9 | 292 | SCM_DEFINE (scm_gc_stats, "gc-stats", 0, 0, 0, |
1bbd0b84 | 293 | (), |
1e6808ea | 294 | "Return an association list of statistics about Guile's current\n" |
c8a1bdc4 | 295 | "use of storage.\n") |
1bbd0b84 | 296 | #define FUNC_NAME s_scm_gc_stats |
0f2d19dd | 297 | { |
c8a1bdc4 HWN |
298 | long i = 0; |
299 | SCM heap_segs = SCM_EOL ; | |
c014a02e ML |
300 | unsigned long int local_scm_mtrigger; |
301 | unsigned long int local_scm_mallocated; | |
302 | unsigned long int local_scm_heap_size; | |
c2cbcc57 HWN |
303 | int local_scm_gc_cell_yield_percentage; |
304 | int local_scm_gc_malloc_yield_percentage; | |
f2893a25 | 305 | unsigned long int local_scm_cells_allocated; |
c014a02e ML |
306 | unsigned long int local_scm_gc_time_taken; |
307 | unsigned long int local_scm_gc_times; | |
308 | unsigned long int local_scm_gc_mark_time_taken; | |
7eec4c37 | 309 | unsigned long int local_protected_obj_count; |
c9b0d4b0 ML |
310 | double local_scm_gc_cells_swept; |
311 | double local_scm_gc_cells_marked; | |
0f2d19dd | 312 | SCM answer; |
c8a1bdc4 HWN |
313 | unsigned long *bounds = 0; |
314 | int table_size = scm_i_heap_segment_table_size; | |
9de87eea | 315 | SCM_CRITICAL_SECTION_START; |
939794ce | 316 | |
c8a1bdc4 HWN |
317 | /* |
318 | temporarily store the numbers, so as not to cause GC. | |
7febb4a2 | 319 | */ |
c8a1bdc4 HWN |
320 | |
321 | bounds = malloc (sizeof (int) * table_size * 2); | |
322 | if (!bounds) | |
323 | abort(); | |
324 | for (i = table_size; i--; ) | |
325 | { | |
326 | bounds[2*i] = (unsigned long)scm_i_heap_segment_table[i]->bounds[0]; | |
327 | bounds[2*i+1] = (unsigned long)scm_i_heap_segment_table[i]->bounds[1]; | |
328 | } | |
0f2d19dd | 329 | |
4c9419ac | 330 | |
c8a1bdc4 HWN |
331 | /* Below, we cons to produce the resulting list. We want a snapshot of |
332 | * the heap situation before consing. | |
333 | */ | |
334 | local_scm_mtrigger = scm_mtrigger; | |
335 | local_scm_mallocated = scm_mallocated; | |
336 | local_scm_heap_size = SCM_HEAP_SIZE; | |
539b08a4 | 337 | |
c8a1bdc4 HWN |
338 | local_scm_cells_allocated = scm_cells_allocated; |
339 | ||
340 | local_scm_gc_time_taken = scm_gc_time_taken; | |
341 | local_scm_gc_mark_time_taken = scm_gc_mark_time_taken; | |
342 | local_scm_gc_times = scm_gc_times; | |
c2cbcc57 HWN |
343 | local_scm_gc_malloc_yield_percentage = scm_gc_malloc_yield_percentage; |
344 | local_scm_gc_cell_yield_percentage= scm_gc_cell_yield_percentage; | |
7eec4c37 | 345 | local_protected_obj_count = protected_obj_count; |
c2cbcc57 HWN |
346 | local_scm_gc_cells_swept = |
347 | (double) scm_gc_cells_swept_acc | |
348 | + (double) scm_gc_cells_swept; | |
c8a1bdc4 HWN |
349 | local_scm_gc_cells_marked = scm_gc_cells_marked_acc |
350 | +(double) scm_gc_cells_swept | |
351 | -(double) scm_gc_cells_collected; | |
0f2d19dd | 352 | |
c8a1bdc4 HWN |
353 | for (i = table_size; i--;) |
354 | { | |
b9bd8526 MV |
355 | heap_segs = scm_cons (scm_cons (scm_from_ulong (bounds[2*i]), |
356 | scm_from_ulong (bounds[2*i+1])), | |
c8a1bdc4 HWN |
357 | heap_segs); |
358 | } | |
33b320ae NJ |
359 | /* njrev: can any of these scm_cons's or scm_list_n signal a memory |
360 | error? If so we need a frame here. */ | |
b9bd8526 MV |
361 | answer = |
362 | scm_list_n (scm_cons (sym_gc_time_taken, | |
363 | scm_from_ulong (local_scm_gc_time_taken)), | |
364 | scm_cons (sym_cells_allocated, | |
365 | scm_from_ulong (local_scm_cells_allocated)), | |
366 | scm_cons (sym_heap_size, | |
367 | scm_from_ulong (local_scm_heap_size)), | |
368 | scm_cons (sym_mallocated, | |
369 | scm_from_ulong (local_scm_mallocated)), | |
370 | scm_cons (sym_mtrigger, | |
371 | scm_from_ulong (local_scm_mtrigger)), | |
372 | scm_cons (sym_times, | |
373 | scm_from_ulong (local_scm_gc_times)), | |
374 | scm_cons (sym_gc_mark_time_taken, | |
