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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 | |
1bbd0b84 | 18 | |
37ddcaf6 MD |
19 | /* #define DEBUGINFO */ |
20 | ||
aa54a9b0 RB |
21 | #if HAVE_CONFIG_H |
22 | # include <config.h> | |
23 | #endif | |
56495472 | 24 | |
0f2d19dd | 25 | #include <stdio.h> |
e6e2e95a | 26 | #include <errno.h> |
783e7774 | 27 | #include <string.h> |
c8a1bdc4 | 28 | #include <assert.h> |
e6e2e95a | 29 | |
d9189652 RB |
30 | #ifdef __ia64__ |
31 | #include <ucontext.h> | |
bb1180ef | 32 | extern unsigned long * __libc_ia64_register_backing_store_base; |
d9189652 RB |
33 | #endif |
34 | ||
a0599745 | 35 | #include "libguile/_scm.h" |
0a7a7445 | 36 | #include "libguile/eval.h" |
a0599745 MD |
37 | #include "libguile/stime.h" |
38 | #include "libguile/stackchk.h" | |
39 | #include "libguile/struct.h" | |
a0599745 MD |
40 | #include "libguile/smob.h" |
41 | #include "libguile/unif.h" | |
42 | #include "libguile/async.h" | |
43 | #include "libguile/ports.h" | |
44 | #include "libguile/root.h" | |
45 | #include "libguile/strings.h" | |
46 | #include "libguile/vectors.h" | |
801cb5e7 | 47 | #include "libguile/weaks.h" |
686765af | 48 | #include "libguile/hashtab.h" |
ecf470a2 | 49 | #include "libguile/tags.h" |
a0599745 | 50 | |
c8a1bdc4 | 51 | #include "libguile/private-gc.h" |
a0599745 | 52 | #include "libguile/validate.h" |
1be6b49c | 53 | #include "libguile/deprecation.h" |
a0599745 | 54 | #include "libguile/gc.h" |
fce59c93 | 55 | |
bc9d9bb2 | 56 | #ifdef GUILE_DEBUG_MALLOC |
a0599745 | 57 | #include "libguile/debug-malloc.h" |
bc9d9bb2 MD |
58 | #endif |
59 | ||
0f2d19dd | 60 | #ifdef HAVE_MALLOC_H |
95b88819 | 61 | #include <malloc.h> |
0f2d19dd JB |
62 | #endif |
63 | ||
64 | #ifdef HAVE_UNISTD_H | |
95b88819 | 65 | #include <unistd.h> |
0f2d19dd JB |
66 | #endif |
67 | ||
406c7d90 | 68 | |
8c494e99 | 69 | |
406c7d90 DH |
70 | unsigned int scm_gc_running_p = 0; |
71 | ||
fb50ef08 MD |
72 | /* Lock this mutex before doing lazy sweeping. |
73 | */ | |
74 | scm_t_rec_mutex scm_i_sweep_mutex; | |
75 | ||
eae33935 | 76 | /* Set this to != 0 if every cell that is accessed shall be checked: |
61045190 | 77 | */ |
eab1b259 HWN |
78 | int scm_debug_cell_accesses_p = 0; |
79 | int scm_expensive_debug_cell_accesses_p = 0; | |
406c7d90 | 80 | |
e81d98ec DH |
81 | /* Set this to 0 if no additional gc's shall be performed, otherwise set it to |
82 | * the number of cell accesses after which a gc shall be called. | |
83 | */ | |
eab1b259 | 84 | int scm_debug_cells_gc_interval = 0; |
e81d98ec | 85 | |
eab1b259 HWN |
86 | /* |
87 | Global variable, so you can switch it off at runtime by setting | |
88 | scm_i_cell_validation_already_running. | |
406c7d90 | 89 | */ |
eab1b259 HWN |
90 | int scm_i_cell_validation_already_running ; |
91 | ||
92 | #if (SCM_DEBUG_CELL_ACCESSES == 1) | |
93 | ||
94 | ||
95 | /* | |
96 | ||
97 | Assert that the given object is a valid reference to a valid cell. This | |
98 | test involves to determine whether the object is a cell pointer, whether | |
99 | this pointer actually points into a heap segment and whether the cell | |
100 | pointed to is not a free cell. Further, additional garbage collections may | |
101 | get executed after a user defined number of cell accesses. This helps to | |
102 | find places in the C code where references are dropped for extremely short | |
103 | periods. | |
104 | ||
105 | */ | |
406c7d90 | 106 | void |
eab1b259 | 107 | scm_i_expensive_validation_check (SCM cell) |
406c7d90 | 108 | { |
eab1b259 HWN |
109 | if (!scm_in_heap_p (cell)) |
110 | { | |
111 | fprintf (stderr, "scm_assert_cell_valid: this object does not live in the heap: %lux\n", | |
112 | (unsigned long) SCM_UNPACK (cell)); | |
113 | abort (); | |
114 | } | |
115 | ||
116 | /* If desired, perform additional garbage collections after a user | |
117 | * defined number of cell accesses. | |
118 | */ | |
119 | if (scm_debug_cells_gc_interval) | |
120 | { | |
121 | static unsigned int counter = 0; | |
61045190 | 122 | |
eab1b259 HWN |
123 | if (counter != 0) |
124 | { | |
125 | --counter; | |
126 | } | |
127 | else | |
128 | { | |
129 | counter = scm_debug_cells_gc_interval; | |
130 | scm_igc ("scm_assert_cell_valid"); | |
131 | } | |
132 | } | |
133 | } | |
134 | ||
135 | void | |
136 | scm_assert_cell_valid (SCM cell) | |
137 | { | |
138 | if (!scm_i_cell_validation_already_running && scm_debug_cell_accesses_p) | |
406c7d90 | 139 | { |
eab1b259 | 140 | scm_i_cell_validation_already_running = 1; /* set to avoid recursion */ |
406c7d90 | 141 | |
c8a1bdc4 | 142 | /* |
eab1b259 HWN |
143 | During GC, no user-code should be run, and the guile core |
144 | should use non-protected accessors. | |
145 | */ | |
c8a1bdc4 | 146 | if (scm_gc_running_p) |
eab1b259 | 147 | return; |
c8a1bdc4 HWN |
148 | |
149 | /* | |
eab1b259 HWN |
150 | Only scm_in_heap_p and rescanning the heap is wildly |
151 | expensive. | |
152 | */ | |
153 | if (scm_expensive_debug_cell_accesses_p) | |
154 | scm_i_expensive_validation_check (cell); | |
