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c709de7f | 1 | /* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2002 Free Software Foundation, Inc. |
a00c95d9 | 2 | * |
0f2d19dd JB |
3 | * This program is free software; you can redistribute it and/or modify |
4 | * it under the terms of the GNU General Public License as published by | |
5 | * the Free Software Foundation; either version 2, or (at your option) | |
6 | * any later version. | |
a00c95d9 | 7 | * |
0f2d19dd JB |
8 | * This program is distributed in the hope that it will be useful, |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
11 | * GNU General Public License for more details. | |
a00c95d9 | 12 | * |
0f2d19dd JB |
13 | * You should have received a copy of the GNU General Public License |
14 | * along with this software; see the file COPYING. If not, write to | |
82892bed JB |
15 | * the Free Software Foundation, Inc., 59 Temple Place, Suite 330, |
16 | * Boston, MA 02111-1307 USA | |
0f2d19dd JB |
17 | * |
18 | * As a special exception, the Free Software Foundation gives permission | |
19 | * for additional uses of the text contained in its release of GUILE. | |
20 | * | |
21 | * The exception is that, if you link the GUILE library with other files | |
22 | * to produce an executable, this does not by itself cause the | |
23 | * resulting executable to be covered by the GNU General Public License. | |
24 | * Your use of that executable is in no way restricted on account of | |
25 | * linking the GUILE library code into it. | |
26 | * | |
27 | * This exception does not however invalidate any other reasons why | |
28 | * the executable file might be covered by the GNU General Public License. | |
29 | * | |
30 | * This exception applies only to the code released by the | |
31 | * Free Software Foundation under the name GUILE. If you copy | |
32 | * code from other Free Software Foundation releases into a copy of | |
33 | * GUILE, as the General Public License permits, the exception does | |
34 | * not apply to the code that you add in this way. To avoid misleading | |
35 | * anyone as to the status of such modified files, you must delete | |
36 | * this exception notice from them. | |
37 | * | |
38 | * If you write modifications of your own for GUILE, it is your choice | |
39 | * whether to permit this exception to apply to your modifications. | |
82892bed | 40 | * If you do not wish that, delete this exception notice. */ |
1bbd0b84 | 41 | |
1bbd0b84 | 42 | |
37ddcaf6 MD |
43 | /* #define DEBUGINFO */ |
44 | ||
56495472 | 45 | |
0f2d19dd | 46 | #include <stdio.h> |
e6e2e95a | 47 | #include <errno.h> |
783e7774 | 48 | #include <string.h> |
c8a1bdc4 | 49 | #include <assert.h> |
e6e2e95a | 50 | |
d9189652 RB |
51 | #ifdef __ia64__ |
52 | #include <ucontext.h> | |
bb1180ef | 53 | extern unsigned long * __libc_ia64_register_backing_store_base; |
d9189652 RB |
54 | #endif |
55 | ||
a0599745 | 56 | #include "libguile/_scm.h" |
0a7a7445 | 57 | #include "libguile/eval.h" |
a0599745 MD |
58 | #include "libguile/stime.h" |
59 | #include "libguile/stackchk.h" | |
60 | #include "libguile/struct.h" | |
a0599745 MD |
61 | #include "libguile/smob.h" |
62 | #include "libguile/unif.h" | |
63 | #include "libguile/async.h" | |
64 | #include "libguile/ports.h" | |
65 | #include "libguile/root.h" | |
66 | #include "libguile/strings.h" | |
67 | #include "libguile/vectors.h" | |
801cb5e7 | 68 | #include "libguile/weaks.h" |
686765af | 69 | #include "libguile/hashtab.h" |
ecf470a2 | 70 | #include "libguile/tags.h" |
a0599745 | 71 | |
c8a1bdc4 | 72 | #include "libguile/private-gc.h" |
a0599745 | 73 | #include "libguile/validate.h" |
1be6b49c | 74 | #include "libguile/deprecation.h" |
a0599745 | 75 | #include "libguile/gc.h" |
fce59c93 | 76 | |
bc9d9bb2 | 77 | #ifdef GUILE_DEBUG_MALLOC |
a0599745 | 78 | #include "libguile/debug-malloc.h" |
bc9d9bb2 MD |
79 | #endif |
80 | ||
0f2d19dd | 81 | #ifdef HAVE_MALLOC_H |
95b88819 | 82 | #include <malloc.h> |
0f2d19dd JB |
83 | #endif |
84 | ||
85 | #ifdef HAVE_UNISTD_H | |
95b88819 | 86 | #include <unistd.h> |
0f2d19dd JB |
87 | #endif |
88 | ||
406c7d90 | 89 | |
8c494e99 | 90 | |
406c7d90 DH |
91 | unsigned int scm_gc_running_p = 0; |
92 | ||
eae33935 | 93 | /* Set this to != 0 if every cell that is accessed shall be checked: |
61045190 | 94 | */ |
eab1b259 HWN |
95 | int scm_debug_cell_accesses_p = 0; |
96 | int scm_expensive_debug_cell_accesses_p = 0; | |
406c7d90 | 97 | |
e81d98ec DH |
98 | /* Set this to 0 if no additional gc's shall be performed, otherwise set it to |
