Commit | Line | Data |
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d823b11b | 1 | /* Copyright (C) 1995,1996,1997,1998,2000,2001, 2002 Free Software Foundation, Inc. |
7bfd3b9e JB |
2 | * |
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. | |
7 | * | |
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. | |
12 | * | |
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 | |
7bfd3b9e 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 | |
7bfd3b9e JB |
43 | \f |
44 | ||
d823b11b MV |
45 | /* This file implements nice Scheme level threads on top of the gastly |
46 | C level threads. | |
7f0f3eaa JB |
47 | */ |
48 | ||
d823b11b MV |
49 | #include <unistd.h> |
50 | #include <stdio.h> | |
51 | #include <assert.h> | |
52 | #include <sys/time.h> | |
5f05c406 | 53 | |
a0599745 | 54 | #include "libguile/_scm.h" |
d823b11b MV |
55 | #include "libguile/validate.h" |
56 | #include "libguile/root.h" | |
57 | #include "libguile/eval.h" | |
58 | #include "libguile/async.h" | |
59 | #include "libguile/ports.h" | |
60 | #include "libguile/threads.h" | |
a0599745 | 61 | #include "libguile/dynwind.h" |
d823b11b | 62 | #include "libguile/iselect.h" |
7bfd3b9e | 63 | |
d823b11b | 64 | /*** Queues */ |
7bfd3b9e | 65 | |
d823b11b MV |
66 | static SCM |
67 | make_queue () | |
68 | { | |
69 | return scm_cons (SCM_EOL, SCM_EOL); | |
70 | } | |
7bfd3b9e | 71 | |
d823b11b MV |
72 | static SCM |
73 | enqueue (SCM q, SCM t) | |
74 | { | |
75 | SCM c = scm_cons (t, SCM_EOL); | |
76 | if (SCM_NULLP (SCM_CDR (q))) | |
77 | SCM_SETCDR (q, c); | |
78 | else | |
79 | SCM_SETCDR (SCM_CAR (q), c); | |
80 | SCM_SETCAR (q, c); | |
81 | return c; | |
82 | } | |
7bfd3b9e | 83 | |
d823b11b MV |
84 | static void |
85 | remqueue (SCM q, SCM c) | |
86 | { | |
87 | SCM p, prev = q; | |
88 | for (p = SCM_CDR (q); !SCM_NULLP (p); p = SCM_CDR (p)) | |
89 | { | |
90 | if (SCM_EQ_P (p, c)) | |
91 | { | |
92 | if (SCM_EQ_P (c, SCM_CAR (q))) | |
93 | SCM_SETCAR (q, SCM_CDR (c)); | |
94 | SCM_SETCDR (prev, SCM_CDR (c)); | |
95 | return; | |
96 | } | |
97 | prev = p; | |
98 | } | |
99 | abort (); | |
100 | } | |
101 | ||
102 | static SCM | |
103 | dequeue (SCM q) | |
104 | { | |
105 | SCM c = SCM_CDR (q); | |
106 | if (SCM_NULLP (c)) | |
107 | return SCM_BOOL_F; | |
108 | else | |
109 | { | |
110 | SCM_SETCDR (q, SCM_CDR (c)); | |
111 | if (SCM_NULLP (SCM_CDR (q))) | |
112 | SCM_SETCAR (q, SCM_EOL); | |
113 | return SCM_CAR (c); | |
114 | } | |
115 | } | |
7bfd3b9e | 116 | |
d823b11b MV |
117 | /*** Threads */ |
118 | ||
9bc4701c MD |
119 | #define THREAD_INITIALIZED_P(t) (t->base != NULL) |
120 | ||
121 | struct scm_thread { | |
d823b11b MV |
122 | |
123 | /* Blocking. | |
124 | */ | |
125 | scm_t_cond sleep_cond; | |
126 | struct scm_thread *next_waiting; | |
127 | ||
9bc4701c MD |
128 | /* This mutex represents this threads right to access the heap. |
129 | That right can temporarily be taken away by the GC. */ | |
130 | scm_t_mutex heap_mutex; | |
131 | int clear_freelists_p; /* set if GC was done while thread was asleep */ | |
132 | ||
d823b11b MV |
133 | scm_root_state *root; |
134 | SCM handle; | |