c8a1bdc4 HWN |
155 | |
156 | if (!SCM_GC_MARK_P (cell)) | |
406c7d90 | 157 | { |
c8a1bdc4 HWN |
158 | fprintf (stderr, |
159 | "scm_assert_cell_valid: this object is unmarked. \n" | |
160 | "It has been garbage-collected in the last GC run: " | |
161 | "%lux\n", | |
1be6b49c | 162 | (unsigned long) SCM_UNPACK (cell)); |
406c7d90 DH |
163 | abort (); |
164 | } | |
c8a1bdc4 | 165 | |
eab1b259 | 166 | scm_i_cell_validation_already_running = 0; /* re-enable */ |
406c7d90 DH |
167 | } |
168 | } | |
169 | ||
170 | ||
eab1b259 | 171 | |
406c7d90 DH |
172 | SCM_DEFINE (scm_set_debug_cell_accesses_x, "set-debug-cell-accesses!", 1, 0, 0, |
173 | (SCM flag), | |
1e6808ea | 174 | "If @var{flag} is @code{#f}, cell access checking is disabled.\n" |
eab1b259 | 175 | "If @var{flag} is @code{#t}, cheap cell access checking is enabled,\n" |
e81d98ec | 176 | "but no additional calls to garbage collection are issued.\n" |
eab1b259 | 177 | "If @var{flag} is a number, strict cell access checking is enabled,\n" |
e81d98ec DH |
178 | "with an additional garbage collection after the given\n" |
179 | "number of cell accesses.\n" | |
1e6808ea MG |
180 | "This procedure only exists when the compile-time flag\n" |
181 | "@code{SCM_DEBUG_CELL_ACCESSES} was set to 1.") | |
406c7d90 DH |
182 | #define FUNC_NAME s_scm_set_debug_cell_accesses_x |
183 | { | |
7888309b | 184 | if (scm_is_false (flag)) |
eab1b259 HWN |
185 | { |
186 | scm_debug_cell_accesses_p = 0; | |
187 | } | |
bc36d050 | 188 | else if (scm_is_eq (flag, SCM_BOOL_T)) |
eab1b259 HWN |
189 | { |
190 | scm_debug_cells_gc_interval = 0; | |
191 | scm_debug_cell_accesses_p = 1; | |
192 | scm_expensive_debug_cell_accesses_p = 0; | |
193 | } | |
e11e83f3 | 194 | else |
eab1b259 | 195 | { |
e11e83f3 | 196 | scm_debug_cells_gc_interval = scm_to_signed_integer (flag, 0, INT_MAX); |
eab1b259 HWN |
197 | scm_debug_cell_accesses_p = 1; |
198 | scm_expensive_debug_cell_accesses_p = 1; | |
199 | } | |
406c7d90 DH |
200 | return SCM_UNSPECIFIED; |
201 | } | |
202 | #undef FUNC_NAME | |
0f2d19dd | 203 | |
ecf470a2 | 204 | |
c8a1bdc4 | 205 | #endif /* SCM_DEBUG_CELL_ACCESSES == 1 */ |
0f2d19dd JB |
206 | |
207 | \f | |
945fec60 | 208 | |
9bc4701c MD |
209 | scm_t_key scm_i_freelist; |
210 | scm_t_key scm_i_freelist2; | |
c8a1bdc4 | 211 | |
0f2d19dd JB |
212 | |
213 | /* scm_mtrigger | |
539b08a4 | 214 | * is the number of bytes of malloc allocation needed to trigger gc. |
0f2d19dd | 215 | */ |
c014a02e | 216 | unsigned long scm_mtrigger; |
0f2d19dd | 217 | |
0f2d19dd JB |
218 | /* scm_gc_heap_lock |
219 | * If set, don't expand the heap. Set only during gc, during which no allocation | |
220 | * is supposed to take place anyway. | |
221 | */ | |
222 | int scm_gc_heap_lock = 0; | |
223 | ||
224 | /* GC Blocking | |
225 | * Don't pause for collection if this is set -- just | |
226 | * expand the heap. | |
227 | */ | |
0f2d19dd JB |
228 | int scm_block_gc = 1; |
229 | ||
0f2d19dd JB |
230 | /* During collection, this accumulates objects holding |
231 | * weak references. | |
232 | */ | |
ab4bef85 | 233 | SCM scm_weak_vectors; |
0f2d19dd JB |
234 | |
235 | /* GC Statistics Keeping | |
236 | */ | |
f2893a25 | 237 | unsigned long scm_cells_allocated = 0; |
c014a02e ML |
238 | unsigned long scm_mallocated = 0; |
239 | unsigned long scm_gc_cells_collected; | |
c8a1bdc4 | 240 | unsigned long scm_gc_cells_collected_1 = 0; /* previous GC yield */ |
c014a02e ML |
241 | unsigned long scm_gc_malloc_collected; |
242 | unsigned long scm_gc_ports_collected; | |
0f2d19dd | 243 | unsigned long scm_gc_time_taken = 0; |
c014a02e | 244 | static unsigned long t_before_gc; |
c9b0d4b0 | 245 | unsigned long scm_gc_mark_time_taken = 0; |
c014a02e ML |
246 | unsigned long scm_gc_times = 0; |
247 | unsigned long scm_gc_cells_swept = 0; | |
c9b0d4b0 ML |
248 | double scm_gc_cells_marked_acc = 0.; |
249 | double scm_gc_cells_swept_acc = 0.; | |
c2cbcc57 HWN |
250 | int scm_gc_cell_yield_percentage =0; |
251 | int scm_gc_malloc_yield_percentage = 0; | |
7eec4c37 | 252 | unsigned long protected_obj_count = 0; |
c2cbcc57 | 253 | |
0f2d19dd JB |
254 | |
255 | SCM_SYMBOL (sym_cells_allocated, "cells-allocated"); | |
256 | SCM_SYMBOL (sym_heap_size, "cell-heap-size"); | |
257 | SCM_SYMBOL (sym_mallocated, "bytes-malloced"); | |
258 | SCM_SYMBOL (sym_mtrigger, "gc-malloc-threshold"); | |
259 | SCM_SYMBOL (sym_heap_segments, "cell-heap-segments"); | |
260 | SCM_SYMBOL (sym_gc_time_taken, "gc-time-taken"); | |
c9b0d4b0 | 261 | SCM_SYMBOL (sym_gc_mark_time_taken, "gc-mark-time-taken"); |
c9b0d4b0 ML |
262 | SCM_SYMBOL (sym_times, "gc-times"); |
263 | SCM_SYMBOL (sym_cells_marked, "cells-marked"); | |
264 | SCM_SYMBOL (sym_cells_swept, "cells-swept"); | |
c2cbcc57 HWN |
265 | SCM_SYMBOL (sym_malloc_yield, "malloc-yield"); |
266 | SCM_SYMBOL (sym_cell_yield, "cell-yield"); | |
7eec4c37 | 267 | SCM_SYMBOL (sym_protected_objects, "protected-objects"); |
0f2d19dd | 268 | |
bb2c57fa | 269 | |
cf2d30f6 | 270 | |
d3dd80ab | 271 | |
cf2d30f6 | 272 | /* Number of calls to SCM_NEWCELL since startup. */ |