99 | * the number of cell accesses after which a gc shall be called. | |
100 | */ | |
eab1b259 | 101 | int scm_debug_cells_gc_interval = 0; |
e81d98ec | 102 | |
eab1b259 HWN |
103 | /* |
104 | Global variable, so you can switch it off at runtime by setting | |
105 | scm_i_cell_validation_already_running. | |
406c7d90 | 106 | */ |
eab1b259 HWN |
107 | int scm_i_cell_validation_already_running ; |
108 | ||
109 | #if (SCM_DEBUG_CELL_ACCESSES == 1) | |
110 | ||
111 | ||
112 | /* | |
113 | ||
114 | Assert that the given object is a valid reference to a valid cell. This | |
115 | test involves to determine whether the object is a cell pointer, whether | |
116 | this pointer actually points into a heap segment and whether the cell | |
117 | pointed to is not a free cell. Further, additional garbage collections may | |
118 | get executed after a user defined number of cell accesses. This helps to | |
119 | find places in the C code where references are dropped for extremely short | |
120 | periods. | |
121 | ||
122 | */ | |
406c7d90 | 123 | void |
eab1b259 | 124 | scm_i_expensive_validation_check (SCM cell) |
406c7d90 | 125 | { |
eab1b259 HWN |
126 | if (!scm_in_heap_p (cell)) |
127 | { | |
128 | fprintf (stderr, "scm_assert_cell_valid: this object does not live in the heap: %lux\n", | |
129 | (unsigned long) SCM_UNPACK (cell)); | |
130 | abort (); | |
131 | } | |
132 | ||
133 | /* If desired, perform additional garbage collections after a user | |
134 | * defined number of cell accesses. | |
135 | */ | |
136 | if (scm_debug_cells_gc_interval) | |
137 | { | |
138 | static unsigned int counter = 0; | |
61045190 | 139 | |
eab1b259 HWN |
140 | if (counter != 0) |
141 | { | |
142 | --counter; | |
143 | } | |
144 | else | |
145 | { | |
146 | counter = scm_debug_cells_gc_interval; | |
9bc4701c | 147 | scm_i_thread_put_to_sleep (); |
eab1b259 | 148 | scm_igc ("scm_assert_cell_valid"); |
9bc4701c | 149 | scm_i_thread_wake_up (); |
eab1b259 HWN |
150 | } |
151 | } | |
152 | } | |
153 | ||
154 | void | |
155 | scm_assert_cell_valid (SCM cell) | |
156 | { | |
157 | if (!scm_i_cell_validation_already_running && scm_debug_cell_accesses_p) | |
406c7d90 | 158 | { |
eab1b259 | 159 | scm_i_cell_validation_already_running = 1; /* set to avoid recursion */ |
406c7d90 | 160 | |
c8a1bdc4 | 161 | /* |
eab1b259 HWN |
162 | During GC, no user-code should be run, and the guile core |
163 | should use non-protected accessors. | |
164 | */ | |
c8a1bdc4 | 165 | if (scm_gc_running_p) |
eab1b259 | 166 | return; |
c8a1bdc4 HWN |
167 | |
168 | /* | |
eab1b259 HWN |
169 | Only scm_in_heap_p and rescanning the heap is wildly |
170 | expensive. | |
171 | */ | |
172 | if (scm_expensive_debug_cell_accesses_p) | |
173 | scm_i_expensive_validation_check (cell); | |
c8a1bdc4 HWN |
174 | |
175 | if (!SCM_GC_MARK_P (cell)) | |
406c7d90 | 176 | { |
c8a1bdc4 HWN |
177 | fprintf (stderr, |
178 | "scm_assert_cell_valid: this object is unmarked. \n" | |
179 | "It has been garbage-collected in the last GC run: " | |
180 | "%lux\n", | |
1be6b49c | 181 | (unsigned long) SCM_UNPACK (cell)); |
406c7d90 DH |
182 | abort (); |
183 | } | |
c8a1bdc4 | 184 | |
eab1b259 | 185 | scm_i_cell_validation_already_running = 0; /* re-enable */ |
406c7d90 DH |
186 | } |
187 | } | |
188 | ||
189 | ||
eab1b259 | 190 | |
406c7d90 DH |
191 | SCM_DEFINE (scm_set_debug_cell_accesses_x, "set-debug-cell-accesses!", 1, 0, 0, |
192 | (SCM flag), | |
1e6808ea | 193 | "If @var{flag} is @code{#f}, cell access checking is disabled.\n" |
eab1b259 | 194 | "If @var{flag} is @code{#t}, cheap cell access checking is enabled,\n" |
e81d98ec | 195 | "but no additional calls to garbage collection are issued.\n" |
eab1b259 | 196 | "If @var{flag} is a number, strict cell access checking is enabled,\n" |
e81d98ec DH |
197 | "with an additional garbage collection after the given\n" |
198 | "number of cell accesses.\n" | |
1e6808ea MG |
199 | "This procedure only exists when the compile-time flag\n" |
200 | "@code{SCM_DEBUG_CELL_ACCESSES} was set to 1.") | |
406c7d90 DH |
201 | #define FUNC_NAME s_scm_set_debug_cell_accesses_x |
202 | { | |
eab1b259 HWN |
203 | if (SCM_FALSEP (flag)) |
204 | { | |
205 | scm_debug_cell_accesses_p = 0; | |
206 | } | |
207 | else if (SCM_EQ_P (flag, SCM_BOOL_T)) | |
208 | { | |
209 | scm_debug_cells_gc_interval = 0; | |
210 | scm_debug_cell_accesses_p = 1; | |
211 | scm_expensive_debug_cell_accesses_p = 0; | |
212 | } | |
213 | else if (SCM_INUMP (flag)) | |
214 | { | |
215 | long int f = SCM_INUM (flag); | |
216 | if (f <= 0) | |