135 | scm_t_thread thread; | |
136 | SCM result; | |
137 | int exited; | |
138 | ||
d823b11b MV |
139 | /* For keeping track of the stack and registers. */ |
140 | SCM_STACKITEM *base; | |
141 | SCM_STACKITEM *top; | |
142 | jmp_buf regs; | |
143 | ||
9bc4701c | 144 | }; |
d823b11b MV |
145 | |
146 | static SCM | |
147 | make_thread (SCM creation_protects) | |
148 | { | |
149 | SCM z; | |
150 | scm_thread *t; | |
151 | z = scm_make_smob (scm_tc16_thread); | |
152 | t = SCM_THREAD_DATA (z); | |
153 | t->handle = z; | |
154 | t->result = creation_protects; | |
155 | t->base = NULL; | |
9bc4701c | 156 | scm_i_plugin_cond_init (&t->sleep_cond, 0); |
dea5539e | 157 | scm_i_plugin_mutex_init (&t->heap_mutex, &scm_i_plugin_mutex); |
9bc4701c | 158 | t->clear_freelists_p = 0; |
d823b11b MV |
159 | t->exited = 0; |
160 | return z; | |
161 | } | |
162 | ||
163 | static void | |
9bc4701c MD |
164 | init_thread_creatant (SCM thread, |
165 | SCM_STACKITEM *base) | |
d823b11b | 166 | { |
9bc4701c MD |
167 | scm_thread *t = SCM_THREAD_DATA (thread); |
168 | t->thread = scm_thread_self (); | |
d823b11b MV |
169 | t->base = base; |
170 | t->top = NULL; | |
171 | } | |
4079f87e | 172 | |
d823b11b MV |
173 | static SCM |
174 | thread_mark (SCM obj) | |
175 | { | |
176 | scm_thread *t = SCM_THREAD_DATA (obj); | |
177 | scm_gc_mark (t->result); | |
9bc4701c | 178 | return t->root->handle; /* mark root-state of this thread */ |
d823b11b MV |
179 | } |
180 | ||
181 | static int | |
182 | thread_print (SCM exp, SCM port, scm_print_state *pstate SCM_UNUSED) | |
183 | { | |
184 | scm_thread *t = SCM_THREAD_DATA (exp); | |
185 | scm_puts ("#<thread ", port); | |
1b92fb6b MD |
186 | scm_intprint ((unsigned long)t->thread, 10, port); |
187 | scm_puts (" (", port); | |
d823b11b | 188 | scm_intprint ((unsigned long)t, 16, port); |
1b92fb6b | 189 | scm_puts (")>", port); |
d823b11b MV |
190 | return 1; |
191 | } | |
192 | ||
193 | static size_t | |
194 | thread_free (SCM obj) | |
195 | { | |
196 | scm_thread *t = SCM_THREAD_DATA (obj); | |
197 | if (!t->exited) | |
198 | abort (); | |
199 | scm_gc_free (t, sizeof (*t), "thread"); | |
200 | return 0; | |
201 | } | |
202 | ||
d823b11b | 203 | /*** Scheduling */ |
f7eca35d | 204 | |
9bc4701c MD |
205 | #define cur_thread (SCM_CURRENT_THREAD->handle) |
206 | scm_t_key scm_i_thread_key; | |
207 | scm_t_key scm_i_root_state_key; | |
d823b11b MV |
208 | |
209 | void | |
210 | scm_i_set_thread_data (void *data) | |
211 | { | |
9bc4701c MD |
212 | scm_thread *t = SCM_CURRENT_THREAD; |
213 | scm_setspecific (scm_i_root_state_key, data); | |
d823b11b MV |
214 | t->root = (scm_root_state *)data; |
215 | } | |
216 | ||
217 | static void | |
218 | resume (scm_thread *t) | |
219 | { | |
d823b11b | 220 | t->top = NULL; |
9bc4701c MD |
221 | if (t->clear_freelists_p) |
222 | { | |
223 | *SCM_FREELIST_LOC (scm_i_freelist) = SCM_EOL; | |
224 | *SCM_FREELIST_LOC (scm_i_freelist2) = SCM_EOL; | |
225 | t->clear_freelists_p = 0; | |
226 | } | |
d823b11b MV |
227 | } |
228 | ||
9bc4701c MD |
229 | void |
230 | scm_i_enter_guile (scm_thread *t) | |
d823b11b | 231 | { |