375 | scm_from_ulong (local_scm_gc_mark_time_taken)), | |
376 | scm_cons (sym_cells_marked, | |
377 | scm_from_double (local_scm_gc_cells_marked)), | |
378 | scm_cons (sym_cells_swept, | |
379 | scm_from_double (local_scm_gc_cells_swept)), | |
380 | scm_cons (sym_malloc_yield, | |
381 | scm_from_long(local_scm_gc_malloc_yield_percentage)), | |
382 | scm_cons (sym_cell_yield, | |
383 | scm_from_long (local_scm_gc_cell_yield_percentage)), | |
384 | scm_cons (sym_protected_objects, | |
385 | scm_from_ulong (local_protected_obj_count)), | |
386 | scm_cons (sym_heap_segments, heap_segs), | |
387 | SCM_UNDEFINED); | |
9de87eea | 388 | SCM_CRITICAL_SECTION_END; |
c8a1bdc4 HWN |
389 | |
390 | free (bounds); | |
391 | return answer; | |
0f2d19dd | 392 | } |
c8a1bdc4 | 393 | #undef FUNC_NAME |
0f2d19dd | 394 | |
c8a1bdc4 HWN |
395 | static void |
396 | gc_start_stats (const char *what SCM_UNUSED) | |
e4a7824f | 397 | { |
c8a1bdc4 | 398 | t_before_gc = scm_c_get_internal_run_time (); |
539b08a4 | 399 | |
c8a1bdc4 HWN |
400 | scm_gc_cells_marked_acc += (double) scm_gc_cells_swept |
401 | - (double) scm_gc_cells_collected; | |
c2cbcc57 | 402 | scm_gc_cells_swept_acc += (double) scm_gc_cells_swept; |
e4a7824f | 403 | |
c2cbcc57 HWN |
404 | scm_gc_cell_yield_percentage = ( scm_gc_cells_collected * 100 ) / SCM_HEAP_SIZE; |
405 | ||
c8a1bdc4 HWN |
406 | scm_gc_cells_swept = 0; |
407 | scm_gc_cells_collected_1 = scm_gc_cells_collected; | |
539b08a4 | 408 | |
c8a1bdc4 HWN |
409 | /* |
410 | CELLS SWEPT is another word for the number of cells that were | |
411 | examined during GC. YIELD is the number that we cleaned | |
412 | out. MARKED is the number that weren't cleaned. | |
413 | */ | |
414 | scm_gc_cells_collected = 0; | |
415 | scm_gc_malloc_collected = 0; | |
416 | scm_gc_ports_collected = 0; | |
e4a7824f | 417 | } |
acf4331f | 418 | |
c8a1bdc4 HWN |
419 | static void |
420 | gc_end_stats () | |
0f2d19dd | 421 | { |
c8a1bdc4 HWN |
422 | unsigned long t = scm_c_get_internal_run_time (); |
423 | scm_gc_time_taken += (t - t_before_gc); | |
539b08a4 | 424 | |
c8a1bdc4 | 425 | ++scm_gc_times; |
0f2d19dd | 426 | } |
acf4331f | 427 | |
0f2d19dd | 428 | |
c8a1bdc4 HWN |
429 | SCM_DEFINE (scm_object_address, "object-address", 1, 0, 0, |
430 | (SCM obj), | |
431 | "Return an integer that for the lifetime of @var{obj} is uniquely\n" | |
432 | "returned by this function for @var{obj}") | |
433 | #define FUNC_NAME s_scm_object_address | |
c68296f8 | 434 | { |
b9bd8526 | 435 | return scm_from_ulong (SCM_UNPACK (obj)); |
c68296f8 | 436 | } |
c8a1bdc4 | 437 | #undef FUNC_NAME |
c68296f8 | 438 | |
1be6b49c | 439 | |
c8a1bdc4 HWN |
440 | SCM_DEFINE (scm_gc, "gc", 0, 0, 0, |
441 | (), | |
442 | "Scans all of SCM objects and reclaims for further use those that are\n" | |
443 | "no longer accessible.") | |
444 | #define FUNC_NAME s_scm_gc | |
445 | { | |
b17e0ac3 MV |
446 | scm_i_scm_pthread_mutex_lock (&scm_i_sweep_mutex); |
447 | scm_gc_running_p = 1; | |
448 | scm_i_gc ("call"); | |
33b320ae NJ |
449 | /* njrev: It looks as though other places, e.g. scm_realloc, |
450 | can call scm_i_gc without acquiring the sweep mutex. Does this | |
451 | matter? Also scm_i_gc (or its descendants) touch the | |
452 | scm_sys_protects, which are protected in some cases | |
453 | (e.g. scm_permobjs above in scm_gc_stats) by a critical section, | |
454 | not by the sweep mutex. Shouldn't all the GC-relevant objects be | |
455 | protected in the same way? */ | |
b17e0ac3 MV |
456 | scm_gc_running_p = 0; |
457 | scm_i_pthread_mutex_unlock (&scm_i_sweep_mutex); | |
458 | scm_c_hook_run (&scm_after_gc_c_hook, 0); | |
c8a1bdc4 | 459 | return SCM_UNSPECIFIED; |
9d47a1e6 | 460 | } |
c8a1bdc4 | 461 | #undef FUNC_NAME |
9d47a1e6 | 462 | |
c68296f8 MV |
463 | |
464 | \f | |
0f2d19dd | 465 | |
b17e0ac3 MV |