217 | SCM_OUT_OF_RANGE (1, flag); | |
218 | scm_debug_cells_gc_interval = f; | |
219 | scm_debug_cell_accesses_p = 1; | |
220 | scm_expensive_debug_cell_accesses_p = 1; | |
221 | } | |
222 | else | |
223 | { | |
224 | SCM_WRONG_TYPE_ARG (1, flag); | |
225 | } | |
406c7d90 DH |
226 | return SCM_UNSPECIFIED; |
227 | } | |
228 | #undef FUNC_NAME | |
c8a1bdc4 | 229 | #else |
0f2d19dd | 230 | |
8fef55a8 | 231 | /* |
c8a1bdc4 HWN |
232 | Provide a stub, so people can use their Scheme code on non-debug |
233 | versions of GUILE as well. | |
4c48ba06 | 234 | */ |
c8a1bdc4 HWN |
235 | SCM_DEFINE (scm_set_debug_cell_accesses_x, "set-debug-cell-accesses!", 1, 0, 0, |
236 | (SCM flag), | |
237 | "This function is used to turn on checking for a debug version of GUILE. This version does not support this functionality\n") | |
238 | #define FUNC_NAME s_scm_set_debug_cell_accesses_x | |
239 | { | |
240 | ||
241 | /* | |
242 | do nothing | |
243 | */ | |
1e71eafb | 244 | fprintf (stderr, "\nWARNING: GUILE was not compiled with SCM_DEBUG_CELL_ACCESSES"); |
c8a1bdc4 HWN |
245 | scm_remember_upto_here (flag); |
246 | return SCM_UNSPECIFIED; | |
247 | } | |
248 | #undef FUNC_NAME | |
ecf470a2 | 249 | |
c8a1bdc4 | 250 | #endif /* SCM_DEBUG_CELL_ACCESSES == 1 */ |
0f2d19dd JB |
251 | |
252 | \f | |
945fec60 | 253 | |
9bc4701c MD |
254 | scm_t_key scm_i_freelist; |
255 | scm_t_key scm_i_freelist2; | |
c8a1bdc4 | 256 | |
0f2d19dd JB |
257 | |
258 | /* scm_mtrigger | |
539b08a4 | 259 | * is the number of bytes of malloc allocation needed to trigger gc. |
0f2d19dd | 260 | */ |
c014a02e | 261 | unsigned long scm_mtrigger; |
0f2d19dd | 262 | |
0f2d19dd JB |
263 | /* scm_gc_heap_lock |
264 | * If set, don't expand the heap. Set only during gc, during which no allocation | |
265 | * is supposed to take place anyway. | |
266 | */ | |
267 | int scm_gc_heap_lock = 0; | |
268 | ||
269 | /* GC Blocking | |
270 | * Don't pause for collection if this is set -- just | |
271 | * expand the heap. | |
272 | */ | |
0f2d19dd JB |
273 | int scm_block_gc = 1; |
274 | ||
0f2d19dd JB |
275 | /* During collection, this accumulates objects holding |
276 | * weak references. | |
277 | */ | |
ab4bef85 | 278 | SCM scm_weak_vectors; |
0f2d19dd JB |
279 | |
280 | /* GC Statistics Keeping | |
281 | */ | |
f2893a25 | 282 | unsigned long scm_cells_allocated = 0; |
c014a02e ML |
283 | unsigned long scm_mallocated = 0; |
284 | unsigned long scm_gc_cells_collected; | |
c8a1bdc4 | 285 | unsigned long scm_gc_cells_collected_1 = 0; /* previous GC yield */ |
c014a02e ML |
286 | unsigned long scm_gc_malloc_collected; |
287 | unsigned long scm_gc_ports_collected; | |
0f2d19dd | 288 | unsigned long scm_gc_time_taken = 0; |
c014a02e | 289 | static unsigned long t_before_gc; |
c9b0d4b0 | 290 | unsigned long scm_gc_mark_time_taken = 0; |
c014a02e ML |
291 | unsigned long scm_gc_times = 0; |
292 | unsigned long scm_gc_cells_swept = 0; | |
c9b0d4b0 ML |
293 | double scm_gc_cells_marked_acc = 0.; |
294 | double scm_gc_cells_swept_acc = 0.; | |
c2cbcc57 HWN |
295 | int scm_gc_cell_yield_percentage =0; |
296 | int scm_gc_malloc_yield_percentage = 0; | |
297 | ||
0f2d19dd JB |
298 | |
299 | SCM_SYMBOL (sym_cells_allocated, "cells-allocated"); | |
300 | SCM_SYMBOL (sym_heap_size, "cell-heap-size"); | |
301 | SCM_SYMBOL (sym_mallocated, "bytes-malloced"); | |
302 | SCM_SYMBOL (sym_mtrigger, "gc-malloc-threshold"); | |
303 | SCM_SYMBOL (sym_heap_segments, "cell-heap-segments"); | |
304 | SCM_SYMBOL (sym_gc_time_taken, "gc-time-taken"); | |
c9b0d4b0 | 305 | SCM_SYMBOL (sym_gc_mark_time_taken, "gc-mark-time-taken"); |
c9b0d4b0 ML |
306 | SCM_SYMBOL (sym_times, "gc-times"); |
307 | SCM_SYMBOL (sym_cells_marked, "cells-marked"); | |
308 | SCM_SYMBOL (sym_cells_swept, "cells-swept"); | |
c2cbcc57 HWN |
309 | SCM_SYMBOL (sym_malloc_yield, "malloc-yield"); |
310 | SCM_SYMBOL (sym_cell_yield, "cell-yield"); | |
0f2d19dd | 311 | |
bb2c57fa | 312 | |
cf2d30f6 | 313 | |
d3dd80ab | 314 | |
cf2d30f6 | 315 | /* Number of calls to SCM_NEWCELL since startup. */ |
c8a1bdc4 HWN |
316 | unsigned scm_newcell_count; |
317 | unsigned scm_newcell2_count; | |
b37fe1c5 | 318 | |
b37fe1c5 | 319 | |
0f2d19dd JB |
320 | /* {Scheme Interface to GC} |
321 | */ | |
c2cbcc57 | 322 | extern int scm_gc_malloc_yield_percentage; |
a00c95d9 | 323 | SCM_DEFINE (scm_gc_stats, "gc-stats", 0, 0, 0, |
1bbd0b84 | 324 | (), |
1e6808ea | 325 | "Return an association list of statistics about Guile's current\n" |
c8a1bdc4 | 326 | "use of storage.\n") |
1bbd0b84 | 327 | #define FUNC_NAME s_scm_gc_stats |
