Commit | Line | Data |
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0f595d7d LC |
1 | /* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2002, 2003, 2006, |
2 | * 2008, 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc. | |
a00c95d9 | 3 | * |
73be1d9e | 4 | * This library is free software; you can redistribute it and/or |
53befeb7 NJ |
5 | * modify it under the terms of the GNU Lesser General Public License |
6 | * as published by the Free Software Foundation; either version 3 of | |
7 | * the License, or (at your option) any later version. | |
a00c95d9 | 8 | * |
53befeb7 NJ |
9 | * This library is distributed in the hope that it will be useful, but |
10 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
73be1d9e MV |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
12 | * Lesser General Public License for more details. | |
a00c95d9 | 13 | * |
73be1d9e MV |
14 | * You should have received a copy of the GNU Lesser General Public |
15 | * License along with this library; if not, write to the Free Software | |
53befeb7 NJ |
16 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
17 | * 02110-1301 USA | |
73be1d9e | 18 | */ |
1bbd0b84 | 19 | |
37ddcaf6 MD |
20 | /* #define DEBUGINFO */ |
21 | ||
dbb605f5 | 22 | #ifdef HAVE_CONFIG_H |
aa54a9b0 RB |
23 | # include <config.h> |
24 | #endif | |
56495472 | 25 | |
e7bca227 LC |
26 | #include "libguile/gen-scmconfig.h" |
27 | ||
0f2d19dd | 28 | #include <stdio.h> |
e6e2e95a | 29 | #include <errno.h> |
783e7774 | 30 | #include <string.h> |
34cf38c3 | 31 | #include <stdlib.h> |
6360beb2 | 32 | #include <math.h> |
e6e2e95a | 33 | |
3ec17f28 LC |
34 | #ifdef __ia64__ |
35 | #include <ucontext.h> | |
36 | extern unsigned long * __libc_ia64_register_backing_store_base; | |
37 | #endif | |
38 | ||
a0599745 | 39 | #include "libguile/_scm.h" |
0a7a7445 | 40 | #include "libguile/eval.h" |
a0599745 MD |
41 | #include "libguile/stime.h" |
42 | #include "libguile/stackchk.h" | |
43 | #include "libguile/struct.h" | |
a0599745 | 44 | #include "libguile/smob.h" |
2fa901a5 | 45 | #include "libguile/arrays.h" |
a0599745 MD |
46 | #include "libguile/async.h" |
47 | #include "libguile/ports.h" | |
48 | #include "libguile/root.h" | |
87fc4596 | 49 | #include "libguile/simpos.h" |
a0599745 MD |
50 | #include "libguile/strings.h" |
51 | #include "libguile/vectors.h" | |
686765af | 52 | #include "libguile/hashtab.h" |
ecf470a2 | 53 | #include "libguile/tags.h" |
a0599745 MD |
54 | |
55 | #include "libguile/validate.h" | |
1be6b49c | 56 | #include "libguile/deprecation.h" |
a0599745 | 57 | #include "libguile/gc.h" |
9de87eea | 58 | #include "libguile/dynwind.h" |
fce59c93 | 59 | |
1c44468d | 60 | #include "libguile/bdw-gc.h" |
a82e7953 | 61 | |
cc3546b0 AW |
62 | /* For GC_set_start_callback. */ |
63 | #include <gc/gc_mark.h> | |
64 | ||
bc9d9bb2 | 65 | #ifdef GUILE_DEBUG_MALLOC |
a0599745 | 66 | #include "libguile/debug-malloc.h" |
bc9d9bb2 MD |
67 | #endif |
68 | ||
0f2d19dd | 69 | #ifdef HAVE_UNISTD_H |
95b88819 | 70 | #include <unistd.h> |
0f2d19dd JB |
71 | #endif |
72 | ||
064d2409 AW |
73 | /* Size in bytes of the initial heap. This should be about the size of |
74 | result of 'guile -c "(display (assq-ref (gc-stats) | |
75 | 'heap-total-allocated))"'. */ | |
76 | ||
77 | #define DEFAULT_INITIAL_HEAP_SIZE (128 * 1024 * SIZEOF_SCM_T_BITS) | |
78 | ||
eae33935 | 79 | /* Set this to != 0 if every cell that is accessed shall be checked: |
61045190 | 80 | */ |
eab1b259 HWN |
81 | int scm_debug_cell_accesses_p = 0; |
82 | int scm_expensive_debug_cell_accesses_p = 0; | |
406c7d90 | 83 | |
e81d98ec DH |
84 | /* Set this to 0 if no additional gc's shall be performed, otherwise set it to |
85 | * the number of cell accesses after which a gc shall be called. | |
86 | */ | |
eab1b259 | 87 | int scm_debug_cells_gc_interval = 0; |
e81d98ec | 88 | |
acbccb0c | 89 | /* Hash table that keeps a reference to objects the user wants to protect from |
fbe1cb7f AW |
90 | garbage collection. */ |
91 | static SCM scm_protects; | |
e7efe8e7 AW |
92 | |
93 | ||
eab1b259 HWN |
94 | #if (SCM_DEBUG_CELL_ACCESSES == 1) |
95 | ||
96 | ||
97 | /* | |
98 | ||
99 | Assert that the given object is a valid reference to a valid cell. This | |
100 | test involves to determine whether the object is a cell pointer, whether | |
101 | this pointer actually points into a heap segment and whether the cell | |
102 | pointed to is not a free cell. Further, additional garbage collections may | |
103 | get executed after a user defined number of cell accesses. This helps to | |
104 | find places in the C code where references are dropped for extremely short | |
105 | periods. | |
106 | ||
107 | */ | |
406c7d90 | 108 | void |