466 | /* The master is global and common while the freelist will be |
467 | * individual for each thread. | |
0f2d19dd JB |
468 | */ |
469 | ||
c8a1bdc4 HWN |
470 | SCM |
471 | scm_gc_for_newcell (scm_t_cell_type_statistics *freelist, SCM *free_cells) | |
0f2d19dd | 472 | { |
c8a1bdc4 | 473 | SCM cell; |
b17e0ac3 | 474 | int did_gc = 0; |
c8a1bdc4 | 475 | |
9de87eea | 476 | scm_i_scm_pthread_mutex_lock (&scm_i_sweep_mutex); |
b17e0ac3 | 477 | scm_gc_running_p = 1; |
9bc4701c | 478 | |
c8a1bdc4 HWN |
479 | *free_cells = scm_i_sweep_some_segments (freelist); |
480 | if (*free_cells == SCM_EOL && scm_i_gc_grow_heap_p (freelist)) | |
481 | { | |
482 | freelist->heap_segment_idx = scm_i_get_new_heap_segment (freelist, abort_on_error); | |
483 | *free_cells = scm_i_sweep_some_segments (freelist); | |
484 | } | |
acb0a19c | 485 | |
b17e0ac3 | 486 | if (*free_cells == SCM_EOL) |
c8a1bdc4 HWN |
487 | { |
488 | /* | |
b17e0ac3 | 489 | with the advent of lazy sweep, GC yield is only known just |
c8a1bdc4 HWN |
490 | before doing the GC. |
491 | */ | |
492 | scm_i_adjust_min_yield (freelist); | |
493 | ||
494 | /* | |
495 | out of fresh cells. Try to get some new ones. | |
496 | */ | |
0f2d19dd | 497 | |
b17e0ac3 MV |
498 | did_gc = 1; |
499 | scm_i_gc ("cells"); | |
a00c95d9 | 500 | |
c8a1bdc4 HWN |
501 | *free_cells = scm_i_sweep_some_segments (freelist); |
502 | } | |
503 | ||
504 | if (*free_cells == SCM_EOL) | |
505 | { | |
506 | /* | |
507 | failed getting new cells. Get new juice or die. | |
508 | */ | |
509 | freelist->heap_segment_idx = scm_i_get_new_heap_segment (freelist, abort_on_error); | |
510 | *free_cells = scm_i_sweep_some_segments (freelist); | |
511 | } | |
512 | ||
513 | if (*free_cells == SCM_EOL) | |
514 | abort (); | |
0f2d19dd | 515 | |
c8a1bdc4 | 516 | cell = *free_cells; |
0f2d19dd | 517 | |
c8a1bdc4 | 518 | *free_cells = SCM_FREE_CELL_CDR (cell); |
eab1b259 | 519 | |
b17e0ac3 | 520 | scm_gc_running_p = 0; |
9de87eea | 521 | scm_i_pthread_mutex_unlock (&scm_i_sweep_mutex); |
eab1b259 | 522 | |
b17e0ac3 MV |
523 | if (did_gc) |
524 | scm_c_hook_run (&scm_after_gc_c_hook, 0); | |
525 | ||
c8a1bdc4 HWN |
526 | return cell; |
527 | } | |
4a4c9785 | 528 | |
4a4c9785 | 529 | |
c8a1bdc4 HWN |
530 | scm_t_c_hook scm_before_gc_c_hook; |
531 | scm_t_c_hook scm_before_mark_c_hook; | |
532 | scm_t_c_hook scm_before_sweep_c_hook; | |
533 | scm_t_c_hook scm_after_sweep_c_hook; | |
534 | scm_t_c_hook scm_after_gc_c_hook; | |
4a4c9785 | 535 | |
b17e0ac3 MV |
536 | /* Must be called while holding scm_i_sweep_mutex. |
537 | */ | |
538 | ||
c8a1bdc4 | 539 | void |
b17e0ac3 | 540 | scm_i_gc (const char *what) |
c8a1bdc4 | 541 | { |
9de87eea MV |
542 | scm_i_thread_put_to_sleep (); |
543 | ||
c8a1bdc4 | 544 | scm_c_hook_run (&scm_before_gc_c_hook, 0); |
a00c95d9 | 545 | |
c8a1bdc4 HWN |
546 | #ifdef DEBUGINFO |
547 | fprintf (stderr,"gc reason %s\n", what); | |
548 | ||
549 | fprintf (stderr, | |
d2e53ed6 | 550 | scm_is_null (*SCM_FREELIST_LOC (scm_i_freelist)) |
c8a1bdc4 | 551 | ? "*" |
d2e53ed6 | 552 | : (scm_is_null (*SCM_FREELIST_LOC (scm_i_freelist2)) ? "o" : "m")); |
c8a1bdc4 | 553 | #endif |
4c48ba06 | 554 | |
c8a1bdc4 | 555 | gc_start_stats (what); |
a00c95d9 | 556 | |
1367aa5e HWN |
557 | /* |
558 | Set freelists to NULL so scm_cons() always triggers gc, causing | |
b17e0ac3 | 559 | the assertion above to fail. |
1367aa5e HWN |
560 | */ |
561 | *SCM_FREELIST_LOC (scm_i_freelist) = SCM_EOL; | |
562 | *SCM_FREELIST_LOC (scm_i_freelist2) = SCM_EOL; | |
563 | ||
c8a1bdc4 HWN |
564 | /* |
565 | Let's finish the sweep. The conservative GC might point into the | |
566 | garbage, and marking that would create a mess. | |
567 | */ | |
568 | scm_i_sweep_all_segments("GC"); | |
569 | if (scm_mallocated < scm_i_deprecated_memory_return) | |
b6efc951 | 570 | { |
c8a1bdc4 HWN |