c8a1bdc4 HWN |
273 | unsigned scm_newcell_count; |
274 | unsigned scm_newcell2_count; | |
b37fe1c5 | 275 | |
b37fe1c5 | 276 | |
0f2d19dd JB |
277 | /* {Scheme Interface to GC} |
278 | */ | |
c2cbcc57 | 279 | extern int scm_gc_malloc_yield_percentage; |
a00c95d9 | 280 | SCM_DEFINE (scm_gc_stats, "gc-stats", 0, 0, 0, |
1bbd0b84 | 281 | (), |
1e6808ea | 282 | "Return an association list of statistics about Guile's current\n" |
c8a1bdc4 | 283 | "use of storage.\n") |
1bbd0b84 | 284 | #define FUNC_NAME s_scm_gc_stats |
0f2d19dd | 285 | { |
c8a1bdc4 HWN |
286 | long i = 0; |
287 | SCM heap_segs = SCM_EOL ; | |
c014a02e ML |
288 | unsigned long int local_scm_mtrigger; |
289 | unsigned long int local_scm_mallocated; | |
290 | unsigned long int local_scm_heap_size; | |
c2cbcc57 HWN |
291 | int local_scm_gc_cell_yield_percentage; |
292 | int local_scm_gc_malloc_yield_percentage; | |
f2893a25 | 293 | unsigned long int local_scm_cells_allocated; |
c014a02e ML |
294 | unsigned long int local_scm_gc_time_taken; |
295 | unsigned long int local_scm_gc_times; | |
296 | unsigned long int local_scm_gc_mark_time_taken; | |
7eec4c37 | 297 | unsigned long int local_protected_obj_count; |
c9b0d4b0 ML |
298 | double local_scm_gc_cells_swept; |
299 | double local_scm_gc_cells_marked; | |
0f2d19dd | 300 | SCM answer; |
c8a1bdc4 HWN |
301 | unsigned long *bounds = 0; |
302 | int table_size = scm_i_heap_segment_table_size; | |
0f2d19dd | 303 | SCM_DEFER_INTS; |
939794ce | 304 | |
c8a1bdc4 HWN |
305 | /* |
306 | temporarily store the numbers, so as not to cause GC. | |
7febb4a2 | 307 | */ |
c8a1bdc4 HWN |
308 | |
309 | bounds = malloc (sizeof (int) * table_size * 2); | |
310 | if (!bounds) | |
311 | abort(); | |
312 | for (i = table_size; i--; ) | |
313 | { | |
314 | bounds[2*i] = (unsigned long)scm_i_heap_segment_table[i]->bounds[0]; | |
315 | bounds[2*i+1] = (unsigned long)scm_i_heap_segment_table[i]->bounds[1]; | |
316 | } | |
0f2d19dd | 317 | |
4c9419ac | 318 | |
c8a1bdc4 HWN |
319 | /* Below, we cons to produce the resulting list. We want a snapshot of |
320 | * the heap situation before consing. | |
321 | */ | |
322 | local_scm_mtrigger = scm_mtrigger; | |
323 | local_scm_mallocated = scm_mallocated; | |
324 | local_scm_heap_size = SCM_HEAP_SIZE; | |
539b08a4 | 325 | |
c8a1bdc4 HWN |
326 | local_scm_cells_allocated = scm_cells_allocated; |
327 | ||
328 | local_scm_gc_time_taken = scm_gc_time_taken; | |
329 | local_scm_gc_mark_time_taken = scm_gc_mark_time_taken; | |
330 | local_scm_gc_times = scm_gc_times; | |
c2cbcc57 HWN |
331 | local_scm_gc_malloc_yield_percentage = scm_gc_malloc_yield_percentage; |
332 | local_scm_gc_cell_yield_percentage= scm_gc_cell_yield_percentage; | |
7eec4c37 | 333 | local_protected_obj_count = protected_obj_count; |
c2cbcc57 HWN |
334 | local_scm_gc_cells_swept = |
335 | (double) scm_gc_cells_swept_acc | |
336 | + (double) scm_gc_cells_swept; | |
c8a1bdc4 HWN |
337 | local_scm_gc_cells_marked = scm_gc_cells_marked_acc |
338 | +(double) scm_gc_cells_swept | |
339 | -(double) scm_gc_cells_collected; | |
0f2d19dd | 340 | |
c8a1bdc4 HWN |
341 | for (i = table_size; i--;) |
342 | { | |
b9bd8526 MV |
343 | heap_segs = scm_cons (scm_cons (scm_from_ulong (bounds[2*i]), |
344 | scm_from_ulong (bounds[2*i+1])), | |
c8a1bdc4 HWN |
345 | heap_segs); |
346 | } | |
347 | ||
b9bd8526 MV |
348 | answer = |
349 | scm_list_n (scm_cons (sym_gc_time_taken, | |
350 | scm_from_ulong (local_scm_gc_time_taken)), | |
351 | scm_cons (sym_cells_allocated, | |
352 | scm_from_ulong (local_scm_cells_allocated)), | |
353 | scm_cons (sym_heap_size, | |
354 | scm_from_ulong (local_scm_heap_size)), | |
355 | scm_cons (sym_mallocated, | |
356 | scm_from_ulong (local_scm_mallocated)), | |
357 | scm_cons (sym_mtrigger, | |
358 | scm_from_ulong (local_scm_mtrigger)), | |
359 | scm_cons (sym_times, | |
360 | scm_from_ulong (local_scm_gc_times)), | |
361 | scm_cons (sym_gc_mark_time_taken, | |
362 | scm_from_ulong (local_scm_gc_mark_time_taken)), | |
363 | scm_cons (sym_cells_marked, | |
364 | scm_from_double (local_scm_gc_cells_marked)), | |
365 | scm_cons (sym_cells_swept, | |
366 | scm_from_double (local_scm_gc_cells_swept)), | |
367 | scm_cons (sym_malloc_yield, | |
368 | scm_from_long(local_scm_gc_malloc_yield_percentage)), | |
369 | scm_cons (sym_cell_yield, | |
370 | scm_from_long (local_scm_gc_cell_yield_percentage)), | |
371 | scm_cons (sym_protected_objects, | |
372 | scm_from_ulong (local_protected_obj_count)), | |
373 | scm_cons (sym_heap_segments, heap_segs), | |
374 | SCM_UNDEFINED); | |
c8a1bdc4 HWN |
375 | SCM_ALLOW_INTS; |
376 | ||
377 | free (bounds); | |
378 | return answer; | |
0f2d19dd | 379 | } |
c8a1bdc4 | 380 | #undef FUNC_NAME |
0f2d19dd | 381 | |
c8a1bdc4 HWN |
382 | static void |
383 | gc_start_stats (const char *what SCM_UNUSED) | |
e4a7824f | 384 | { |
c8a1bdc4 | 385 | t_before_gc = scm_c_get_internal_run_time (); |
539b08a4 | 386 | |
c8a1bdc4 HWN |
387 | scm_gc_cells_marked_acc += (double) scm_gc_cells_swept |
388 | - (double) scm_gc_cells_collected; | |