eab1b259 | 109 | scm_i_expensive_validation_check (SCM cell) |
406c7d90 | 110 | { |
eab1b259 HWN |
111 | /* If desired, perform additional garbage collections after a user |
112 | * defined number of cell accesses. | |
113 | */ | |
114 | if (scm_debug_cells_gc_interval) | |
115 | { | |
116 | static unsigned int counter = 0; | |
61045190 | 117 | |
eab1b259 HWN |
118 | if (counter != 0) |
119 | { | |
120 | --counter; | |
121 | } | |
122 | else | |
123 | { | |
124 | counter = scm_debug_cells_gc_interval; | |
b17e0ac3 | 125 | scm_gc (); |
eab1b259 HWN |
126 | } |
127 | } | |
128 | } | |
129 | ||
8c93b597 LC |
130 | /* Whether cell validation is already running. */ |
131 | static int scm_i_cell_validation_already_running = 0; | |
132 | ||
eab1b259 HWN |
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); | |
b4246e5b | 153 | |
eab1b259 | 154 | scm_i_cell_validation_already_running = 0; /* re-enable */ |
406c7d90 DH |
155 | } |
156 | } | |
157 | ||
158 | ||
eab1b259 | 159 | |
406c7d90 DH |
160 | SCM_DEFINE (scm_set_debug_cell_accesses_x, "set-debug-cell-accesses!", 1, 0, 0, |
161 | (SCM flag), | |
1e6808ea | 162 | "If @var{flag} is @code{#f}, cell access checking is disabled.\n" |
eab1b259 | 163 | "If @var{flag} is @code{#t}, cheap cell access checking is enabled,\n" |
e81d98ec | 164 | "but no additional calls to garbage collection are issued.\n" |
eab1b259 | 165 | "If @var{flag} is a number, strict cell access checking is enabled,\n" |
e81d98ec DH |
166 | "with an additional garbage collection after the given\n" |
167 | "number of cell accesses.\n" | |
1e6808ea MG |
168 | "This procedure only exists when the compile-time flag\n" |
169 | "@code{SCM_DEBUG_CELL_ACCESSES} was set to 1.") | |
406c7d90 DH |
170 | #define FUNC_NAME s_scm_set_debug_cell_accesses_x |
171 | { | |
7888309b | 172 | if (scm_is_false (flag)) |
eab1b259 HWN |
173 | { |
174 | scm_debug_cell_accesses_p = 0; | |
175 | } | |
bc36d050 | 176 | else if (scm_is_eq (flag, SCM_BOOL_T)) |
eab1b259 HWN |
177 | { |
178 | scm_debug_cells_gc_interval = 0; | |
179 | scm_debug_cell_accesses_p = 1; | |
180 | scm_expensive_debug_cell_accesses_p = 0; | |
181 | } | |
e11e83f3 | 182 | else |
eab1b259 | 183 | { |
e11e83f3 | 184 | scm_debug_cells_gc_interval = scm_to_signed_integer (flag, 0, INT_MAX); |
eab1b259 HWN |
185 | scm_debug_cell_accesses_p = 1; |
186 | scm_expensive_debug_cell_accesses_p = 1; | |
187 | } | |
406c7d90 DH |
188 | return SCM_UNSPECIFIED; |
189 | } | |
190 | #undef FUNC_NAME | |
0f2d19dd | 191 | |
ecf470a2 | 192 | |
c8a1bdc4 | 193 | #endif /* SCM_DEBUG_CELL_ACCESSES == 1 */ |
0f2d19dd JB |
194 | |
195 | \f | |
14294ce0 | 196 | |
26224b3f LC |
197 | /* Hooks. */ |
198 | scm_t_c_hook scm_before_gc_c_hook; | |
199 | scm_t_c_hook scm_before_mark_c_hook; | |
200 | scm_t_c_hook scm_before_sweep_c_hook; | |
201 | scm_t_c_hook scm_after_sweep_c_hook; | |
202 | scm_t_c_hook scm_after_gc_c_hook; | |
945fec60 | 203 | |
0f2d19dd | 204 | |
0fbdbe6c AW |
205 | static void |
206 | run_before_gc_c_hook (void) | |
207 | { | |
e1fbe716 AW |
208 | if (!SCM_I_CURRENT_THREAD) |
209 | /* GC while a thread is spinning up; punt. */ | |
210 | return; | |
211 | ||
0fbdbe6c AW |
212 | scm_c_hook_run (&scm_before_gc_c_hook, NULL); |
213 | } | |
214 | ||
215 | ||
0f2d19dd JB |
216 | /* GC Statistics Keeping |
217 | */ | |
b74e86cf | 218 | unsigned long scm_gc_ports_collected = 0; |
00b6ef23 AW |
219 | static long gc_time_taken = 0; |
220 | static long gc_start_time = 0; | |
221 | ||
6360beb2 AW |
222 | static unsigned long free_space_divisor; |
223 | static unsigned long minimum_free_space_divisor; | |
224 | static double target_free_space_divisor; | |
b74e86cf | 225 | |
915b3f9f | 226 | static unsigned long protected_obj_count = 0; |
c2cbcc57 | 227 | |
0f2d19dd | 228 | |
17ab1dc3 | 229 | SCM_SYMBOL (sym_gc_time_taken, "gc-time-taken"); |
915b3f9f LC |
230 | SCM_SYMBOL (sym_heap_size, "heap-size"); |
231 | SCM_SYMBOL (sym_heap_free_size, "heap-free-size"); | |
232 | SCM_SYMBOL (sym_heap_total_allocated, "heap-total-allocated"); | |
17ab1dc3 | 233 | SCM_SYMBOL (sym_heap_allocated_since_gc, "heap-allocated-since-gc"); |
7eec4c37 | 234 | SCM_SYMBOL (sym_protected_objects, "protected-objects"); |
17ab1dc3 | 235 | SCM_SYMBOL (sym_times, "gc-times"); |
cf2d30f6 | 236 | |
d3dd80ab | 237 | |
0f2d19dd JB |
238 | /* {Scheme Interface to GC} |
239 | */ | |
c2cbcc57 | 240 | extern int scm_gc_malloc_yield_percentage; |
a00c95d9 | 241 | SCM_DEFINE (scm_gc_stats, "gc-stats", 0, 0, 0, |
1bbd0b84 | 242 | (), |
1e6808ea | 243 | "Return an association list of statistics about Guile's current\n" |
c8a1bdc4 | 244 | "use of storage.\n") |
1bbd0b84 | 245 | #define FUNC_NAME s_scm_gc_stats |
0f2d19dd | 246 | { |
0f2d19dd | 247 | SCM answer; |