0f2d19dd | 328 | { |
c8a1bdc4 HWN |
329 | long i = 0; |
330 | SCM heap_segs = SCM_EOL ; | |
c014a02e ML |
331 | unsigned long int local_scm_mtrigger; |
332 | unsigned long int local_scm_mallocated; | |
333 | unsigned long int local_scm_heap_size; | |
c2cbcc57 HWN |
334 | int local_scm_gc_cell_yield_percentage; |
335 | int local_scm_gc_malloc_yield_percentage; | |
f2893a25 | 336 | unsigned long int local_scm_cells_allocated; |
c014a02e ML |
337 | unsigned long int local_scm_gc_time_taken; |
338 | unsigned long int local_scm_gc_times; | |
339 | unsigned long int local_scm_gc_mark_time_taken; | |
c9b0d4b0 ML |
340 | double local_scm_gc_cells_swept; |
341 | double local_scm_gc_cells_marked; | |
0f2d19dd | 342 | SCM answer; |
c8a1bdc4 HWN |
343 | unsigned long *bounds = 0; |
344 | int table_size = scm_i_heap_segment_table_size; | |
0f2d19dd | 345 | SCM_DEFER_INTS; |
939794ce | 346 | |
c8a1bdc4 HWN |
347 | /* |
348 | temporarily store the numbers, so as not to cause GC. | |
7febb4a2 | 349 | */ |
c8a1bdc4 HWN |
350 | |
351 | bounds = malloc (sizeof (int) * table_size * 2); | |
352 | if (!bounds) | |
353 | abort(); | |
354 | for (i = table_size; i--; ) | |
355 | { | |
356 | bounds[2*i] = (unsigned long)scm_i_heap_segment_table[i]->bounds[0]; | |
357 | bounds[2*i+1] = (unsigned long)scm_i_heap_segment_table[i]->bounds[1]; | |
358 | } | |
0f2d19dd | 359 | |
4c9419ac | 360 | |
c8a1bdc4 HWN |
361 | /* Below, we cons to produce the resulting list. We want a snapshot of |
362 | * the heap situation before consing. | |
363 | */ | |
364 | local_scm_mtrigger = scm_mtrigger; | |
365 | local_scm_mallocated = scm_mallocated; | |
366 | local_scm_heap_size = SCM_HEAP_SIZE; | |
539b08a4 | 367 | |
c8a1bdc4 HWN |
368 | local_scm_cells_allocated = scm_cells_allocated; |
369 | ||
370 | local_scm_gc_time_taken = scm_gc_time_taken; | |
371 | local_scm_gc_mark_time_taken = scm_gc_mark_time_taken; | |
372 | local_scm_gc_times = scm_gc_times; | |
c2cbcc57 HWN |
373 | local_scm_gc_malloc_yield_percentage = scm_gc_malloc_yield_percentage; |
374 | local_scm_gc_cell_yield_percentage= scm_gc_cell_yield_percentage; | |
375 | ||
376 | local_scm_gc_cells_swept = | |
377 | (double) scm_gc_cells_swept_acc | |
378 | + (double) scm_gc_cells_swept; | |
c8a1bdc4 HWN |
379 | local_scm_gc_cells_marked = scm_gc_cells_marked_acc |
380 | +(double) scm_gc_cells_swept | |
381 | -(double) scm_gc_cells_collected; | |
0f2d19dd | 382 | |
c8a1bdc4 HWN |
383 | for (i = table_size; i--;) |
384 | { | |
385 | heap_segs = scm_cons (scm_cons (scm_ulong2num (bounds[2*i]), | |
386 | scm_ulong2num (bounds[2*i+1])), | |
387 | heap_segs); | |
388 | } | |
389 | ||
390 | answer = scm_list_n (scm_cons (sym_gc_time_taken, scm_ulong2num (local_scm_gc_time_taken)), | |
f2893a25 | 391 | scm_cons (sym_cells_allocated, scm_ulong2num (local_scm_cells_allocated)), |
c8a1bdc4 HWN |
392 | scm_cons (sym_heap_size, scm_ulong2num (local_scm_heap_size)), |
393 | scm_cons (sym_mallocated, scm_ulong2num (local_scm_mallocated)), | |
394 | scm_cons (sym_mtrigger, scm_ulong2num (local_scm_mtrigger)), | |
395 | scm_cons (sym_times, scm_ulong2num (local_scm_gc_times)), | |
396 | scm_cons (sym_gc_mark_time_taken, scm_ulong2num (local_scm_gc_mark_time_taken)), | |
397 | scm_cons (sym_cells_marked, scm_i_dbl2big (local_scm_gc_cells_marked)), | |
398 | scm_cons (sym_cells_swept, scm_i_dbl2big (local_scm_gc_cells_swept)), | |
c2cbcc57 HWN |
399 | scm_cons (sym_malloc_yield, scm_long2num (local_scm_gc_malloc_yield_percentage)), |
400 | scm_cons (sym_cell_yield, scm_long2num (local_scm_gc_cell_yield_percentage)), | |
c8a1bdc4 HWN |
401 | scm_cons (sym_heap_segments, heap_segs), |
402 | SCM_UNDEFINED); | |
403 | SCM_ALLOW_INTS; | |
404 | ||
405 | free (bounds); | |
406 | return answer; | |
0f2d19dd | 407 | } |
c8a1bdc4 | 408 | #undef FUNC_NAME |
0f2d19dd | 409 | |
c8a1bdc4 HWN |
410 | static void |
411 | gc_start_stats (const char *what SCM_UNUSED) | |
e4a7824f | 412 | { |
c8a1bdc4 | 413 | t_before_gc = scm_c_get_internal_run_time (); |
539b08a4 | 414 | |
c8a1bdc4 HWN |
415 | scm_gc_cells_marked_acc += (double) scm_gc_cells_swept |
416 | - (double) scm_gc_cells_collected; | |
c2cbcc57 | 417 | scm_gc_cells_swept_acc += (double) scm_gc_cells_swept; |
e4a7824f | 418 | |
c2cbcc57 HWN |
419 | scm_gc_cell_yield_percentage = ( scm_gc_cells_collected * 100 ) / SCM_HEAP_SIZE; |
420 | ||
c8a1bdc4 HWN |
421 | scm_gc_cells_swept = 0; |
422 | scm_gc_cells_collected_1 = scm_gc_cells_collected; | |
539b08a4 | 423 | |
c8a1bdc4 HWN |
424 | /* |
425 | CELLS SWEPT is another word for the number of cells that were | |