c2cbcc57 | 389 | scm_gc_cells_swept_acc += (double) scm_gc_cells_swept; |
e4a7824f | 390 | |
c2cbcc57 HWN |
391 | scm_gc_cell_yield_percentage = ( scm_gc_cells_collected * 100 ) / SCM_HEAP_SIZE; |
392 | ||
c8a1bdc4 HWN |
393 | scm_gc_cells_swept = 0; |
394 | scm_gc_cells_collected_1 = scm_gc_cells_collected; | |
539b08a4 | 395 | |
c8a1bdc4 HWN |
396 | /* |
397 | CELLS SWEPT is another word for the number of cells that were | |
398 | examined during GC. YIELD is the number that we cleaned | |
399 | out. MARKED is the number that weren't cleaned. | |
400 | */ | |
401 | scm_gc_cells_collected = 0; | |
402 | scm_gc_malloc_collected = 0; | |
403 | scm_gc_ports_collected = 0; | |
e4a7824f | 404 | } |
acf4331f | 405 | |
c8a1bdc4 HWN |
406 | static void |
407 | gc_end_stats () | |
0f2d19dd | 408 | { |
c8a1bdc4 HWN |
409 | unsigned long t = scm_c_get_internal_run_time (); |
410 | scm_gc_time_taken += (t - t_before_gc); | |
539b08a4 | 411 | |
c8a1bdc4 | 412 | ++scm_gc_times; |
0f2d19dd | 413 | } |
acf4331f | 414 | |
0f2d19dd | 415 | |
c8a1bdc4 HWN |
416 | SCM_DEFINE (scm_object_address, "object-address", 1, 0, 0, |
417 | (SCM obj), | |
418 | "Return an integer that for the lifetime of @var{obj} is uniquely\n" | |
419 | "returned by this function for @var{obj}") | |
420 | #define FUNC_NAME s_scm_object_address | |
c68296f8 | 421 | { |
b9bd8526 | 422 | return scm_from_ulong (SCM_UNPACK (obj)); |
c68296f8 | 423 | } |
c8a1bdc4 | 424 | #undef FUNC_NAME |
c68296f8 | 425 | |
1be6b49c | 426 | |
c8a1bdc4 HWN |
427 | SCM_DEFINE (scm_gc, "gc", 0, 0, 0, |
428 | (), | |
429 | "Scans all of SCM objects and reclaims for further use those that are\n" | |
430 | "no longer accessible.") | |
431 | #define FUNC_NAME s_scm_gc | |
432 | { | |
c8a1bdc4 | 433 | scm_igc ("call"); |
c8a1bdc4 | 434 | return SCM_UNSPECIFIED; |
9d47a1e6 | 435 | } |
c8a1bdc4 | 436 | #undef FUNC_NAME |
9d47a1e6 | 437 | |
c68296f8 MV |
438 | |
439 | \f | |
0f2d19dd | 440 | |
c8a1bdc4 HWN |
441 | /* When we get POSIX threads support, the master will be global and |
442 | * common while the freelist will be individual for each thread. | |
0f2d19dd JB |
443 | */ |
444 | ||
c8a1bdc4 HWN |
445 | SCM |
446 | scm_gc_for_newcell (scm_t_cell_type_statistics *freelist, SCM *free_cells) | |
0f2d19dd | 447 | { |
c8a1bdc4 HWN |
448 | SCM cell; |
449 | ||
fb50ef08 | 450 | scm_rec_mutex_lock (&scm_i_sweep_mutex); |
9bc4701c | 451 | |
c8a1bdc4 HWN |
452 | *free_cells = scm_i_sweep_some_segments (freelist); |
453 | if (*free_cells == SCM_EOL && scm_i_gc_grow_heap_p (freelist)) | |
454 | { | |
455 | freelist->heap_segment_idx = scm_i_get_new_heap_segment (freelist, abort_on_error); | |
456 | *free_cells = scm_i_sweep_some_segments (freelist); | |
457 | } | |
acb0a19c | 458 | |
c8a1bdc4 HWN |
459 | if (*free_cells == SCM_EOL && !scm_block_gc) |
460 | { | |
461 | /* | |
462 | with the advent of lazy sweep, GC yield is only know just | |
463 | before doing the GC. | |
464 | */ | |
465 | scm_i_adjust_min_yield (freelist); | |
466 | ||
467 | /* | |
468 | out of fresh cells. Try to get some new ones. | |
469 | */ | |
0f2d19dd | 470 | |
c8a1bdc4 | 471 | scm_igc ("cells"); |
a00c95d9 | 472 | |
c8a1bdc4 HWN |
473 | *free_cells = scm_i_sweep_some_segments (freelist); |
474 | } | |
475 | ||
476 | if (*free_cells == SCM_EOL) | |
477 | { | |
478 | /* | |
479 | failed getting new cells. Get new juice or die. | |
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 | } | |
484 | ||
485 | if (*free_cells == SCM_EOL) | |
486 | abort (); | |
0f2d19dd | 487 | |
c8a1bdc4 | 488 | cell = *free_cells; |
0f2d19dd | 489 | |
c8a1bdc4 | 490 | *free_cells = SCM_FREE_CELL_CDR (cell); |
eab1b259 | 491 | |
fb50ef08 | 492 | scm_rec_mutex_unlock (&scm_i_sweep_mutex); |
eab1b259 | 493 | |
c8a1bdc4 HWN |
494 | return cell; |
495 | } | |
4a4c9785 | 496 | |
4a4c9785 | 497 | |
c8a1bdc4 HWN |
498 | scm_t_c_hook scm_before_gc_c_hook; |
499 | scm_t_c_hook scm_before_mark_c_hook; | |
500 | scm_t_c_hook scm_before_sweep_c_hook; | |
501 | scm_t_c_hook scm_after_sweep_c_hook; | |
502 | scm_t_c_hook scm_after_gc_c_hook; | |
4a4c9785 | 503 | |
c8a1bdc4 HWN |
504 | void |
505 | scm_igc (const char *what) | |
506 | { | |
fb50ef08 | 507 | scm_rec_mutex_lock (&scm_i_sweep_mutex); |
c8a1bdc4 HWN |
508 | ++scm_gc_running_p; |
509 | scm_c_hook_run (&scm_before_gc_c_hook, 0); | |
a00c95d9 | 510 | |
c8a1bdc4 HWN |
511 | #ifdef DEBUGINFO |
512 | fprintf (stderr,"gc reason %s\n", what); | |
513 | ||
514 | fprintf (stderr, | |
d2e53ed6 | 515 | scm_is_null (*SCM_FREELIST_LOC (scm_i_freelist)) |
c8a1bdc4 | 516 | ? "*" |
d2e53ed6 | 517 | : (scm_is_null (*SCM_FREELIST_LOC (scm_i_freelist2)) ? "o" : "m")); |
c8a1bdc4 | 518 | #endif |
4c48ba06 | 519 | |
c8a1bdc4 | 520 | /* During the critical section, only the current thread may run. */ |
fb50ef08 | 521 | scm_i_thread_put_to_sleep (); |
a00c95d9 | 522 | |
eab1b259 | 523 | if (!scm_root || !scm_stack_base || scm_block_gc) |
d6884e63 | 524 | { |
c8a1bdc4 HWN |
525 | --scm_gc_running_p; |
526 | return; | |
d6884e63 ML |
527 | } |
528 | ||