9bc4701c | 232 | scm_i_plugin_mutex_lock (&t->heap_mutex); |
d823b11b MV |
233 | resume (t); |
234 | } | |
235 | ||
236 | static scm_thread * | |
237 | suspend () | |
238 | { | |
9bc4701c | 239 | scm_thread *c = SCM_CURRENT_THREAD; |
d823b11b MV |
240 | |
241 | /* record top of stack for the GC */ | |
242 | c->top = (SCM_STACKITEM *)&c; | |
243 | /* save registers. */ | |
244 | SCM_FLUSH_REGISTER_WINDOWS; | |
245 | setjmp (c->regs); | |
246 | ||
247 | return c; | |
248 | } | |
249 | ||
9bc4701c MD |
250 | scm_thread * |
251 | scm_i_leave_guile () | |
d823b11b | 252 | { |
9bc4701c MD |
253 | scm_thread *t = suspend (); |
254 | scm_i_plugin_mutex_unlock (&t->heap_mutex); | |
255 | return t; | |
d823b11b MV |
256 | } |
257 | ||
258 | /* Put the current thread to sleep until it is explicitely unblocked. | |
259 | */ | |
260 | static int | |
261 | block () | |
262 | { | |
263 | int err; | |
264 | scm_thread *t = suspend (); | |
9bc4701c | 265 | err = scm_i_plugin_cond_wait (&t->sleep_cond, &t->heap_mutex); |
d823b11b MV |
266 | resume (t); |
267 | return err; | |
268 | } | |
269 | ||
270 | /* Put the current thread to sleep until it is explicitely unblocked | |
271 | or until a signal arrives or until time AT (absolute time) is | |
272 | reached. Return 0 when it has been unblocked; errno otherwise. | |
273 | */ | |
274 | static int | |
9bc4701c | 275 | timed_block (const struct timespec *at) |
d823b11b MV |
276 | { |
277 | int err; | |
278 | scm_thread *t = suspend (); | |
9bc4701c | 279 | err = scm_i_plugin_cond_timedwait (&t->sleep_cond, &t->heap_mutex, at); |
d823b11b MV |
280 | resume (t); |
281 | return err; | |
282 | } | |
283 | ||
284 | /* Unblock a sleeping thread. | |
285 | */ | |
286 | static void | |
287 | unblock (scm_thread *t) | |
288 | { | |
9bc4701c | 289 | scm_i_plugin_cond_signal (&t->sleep_cond); |
d823b11b MV |
290 | } |
291 | ||
292 | /*** Thread creation */ | |
293 | ||
9bc4701c | 294 | static scm_t_mutex thread_admin_mutex; |
d823b11b MV |
295 | static SCM all_threads; |
296 | static int thread_count; | |
297 | ||
298 | typedef struct launch_data { | |
299 | SCM thread; | |
300 | SCM rootcont; | |
301 | scm_t_catch_body body; | |
302 | void *body_data; | |
303 | scm_t_catch_handler handler; | |
304 | void *handler_data; | |
305 | } launch_data; | |
306 | ||
307 | static SCM | |
308 | body_bootstrip (launch_data* data) | |
309 | { | |
310 | /* First save the new root continuation */ | |
311 | data->rootcont = scm_root->rootcont; | |
312 | return (data->body) (data->body_data); | |
313 | } | |
314 | ||
315 | static SCM | |
316 | handler_bootstrip (launch_data* data, SCM tag, SCM throw_args) | |
317 | { | |
318 | scm_root->rootcont = data->rootcont; | |
319 | return (data->handler) (data->handler_data, tag, throw_args); | |
320 | } | |
321 | ||
322 | static void | |
323 | really_launch (SCM_STACKITEM *base, launch_data *data) | |
324 | { | |
9bc4701c MD |
325 | SCM thread; |
326 | scm_thread *t; | |
327 | thread = data->thread; | |
328 | t = SCM_THREAD_DATA (thread); | |
329 | SCM_FREELIST_CREATE (scm_i_freelist); | |
330 | SCM_FREELIST_CREATE (scm_i_freelist2); | |