426 | examined during GC. YIELD is the number that we cleaned | |
427 | out. MARKED is the number that weren't cleaned. | |
428 | */ | |
429 | scm_gc_cells_collected = 0; | |
430 | scm_gc_malloc_collected = 0; | |
431 | scm_gc_ports_collected = 0; | |
e4a7824f | 432 | } |
acf4331f | 433 | |
c8a1bdc4 HWN |
434 | static void |
435 | gc_end_stats () | |
0f2d19dd | 436 | { |
c8a1bdc4 HWN |
437 | unsigned long t = scm_c_get_internal_run_time (); |
438 | scm_gc_time_taken += (t - t_before_gc); | |
539b08a4 | 439 | |
c8a1bdc4 | 440 | ++scm_gc_times; |
0f2d19dd | 441 | } |
acf4331f | 442 | |
0f2d19dd | 443 | |
c8a1bdc4 HWN |
444 | SCM_DEFINE (scm_object_address, "object-address", 1, 0, 0, |
445 | (SCM obj), | |
446 | "Return an integer that for the lifetime of @var{obj} is uniquely\n" | |
447 | "returned by this function for @var{obj}") | |
448 | #define FUNC_NAME s_scm_object_address | |
c68296f8 | 449 | { |
c8a1bdc4 | 450 | return scm_ulong2num ((unsigned long) SCM_UNPACK (obj)); |
c68296f8 | 451 | } |
c8a1bdc4 | 452 | #undef FUNC_NAME |
c68296f8 | 453 | |
1be6b49c | 454 | |
c8a1bdc4 HWN |
455 | SCM_DEFINE (scm_gc, "gc", 0, 0, 0, |
456 | (), | |
457 | "Scans all of SCM objects and reclaims for further use those that are\n" | |
458 | "no longer accessible.") | |
459 | #define FUNC_NAME s_scm_gc | |
460 | { | |
461 | SCM_DEFER_INTS; | |
9bc4701c | 462 | scm_i_thread_put_to_sleep (); |
c8a1bdc4 | 463 | scm_igc ("call"); |
9bc4701c | 464 | scm_i_thread_wake_up (); |
c8a1bdc4 HWN |
465 | SCM_ALLOW_INTS; |
466 | return SCM_UNSPECIFIED; | |
9d47a1e6 | 467 | } |
c8a1bdc4 | 468 | #undef FUNC_NAME |
9d47a1e6 | 469 | |
c68296f8 MV |
470 | |
471 | \f | |
0f2d19dd | 472 | |
c8a1bdc4 HWN |
473 | /* When we get POSIX threads support, the master will be global and |
474 | * common while the freelist will be individual for each thread. | |
0f2d19dd JB |
475 | */ |
476 | ||
c8a1bdc4 HWN |
477 | SCM |
478 | scm_gc_for_newcell (scm_t_cell_type_statistics *freelist, SCM *free_cells) | |
0f2d19dd | 479 | { |
c8a1bdc4 HWN |
480 | SCM cell; |
481 | ||
9bc4701c MD |
482 | scm_i_thread_put_to_sleep (); |
483 | ||
c8a1bdc4 | 484 | ++scm_ints_disabled; |
0f2d19dd | 485 | |
c8a1bdc4 HWN |
486 | *free_cells = scm_i_sweep_some_segments (freelist); |
487 | if (*free_cells == SCM_EOL && scm_i_gc_grow_heap_p (freelist)) | |
488 | { | |
489 | freelist->heap_segment_idx = scm_i_get_new_heap_segment (freelist, abort_on_error); | |
490 | *free_cells = scm_i_sweep_some_segments (freelist); | |
491 | } | |
acb0a19c | 492 | |
c8a1bdc4 HWN |
493 | if (*free_cells == SCM_EOL && !scm_block_gc) |
494 | { | |
495 | /* | |
496 | with the advent of lazy sweep, GC yield is only know just | |
497 | before doing the GC. | |
498 | */ | |
499 | scm_i_adjust_min_yield (freelist); | |
500 | ||
501 | /* | |
502 | out of fresh cells. Try to get some new ones. | |
503 | */ | |
0f2d19dd | 504 | |
c8a1bdc4 | 505 | scm_igc ("cells"); |
a00c95d9 | 506 | |
c8a1bdc4 HWN |
507 | *free_cells = scm_i_sweep_some_segments (freelist); |
508 | } | |
509 | ||
510 | if (*free_cells == SCM_EOL) | |
511 | { | |
512 | /* | |
513 | failed getting new cells. Get new juice or die. | |
514 | */ | |
515 | freelist->heap_segment_idx = scm_i_get_new_heap_segment (freelist, abort_on_error); | |
516 | *free_cells = scm_i_sweep_some_segments (freelist); | |
517 | } | |
518 | ||
519 | if (*free_cells == SCM_EOL) | |
520 | abort (); | |
0f2d19dd | 521 | |
c8a1bdc4 | 522 | cell = *free_cells; |
0f2d19dd | 523 | |
c8a1bdc4 | 524 | --scm_ints_disabled; |
0f2d19dd | 525 | |
c8a1bdc4 | 526 | *free_cells = SCM_FREE_CELL_CDR (cell); |
eab1b259 | 527 | |
9bc4701c | 528 | scm_i_thread_wake_up (); |
eab1b259 | 529 | |
c8a1bdc4 HWN |
530 | return cell; |
531 | } | |
4a4c9785 | 532 | |
4a4c9785 | 533 | |
c8a1bdc4 HWN |
534 | scm_t_c_hook scm_before_gc_c_hook; |
535 | scm_t_c_hook scm_before_mark_c_hook; | |
536 | scm_t_c_hook scm_before_sweep_c_hook; | |
537 | scm_t_c_hook scm_after_sweep_c_hook; | |
538 | scm_t_c_hook scm_after_gc_c_hook; | |
4a4c9785 | 539 | |
c8a1bdc4 HWN |
540 | void |
541 | scm_igc (const char *what) | |
542 | { | |
543 | ++scm_gc_running_p; | |
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, | |
9bc4701c | 550 | SCM_NULLP (*SCM_FREELIST_LOC (scm_i_freelist)) |
c8a1bdc4 | 551 | ? "*" |
9bc4701c | 552 | : (SCM_NULLP (*SCM_FREELIST_LOC (scm_i_freelist2)) ? "o" : "m")); |
c8a1bdc4 | 553 | #endif |
4c48ba06 | 554 | |
c8a1bdc4 | 555 | /* During the critical section, only the current thread may run. */ |
9bc4701c MD |