c8a1bdc4 | 529 | gc_start_stats (what); |
a00c95d9 | 530 | |
c8a1bdc4 HWN |
531 | if (scm_gc_heap_lock) |
532 | /* We've invoked the collector while a GC is already in progress. | |
533 | That should never happen. */ | |
534 | abort (); | |
a00c95d9 | 535 | |
c8a1bdc4 | 536 | ++scm_gc_heap_lock; |
a00c95d9 | 537 | |
c8a1bdc4 HWN |
538 | /* |
539 | Let's finish the sweep. The conservative GC might point into the | |
540 | garbage, and marking that would create a mess. | |
541 | */ | |
542 | scm_i_sweep_all_segments("GC"); | |
543 | if (scm_mallocated < scm_i_deprecated_memory_return) | |
b6efc951 | 544 | { |
c8a1bdc4 HWN |
545 | /* The byte count of allocated objects has underflowed. This is |
546 | probably because you forgot to report the sizes of objects you | |
547 | have allocated, by calling scm_done_malloc or some such. When | |
548 | the GC freed them, it subtracted their size from | |
549 | scm_mallocated, which underflowed. */ | |
550 | fprintf (stderr, | |
551 | "scm_gc_sweep: Byte count of allocated objects has underflowed.\n" | |
552 | "This is probably because the GC hasn't been correctly informed\n" | |
553 | "about object sizes\n"); | |
b6efc951 DH |
554 | abort (); |
555 | } | |
c8a1bdc4 | 556 | scm_mallocated -= scm_i_deprecated_memory_return; |
0f2d19dd | 557 | |
c8a1bdc4 HWN |
558 | |
559 | ||
560 | scm_c_hook_run (&scm_before_mark_c_hook, 0); | |
b6efc951 | 561 | |
c8a1bdc4 HWN |
562 | scm_mark_all (); |
563 | ||
c2cbcc57 | 564 | scm_gc_mark_time_taken += (scm_c_get_internal_run_time () - t_before_gc); |
c8a1bdc4 HWN |
565 | |
566 | scm_c_hook_run (&scm_before_sweep_c_hook, 0); | |
567 | ||
568 | /* | |
569 | Moved this lock upwards so that we can alloc new heap at the end of a sweep. | |
0f2d19dd | 570 | |
c8a1bdc4 | 571 | DOCME: why should the heap be locked anyway? |
0f2d19dd | 572 | */ |
c8a1bdc4 | 573 | --scm_gc_heap_lock; |
a00c95d9 | 574 | |
c8a1bdc4 | 575 | scm_gc_sweep (); |
0f2d19dd | 576 | |
ffd72400 HWN |
577 | |
578 | /* | |
579 | TODO: this hook should probably be moved to just before the mark, | |
580 | since that's where the sweep is finished in lazy sweeping. | |
c35738c1 MD |
581 | |
582 | MDJ 030219 <djurfeldt@nada.kth.se>: No, probably not. The | |
583 | original meaning implied at least two things: that it would be | |
584 | called when | |
585 | ||
586 | 1. the freelist is re-initialized (no evaluation possible, though) | |
587 | ||
588 | and | |
589 | ||
590 | 2. the heap is "fresh" | |
591 | (it is well-defined what data is used and what is not) | |
592 | ||
593 | Neither of these conditions would hold just before the mark phase. | |
594 | ||
595 | Of course, the lazy sweeping has muddled the distinction between | |
596 | scm_before_sweep_c_hook and scm_after_sweep_c_hook, but even if | |
597 | there were no difference, it would still be useful to have two | |
598 | distinct classes of hook functions since this can prevent some | |
599 | bad interference when several modules adds gc hooks. | |
ffd72400 | 600 | */ |
c8a1bdc4 HWN |
601 | scm_c_hook_run (&scm_after_sweep_c_hook, 0); |
602 | gc_end_stats (); | |
603 | ||
fb50ef08 | 604 | scm_i_thread_wake_up (); |
ffd72400 HWN |
605 | |
606 | /* | |
607 | See above. | |
608 | */ | |
c8a1bdc4 HWN |
609 | scm_c_hook_run (&scm_after_gc_c_hook, 0); |
610 | --scm_gc_running_p; | |
fb50ef08 | 611 | scm_rec_mutex_unlock (&scm_i_sweep_mutex); |
a00c95d9 | 612 | |
eab1b259 HWN |
613 | /* |
614 | For debugging purposes, you could do | |
615 | scm_i_sweep_all_segments("debug"), but then the remains of the | |
616 | cell aren't left to analyse. | |
617 | */ | |
618 | } | |
0f2d19dd | 619 | |
0f2d19dd JB |
620 | \f |
621 | /* {GC Protection Helper Functions} | |
622 | */ | |
623 | ||
624 | ||
5d2b97cd DH |
625 | /* |
626 | * If within a function you need to protect one or more scheme objects from | |
627 | * garbage collection, pass them as parameters to one of the | |
628 | * scm_remember_upto_here* functions below. These functions don't do | |
629 | * anything, but since the compiler does not know that they are actually | |
630 | * no-ops, it will generate code that calls these functions with the given | |
631 | * parameters. Therefore, you can be sure that the compiler will keep those | |
632 | * scheme values alive (on the stack or in a register) up to the point where | |
633 | * scm_remember_upto_here* is called. In other words, place the call to | |
592996c9 | 634 | * scm_remember_upto_here* _behind_ the last code in your function, that |
5d2b97cd DH |
635 | * depends on the scheme object to exist. |
636 | * | |
8c494e99 DH |
637 | * Example: We want to make sure that the string object str does not get |
638 | * garbage collected during the execution of 'some_function' in the code | |
639 | * below, because otherwise the characters belonging to str would be freed and | |
5d2b97cd DH |
640 | * 'some_function' might access freed memory. To make sure that the compiler |
641 | * keeps str alive on the stack or in a register such that it is visible to | |