14294ce0 | 248 | GC_word heap_size, free_bytes, unmapped_bytes, bytes_since_gc, total_bytes; |
915b3f9f | 249 | size_t gc_times; |
4c9419ac | 250 | |
14294ce0 AW |
251 | GC_get_heap_usage_safe (&heap_size, &free_bytes, &unmapped_bytes, |
252 | &bytes_since_gc, &total_bytes); | |
0f595d7d | 253 | gc_times = GC_get_gc_no (); |
fca43887 | 254 | |
b9bd8526 | 255 | answer = |
00b6ef23 | 256 | scm_list_n (scm_cons (sym_gc_time_taken, scm_from_long (gc_time_taken)), |
915b3f9f LC |
257 | scm_cons (sym_heap_size, scm_from_size_t (heap_size)), |
258 | scm_cons (sym_heap_free_size, scm_from_size_t (free_bytes)), | |
259 | scm_cons (sym_heap_total_allocated, | |
260 | scm_from_size_t (total_bytes)), | |
17ab1dc3 AW |
261 | scm_cons (sym_heap_allocated_since_gc, |
262 | scm_from_size_t (bytes_since_gc)), | |
915b3f9f LC |
263 | scm_cons (sym_protected_objects, |
264 | scm_from_ulong (protected_obj_count)), | |
265 | scm_cons (sym_times, scm_from_size_t (gc_times)), | |
b9bd8526 | 266 | SCM_UNDEFINED); |
fca43887 | 267 | |
c8a1bdc4 | 268 | return answer; |
0f2d19dd | 269 | } |
c8a1bdc4 | 270 | #undef FUNC_NAME |
0f2d19dd | 271 | |
539b08a4 | 272 | |
7f9ec18a LC |
273 | SCM_DEFINE (scm_gc_dump, "gc-dump", 0, 0, 0, |
274 | (void), | |
275 | "Dump information about the garbage collector's internal data " | |
276 | "structures and memory usage to the standard output.") | |
277 | #define FUNC_NAME s_scm_gc_dump | |
278 | { | |
279 | GC_dump (); | |
280 | ||
281 | return SCM_UNSPECIFIED; | |
282 | } | |
283 | #undef FUNC_NAME | |
284 | ||
acf4331f | 285 | |
c8a1bdc4 HWN |
286 | SCM_DEFINE (scm_object_address, "object-address", 1, 0, 0, |
287 | (SCM obj), | |
288 | "Return an integer that for the lifetime of @var{obj} is uniquely\n" | |
289 | "returned by this function for @var{obj}") | |
290 | #define FUNC_NAME s_scm_object_address | |
c68296f8 | 291 | { |
b9bd8526 | 292 | return scm_from_ulong (SCM_UNPACK (obj)); |
c68296f8 | 293 | } |
c8a1bdc4 | 294 | #undef FUNC_NAME |
c68296f8 | 295 | |
1be6b49c | 296 | |
915b3f9f LC |
297 | SCM_DEFINE (scm_gc_disable, "gc-disable", 0, 0, 0, |
298 | (), | |
299 | "Disables the garbage collector. Nested calls are permitted. " | |
300 | "GC is re-enabled once @code{gc-enable} has been called the " | |
301 | "same number of times @code{gc-disable} was called.") | |
302 | #define FUNC_NAME s_scm_gc_disable | |
303 | { | |
304 | GC_disable (); | |
305 | return SCM_UNSPECIFIED; | |
306 | } | |
307 | #undef FUNC_NAME | |
308 | ||
309 | SCM_DEFINE (scm_gc_enable, "gc-enable", 0, 0, 0, | |
310 | (), | |
311 | "Enables the garbage collector.") | |
312 | #define FUNC_NAME s_scm_gc_enable | |
313 | { | |
314 | GC_enable (); | |
315 | return SCM_UNSPECIFIED; | |
316 | } | |
317 | #undef FUNC_NAME | |
318 | ||
319 | ||
c8a1bdc4 HWN |
320 | SCM_DEFINE (scm_gc, "gc", 0, 0, 0, |
321 | (), | |
322 | "Scans all of SCM objects and reclaims for further use those that are\n" | |
323 | "no longer accessible.") | |
324 | #define FUNC_NAME s_scm_gc | |
325 | { | |
b17e0ac3 | 326 | scm_i_gc ("call"); |
f740445a AW |
327 | /* If you're calling scm_gc(), you probably want synchronous |
328 | finalization. */ | |
eaf99988 | 329 | GC_invoke_finalizers (); |
c8a1bdc4 | 330 | return SCM_UNSPECIFIED; |
9d47a1e6 | 331 | } |
c8a1bdc4 | 332 | #undef FUNC_NAME |
9d47a1e6 | 333 | |
c8a1bdc4 | 334 | void |
b17e0ac3 | 335 | scm_i_gc (const char *what) |
c8a1bdc4 | 336 | { |
26224b3f | 337 | GC_gcollect (); |
eab1b259 | 338 | } |
0f2d19dd | 339 | |
4c7016dc | 340 | |
0f2d19dd JB |
341 | \f |
342 | /* {GC Protection Helper Functions} | |
343 | */ | |
344 | ||
345 | ||
5d2b97cd DH |
346 | /* |
347 | * If within a function you need to protect one or more scheme objects from | |
348 | * garbage collection, pass them as parameters to one of the | |
349 | * scm_remember_upto_here* functions below. These functions don't do | |
350 | * anything, but since the compiler does not know that they are actually | |
351 | * no-ops, it will generate code that calls these functions with the given | |
352 | * parameters. Therefore, you can be sure that the compiler will keep those | |
353 | * scheme values alive (on the stack or in a register) up to the point where | |
354 | * scm_remember_upto_here* is called. In other words, place the call to | |
592996c9 | 355 | * scm_remember_upto_here* _behind_ the last code in your function, that |
5d2b97cd DH |
356 | * depends on the scheme object to exist. |
357 | * | |
8c494e99 DH |
358 | * Example: We want to make sure that the string object str does not get |
359 | * garbage collected during the execution of 'some_function' in the code | |
360 | * below, because otherwise the characters belonging to str would be freed and | |