556 | #if 0 /* MDJ 021207 <djurfeldt@nada.kth.se> |
557 | Currently, a much larger piece of the GC is single threaded. | |
558 | Can we shrink it again? */ | |
c8a1bdc4 | 559 | SCM_CRITICAL_SECTION_START; |
9bc4701c | 560 | #endif |
a00c95d9 | 561 | |
eab1b259 | 562 | if (!scm_root || !scm_stack_base || scm_block_gc) |
d6884e63 | 563 | { |
c8a1bdc4 HWN |
564 | --scm_gc_running_p; |
565 | return; | |
d6884e63 ML |
566 | } |
567 | ||
c8a1bdc4 | 568 | gc_start_stats (what); |
a00c95d9 | 569 | |
c8a1bdc4 HWN |
570 | if (scm_gc_heap_lock) |
571 | /* We've invoked the collector while a GC is already in progress. | |
572 | That should never happen. */ | |
573 | abort (); | |
a00c95d9 | 574 | |
c8a1bdc4 | 575 | ++scm_gc_heap_lock; |
a00c95d9 | 576 | |
c8a1bdc4 HWN |
577 | /* |
578 | Let's finish the sweep. The conservative GC might point into the | |
579 | garbage, and marking that would create a mess. | |
580 | */ | |
581 | scm_i_sweep_all_segments("GC"); | |
582 | if (scm_mallocated < scm_i_deprecated_memory_return) | |
b6efc951 | 583 | { |
c8a1bdc4 HWN |
584 | /* The byte count of allocated objects has underflowed. This is |
585 | probably because you forgot to report the sizes of objects you | |
586 | have allocated, by calling scm_done_malloc or some such. When | |
587 | the GC freed them, it subtracted their size from | |
588 | scm_mallocated, which underflowed. */ | |
589 | fprintf (stderr, | |
590 | "scm_gc_sweep: Byte count of allocated objects has underflowed.\n" | |
591 | "This is probably because the GC hasn't been correctly informed\n" | |
592 | "about object sizes\n"); | |
b6efc951 DH |
593 | abort (); |
594 | } | |
c8a1bdc4 | 595 | scm_mallocated -= scm_i_deprecated_memory_return; |
0f2d19dd | 596 | |
c8a1bdc4 HWN |
597 | |
598 | ||
599 | scm_c_hook_run (&scm_before_mark_c_hook, 0); | |
b6efc951 | 600 | |
c8a1bdc4 HWN |
601 | scm_mark_all (); |
602 | ||
c2cbcc57 | 603 | scm_gc_mark_time_taken += (scm_c_get_internal_run_time () - t_before_gc); |
c8a1bdc4 HWN |
604 | |
605 | scm_c_hook_run (&scm_before_sweep_c_hook, 0); | |
606 | ||
607 | /* | |
608 | Moved this lock upwards so that we can alloc new heap at the end of a sweep. | |
0f2d19dd | 609 | |
c8a1bdc4 | 610 | DOCME: why should the heap be locked anyway? |
0f2d19dd | 611 | */ |
c8a1bdc4 | 612 | --scm_gc_heap_lock; |
a00c95d9 | 613 | |
c8a1bdc4 | 614 | scm_gc_sweep (); |
0f2d19dd | 615 | |
ffd72400 HWN |
616 | |
617 | /* | |
618 | TODO: this hook should probably be moved to just before the mark, | |
619 | since that's where the sweep is finished in lazy sweeping. | |
620 | */ | |
c8a1bdc4 HWN |
621 | scm_c_hook_run (&scm_after_sweep_c_hook, 0); |
622 | gc_end_stats (); | |
623 | ||
9bc4701c | 624 | #if 0 /* MDJ 021207 <djurfeldt@nada.kth.se> */ |
c8a1bdc4 | 625 | SCM_CRITICAL_SECTION_END; |
9bc4701c | 626 | #endif |
ffd72400 HWN |
627 | |
628 | /* | |
629 | See above. | |
630 | */ | |
c8a1bdc4 HWN |
631 | scm_c_hook_run (&scm_after_gc_c_hook, 0); |
632 | --scm_gc_running_p; | |
a00c95d9 | 633 | |
eab1b259 HWN |
634 | /* |
635 | For debugging purposes, you could do | |
636 | scm_i_sweep_all_segments("debug"), but then the remains of the | |
637 | cell aren't left to analyse. | |
638 | */ | |
639 | } | |
0f2d19dd | 640 | |
0f2d19dd JB |
641 | \f |
642 | /* {GC Protection Helper Functions} | |
643 | */ | |
644 | ||
645 | ||
5d2b97cd DH |
646 | /* |
647 | * If within a function you need to protect one or more scheme objects from | |
648 | * garbage collection, pass them as parameters to one of the | |
649 | * scm_remember_upto_here* functions below. These functions don't do | |
650 | * anything, but since the compiler does not know that they are actually | |
651 | * no-ops, it will generate code that calls these functions with the given | |
652 | * parameters. Therefore, you can be sure that the compiler will keep those | |
653 | * scheme values alive (on the stack or in a register) up to the point where | |
654 | * scm_remember_upto_here* is called. In other words, place the call to | |
592996c9 | 655 | * scm_remember_upto_here* _behind_ the last code in your function, that |
5d2b97cd DH |
656 | * depends on the scheme object to exist. |
657 | * | |
8c494e99 DH |
658 | * Example: We want to make sure that the string object str does not get |
659 | * garbage collected during the execution of 'some_function' in the code | |
660 | * below, because otherwise the characters belonging to str would be freed and | |
5d2b97cd DH |
661 | * 'some_function' might access freed memory. To make sure that the compiler |