331 | scm_setspecific (scm_i_thread_key, t); | |
332 | scm_setspecific (scm_i_root_state_key, t->root); | |
333 | scm_i_plugin_mutex_lock (&t->heap_mutex); /* ensure that we "own" the heap */ | |
334 | init_thread_creatant (thread, base); /* must own the heap */ | |
335 | ||
d823b11b MV |
336 | data->rootcont = SCM_BOOL_F; |
337 | t->result = | |
338 | scm_internal_cwdr ((scm_t_catch_body) body_bootstrip, | |
339 | data, | |
340 | (scm_t_catch_handler) handler_bootstrip, | |
341 | data, base); | |
094b640d | 342 | scm_i_leave_guile (); /* release the heap */ |
d823b11b MV |
343 | free (data); |
344 | ||
9bc4701c MD |
345 | scm_i_plugin_mutex_lock (&thread_admin_mutex); |
346 | all_threads = scm_delq_x (thread, all_threads); | |
d823b11b MV |
347 | t->exited = 1; |
348 | thread_count--; | |
9bc4701c | 349 | scm_i_plugin_mutex_unlock (&thread_admin_mutex); |
5b5947a2 | 350 | |
c4c52ebe | 351 | scm_thread_detach (t->thread); |
d823b11b MV |
352 | } |
353 | ||
9bc4701c | 354 | static void * |
d823b11b MV |
355 | launch_thread (void *p) |
356 | { | |
357 | really_launch ((SCM_STACKITEM *)&p, (launch_data *)p); | |
9bc4701c | 358 | return 0; |
d823b11b MV |
359 | } |
360 | ||
361 | static SCM | |
362 | create_thread (scm_t_catch_body body, void *body_data, | |
363 | scm_t_catch_handler handler, void *handler_data, | |
364 | SCM protects) | |
365 | { | |
366 | SCM thread; | |
367 | ||
368 | /* Make new thread. The first thing the new thread will do is to | |
369 | lock guile_mutex. Thus, we can safely complete its | |
370 | initialization after creating it. While the new thread starts, | |
371 | all its data is protected via all_threads. | |
372 | */ | |
373 | ||
374 | { | |
375 | scm_t_thread th; | |
c4c52ebe | 376 | SCM root, old_winds; |
d823b11b | 377 | launch_data *data; |
9bc4701c | 378 | scm_thread *t; |
d823b11b MV |
379 | int err; |
380 | ||
381 | /* Unwind wind chain. */ | |
382 | old_winds = scm_dynwinds; | |
383 | scm_dowinds (SCM_EOL, scm_ilength (scm_root->dynwinds)); | |
384 | ||
385 | /* Allocate thread locals. */ | |
386 | root = scm_make_root (scm_root->handle); | |
387 | data = scm_malloc (sizeof (launch_data)); | |
388 | ||
389 | /* Make thread. */ | |
390 | thread = make_thread (protects); | |
391 | data->thread = thread; | |
392 | data->body = body; | |
393 | data->body_data = body_data; | |
394 | data->handler = handler; | |
395 | data->handler_data = handler_data; | |
9bc4701c MD |
396 | t = SCM_THREAD_DATA (thread); |
397 | /* must initialize root state pointer before the thread is linked | |
398 | into all_threads */ | |
399 | t->root = SCM_ROOT_STATE (root); | |
400 | ||
401 | /* In order to avoid the need of synchronization between parent | |
402 | and child thread, we need to insert the child into all_threads | |
403 | before creation. */ | |
c4c52ebe MD |
404 | { |
405 | SCM new_threads = scm_cons (thread, SCM_BOOL_F); /* could cause GC */ | |
406 | scm_thread *parent = scm_i_leave_guile (); /* to prevent deadlock */ | |
407 | scm_i_plugin_mutex_lock (&thread_admin_mutex); | |
408 | SCM_SETCDR (new_threads, all_threads); | |
409 | all_threads = new_threads; | |