571 | /* The byte count of allocated objects has underflowed. This is |
572 | probably because you forgot to report the sizes of objects you | |
573 | have allocated, by calling scm_done_malloc or some such. When | |
574 | the GC freed them, it subtracted their size from | |
575 | scm_mallocated, which underflowed. */ | |
576 | fprintf (stderr, | |
577 | "scm_gc_sweep: Byte count of allocated objects has underflowed.\n" | |
578 | "This is probably because the GC hasn't been correctly informed\n" | |
579 | "about object sizes\n"); | |
b6efc951 DH |
580 | abort (); |
581 | } | |
c8a1bdc4 | 582 | scm_mallocated -= scm_i_deprecated_memory_return; |
0f2d19dd | 583 | |
c8a1bdc4 | 584 | |
b17e0ac3 | 585 | /* Mark */ |
b6efc951 | 586 | |
b17e0ac3 | 587 | scm_c_hook_run (&scm_before_mark_c_hook, 0); |
c8a1bdc4 | 588 | scm_mark_all (); |
c2cbcc57 | 589 | scm_gc_mark_time_taken += (scm_c_get_internal_run_time () - t_before_gc); |
c8a1bdc4 | 590 | |
b17e0ac3 | 591 | /* Sweep |
ffd72400 | 592 | |
b17e0ac3 MV |
593 | TODO: the after_sweep hook should probably be moved to just before |
594 | the mark, since that's where the sweep is finished in lazy | |
595 | sweeping. | |
c35738c1 MD |
596 | |
597 | MDJ 030219 <djurfeldt@nada.kth.se>: No, probably not. The | |
598 | original meaning implied at least two things: that it would be | |
599 | called when | |
600 | ||
601 | 1. the freelist is re-initialized (no evaluation possible, though) | |
602 | ||
603 | and | |
604 | ||
605 | 2. the heap is "fresh" | |
606 | (it is well-defined what data is used and what is not) | |
607 | ||
608 | Neither of these conditions would hold just before the mark phase. | |
609 | ||
610 | Of course, the lazy sweeping has muddled the distinction between | |
611 | scm_before_sweep_c_hook and scm_after_sweep_c_hook, but even if | |
612 | there were no difference, it would still be useful to have two | |
613 | distinct classes of hook functions since this can prevent some | |
614 | bad interference when several modules adds gc hooks. | |
ffd72400 | 615 | */ |
b17e0ac3 MV |
616 | |
617 | scm_c_hook_run (&scm_before_sweep_c_hook, 0); | |
618 | scm_gc_sweep (); | |
c8a1bdc4 | 619 | scm_c_hook_run (&scm_after_sweep_c_hook, 0); |
b17e0ac3 | 620 | |
c8a1bdc4 HWN |
621 | gc_end_stats (); |
622 | ||
fb50ef08 | 623 | scm_i_thread_wake_up (); |
ffd72400 | 624 | |
eab1b259 HWN |
625 | /* |
626 | For debugging purposes, you could do | |
627 | scm_i_sweep_all_segments("debug"), but then the remains of the | |
628 | cell aren't left to analyse. | |
629 | */ | |
630 | } | |
0f2d19dd | 631 | |
0f2d19dd JB |
632 | \f |
633 | /* {GC Protection Helper Functions} | |
634 | */ | |
635 | ||
636 | ||
5d2b97cd DH |
637 | /* |
638 | * If within a function you need to protect one or more scheme objects from | |
639 | * garbage collection, pass them as parameters to one of the | |
640 | * scm_remember_upto_here* functions below. These functions don't do | |
641 | * anything, but since the compiler does not know that they are actually | |
642 | * no-ops, it will generate code that calls these functions with the given | |
643 | * parameters. Therefore, you can be sure that the compiler will keep those | |
644 | * scheme values alive (on the stack or in a register) up to the point where | |
645 | * scm_remember_upto_here* is called. In other words, place the call to | |
592996c9 | 646 | * scm_remember_upto_here* _behind_ the last code in your function, that |
5d2b97cd DH |
647 | * depends on the scheme object to exist. |
648 | * | |
8c494e99 DH |
649 | * Example: We want to make sure that the string object str does not get |
650 | * garbage collected during the execution of 'some_function' in the code | |
651 | * below, because otherwise the characters belonging to str would be freed and | |
5d2b97cd DH |
652 | * 'some_function' might access freed memory. To make sure that the compiler |