642 | * the conservative gc we add the call to scm_remember_upto_here_1 _after_ the | |
643 | * call to 'some_function'. Note that this would not be necessary if str was | |
644 | * used anyway after the call to 'some_function'. | |
eb01cb64 | 645 | * char *chars = scm_i_string_chars (str); |
5d2b97cd DH |
646 | * some_function (chars); |
647 | * scm_remember_upto_here_1 (str); // str will be alive up to this point. | |
648 | */ | |
649 | ||
9e1569bd KR |
650 | /* Remove any macro versions of these while defining the functions. |
651 | Functions are always included in the library, for upward binary | |
652 | compatibility and in case combinations of GCC and non-GCC are used. */ | |
653 | #undef scm_remember_upto_here_1 | |
654 | #undef scm_remember_upto_here_2 | |
655 | ||
5d2b97cd | 656 | void |
e81d98ec | 657 | scm_remember_upto_here_1 (SCM obj SCM_UNUSED) |
5d2b97cd DH |
658 | { |
659 | /* Empty. Protects a single object from garbage collection. */ | |
660 | } | |
661 | ||
662 | void | |
e81d98ec | 663 | scm_remember_upto_here_2 (SCM obj1 SCM_UNUSED, SCM obj2 SCM_UNUSED) |
5d2b97cd DH |
664 | { |
665 | /* Empty. Protects two objects from garbage collection. */ | |
666 | } | |
667 | ||
668 | void | |
e81d98ec | 669 | scm_remember_upto_here (SCM obj SCM_UNUSED, ...) |
5d2b97cd DH |
670 | { |
671 | /* Empty. Protects any number of objects from garbage collection. */ | |
672 | } | |
673 | ||
c209c88e | 674 | /* |
41b0806d GB |
675 | These crazy functions prevent garbage collection |
676 | of arguments after the first argument by | |
677 | ensuring they remain live throughout the | |
678 | function because they are used in the last | |
679 | line of the code block. | |
680 | It'd be better to have a nice compiler hint to | |
681 | aid the conservative stack-scanning GC. --03/09/00 gjb */ | |
0f2d19dd JB |
682 | SCM |
683 | scm_return_first (SCM elt, ...) | |
0f2d19dd JB |
684 | { |
685 | return elt; | |
686 | } | |
687 | ||
41b0806d GB |
688 | int |
689 | scm_return_first_int (int i, ...) | |
690 | { | |
691 | return i; | |
692 | } | |
693 | ||
0f2d19dd | 694 | |
0f2d19dd | 695 | SCM |
6e8d25a6 | 696 | scm_permanent_object (SCM obj) |
0f2d19dd JB |
697 | { |
698 | SCM_REDEFER_INTS; | |
699 | scm_permobjs = scm_cons (obj, scm_permobjs); | |
700 | SCM_REALLOW_INTS; | |
701 | return obj; | |
702 | } | |
703 | ||
704 | ||
7bd4fbe2 MD |
705 | /* Protect OBJ from the garbage collector. OBJ will not be freed, even if all |
706 | other references are dropped, until the object is unprotected by calling | |
6b1b030e | 707 | scm_gc_unprotect_object (OBJ). Calls to scm_gc_protect/unprotect_object nest, |
7bd4fbe2 MD |
708 | i. e. it is possible to protect the same object several times, but it is |
709 | necessary to unprotect the object the same number of times to actually get | |
710 | the object unprotected. It is an error to unprotect an object more often | |
711 | than it has been protected before. The function scm_protect_object returns | |
712 | OBJ. | |
713 | */ | |
714 | ||
715 | /* Implementation note: For every object X, there is a counter which | |
6b1b030e | 716 | scm_gc_protect_object(X) increments and scm_gc_unprotect_object(X) decrements. |
7bd4fbe2 | 717 | */ |
686765af | 718 | |
7eec4c37 HWN |
719 | |
720 | ||
ef290276 | 721 | SCM |
6b1b030e | 722 | scm_gc_protect_object (SCM obj) |
ef290276 | 723 | { |
686765af | 724 | SCM handle; |
9d47a1e6 | 725 | |
686765af | 726 | /* This critical section barrier will be replaced by a mutex. */ |
2dd6a83a | 727 | SCM_REDEFER_INTS; |
9d47a1e6 | 728 | |
e11e83f3 MV |
729 | handle = scm_hashq_create_handle_x (scm_protects, obj, scm_from_int (0)); |
730 | SCM_SETCDR (handle, scm_sum (SCM_CDR (handle), scm_from_int (1))); | |
9d47a1e6 | 731 | |
7eec4c37 HWN |
732 | protected_obj_count ++; |
733 | ||
2dd6a83a | 734 | SCM_REALLOW_INTS; |
9d47a1e6 | 735 | |
ef290276 JB |
736 | return obj; |
737 | } | |
738 | ||
739 | ||
740 | /* Remove any protection for OBJ established by a prior call to | |
dab7f566 | 741 | scm_protect_object. This function returns OBJ. |
ef290276 | 742 | |
dab7f566 | 743 | See scm_protect_object for more information. */ |
ef290276 | 744 | SCM |
6b1b030e | 745 | scm_gc_unprotect_object (SCM obj) |
ef290276 | 746 | { |
686765af | 747 | SCM handle; |
9d47a1e6 | 748 | |
686765af | 749 | /* This critical section barrier will be replaced by a mutex. */ |
2dd6a83a | 750 | SCM_REDEFER_INTS; |
9d47a1e6 | 751 | |
686765af | 752 | handle = scm_hashq_get_handle (scm_protects, obj); |
9d47a1e6 | 753 | |
7888309b | 754 | if (scm_is_false (handle)) |
686765af | 755 | { |
0f0f0899 MD |
756 | fprintf (stderr, "scm_unprotect_object called on unprotected object\n"); |
757 | abort (); | |
686765af | 758 | } |
6a199940 DH |
759 | else |
760 | { | |
e11e83f3 | 761 | SCM count = scm_difference (SCM_CDR (handle), scm_from_int (1)); |
bc36d050 | 762 | if (scm_is_eq (count, scm_from_int (0))) |
6a199940 DH |
763 | scm_hashq_remove_x (scm_protects, obj); |
764 | else | |
1be6b49c | 765 | SCM_SETCDR (handle, count); |
6a199940 | 766 | } |
7eec4c37 | 767 | protected_obj_count --; |