662 | * keeps str alive on the stack or in a register such that it is visible to | |
663 | * the conservative gc we add the call to scm_remember_upto_here_1 _after_ the | |
664 | * call to 'some_function'. Note that this would not be necessary if str was | |
665 | * used anyway after the call to 'some_function'. | |
666 | * char *chars = SCM_STRING_CHARS (str); | |
667 | * some_function (chars); | |
668 | * scm_remember_upto_here_1 (str); // str will be alive up to this point. | |
669 | */ | |
670 | ||
671 | void | |
e81d98ec | 672 | scm_remember_upto_here_1 (SCM obj SCM_UNUSED) |
5d2b97cd DH |
673 | { |
674 | /* Empty. Protects a single object from garbage collection. */ | |
675 | } | |
676 | ||
677 | void | |
e81d98ec | 678 | scm_remember_upto_here_2 (SCM obj1 SCM_UNUSED, SCM obj2 SCM_UNUSED) |
5d2b97cd DH |
679 | { |
680 | /* Empty. Protects two objects from garbage collection. */ | |
681 | } | |
682 | ||
683 | void | |
e81d98ec | 684 | scm_remember_upto_here (SCM obj SCM_UNUSED, ...) |
5d2b97cd DH |
685 | { |
686 | /* Empty. Protects any number of objects from garbage collection. */ | |
687 | } | |
688 | ||
c209c88e | 689 | /* |
41b0806d GB |
690 | These crazy functions prevent garbage collection |
691 | of arguments after the first argument by | |
692 | ensuring they remain live throughout the | |
693 | function because they are used in the last | |
694 | line of the code block. | |
695 | It'd be better to have a nice compiler hint to | |
696 | aid the conservative stack-scanning GC. --03/09/00 gjb */ | |
0f2d19dd JB |
697 | SCM |
698 | scm_return_first (SCM elt, ...) | |
0f2d19dd JB |
699 | { |
700 | return elt; | |
701 | } | |
702 | ||
41b0806d GB |
703 | int |
704 | scm_return_first_int (int i, ...) | |
705 | { | |
706 | return i; | |
707 | } | |
708 | ||
0f2d19dd | 709 | |
0f2d19dd | 710 | SCM |
6e8d25a6 | 711 | scm_permanent_object (SCM obj) |
0f2d19dd JB |
712 | { |
713 | SCM_REDEFER_INTS; | |
714 | scm_permobjs = scm_cons (obj, scm_permobjs); | |
715 | SCM_REALLOW_INTS; | |
716 | return obj; | |
717 | } | |
718 | ||
719 | ||
7bd4fbe2 MD |
720 | /* Protect OBJ from the garbage collector. OBJ will not be freed, even if all |
721 | other references are dropped, until the object is unprotected by calling | |
6b1b030e | 722 | scm_gc_unprotect_object (OBJ). Calls to scm_gc_protect/unprotect_object nest, |
7bd4fbe2 MD |
723 | i. e. it is possible to protect the same object several times, but it is |
724 | necessary to unprotect the object the same number of times to actually get | |
725 | the object unprotected. It is an error to unprotect an object more often | |
726 | than it has been protected before. The function scm_protect_object returns | |
727 | OBJ. | |
728 | */ | |
729 | ||
730 | /* Implementation note: For every object X, there is a counter which | |
6b1b030e | 731 | scm_gc_protect_object(X) increments and scm_gc_unprotect_object(X) decrements. |
7bd4fbe2 | 732 | */ |
686765af | 733 | |
ef290276 | 734 | SCM |
6b1b030e | 735 | scm_gc_protect_object (SCM obj) |
ef290276 | 736 | { |
686765af | 737 | SCM handle; |
9d47a1e6 | 738 | |
686765af | 739 | /* This critical section barrier will be replaced by a mutex. */ |
2dd6a83a | 740 | SCM_REDEFER_INTS; |
9d47a1e6 | 741 | |
0f0f0899 | 742 | handle = scm_hashq_create_handle_x (scm_protects, obj, SCM_MAKINUM (0)); |
1be6b49c | 743 | SCM_SETCDR (handle, scm_sum (SCM_CDR (handle), SCM_MAKINUM (1))); |
9d47a1e6 | 744 | |
2dd6a83a | 745 | SCM_REALLOW_INTS; |
9d47a1e6 | 746 | |
ef290276 JB |
747 | return obj; |
748 | } | |
749 | ||
750 | ||
751 | /* Remove any protection for OBJ established by a prior call to | |
dab7f566 | 752 | scm_protect_object. This function returns OBJ. |
ef290276 | 753 | |
dab7f566 | 754 | See scm_protect_object for more information. */ |
ef290276 | 755 | SCM |
6b1b030e | 756 | scm_gc_unprotect_object (SCM obj) |
ef290276 | 757 | { |
686765af | 758 | SCM handle; |
9d47a1e6 | 759 | |
686765af | 760 | /* This critical section barrier will be replaced by a mutex. */ |
2dd6a83a | 761 | SCM_REDEFER_INTS; |
9d47a1e6 | 762 | |
686765af | 763 | handle = scm_hashq_get_handle (scm_protects, obj); |
9d47a1e6 | 764 | |
22a52da1 | 765 | if (SCM_FALSEP (handle)) |
686765af | 766 | { |
0f0f0899 MD |
767 | fprintf (stderr, "scm_unprotect_object called on unprotected object\n"); |
768 | abort (); | |
686765af | 769 | } |
6a199940 DH |
770 | else |
771 | { | |
1be6b49c ML |
772 | SCM count = scm_difference (SCM_CDR (handle), SCM_MAKINUM (1)); |
773 | if (SCM_EQ_P (count, SCM_MAKINUM (0))) | |
6a199940 DH |