653 | * keeps str alive on the stack or in a register such that it is visible to | |
654 | * the conservative gc we add the call to scm_remember_upto_here_1 _after_ the | |
655 | * call to 'some_function'. Note that this would not be necessary if str was | |
656 | * used anyway after the call to 'some_function'. | |
eb01cb64 | 657 | * char *chars = scm_i_string_chars (str); |
5d2b97cd DH |
658 | * some_function (chars); |
659 | * scm_remember_upto_here_1 (str); // str will be alive up to this point. | |
660 | */ | |
661 | ||
9e1569bd KR |
662 | /* Remove any macro versions of these while defining the functions. |
663 | Functions are always included in the library, for upward binary | |
664 | compatibility and in case combinations of GCC and non-GCC are used. */ | |
665 | #undef scm_remember_upto_here_1 | |
666 | #undef scm_remember_upto_here_2 | |
667 | ||
5d2b97cd | 668 | void |
e81d98ec | 669 | scm_remember_upto_here_1 (SCM obj SCM_UNUSED) |
5d2b97cd DH |
670 | { |
671 | /* Empty. Protects a single object from garbage collection. */ | |
672 | } | |
673 | ||
674 | void | |
e81d98ec | 675 | scm_remember_upto_here_2 (SCM obj1 SCM_UNUSED, SCM obj2 SCM_UNUSED) |
5d2b97cd DH |
676 | { |
677 | /* Empty. Protects two objects from garbage collection. */ | |
678 | } | |
679 | ||
680 | void | |
e81d98ec | 681 | scm_remember_upto_here (SCM obj SCM_UNUSED, ...) |
5d2b97cd DH |
682 | { |
683 | /* Empty. Protects any number of objects from garbage collection. */ | |
684 | } | |
685 | ||
c209c88e | 686 | /* |
41b0806d GB |
687 | These crazy functions prevent garbage collection |
688 | of arguments after the first argument by | |
689 | ensuring they remain live throughout the | |
690 | function because they are used in the last | |
691 | line of the code block. | |
692 | It'd be better to have a nice compiler hint to | |
693 | aid the conservative stack-scanning GC. --03/09/00 gjb */ | |
0f2d19dd JB |
694 | SCM |
695 | scm_return_first (SCM elt, ...) | |
0f2d19dd JB |
696 | { |
697 | return elt; | |
698 | } | |
699 | ||
41b0806d GB |
700 | int |
701 | scm_return_first_int (int i, ...) | |
702 | { | |
703 | return i; | |
704 | } | |
705 | ||
0f2d19dd | 706 | |
0f2d19dd | 707 | SCM |
6e8d25a6 | 708 | scm_permanent_object (SCM obj) |
0f2d19dd | 709 | { |
9de87eea MV |
710 | SCM cell = scm_cons (obj, SCM_EOL); |
711 | SCM_CRITICAL_SECTION_START; | |
712 | SCM_SETCDR (cell, scm_permobjs); | |
713 | scm_permobjs = cell; | |
714 | SCM_CRITICAL_SECTION_END; | |
0f2d19dd JB |
715 | return obj; |
716 | } | |
717 | ||
718 | ||
7bd4fbe2 MD |
719 | /* Protect OBJ from the garbage collector. OBJ will not be freed, even if all |
720 | other references are dropped, until the object is unprotected by calling | |
6b1b030e | 721 | scm_gc_unprotect_object (OBJ). Calls to scm_gc_protect/unprotect_object nest, |
7bd4fbe2 MD |
722 | i. e. it is possible to protect the same object several times, but it is |
723 | necessary to unprotect the object the same number of times to actually get | |
724 | the object unprotected. It is an error to unprotect an object more often | |
725 | than it has been protected before. The function scm_protect_object returns | |
726 | OBJ. | |
727 | */ | |
728 | ||
729 | /* Implementation note: For every object X, there is a counter which | |
6b1b030e | 730 | scm_gc_protect_object(X) increments and scm_gc_unprotect_object(X) decrements. |
7bd4fbe2 | 731 | */ |
686765af | 732 | |
7eec4c37 HWN |
733 | |
734 | ||
ef290276 | 735 | SCM |
6b1b030e | 736 | scm_gc_protect_object (SCM obj) |
ef290276 | 737 | { |
686765af | 738 | SCM handle; |
9d47a1e6 | 739 | |
686765af | 740 | /* This critical section barrier will be replaced by a mutex. */ |
33b320ae NJ |
741 | /* njrev: Indeed; if my comment above is correct, there is the same |