410 | thread_count++; | |
411 | scm_i_plugin_mutex_unlock (&thread_admin_mutex); | |
392d2833 MD |
412 | |
413 | scm_remember_upto_here_1 (root); | |
414 | ||
c4c52ebe MD |
415 | scm_i_enter_guile (parent); |
416 | } | |
9bc4701c MD |
417 | |
418 | err = scm_i_plugin_thread_create (&th, 0, launch_thread, (void *) data); | |
419 | if (err != 0) | |
d823b11b | 420 | { |
9bc4701c MD |
421 | scm_i_plugin_mutex_lock (&thread_admin_mutex); |
422 | all_threads = scm_delq_x (thread, all_threads); | |
423 | ((scm_thread *) SCM_THREAD_DATA(thread))->exited = 1; | |
424 | thread_count--; | |
425 | scm_i_plugin_mutex_unlock (&thread_admin_mutex); | |
d823b11b | 426 | } |
d823b11b MV |
427 | |
428 | /* Return to old dynamic context. */ | |
429 | scm_dowinds (old_winds, - scm_ilength (old_winds)); | |
430 | ||
431 | if (err) | |
432 | { | |
433 | errno = err; | |
434 | scm_syserror ("create-thread"); | |
435 | } | |
436 | } | |
437 | ||
438 | return thread; | |
439 | } | |
440 | ||
441 | SCM_DEFINE (scm_call_with_new_thread, "call-with-new-thread", 2, 0, 0, | |
442 | (SCM thunk, SCM handler), | |
443 | "Evaluate @var{(thunk)} in a new thread, and new dynamic context, " | |
444 | "returning a new thread object representing the thread. " | |
445 | "If an error occurs during evaluation, call error-thunk, passing it an " | |
446 | "error code describing the condition. " | |
447 | "If this happens, the error-thunk is called outside the scope of the new " | |
448 | "root -- it is called in the same dynamic context in which " | |
449 | "with-new-thread was evaluated, but not in the callers thread. " | |
450 | "All the evaluation rules for dynamic roots apply to threads.") | |
451 | #define FUNC_NAME s_scm_call_with_new_thread | |
452 | { | |
453 | SCM_ASSERT (SCM_NFALSEP (scm_thunk_p (thunk)), thunk, SCM_ARG1, FUNC_NAME); | |
454 | SCM_ASSERT (SCM_NFALSEP (scm_procedure_p (handler)), handler, SCM_ARG2, | |
455 | FUNC_NAME); | |
456 | ||
457 | return create_thread ((scm_t_catch_body) scm_call_0, thunk, | |
458 | (scm_t_catch_handler) scm_apply_1, handler, | |
459 | scm_cons (thunk, handler)); | |
460 | } | |
461 | #undef FUNC_NAME | |
462 | ||
d823b11b | 463 | SCM_DEFINE (scm_join_thread, "join-thread", 1, 0, 0, |
5f05c406 | 464 | (SCM thread), |
d823b11b MV |
465 | "Suspend execution of the calling thread until the target @var{thread} " |
466 | "terminates, unless the target @var{thread} has already terminated. ") | |
467 | #define FUNC_NAME s_scm_join_thread | |
5f05c406 | 468 | { |
d823b11b MV |
469 | scm_thread *t; |
470 | SCM res; | |
471 | ||
472 | SCM_VALIDATE_THREAD (1, thread); | |
473 | if (SCM_EQ_P (cur_thread, thread)) | |
474 | SCM_MISC_ERROR ("can not join the current thread", SCM_EOL); | |
475 | ||
476 | t = SCM_THREAD_DATA (thread); | |
477 | if (!t->exited) | |
478 | { | |
9bc4701c MD |
479 | scm_thread *c = scm_i_leave_guile (); |
480 | while (!THREAD_INITIALIZED_P (t)) | |
481 | SCM_TICK; | |
482 | scm_thread_join (t->thread, 0); | |
483 | scm_i_enter_guile (c); | |
d823b11b MV |
484 | } |
485 | res = t->result; | |
486 | t->result = SCM_BOOL_F; | |
487 | return res; | |
5f05c406 MV |