686765af | 768 | |
2dd6a83a | 769 | SCM_REALLOW_INTS; |
ef290276 JB |
770 | |
771 | return obj; | |
772 | } | |
773 | ||
6b1b030e ML |
774 | void |
775 | scm_gc_register_root (SCM *p) | |
776 | { | |
777 | SCM handle; | |
b9bd8526 | 778 | SCM key = scm_from_ulong ((unsigned long) p); |
eae33935 | 779 | |
6b1b030e ML |
780 | /* This critical section barrier will be replaced by a mutex. */ |
781 | SCM_REDEFER_INTS; | |
782 | ||
e11e83f3 MV |
783 | handle = scm_hashv_create_handle_x (scm_gc_registered_roots, key, |
784 | scm_from_int (0)); | |
785 | SCM_SETCDR (handle, scm_sum (SCM_CDR (handle), scm_from_int (1))); | |
6b1b030e ML |
786 | |
787 | SCM_REALLOW_INTS; | |
788 | } | |
789 | ||
790 | void | |
791 | scm_gc_unregister_root (SCM *p) | |
792 | { | |
793 | SCM handle; | |
b9bd8526 | 794 | SCM key = scm_from_ulong ((unsigned long) p); |
6b1b030e ML |
795 | |
796 | /* This critical section barrier will be replaced by a mutex. */ | |
797 | SCM_REDEFER_INTS; | |
798 | ||
799 | handle = scm_hashv_get_handle (scm_gc_registered_roots, key); | |
800 | ||
7888309b | 801 | if (scm_is_false (handle)) |
6b1b030e ML |
802 | { |
803 | fprintf (stderr, "scm_gc_unregister_root called on unregistered root\n"); | |
804 | abort (); | |
805 | } | |
806 | else | |
807 | { | |
e11e83f3 | 808 | SCM count = scm_difference (SCM_CDR (handle), scm_from_int (1)); |
bc36d050 | 809 | if (scm_is_eq (count, scm_from_int (0))) |
6b1b030e ML |
810 | scm_hashv_remove_x (scm_gc_registered_roots, key); |
811 | else | |
812 | SCM_SETCDR (handle, count); | |
813 | } | |
814 | ||
815 | SCM_REALLOW_INTS; | |
816 | } | |
817 | ||
818 | void | |
819 | scm_gc_register_roots (SCM *b, unsigned long n) | |
820 | { | |
821 | SCM *p = b; | |
822 | for (; p < b + n; ++p) | |
823 | scm_gc_register_root (p); | |
824 | } | |
825 | ||
826 | void | |
827 | scm_gc_unregister_roots (SCM *b, unsigned long n) | |
828 | { | |
829 | SCM *p = b; | |
830 | for (; p < b + n; ++p) | |
831 | scm_gc_unregister_root (p); | |
832 | } | |
833 | ||
04a98cff | 834 | int scm_i_terminating; |
c45acc34 JB |
835 | |
836 | /* called on process termination. */ | |
e52ceaac MD |
837 | #ifdef HAVE_ATEXIT |
838 | static void | |
839 | cleanup (void) | |
840 | #else | |
841 | #ifdef HAVE_ON_EXIT | |
51157deb MD |
842 | extern int on_exit (void (*procp) (), int arg); |
843 | ||
e52ceaac MD |
844 | static void |
845 | cleanup (int status, void *arg) | |
846 | #else | |
847 | #error Dont know how to setup a cleanup handler on your system. | |
848 | #endif | |
849 | #endif | |
c45acc34 | 850 | { |
04a98cff | 851 | scm_i_terminating = 1; |
c45acc34 JB |
852 | scm_flush_all_ports (); |
853 | } | |
ef290276 | 854 | |
0f2d19dd | 855 | \f |
a00c95d9 | 856 | |
4c48ba06 | 857 | |
c8a1bdc4 HWN |
858 | /* |
859 | MOVE THIS FUNCTION. IT DOES NOT HAVE ANYTHING TODO WITH GC. | |
860 | */ | |
85db4a2c DH |
861 | |
862 | /* Get an integer from an environment variable. */ | |
c8a1bdc4 HWN |
863 | int |
864 | scm_getenv_int (const char *var, int def) | |
85db4a2c | 865 | { |
c8a1bdc4 HWN |
866 | char *end = 0; |
867 | char *val = getenv (var); | |
868 | long res = def; | |
85db4a2c DH |
869 | if (!val) |
870 | return def; | |
871 | res = strtol (val, &end, 10); | |
872 | if (end == val) | |
873 | return def; | |
874 | return res; | |
875 | } | |
876 | ||
c35738c1 MD |
877 | void |
878 | scm_storage_prehistory () | |
879 | { | |
880 | scm_c_hook_init (&scm_before_gc_c_hook, 0, SCM_C_HOOK_NORMAL); | |
881 | scm_c_hook_init (&scm_before_mark_c_hook, 0, SCM_C_HOOK_NORMAL); | |
882 | scm_c_hook_init (&scm_before_sweep_c_hook, 0, SCM_C_HOOK_NORMAL); | |
883 | scm_c_hook_init (&scm_after_sweep_c_hook, 0, SCM_C_HOOK_NORMAL); | |
884 | scm_c_hook_init (&scm_after_gc_c_hook, 0, SCM_C_HOOK_NORMAL); | |
885 | } | |
85db4a2c | 886 | |
eb01cb64 MV |
887 | scm_t_mutex scm_i_gc_admin_mutex; |
888 | ||
4a4c9785 | 889 | int |
85db4a2c | 890 | scm_init_storage () |
0f2d19dd | 891 | { |
1be6b49c | 892 | size_t j; |
0f2d19dd | 893 | |
fb50ef08 MD |
894 | /* Fixme: Should use mutexattr from the low-level API. */ |
895 | scm_rec_mutex_init (&scm_i_sweep_mutex, &scm_i_plugin_rec_mutex); | |
eb01cb64 MV |
896 | |
897 | scm_i_plugin_mutex_init (&scm_i_gc_admin_mutex, &scm_i_plugin_mutex); | |
fb50ef08 | 898 | |
0f2d19dd JB |
899 | j = SCM_NUM_PROTECTS; |
900 | while (j) | |
901 | scm_sys_protects[--j] = SCM_BOOL_F; | |
902 | scm_block_gc = 1; | |
4a4c9785 | 903 | |
c8a1bdc4 HWN |
904 | scm_gc_init_freelist(); |
905 | scm_gc_init_malloc (); | |
0f2d19dd JB |
906 | |
907 | j = SCM_HEAP_SEG_SIZE; | |
d6884e63 | 908 | |
c8a1bdc4 | 909 | |
0f2d19dd | 910 | /* Initialise the list of ports. */ |
67329a9e HWN |
911 | scm_i_port_table = (scm_t_port **) |
912 | malloc (sizeof (scm_t_port *) * scm_i_port_table_room); | |
913 | if (!scm_i_port_table) | |
0f2d19dd JB |
914 | return 1; |
915 | ||
a18bcd0e | 916 | #ifdef HAVE_ATEXIT |
c45acc34 | 917 | atexit (cleanup); |
e52ceaac MD |
918 | #else |
919 | #ifdef HAVE_ON_EXIT | |
920 | on_exit (cleanup, 0); | |
921 | #endif | |