742 | critsec/mutex inconsistency here. */ | |
9de87eea | 743 | SCM_CRITICAL_SECTION_START; |
9d47a1e6 | 744 | |
e11e83f3 MV |
745 | handle = scm_hashq_create_handle_x (scm_protects, obj, scm_from_int (0)); |
746 | SCM_SETCDR (handle, scm_sum (SCM_CDR (handle), scm_from_int (1))); | |
9d47a1e6 | 747 | |
7eec4c37 HWN |
748 | protected_obj_count ++; |
749 | ||
9de87eea | 750 | SCM_CRITICAL_SECTION_END; |
9d47a1e6 | 751 | |
ef290276 JB |
752 | return obj; |
753 | } | |
754 | ||
755 | ||
756 | /* Remove any protection for OBJ established by a prior call to | |
dab7f566 | 757 | scm_protect_object. This function returns OBJ. |
ef290276 | 758 | |
dab7f566 | 759 | See scm_protect_object for more information. */ |
ef290276 | 760 | SCM |
6b1b030e | 761 | scm_gc_unprotect_object (SCM obj) |
ef290276 | 762 | { |
686765af | 763 | SCM handle; |
9d47a1e6 | 764 | |
686765af | 765 | /* This critical section barrier will be replaced by a mutex. */ |
33b320ae | 766 | /* njrev: and again. */ |
9de87eea | 767 | SCM_CRITICAL_SECTION_START; |
9d47a1e6 | 768 | |
0ff7e3ff HWN |
769 | if (scm_gc_running_p) |
770 | { | |
771 | fprintf (stderr, "scm_unprotect_object called during GC.\n"); | |
772 | abort (); | |
773 | } | |
b17e0ac3 | 774 | |
686765af | 775 | handle = scm_hashq_get_handle (scm_protects, obj); |
9d47a1e6 | 776 | |
7888309b | 777 | if (scm_is_false (handle)) |
686765af | 778 | { |
0f0f0899 MD |
779 | fprintf (stderr, "scm_unprotect_object called on unprotected object\n"); |
780 | abort (); | |
686765af | 781 | } |
6a199940 DH |
782 | else |
783 | { | |
e11e83f3 | 784 | SCM count = scm_difference (SCM_CDR (handle), scm_from_int (1)); |
bc36d050 | 785 | if (scm_is_eq (count, scm_from_int (0))) |
6a199940 DH |
786 | scm_hashq_remove_x (scm_protects, obj); |
787 | else | |
1be6b49c | 788 | SCM_SETCDR (handle, count); |
6a199940 | 789 | } |
7eec4c37 | 790 | protected_obj_count --; |
686765af | 791 | |
9de87eea | 792 | SCM_CRITICAL_SECTION_END; |
ef290276 JB |
793 | |
794 | return obj; | |
795 | } | |
796 | ||
6b1b030e ML |
797 | void |
798 | scm_gc_register_root (SCM *p) | |
799 | { | |
800 | SCM handle; | |
b9bd8526 | 801 | SCM key = scm_from_ulong ((unsigned long) p); |
eae33935 | 802 | |
6b1b030e | 803 | /* This critical section barrier will be replaced by a mutex. */ |
33b320ae | 804 | /* njrev: and again. */ |
9de87eea | 805 | SCM_CRITICAL_SECTION_START; |
6b1b030e | 806 | |
e11e83f3 MV |
807 | handle = scm_hashv_create_handle_x (scm_gc_registered_roots, key, |
808 | scm_from_int (0)); | |
33b320ae | 809 | /* njrev: note also that the above can probably signal an error */ |
e11e83f3 | 810 | SCM_SETCDR (handle, scm_sum (SCM_CDR (handle), scm_from_int (1))); |
6b1b030e | 811 | |
9de87eea | 812 | SCM_CRITICAL_SECTION_END; |
6b1b030e ML |
813 | } |
814 | ||
815 | void | |
816 | scm_gc_unregister_root (SCM *p) | |
817 | { | |
818 | SCM handle; | |
b9bd8526 | 819 | SCM key = scm_from_ulong ((unsigned long) p); |
6b1b030e ML |
820 | |
821 | /* This critical section barrier will be replaced by a mutex. */ | |
33b320ae | 822 | /* njrev: and again. */ |
9de87eea | 823 | SCM_CRITICAL_SECTION_START; |
6b1b030e ML |
824 | |
825 | handle = scm_hashv_get_handle (scm_gc_registered_roots, key); | |
826 | ||
7888309b | 827 | if (scm_is_false (handle)) |
6b1b030e ML |
828 | { |
829 | fprintf (stderr, "scm_gc_unregister_root called on unregistered root\n"); | |
830 | abort (); | |
831 | } | |
832 | else | |
833 | { | |
e11e83f3 | 834 | SCM count = scm_difference (SCM_CDR (handle), scm_from_int (1)); |
bc36d050 | 835 | if (scm_is_eq (count, scm_from_int (0))) |
6b1b030e ML |
836 | scm_hashv_remove_x (scm_gc_registered_roots, key); |
837 | else | |
838 | SCM_SETCDR (handle, count); | |
839 | } | |
840 | ||
9de87eea | 841 | SCM_CRITICAL_SECTION_END; |
6b1b030e ML |
842 | } |
843 | ||
844 | void | |