488 | } |
489 | #undef FUNC_NAME | |
490 | ||
28d52ebb MD |
491 | SCM *scm_loc_sys_thread_handler; |
492 | ||
493 | SCM | |
494 | scm_i_make_future (SCM thunk) | |
495 | { | |
496 | SCM_RETURN_NEWSMOB2 (scm_tc16_future, | |
497 | create_thread ((scm_t_catch_body) scm_call_0, | |
498 | thunk, | |
499 | (scm_t_catch_handler) scm_apply_1, | |
500 | *scm_loc_sys_thread_handler, | |
501 | scm_cons (thunk, | |
502 | *scm_loc_sys_thread_handler)), | |
503 | scm_make_rec_mutex ()); | |
504 | } | |
505 | ||
506 | static size_t | |
507 | future_free (SCM future) | |
508 | { | |
509 | scm_rec_mutex_free (SCM_FUTURE_MUTEX (future)); | |
510 | return 0; | |
511 | } | |
512 | ||
513 | static int | |
514 | future_print (SCM exp, SCM port, scm_print_state *pstate) | |
515 | { | |
516 | int writingp = SCM_WRITINGP (pstate); | |
517 | scm_puts ("#<future ", port); | |
518 | SCM_SET_WRITINGP (pstate, 1); | |
519 | scm_iprin1 (SCM_FUTURE_DATA (exp), port, pstate); | |
520 | SCM_SET_WRITINGP (pstate, writingp); | |
521 | scm_putc ('>', port); | |
522 | return !0; | |
523 | } | |
524 | ||
525 | SCM_DEFINE (scm_future_ref, "future-ref", 1, 0, 0, | |
526 | (SCM future), | |
527 | "If the future @var{x} has not been computed yet, compute and\n" | |
528 | "return @var{x}, otherwise just return the previously computed\n" | |
529 | "value.") | |
530 | #define FUNC_NAME s_scm_future_ref | |
531 | { | |
532 | SCM_VALIDATE_FUTURE (1, future); | |
533 | scm_rec_mutex_lock (SCM_FUTURE_MUTEX (future)); | |
534 | if (!SCM_FUTURE_COMPUTED_P (future)) | |
535 | { | |
536 | SCM value = scm_join_thread (SCM_FUTURE_DATA (future)); | |
537 | if (!SCM_FUTURE_COMPUTED_P (future)) | |
538 | { | |
539 | SCM_SET_FUTURE_DATA (future, value); | |
540 | SCM_SET_FUTURE_COMPUTED (future); | |
541 | } | |
542 | } | |
543 | scm_rec_mutex_unlock (SCM_FUTURE_MUTEX (future)); | |
544 | return SCM_FUTURE_DATA (future); | |
545 | } | |
546 | #undef FUNC_NAME | |
547 | ||
9bc4701c | 548 | /*** Fair mutexes */ |
4079f87e | 549 | |
d823b11b MV |
550 | /* We implement our own mutex type since we want them to be 'fair', we |
551 | want to do fancy things while waiting for them (like running | |
552 | asyncs) and we want to support waiting on many things at once. | |
553 | Also, we might add things that are nice for debugging. | |
554 | */ | |
4079f87e | 555 | |
9bc4701c | 556 | typedef struct fair_mutex { |
d823b11b | 557 | /* the thread currently owning the mutex, or SCM_BOOL_F. */ |
9bc4701c MD |
558 | scm_t_mutex lock; |
559 | int lockedp; | |
d823b11b MV |
560 | SCM owner; |
561 | /* how much the owner owns us. */ | |
562 | int level; | |
563 | /* the threads waiting for this mutex. */ | |
564 | SCM waiting; | |
9bc4701c | 565 | } fair_mutex; |
5f05c406 | 566 | |
d823b11b | 567 | static SCM |
9bc4701c | 568 | fair_mutex_mark (SCM mx) |
d823b11b | 569 | { |
9bc4701c | 570 | fair_mutex *m = SCM_MUTEX_DATA (mx); |
d823b11b MV |
571 | scm_gc_mark (m->owner); |
572 | return m->waiting; | |
573 | } | |
4079f87e | 574 | |
9bc4701c | 575 | SCM_DEFINE (scm_make_fair_mutex, "make-fair-mutex", 0, 0, 0, |
d823b11b | 576 | (void), |
9bc4701c MD |