5d2b97cd DH |
361 | * 'some_function' might access freed memory. To make sure that the compiler |
362 | * keeps str alive on the stack or in a register such that it is visible to | |
363 | * the conservative gc we add the call to scm_remember_upto_here_1 _after_ the | |
364 | * call to 'some_function'. Note that this would not be necessary if str was | |
365 | * used anyway after the call to 'some_function'. | |
eb01cb64 | 366 | * char *chars = scm_i_string_chars (str); |
5d2b97cd DH |
367 | * some_function (chars); |
368 | * scm_remember_upto_here_1 (str); // str will be alive up to this point. | |
369 | */ | |
370 | ||
9e1569bd KR |
371 | /* Remove any macro versions of these while defining the functions. |
372 | Functions are always included in the library, for upward binary | |
373 | compatibility and in case combinations of GCC and non-GCC are used. */ | |
374 | #undef scm_remember_upto_here_1 | |
375 | #undef scm_remember_upto_here_2 | |
376 | ||
5d2b97cd | 377 | void |
e81d98ec | 378 | scm_remember_upto_here_1 (SCM obj SCM_UNUSED) |
5d2b97cd DH |
379 | { |
380 | /* Empty. Protects a single object from garbage collection. */ | |
381 | } | |
382 | ||
383 | void | |
e81d98ec | 384 | scm_remember_upto_here_2 (SCM obj1 SCM_UNUSED, SCM obj2 SCM_UNUSED) |
5d2b97cd DH |
385 | { |
386 | /* Empty. Protects two objects from garbage collection. */ | |
387 | } | |
388 | ||
389 | void | |
e81d98ec | 390 | scm_remember_upto_here (SCM obj SCM_UNUSED, ...) |
5d2b97cd DH |
391 | { |
392 | /* Empty. Protects any number of objects from garbage collection. */ | |
393 | } | |
394 | ||
c209c88e | 395 | /* |
41b0806d GB |
396 | These crazy functions prevent garbage collection |
397 | of arguments after the first argument by | |
398 | ensuring they remain live throughout the | |
399 | function because they are used in the last | |
400 | line of the code block. | |
401 | It'd be better to have a nice compiler hint to | |
402 | aid the conservative stack-scanning GC. --03/09/00 gjb */ | |
0f2d19dd JB |
403 | SCM |
404 | scm_return_first (SCM elt, ...) | |
0f2d19dd JB |
405 | { |
406 | return elt; | |
407 | } | |
408 | ||
41b0806d GB |
409 | int |
410 | scm_return_first_int (int i, ...) | |
411 | { | |
412 | return i; | |
413 | } | |
414 | ||
0f2d19dd | 415 | |
0f2d19dd | 416 | SCM |
6e8d25a6 | 417 | scm_permanent_object (SCM obj) |
0f2d19dd | 418 | { |
8e7b3e98 | 419 | return (scm_gc_protect_object (obj)); |
0f2d19dd JB |
420 | } |
421 | ||
422 | ||
7bd4fbe2 MD |
423 | /* Protect OBJ from the garbage collector. OBJ will not be freed, even if all |
424 | other references are dropped, until the object is unprotected by calling | |
6b1b030e | 425 | scm_gc_unprotect_object (OBJ). Calls to scm_gc_protect/unprotect_object nest, |
7bd4fbe2 MD |
426 | i. e. it is possible to protect the same object several times, but it is |
427 | necessary to unprotect the object the same number of times to actually get | |
428 | the object unprotected. It is an error to unprotect an object more often | |
429 | than it has been protected before. The function scm_protect_object returns | |
430 | OBJ. | |
431 | */ | |
432 | ||
433 | /* Implementation note: For every object X, there is a counter which | |
1f584400 | 434 | scm_gc_protect_object (X) increments and scm_gc_unprotect_object (X) decrements. |
7bd4fbe2 | 435 | */ |
686765af | 436 | |
7eec4c37 HWN |
437 | |
438 | ||
ef290276 | 439 | SCM |
6b1b030e | 440 | scm_gc_protect_object (SCM obj) |
ef290276 | 441 | { |
686765af | 442 | SCM handle; |
9d47a1e6 | 443 | |
686765af | 444 | /* This critical section barrier will be replaced by a mutex. */ |
33b320ae NJ |
445 | /* njrev: Indeed; if my comment above is correct, there is the same |
446 | critsec/mutex inconsistency here. */ | |
9de87eea | 447 | SCM_CRITICAL_SECTION_START; |
9d47a1e6 | 448 | |
acbccb0c | 449 | handle = scm_hashq_create_handle_x (scm_protects, obj, scm_from_int (0)); |
e11e83f3 | 450 | SCM_SETCDR (handle, scm_sum (SCM_CDR (handle), scm_from_int (1))); |
9d47a1e6 | 451 | |
7eec4c37 HWN |
452 | protected_obj_count ++; |
453 | ||
9de87eea | 454 | SCM_CRITICAL_SECTION_END; |
9d47a1e6 | 455 | |
ef290276 JB |
456 | return obj; |
457 | } | |
458 | ||
459 | ||
460 | /* Remove any protection for OBJ established by a prior call to | |
dab7f566 | 461 | scm_protect_object. This function returns OBJ. |
ef290276 | 462 | |
dab7f566 | 463 | See scm_protect_object for more information. */ |
ef290276 | 464 | SCM |
6b1b030e | 465 | scm_gc_unprotect_object (SCM obj) |
ef290276 | 466 | { |
686765af | 467 | SCM handle; |
9d47a1e6 | 468 | |
686765af | 469 | /* This critical section barrier will be replaced by a mutex. */ |
33b320ae | 470 | /* njrev: and again. */ |