845 | scm_gc_register_roots (SCM *b, unsigned long n) | |
846 | { | |
847 | SCM *p = b; | |
848 | for (; p < b + n; ++p) | |
849 | scm_gc_register_root (p); | |
850 | } | |
851 | ||
852 | void | |
853 | scm_gc_unregister_roots (SCM *b, unsigned long n) | |
854 | { | |
855 | SCM *p = b; | |
856 | for (; p < b + n; ++p) | |
857 | scm_gc_unregister_root (p); | |
858 | } | |
859 | ||
04a98cff | 860 | int scm_i_terminating; |
c45acc34 | 861 | |
0f2d19dd | 862 | \f |
a00c95d9 | 863 | |
4c48ba06 | 864 | |
c8a1bdc4 HWN |
865 | /* |
866 | MOVE THIS FUNCTION. IT DOES NOT HAVE ANYTHING TODO WITH GC. | |
867 | */ | |
85db4a2c DH |
868 | |
869 | /* Get an integer from an environment variable. */ | |
c8a1bdc4 HWN |
870 | int |
871 | scm_getenv_int (const char *var, int def) | |
85db4a2c | 872 | { |
c8a1bdc4 HWN |
873 | char *end = 0; |
874 | char *val = getenv (var); | |
875 | long res = def; | |
85db4a2c DH |
876 | if (!val) |
877 | return def; | |
878 | res = strtol (val, &end, 10); | |
879 | if (end == val) | |
880 | return def; | |
881 | return res; | |
882 | } | |
883 | ||
c35738c1 MD |
884 | void |
885 | scm_storage_prehistory () | |
886 | { | |
887 | scm_c_hook_init (&scm_before_gc_c_hook, 0, SCM_C_HOOK_NORMAL); | |
888 | scm_c_hook_init (&scm_before_mark_c_hook, 0, SCM_C_HOOK_NORMAL); | |
889 | scm_c_hook_init (&scm_before_sweep_c_hook, 0, SCM_C_HOOK_NORMAL); | |
890 | scm_c_hook_init (&scm_after_sweep_c_hook, 0, SCM_C_HOOK_NORMAL); | |
891 | scm_c_hook_init (&scm_after_gc_c_hook, 0, SCM_C_HOOK_NORMAL); | |
892 | } | |
85db4a2c | 893 | |
9de87eea | 894 | scm_i_pthread_mutex_t scm_i_gc_admin_mutex = SCM_I_PTHREAD_MUTEX_INITIALIZER; |
eb01cb64 | 895 | |
4a4c9785 | 896 | int |
85db4a2c | 897 | scm_init_storage () |
0f2d19dd | 898 | { |
1be6b49c | 899 | size_t j; |
0f2d19dd JB |
900 | |
901 | j = SCM_NUM_PROTECTS; | |
902 | while (j) | |
903 | scm_sys_protects[--j] = SCM_BOOL_F; | |
4a4c9785 | 904 | |
c8a1bdc4 HWN |
905 | scm_gc_init_freelist(); |
906 | scm_gc_init_malloc (); | |
0f2d19dd JB |
907 | |
908 | j = SCM_HEAP_SEG_SIZE; | |
d6884e63 | 909 | |
c8a1bdc4 | 910 | |
0f2d19dd | 911 | /* Initialise the list of ports. */ |
67329a9e HWN |
912 | scm_i_port_table = (scm_t_port **) |
913 | malloc (sizeof (scm_t_port *) * scm_i_port_table_room); | |
914 | if (!scm_i_port_table) | |
0f2d19dd JB |
915 | return 1; |
916 | ||
9de87eea MV |
917 | #if 0 |
918 | /* We can't have a cleanup handler since we have no thread to run it | |
919 | in. */ | |
920 | ||
a18bcd0e | 921 | #ifdef HAVE_ATEXIT |
c45acc34 | 922 | atexit (cleanup); |
e52ceaac MD |
923 | #else |
924 | #ifdef HAVE_ON_EXIT | |
925 | on_exit (cleanup, 0); | |
926 | #endif | |
9de87eea MV |
927 | #endif |
928 | ||
a18bcd0e | 929 | #endif |
0f2d19dd | 930 | |
82c76fd3 | 931 | scm_stand_in_procs = scm_c_make_hash_table (257); |
0f2d19dd | 932 | scm_permobjs = SCM_EOL; |
00ffa0e7 | 933 | scm_protects = scm_c_make_hash_table (31); |
6b1b030e | 934 | scm_gc_registered_roots = scm_c_make_hash_table (31); |
d6884e63 | 935 | |
0f2d19dd JB |
936 | return 0; |
937 | } | |
939794ce | 938 | |
0f2d19dd JB |
939 | \f |
940 | ||
939794ce DH |
941 | SCM scm_after_gc_hook; |
942 | ||
939794ce DH |
943 | static SCM gc_async; |
944 | ||
939794ce DH |
945 | /* The function gc_async_thunk causes the execution of the after-gc-hook. It |
946 | * is run after the gc, as soon as the asynchronous events are handled by the | |
947 | * evaluator. | |
948 | */ | |
949 | static SCM | |
950 | gc_async_thunk (void) | |
951 | { | |
952 | scm_c_run_hook (scm_after_gc_hook, SCM_EOL); | |
939794ce DH |
953 | return SCM_UNSPECIFIED; |
954 | } | |
955 | ||
956 | ||
957 | /* The function mark_gc_async is run by the scm_after_gc_c_hook at the end of | |
958 | * the garbage collection. The only purpose of this function is to mark the | |
959 | * gc_async (which will eventually lead to the execution of the | |