774 | scm_hashq_remove_x (scm_protects, obj); |
775 | else | |
1be6b49c | 776 | SCM_SETCDR (handle, count); |
6a199940 | 777 | } |
686765af | 778 | |
2dd6a83a | 779 | SCM_REALLOW_INTS; |
ef290276 JB |
780 | |
781 | return obj; | |
782 | } | |
783 | ||
6b1b030e ML |
784 | void |
785 | scm_gc_register_root (SCM *p) | |
786 | { | |
787 | SCM handle; | |
788 | SCM key = scm_long2num ((long) p); | |
eae33935 | 789 | |
6b1b030e ML |
790 | /* This critical section barrier will be replaced by a mutex. */ |
791 | SCM_REDEFER_INTS; | |
792 | ||
793 | handle = scm_hashv_create_handle_x (scm_gc_registered_roots, key, SCM_MAKINUM (0)); | |
794 | SCM_SETCDR (handle, scm_sum (SCM_CDR (handle), SCM_MAKINUM (1))); | |
795 | ||
796 | SCM_REALLOW_INTS; | |
797 | } | |
798 | ||
799 | void | |
800 | scm_gc_unregister_root (SCM *p) | |
801 | { | |
802 | SCM handle; | |
803 | SCM key = scm_long2num ((long) p); | |
804 | ||
805 | /* This critical section barrier will be replaced by a mutex. */ | |
806 | SCM_REDEFER_INTS; | |
807 | ||
808 | handle = scm_hashv_get_handle (scm_gc_registered_roots, key); | |
809 | ||
810 | if (SCM_FALSEP (handle)) | |
811 | { | |
812 | fprintf (stderr, "scm_gc_unregister_root called on unregistered root\n"); | |
813 | abort (); | |
814 | } | |
815 | else | |
816 | { | |
817 | SCM count = scm_difference (SCM_CDR (handle), SCM_MAKINUM (1)); | |
818 | if (SCM_EQ_P (count, SCM_MAKINUM (0))) | |
819 | scm_hashv_remove_x (scm_gc_registered_roots, key); | |
820 | else | |
821 | SCM_SETCDR (handle, count); | |
822 | } | |
823 | ||
824 | SCM_REALLOW_INTS; | |
825 | } | |
826 | ||
827 | void | |
828 | scm_gc_register_roots (SCM *b, unsigned long n) | |
829 | { | |
830 | SCM *p = b; | |
831 | for (; p < b + n; ++p) | |
832 | scm_gc_register_root (p); | |
833 | } | |
834 | ||
835 | void | |
836 | scm_gc_unregister_roots (SCM *b, unsigned long n) | |
837 | { | |
838 | SCM *p = b; | |
839 | for (; p < b + n; ++p) | |
840 | scm_gc_unregister_root (p); | |
841 | } | |
842 | ||
04a98cff | 843 | int scm_i_terminating; |
c45acc34 JB |
844 | |
845 | /* called on process termination. */ | |
e52ceaac MD |
846 | #ifdef HAVE_ATEXIT |
847 | static void | |
848 | cleanup (void) | |
849 | #else | |
850 | #ifdef HAVE_ON_EXIT | |
51157deb MD |
851 | extern int on_exit (void (*procp) (), int arg); |
852 | ||
e52ceaac MD |
853 | static void |
854 | cleanup (int status, void *arg) | |
855 | #else | |
856 | #error Dont know how to setup a cleanup handler on your system. | |
857 | #endif | |
858 | #endif | |
c45acc34 | 859 | { |
04a98cff | 860 | scm_i_terminating = 1; |
c45acc34 JB |
861 | scm_flush_all_ports (); |
862 | } | |
ef290276 | 863 | |
0f2d19dd | 864 | \f |
a00c95d9 | 865 | |
4c48ba06 | 866 | |
c8a1bdc4 HWN |
867 | /* |
868 | MOVE THIS FUNCTION. IT DOES NOT HAVE ANYTHING TODO WITH GC. | |
869 | */ | |
85db4a2c DH |
870 | |
871 | /* Get an integer from an environment variable. */ | |
c8a1bdc4 HWN |
872 | int |
873 | scm_getenv_int (const char *var, int def) | |
85db4a2c | 874 | { |
c8a1bdc4 HWN |
875 | char *end = 0; |
876 | char *val = getenv (var); | |
877 | long res = def; | |
85db4a2c DH |
878 | if (!val) |
879 | return def; | |
880 | res = strtol (val, &end, 10); | |
881 | if (end == val) | |
882 | return def; | |
883 | return res; | |
884 | } | |
885 | ||
886 | ||
4a4c9785 | 887 | int |
85db4a2c | 888 | scm_init_storage () |
0f2d19dd | 889 | { |
1be6b49c | 890 | size_t j; |
0f2d19dd JB |
891 | |
892 | j = SCM_NUM_PROTECTS; | |
893 | while (j) | |
894 | scm_sys_protects[--j] = SCM_BOOL_F; | |
895 | scm_block_gc = 1; | |
4a4c9785 | 896 | |
c8a1bdc4 HWN |
897 | scm_gc_init_freelist(); |
898 | scm_gc_init_malloc (); | |
0f2d19dd JB |
899 | |
900 | j = SCM_HEAP_SEG_SIZE; | |
d6884e63 | 901 | |
c8a1bdc4 | 902 | |
acb0a19c | 903 | |
801cb5e7 MD |
904 | scm_c_hook_init (&scm_before_gc_c_hook, 0, SCM_C_HOOK_NORMAL); |
905 | scm_c_hook_init (&scm_before_mark_c_hook, 0, SCM_C_HOOK_NORMAL); | |
906 | scm_c_hook_init (&scm_before_sweep_c_hook, 0, SCM_C_HOOK_NORMAL); | |
907 | scm_c_hook_init (&scm_after_sweep_c_hook, 0, SCM_C_HOOK_NORMAL); | |
908 | scm_c_hook_init (&scm_after_gc_c_hook, 0, SCM_C_HOOK_NORMAL); | |
0f2d19dd JB |
909 | |
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 | |
8960e0a0 | 924 | scm_stand_in_procs = SCM_EOL; |
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; | |
c8a1bdc4 HWN |
1029 | } |
1030 | ||
1031 | #undef FUNC_NAME | |
1032 | ||
1033 | ||
56495472 | 1034 | |
89e00824 ML |
1035 | /* |
1036 | Local Variables: | |
1037 | c-file-style: "gnu" | |
1038 | End: | |
1039 | */ |