9de87eea | 471 | SCM_CRITICAL_SECTION_START; |
9d47a1e6 | 472 | |
0ff7e3ff HWN |
473 | if (scm_gc_running_p) |
474 | { | |
475 | fprintf (stderr, "scm_unprotect_object called during GC.\n"); | |
476 | abort (); | |
477 | } | |
b17e0ac3 | 478 | |
acbccb0c | 479 | handle = scm_hashq_get_handle (scm_protects, obj); |
9d47a1e6 | 480 | |
7888309b | 481 | if (scm_is_false (handle)) |
686765af | 482 | { |
0f0f0899 MD |
483 | fprintf (stderr, "scm_unprotect_object called on unprotected object\n"); |
484 | abort (); | |
686765af | 485 | } |
6a199940 DH |
486 | else |
487 | { | |
e11e83f3 | 488 | SCM count = scm_difference (SCM_CDR (handle), scm_from_int (1)); |
bc36d050 | 489 | if (scm_is_eq (count, scm_from_int (0))) |
acbccb0c | 490 | scm_hashq_remove_x (scm_protects, obj); |
6a199940 | 491 | else |
1be6b49c | 492 | SCM_SETCDR (handle, count); |
6a199940 | 493 | } |
7eec4c37 | 494 | protected_obj_count --; |
686765af | 495 | |
9de87eea | 496 | SCM_CRITICAL_SECTION_END; |
ef290276 JB |
497 | |
498 | return obj; | |
499 | } | |
500 | ||
6b1b030e ML |
501 | void |
502 | scm_gc_register_root (SCM *p) | |
503 | { | |
8e7b3e98 | 504 | /* Nothing. */ |
6b1b030e ML |
505 | } |
506 | ||
507 | void | |
508 | scm_gc_unregister_root (SCM *p) | |
509 | { | |
8e7b3e98 | 510 | /* Nothing. */ |
6b1b030e ML |
511 | } |
512 | ||
513 | void | |
514 | scm_gc_register_roots (SCM *b, unsigned long n) | |
515 | { | |
516 | SCM *p = b; | |
517 | for (; p < b + n; ++p) | |
518 | scm_gc_register_root (p); | |
519 | } | |
520 | ||
521 | void | |
522 | scm_gc_unregister_roots (SCM *b, unsigned long n) | |
523 | { | |
524 | SCM *p = b; | |
525 | for (; p < b + n; ++p) | |
526 | scm_gc_unregister_root (p); | |
527 | } | |
528 | ||
0f2d19dd | 529 | \f |
a00c95d9 | 530 | |
4c48ba06 | 531 | |
c35738c1 MD |
532 | void |
533 | scm_storage_prehistory () | |
534 | { | |
0f595d7d | 535 | GC_set_all_interior_pointers (0); |
0f595d7d | 536 | |
6360beb2 AW |
537 | free_space_divisor = scm_getenv_int ("GC_FREE_SPACE_DIVISOR", 3); |
538 | minimum_free_space_divisor = free_space_divisor; | |
539 | target_free_space_divisor = free_space_divisor; | |
540 | GC_set_free_space_divisor (free_space_divisor); | |
eaf99988 | 541 | GC_set_finalize_on_demand (1); |
184327a6 | 542 | |
a82e7953 | 543 | GC_INIT (); |
e7bca227 | 544 | |
064d2409 | 545 | GC_expand_hp (DEFAULT_INITIAL_HEAP_SIZE); |
915b3f9f | 546 | |
184327a6 LC |
547 | /* We only need to register a displacement for those types for which the |
548 | higher bits of the type tag are used to store a pointer (that is, a | |
549 | pointer to an 8-octet aligned region). For `scm_tc3_struct', this is | |
550 | handled in `scm_alloc_struct ()'. */ | |
551 | GC_REGISTER_DISPLACEMENT (scm_tc3_cons); | |
314b8716 | 552 | /* GC_REGISTER_DISPLACEMENT (scm_tc3_unused); */ |
184327a6 | 553 | |
915b3f9f | 554 | /* Sanity check. */ |
acbccb0c | 555 | if (!GC_is_visible (&scm_protects)) |
915b3f9f | 556 | abort (); |
a82e7953 | 557 | |
c35738c1 MD |
558 | scm_c_hook_init (&scm_before_gc_c_hook, 0, SCM_C_HOOK_NORMAL); |
559 | scm_c_hook_init (&scm_before_mark_c_hook, 0, SCM_C_HOOK_NORMAL); | |
560 | scm_c_hook_init (&scm_before_sweep_c_hook, 0, SCM_C_HOOK_NORMAL); | |
561 | scm_c_hook_init (&scm_after_sweep_c_hook, 0, SCM_C_HOOK_NORMAL); | |
562 | scm_c_hook_init (&scm_after_gc_c_hook, 0, SCM_C_HOOK_NORMAL); | |
563 | } | |
85db4a2c | 564 | |
9de87eea | 565 | scm_i_pthread_mutex_t scm_i_gc_admin_mutex = SCM_I_PTHREAD_MUTEX_INITIALIZER; |
eb01cb64 | 566 | |
562cd1b8 AW |
567 | void |
568 | scm_init_gc_protect_object () | |
0f2d19dd | 569 | { |
acbccb0c | 570 | scm_protects = scm_c_make_hash_table (31); |
4a4c9785 | 571 | |
9de87eea MV |
572 | #if 0 |
573 | /* We can't have a cleanup handler since we have no thread to run it | |
574 | in. */ | |
575 | ||
a18bcd0e | 576 | #ifdef HAVE_ATEXIT |
c45acc34 | 577 | atexit (cleanup); |
e52ceaac MD |
578 | #else |
579 | #ifdef HAVE_ON_EXIT | |
580 | on_exit (cleanup, 0); | |
581 | #endif | |
9de87eea MV |
582 | #endif |
583 | ||
a18bcd0e | 584 | #endif |
0f2d19dd | 585 | } |
939794ce | 586 | |
0f2d19dd JB |
587 | \f |
588 | ||
939794ce DH |
589 | SCM scm_after_gc_hook; |
590 | ||
cc3546b0 | 591 | static SCM after_gc_async_cell; |
939794ce | 592 | |
cc3546b0 AW |
593 | /* The function after_gc_async_thunk causes the execution of the |
594 | * after-gc-hook. It is run after the gc, as soon as the asynchronous | |
595 | * events are handled by the evaluator. | |
939794ce DH |
596 | */ |
597 | static SCM | |
cc3546b0 | 598 | after_gc_async_thunk (void) |
939794ce | 599 | { |
cc3546b0 AW |
600 | /* Fun, no? Hook-run *and* run-hook? */ |
601 | scm_c_hook_run (&scm_after_gc_c_hook, NULL); | |
939794ce | 602 | scm_c_run_hook (scm_after_gc_hook, SCM_EOL); |