960 | * gc_async_thunk). | |
961 | */ | |
962 | static void * | |
e81d98ec DH |
963 | mark_gc_async (void * hook_data SCM_UNUSED, |
964 | void *func_data SCM_UNUSED, | |
965 | void *data SCM_UNUSED) | |
966 | { | |
967 | /* If cell access debugging is enabled, the user may choose to perform | |
968 | * additional garbage collections after an arbitrary number of cell | |
969 | * accesses. We don't want the scheme level after-gc-hook to be performed | |
970 | * for each of these garbage collections for the following reason: The | |
971 | * execution of the after-gc-hook causes cell accesses itself. Thus, if the | |
972 | * after-gc-hook was performed with every gc, and if the gc was performed | |
973 | * after a very small number of cell accesses, then the number of cell | |
974 | * accesses during the execution of the after-gc-hook will suffice to cause | |
975 | * the execution of the next gc. Then, guile would keep executing the | |
976 | * after-gc-hook over and over again, and would never come to do other | |
977 | * things. | |
eae33935 | 978 | * |
e81d98ec DH |
979 | * To overcome this problem, if cell access debugging with additional |
980 | * garbage collections is enabled, the after-gc-hook is never run by the | |
981 | * garbage collecter. When running guile with cell access debugging and the | |
982 | * execution of the after-gc-hook is desired, then it is necessary to run | |
983 | * the hook explicitly from the user code. This has the effect, that from | |
984 | * the scheme level point of view it seems that garbage collection is | |
985 | * performed with a much lower frequency than it actually is. Obviously, | |
986 | * this will not work for code that depends on a fixed one to one | |
987 | * relationship between the execution counts of the C level garbage | |
988 | * collection hooks and the execution count of the scheme level | |
989 | * after-gc-hook. | |
990 | */ | |
9de87eea | 991 | |
e81d98ec | 992 | #if (SCM_DEBUG_CELL_ACCESSES == 1) |
eab1b259 | 993 | if (scm_debug_cells_gc_interval == 0) |
e81d98ec DH |
994 | scm_system_async_mark (gc_async); |
995 | #else | |
939794ce | 996 | scm_system_async_mark (gc_async); |
e81d98ec DH |
997 | #endif |
998 | ||
939794ce DH |
999 | return NULL; |
1000 | } | |
1001 | ||
0f2d19dd JB |
1002 | void |
1003 | scm_init_gc () | |
0f2d19dd | 1004 | { |
c8a1bdc4 | 1005 | scm_gc_init_mark (); |
d678e25c | 1006 | |
fde50407 ML |
1007 | scm_after_gc_hook = scm_permanent_object (scm_make_hook (SCM_INUM0)); |
1008 | scm_c_define ("after-gc-hook", scm_after_gc_hook); | |
939794ce | 1009 | |
2592c4c7 MV |
1010 | gc_async = scm_c_make_subr ("%gc-thunk", scm_tc7_subr_0, |
1011 | gc_async_thunk); | |
939794ce DH |
1012 | |
1013 | scm_c_hook_add (&scm_after_gc_c_hook, mark_gc_async, NULL, 0); | |
1014 | ||
a0599745 | 1015 | #include "libguile/gc.x" |
0f2d19dd | 1016 | } |
89e00824 | 1017 | |
c8a1bdc4 HWN |
1018 | |
1019 | void | |
1020 | scm_gc_sweep (void) | |
1021 | #define FUNC_NAME "scm_gc_sweep" | |
1022 | { | |
1023 | scm_i_deprecated_memory_return = 0; | |
1024 | ||
1025 | scm_i_gc_sweep_freelist_reset (&scm_i_master_freelist); | |
1026 | scm_i_gc_sweep_freelist_reset (&scm_i_master_freelist2); | |
1027 | ||
1028 | /* | |
1029 | NOTHING HERE: LAZY SWEEPING ! | |
1030 | */ | |
1031 | scm_i_reset_segments (); | |
1032 | ||
9bc4701c MD |
1033 | *SCM_FREELIST_LOC (scm_i_freelist) = SCM_EOL; |
1034 | *SCM_FREELIST_LOC (scm_i_freelist2) = SCM_EOL; | |
392d2833 MD |
1035 | |
1036 | /* Invalidate the freelists of other threads. */ | |
1037 | scm_i_thread_invalidate_freelists (); | |
c8a1bdc4 HWN |
1038 | } |
1039 | ||
1040 | #undef FUNC_NAME | |
1041 | ||
1042 | ||
56495472 | 1043 | |
89e00824 ML |
1044 | /* |
1045 | Local Variables: | |
1046 | c-file-style: "gnu" | |
1047 | End: | |
1048 | */ |