a18bcd0e | 922 | #endif |
0f2d19dd | 923 | |
82c76fd3 | 924 | scm_stand_in_procs = scm_c_make_hash_table (257); |
0f2d19dd | 925 | scm_permobjs = SCM_EOL; |
00ffa0e7 | 926 | scm_protects = scm_c_make_hash_table (31); |
6b1b030e | 927 | scm_gc_registered_roots = scm_c_make_hash_table (31); |
d6884e63 | 928 | |
0f2d19dd JB |
929 | return 0; |
930 | } | |
939794ce | 931 | |
0f2d19dd JB |
932 | \f |
933 | ||
939794ce DH |
934 | SCM scm_after_gc_hook; |
935 | ||
939794ce DH |
936 | static SCM gc_async; |
937 | ||
939794ce DH |
938 | /* The function gc_async_thunk causes the execution of the after-gc-hook. It |
939 | * is run after the gc, as soon as the asynchronous events are handled by the | |
940 | * evaluator. | |
941 | */ | |
942 | static SCM | |
943 | gc_async_thunk (void) | |
944 | { | |
945 | scm_c_run_hook (scm_after_gc_hook, SCM_EOL); | |
939794ce DH |
946 | return SCM_UNSPECIFIED; |
947 | } | |
948 | ||
949 | ||
950 | /* The function mark_gc_async is run by the scm_after_gc_c_hook at the end of | |
951 | * the garbage collection. The only purpose of this function is to mark the | |
952 | * gc_async (which will eventually lead to the execution of the | |
953 | * gc_async_thunk). | |
954 | */ | |
955 | static void * | |
e81d98ec DH |
956 | mark_gc_async (void * hook_data SCM_UNUSED, |
957 | void *func_data SCM_UNUSED, | |
958 | void *data SCM_UNUSED) | |
959 | { | |
960 | /* If cell access debugging is enabled, the user may choose to perform | |
961 | * additional garbage collections after an arbitrary number of cell | |
962 | * accesses. We don't want the scheme level after-gc-hook to be performed | |
963 | * for each of these garbage collections for the following reason: The | |
964 | * execution of the after-gc-hook causes cell accesses itself. Thus, if the | |
965 | * after-gc-hook was performed with every gc, and if the gc was performed | |
966 | * after a very small number of cell accesses, then the number of cell | |
967 | * accesses during the execution of the after-gc-hook will suffice to cause | |
968 | * the execution of the next gc. Then, guile would keep executing the | |
969 | * after-gc-hook over and over again, and would never come to do other | |
970 | * things. | |
eae33935 | 971 | * |
e81d98ec DH |
972 | * To overcome this problem, if cell access debugging with additional |
973 | * garbage collections is enabled, the after-gc-hook is never run by the | |
974 | * garbage collecter. When running guile with cell access debugging and the | |
975 | * execution of the after-gc-hook is desired, then it is necessary to run | |
976 | * the hook explicitly from the user code. This has the effect, that from | |
977 | * the scheme level point of view it seems that garbage collection is | |
978 | * performed with a much lower frequency than it actually is. Obviously, | |
979 | * this will not work for code that depends on a fixed one to one | |
980 | * relationship between the execution counts of the C level garbage | |
981 | * collection hooks and the execution count of the scheme level | |
982 | * after-gc-hook. | |
983 | */ | |
984 | #if (SCM_DEBUG_CELL_ACCESSES == 1) | |
eab1b259 | 985 | if (scm_debug_cells_gc_interval == 0) |
e81d98ec DH |
986 | scm_system_async_mark (gc_async); |
987 | #else | |
939794ce | 988 | scm_system_async_mark (gc_async); |
e81d98ec DH |
989 | #endif |
990 | ||
939794ce DH |
991 | return NULL; |
992 | } | |
993 | ||
0f2d19dd JB |
994 | void |
995 | scm_init_gc () | |
0f2d19dd | 996 | { |
c8a1bdc4 | 997 | scm_gc_init_mark (); |
d678e25c | 998 | |
fde50407 ML |
999 | scm_after_gc_hook = scm_permanent_object (scm_make_hook (SCM_INUM0)); |
1000 | scm_c_define ("after-gc-hook", scm_after_gc_hook); | |
939794ce | 1001 | |
2592c4c7 MV |
1002 | gc_async = scm_c_make_subr ("%gc-thunk", scm_tc7_subr_0, |
1003 | gc_async_thunk); | |
939794ce DH |
1004 | |
1005 | scm_c_hook_add (&scm_after_gc_c_hook, mark_gc_async, NULL, 0); | |
1006 | ||
a0599745 | 1007 | #include "libguile/gc.x" |
0f2d19dd | 1008 | } |
89e00824 | 1009 | |
c8a1bdc4 HWN |
1010 | |
1011 | void | |
1012 | scm_gc_sweep (void) | |
1013 | #define FUNC_NAME "scm_gc_sweep" | |
1014 | { | |
1015 | scm_i_deprecated_memory_return = 0; | |
1016 | ||
1017 | scm_i_gc_sweep_freelist_reset (&scm_i_master_freelist); | |
1018 | scm_i_gc_sweep_freelist_reset (&scm_i_master_freelist2); | |
1019 | ||
1020 | /* | |
1021 | NOTHING HERE: LAZY SWEEPING ! | |
1022 | */ | |
1023 | scm_i_reset_segments (); | |
1024 | ||
1025 | /* When we move to POSIX threads private freelists should probably | |
1026 | be GC-protected instead. */ | |
9bc4701c MD |
1027 | *SCM_FREELIST_LOC (scm_i_freelist) = SCM_EOL; |
1028 | *SCM_FREELIST_LOC (scm_i_freelist2) = SCM_EOL; | |
392d2833 MD |
1029 | |
1030 | /* Invalidate the freelists of other threads. */ | |
1031 | scm_i_thread_invalidate_freelists (); | |
c8a1bdc4 HWN |
1032 | } |
1033 | ||
1034 | #undef FUNC_NAME | |
1035 | ||
1036 | ||
56495472 | 1037 | |
89e00824 ML |
1038 | /* |
1039 | Local Variables: | |
1040 | c-file-style: "gnu" | |
1041 | End: | |
1042 | */ |