939794ce DH |
603 | return SCM_UNSPECIFIED; |
604 | } | |
605 | ||
606 | ||
cc3546b0 AW |
607 | /* The function queue_after_gc_hook is run by the scm_before_gc_c_hook |
608 | * at the end of the garbage collection. The only purpose of this | |
609 | * function is to mark the after_gc_async (which will eventually lead to | |
610 | * the execution of the after_gc_async_thunk). | |
939794ce DH |
611 | */ |
612 | static void * | |
cc3546b0 AW |
613 | queue_after_gc_hook (void * hook_data SCM_UNUSED, |
614 | void *fn_data SCM_UNUSED, | |
615 | void *data SCM_UNUSED) | |
e81d98ec DH |
616 | { |
617 | /* If cell access debugging is enabled, the user may choose to perform | |
618 | * additional garbage collections after an arbitrary number of cell | |
619 | * accesses. We don't want the scheme level after-gc-hook to be performed | |
620 | * for each of these garbage collections for the following reason: The | |
621 | * execution of the after-gc-hook causes cell accesses itself. Thus, if the | |
622 | * after-gc-hook was performed with every gc, and if the gc was performed | |
623 | * after a very small number of cell accesses, then the number of cell | |
624 | * accesses during the execution of the after-gc-hook will suffice to cause | |
625 | * the execution of the next gc. Then, guile would keep executing the | |
626 | * after-gc-hook over and over again, and would never come to do other | |
627 | * things. | |
eae33935 | 628 | * |
e81d98ec DH |
629 | * To overcome this problem, if cell access debugging with additional |
630 | * garbage collections is enabled, the after-gc-hook is never run by the | |
631 | * garbage collecter. When running guile with cell access debugging and the | |
632 | * execution of the after-gc-hook is desired, then it is necessary to run | |
633 | * the hook explicitly from the user code. This has the effect, that from | |
634 | * the scheme level point of view it seems that garbage collection is | |
635 | * performed with a much lower frequency than it actually is. Obviously, | |
636 | * this will not work for code that depends on a fixed one to one | |
637 | * relationship between the execution counts of the C level garbage | |
638 | * collection hooks and the execution count of the scheme level | |
639 | * after-gc-hook. | |
640 | */ | |
9de87eea | 641 | |
e81d98ec | 642 | #if (SCM_DEBUG_CELL_ACCESSES == 1) |
eab1b259 | 643 | if (scm_debug_cells_gc_interval == 0) |
e81d98ec | 644 | #endif |
cc3546b0 AW |
645 | { |
646 | scm_i_thread *t = SCM_I_CURRENT_THREAD; | |
647 | ||
648 | if (scm_is_false (SCM_CDR (after_gc_async_cell))) | |
649 | { | |
650 | SCM_SETCDR (after_gc_async_cell, t->active_asyncs); | |
651 | t->active_asyncs = after_gc_async_cell; | |
652 | t->pending_asyncs = 1; | |
653 | } | |
654 | } | |
e81d98ec | 655 | |
939794ce DH |
656 | return NULL; |
657 | } | |
658 | ||
00b6ef23 AW |
659 | \f |
660 | ||
661 | static void * | |
662 | start_gc_timer (void * hook_data SCM_UNUSED, | |
663 | void *fn_data SCM_UNUSED, | |
664 | void *data SCM_UNUSED) | |
665 | { | |
666 | if (!gc_start_time) | |
667 | gc_start_time = scm_c_get_internal_run_time (); | |
668 | ||
669 | return NULL; | |
670 | } | |
671 | ||
672 | static void * | |
673 | accumulate_gc_timer (void * hook_data SCM_UNUSED, | |
674 | void *fn_data SCM_UNUSED, | |
675 | void *data SCM_UNUSED) | |
676 | { | |
677 | if (gc_start_time) | |
6360beb2 AW |
678 | { |
679 | long now = scm_c_get_internal_run_time (); | |
00b6ef23 AW |
680 | gc_time_taken += now - gc_start_time; |
681 | gc_start_time = 0; | |
682 | } | |
683 | ||
684 | return NULL; | |
685 | } | |
686 | ||
6360beb2 AW |
687 | /* Return some idea of the memory footprint of a process, in bytes. |
688 | Currently only works on Linux systems. */ | |
689 | static size_t | |
690 | get_image_size (void) | |
691 | { | |
692 | unsigned long size, resident, share; | |
8ac70433 | 693 | size_t ret = 0; |
6360beb2 AW |
694 | |
695 | FILE *fp = fopen ("/proc/self/statm", "r"); | |
696 | ||
697 | if (fp && fscanf (fp, "%lu %lu %lu", &size, &resident, &share) == 3) | |
698 | ret = resident * 4096; | |
699 | ||
700 | if (fp) | |
701 | fclose (fp); | |
702 | ||
703 | return ret; | |
704 | } | |
705 | ||
fd51e661 | 706 | /* These are discussed later. */ |
553294d9 | 707 | static size_t bytes_until_gc = DEFAULT_INITIAL_HEAP_SIZE; |
fd51e661 AW |
708 | static scm_i_pthread_mutex_t bytes_until_gc_lock = SCM_I_PTHREAD_MUTEX_INITIALIZER; |
709 | ||
6360beb2 AW |
710 | /* Make GC run more frequently when the process image size is growing, |
711 | measured against the number of bytes allocated through the GC. | |
712 | ||
713 | If Guile is allocating at a GC-managed heap size H, libgc will tend | |
714 | to limit the process image size to H*N. But if at the same time the | |
715 | user program is mallocating at a rate M bytes per GC-allocated byte, | |
716 | then the process stabilizes at H*N*M -- assuming that collecting data | |
717 | will result in malloc'd data being freed. It doesn't take a very | |
718 | large M for this to be a bad situation. To limit the image size, | |
719 | Guile should GC more often -- the bigger the M, the more often. | |
720 | ||
721 | Numeric functions that produce bigger and bigger integers are | |
722 | pessimal, because M is an increasing function of time. Here is an | |
723 | example of such a function: | |
724 | ||
725 | (define (factorial n) | |
726 | (define (fac n acc) | |
727 | (if (<= n 1) | |
728 | acc | |
729 | (fac (1- n) (* n acc)))) | |
730 | (fac n 1)) | |
731 | ||
732 | It is possible for a process to grow for reasons that will not be | |
733 | solved by faster GC. In that case M will be estimated as | |
734 | artificially high for a while, and so GC will happen more often on | |
735 | the Guile side. But when it stabilizes, Guile can ease back the GC | |
736 | frequency. | |
737 | ||
738 | The key is to measure process image growth, not mallocation rate. | |
739 | For maximum effectiveness, Guile reacts quickly to process growth, | |
740 | and exponentially backs down when the process stops growing. | |
741 | ||
742 | See http://thread.gmane.org/gmane.lisp.guile.devel/12552/focus=12936 | |
743 | for further discussion. | |
744 | */ | |
745 | static void * | |
746 | adjust_gc_frequency (void * hook_data SCM_UNUSED, | |
747 | void *fn_data SCM_UNUSED, | |
748 | void *data SCM_UNUSED) | |
749 | { | |
750 | static size_t prev_image_size = 0; | |
751 | static size_t prev_bytes_alloced = 0; | |
752 | size_t image_size; | |
753 | size_t bytes_alloced; | |
754 | ||
fd51e661 AW |
755 | scm_i_pthread_mutex_lock (&bytes_until_gc_lock); |
756 | bytes_until_gc = GC_get_heap_size (); | |
757 | scm_i_pthread_mutex_unlock (&bytes_until_gc_lock); | |
758 | ||
6360beb2 AW |
759 | image_size = get_image_size (); |
760 | bytes_alloced = GC_get_total_bytes (); | |
761 | ||
d1c03624 | 762 | #define HEURISTICS_DEBUG 0 |
6360beb2 AW |
763 | |
764 | #if HEURISTICS_DEBUG | |
765 | fprintf (stderr, "prev image / alloced: %lu / %lu\n", prev_image_size, prev_bytes_alloced); | |
766 | fprintf (stderr, " image / alloced: %lu / %lu\n", image_size, bytes_alloced); | |
767 | fprintf (stderr, "divisor %lu / %f\n", free_space_divisor, target_free_space_divisor); | |
768 | #endif | |
769 | ||
770 | if (prev_image_size && bytes_alloced != prev_bytes_alloced) | |
771 | { | |
772 | double growth_rate, new_target_free_space_divisor; | |
773 | double decay_factor = 0.5; | |
774 | double hysteresis = 0.1; | |
775 | ||
776 | growth_rate = ((double) image_size - prev_image_size) | |
777 | / ((double)bytes_alloced - prev_bytes_alloced); | |
778 | ||
779 | #if HEURISTICS_DEBUG | |
780 | fprintf (stderr, "growth rate %f\n", growth_rate); | |
781 | #endif | |
782 | ||
783 | new_target_free_space_divisor = minimum_free_space_divisor; | |
784 | ||
785 | if (growth_rate > 0) | |
786 | new_target_free_space_divisor *= 1.0 + growth_rate; | |
787 | ||
788 | #if HEURISTICS_DEBUG | |
789 | fprintf (stderr, "new divisor %f\n", new_target_free_space_divisor); | |
790 | #endif | |
791 | ||
792 | if (new_target_free_space_divisor < target_free_space_divisor) | |
793 | /* Decay down. */ | |
794 | target_free_space_divisor = | |
795 | (decay_factor * target_free_space_divisor | |
796 | + (1.0 - decay_factor) * new_target_free_space_divisor); | |
797 | else | |
798 | /* Jump up. */ | |
799 | target_free_space_divisor = new_target_free_space_divisor; | |
800 | ||
801 | #if HEURISTICS_DEBUG | |
802 | fprintf (stderr, "new target divisor %f\n", target_free_space_divisor); | |
803 | #endif | |
804 | ||
805 | if (free_space_divisor + 0.5 + hysteresis < target_free_space_divisor | |
806 | || free_space_divisor - 0.5 - hysteresis > target_free_space_divisor) | |
807 | { | |
808 | free_space_divisor = lround (target_free_space_divisor); | |
809 | #if HEURISTICS_DEBUG | |
810 | fprintf (stderr, "new divisor %lu\n", free_space_divisor); | |
811 | #endif | |
812 | GC_set_free_space_divisor (free_space_divisor); | |
813 | } | |
814 | } | |
815 | ||
816 | prev_image_size = image_size; | |
817 | prev_bytes_alloced = bytes_alloced; | |
818 | ||
819 | return NULL; | |
820 | } | |
821 | ||
fd51e661 AW |
822 | /* The adjust_gc_frequency routine handles transients in the process |
823 | image size. It can't handle instense non-GC-managed steady-state | |
824 | allocation though, as it decays the FSD at steady-state down to its | |
825 | minimum value. | |
826 | ||
827 | The only real way to handle continuous, high non-GC allocation is to | |
828 | let the GC know about it. This routine can handle non-GC allocation | |
829 | rates that are similar in size to the GC-managed heap size. | |
830 | */ | |
831 | ||
832 | void | |
833 | scm_gc_register_allocation (size_t size) | |
834 | { | |
835 | scm_i_pthread_mutex_lock (&bytes_until_gc_lock); | |
836 | if (bytes_until_gc - size > bytes_until_gc) | |
837 | { | |
838 | bytes_until_gc = GC_get_heap_size (); | |
839 | scm_i_pthread_mutex_unlock (&bytes_until_gc_lock); | |
840 | GC_gcollect (); | |
841 | } | |
842 | else | |
843 | { | |
844 | bytes_until_gc -= size; | |
845 | scm_i_pthread_mutex_unlock (&bytes_until_gc_lock); | |
846 | } | |
847 | } | |
848 | ||
00b6ef23 AW |
849 | |
850 | \f | |
851 | ||
35164d84 | 852 | static char const * |
26224b3f LC |
853 | scm_i_tag_name (scm_t_bits tag) |
854 | { | |
74ec8d78 | 855 | switch (tag & 0x7f) /* 7 bits */ |
26224b3f LC |
856 | { |
857 | case scm_tcs_struct: | |
858 | return "struct"; | |
859 | case scm_tcs_cons_imcar: | |
860 | return "cons (immediate car)"; | |
861 | case scm_tcs_cons_nimcar: | |
862 | return "cons (non-immediate car)"; | |
5b46a8c2 | 863 | case scm_tc7_pointer: |
e2c2a699 | 864 | return "foreign"; |
c99de5aa AW |
865 | case scm_tc7_hashtable: |
866 | return "hashtable"; | |
26b26354 AW |
867 | case scm_tc7_weak_set: |
868 | return "weak-set"; | |
7005c60f AW |
869 | case scm_tc7_weak_table: |
870 | return "weak-table"; | |
9ea31741 AW |
871 | case scm_tc7_fluid: |
872 | return "fluid"; | |
873 | case scm_tc7_dynamic_state: | |
874 | return "dynamic state"; | |
6f3b0cc2 AW |
875 | case scm_tc7_frame: |
876 | return "frame"; | |
6f3b0cc2 AW |
877 | case scm_tc7_vm_cont: |
878 | return "vm continuation"; | |
26224b3f LC |
879 | case scm_tc7_wvect: |
880 | return "weak vector"; | |
881 | case scm_tc7_vector: | |
882 | return "vector"; | |
26224b3f LC |
883 | case scm_tc7_number: |
884 | switch (tag) | |
885 | { | |
886 | case scm_tc16_real: | |
887 | return "real"; | |
888 | break; | |
889 | case scm_tc16_big: | |
890 | return "bignum"; | |
891 | break; | |
892 | case scm_tc16_complex: | |
893 | return "complex number"; | |
894 | break; | |
895 | case scm_tc16_fraction: | |
896 | return "fraction"; | |
897 | break; | |
898 | } | |
899 | break; | |
900 | case scm_tc7_string: | |
901 | return "string"; | |
902 | break; | |
903 | case scm_tc7_stringbuf: | |
904 | return "string buffer"; | |
905 | break; | |
906 | case scm_tc7_symbol: | |
907 | return "symbol"; | |
908 | break; | |
909 | case scm_tc7_variable: | |
910 | return "variable"; | |
911 | break; | |
26224b3f LC |
912 | case scm_tc7_port: |
913 | return "port"; | |
914 | break; | |
915 | case scm_tc7_smob: | |
74ec8d78 AW |
916 | { |
917 | int k = 0xff & (tag >> 8); | |
918 | return (scm_smobs[k].name); | |
919 | } | |
26224b3f LC |
920 | break; |
921 | } | |
922 | ||
923 | return NULL; | |
924 | } | |
925 | ||
926 | ||
26224b3f LC |
927 | |
928 | \f | |
0f2d19dd JB |
929 | void |
930 | scm_init_gc () | |
0f2d19dd | 931 | { |
a82e7953 | 932 | /* `GC_INIT ()' was invoked in `scm_storage_prehistory ()'. */ |
d678e25c | 933 | |
f39448c5 | 934 | scm_after_gc_hook = scm_make_hook (SCM_INUM0); |
fde50407 | 935 | scm_c_define ("after-gc-hook", scm_after_gc_hook); |
939794ce | 936 | |
cc3546b0 AW |
937 | /* When the async is to run, the cdr of the gc_async pair gets set to |
938 | the asyncs queue of the current thread. */ | |
939 | after_gc_async_cell = scm_cons (scm_c_make_gsubr ("%after-gc-thunk", 0, 0, 0, | |
940 | after_gc_async_thunk), | |
941 | SCM_BOOL_F); | |
939794ce | 942 | |
cc3546b0 | 943 | scm_c_hook_add (&scm_before_gc_c_hook, queue_after_gc_hook, NULL, 0); |
00b6ef23 AW |
944 | scm_c_hook_add (&scm_before_gc_c_hook, start_gc_timer, NULL, 0); |
945 | scm_c_hook_add (&scm_after_gc_c_hook, accumulate_gc_timer, NULL, 0); | |
66b229d5 | 946 | |
738c899e AW |
947 | /* GC_get_heap_usage does not take a lock, and so can run in the GC |
948 | start hook. */ | |
949 | scm_c_hook_add (&scm_before_gc_c_hook, adjust_gc_frequency, NULL, 0); | |
738c899e | 950 | |
cc3546b0 | 951 | GC_set_start_callback (run_before_gc_c_hook); |
939794ce | 952 | |
a0599745 | 953 | #include "libguile/gc.x" |
0f2d19dd | 954 | } |
89e00824 | 955 | |
c8a1bdc4 HWN |
956 | |
957 | void | |
958 | scm_gc_sweep (void) | |
959 | #define FUNC_NAME "scm_gc_sweep" | |
960 | { | |
26224b3f | 961 | /* FIXME */ |
cd169c5a | 962 | fprintf (stderr, "%s: doing nothing\n", FUNC_NAME); |
c8a1bdc4 | 963 | } |
c8a1bdc4 HWN |
964 | #undef FUNC_NAME |
965 | ||
89e00824 ML |
966 | /* |
967 | Local Variables: | |
968 | c-file-style: "gnu" | |
969 | End: | |
970 | */ |