577 | "Create a new fair mutex object. ") |
578 | #define FUNC_NAME s_scm_make_fair_mutex | |
d823b11b | 579 | { |
9bc4701c MD |
580 | SCM mx = scm_make_smob (scm_tc16_fair_mutex); |
581 | fair_mutex *m = SCM_MUTEX_DATA (mx); | |
dea5539e | 582 | scm_i_plugin_mutex_init (&m->lock, &scm_i_plugin_mutex); |
9bc4701c | 583 | m->lockedp = 0; |
d823b11b MV |
584 | m->owner = SCM_BOOL_F; |
585 | m->level = 0; | |
586 | m->waiting = make_queue (); | |
587 | return mx; | |
588 | } | |
589 | #undef FUNC_NAME | |
4079f87e | 590 | |
9bc4701c MD |
591 | static int |
592 | fair_mutex_lock (fair_mutex *m) | |
d823b11b | 593 | { |
9bc4701c MD |
594 | scm_i_plugin_mutex_lock (&m->lock); |
595 | #if 0 | |
596 | /* Need to wait if another thread is just temporarily unlocking. | |
597 | This is happens very seldom and only when the other thread is | |
598 | between scm_mutex_unlock and scm_i_plugin_mutex_lock below. */ | |
599 | while (m->lockedp) | |
600 | SCM_TICK; | |
601 | m->lockedp = 1; | |
602 | #endif | |
603 | ||
d823b11b MV |
604 | if (m->owner == SCM_BOOL_F) |
605 | m->owner = cur_thread; | |
606 | else if (m->owner == cur_thread) | |
607 | m->level++; | |
608 | else | |
609 | { | |
610 | while (1) | |
611 | { | |
612 | SCM c = enqueue (m->waiting, cur_thread); | |
9bc4701c MD |
613 | int err; |
614 | /* Note: It's important that m->lock is never locked for | |
615 | any longer amount of time since that could prevent GC */ | |
616 | scm_i_plugin_mutex_unlock (&m->lock); | |
617 | err = block (); | |
d823b11b | 618 | if (m->owner == cur_thread) |
9bc4701c MD |
619 | return 0; |
620 | scm_i_plugin_mutex_lock (&m->lock); | |
d823b11b | 621 | remqueue (m->waiting, c); |
9bc4701c | 622 | scm_i_plugin_mutex_unlock (&m->lock); |
d823b11b | 623 | if (err) |
9bc4701c | 624 | return err; |
d823b11b | 625 | SCM_ASYNC_TICK; |
9bc4701c | 626 | scm_i_plugin_mutex_lock (&m->lock); |
d823b11b MV |
627 | } |
628 | } | |
9bc4701c MD |
629 | scm_i_plugin_mutex_unlock (&m->lock); |
630 | return 0; | |
d823b11b | 631 | } |
7bfd3b9e | 632 | |
9bc4701c MD |
633 | static int |
634 | fair_mutex_trylock (fair_mutex *m) | |
d823b11b | 635 | { |
9bc4701c | 636 | scm_i_plugin_mutex_lock (&m->lock); |
d823b11b MV |
637 | if (m->owner == SCM_BOOL_F) |
638 | m->owner = cur_thread; | |
639 | else if (m->owner == cur_thread) | |
640 | m->level++; | |
641 | else | |
9bc4701c MD |
642 | { |
643 | scm_i_plugin_mutex_unlock (&m->lock); | |
644 | return EBUSY; | |
645 | } | |
646 | scm_i_plugin_mutex_unlock (&m->lock); | |
647 | return 0; | |
d823b11b | 648 | } |
d823b11b | 649 | |
9bc4701c MD |
650 | static int |
651 | fair_mutex_unlock (fair_mutex *m) | |
5f05c406 | 652 | { |
9bc4701c | 653 | scm_i_plugin_mutex_lock (&m->lock); |
d823b11b MV |
654 | if (m->owner != cur_thread) |
655 | { | |
9bc4701c MD |
656 | scm_i_plugin_mutex_unlock (&m->lock); |
657 | return EPERM; | |
d823b11b MV |
658 | } |
659 | else if (m->level > 0) | |
660 | m->level--; | |
661 | else | |
662 | { | |
663 | SCM next = dequeue (m->waiting); | |
664 | if (!SCM_FALSEP (next)) | |
665 | { | |
666 | m->owner = next; | |
667 | unblock (SCM_THREAD_DATA (next)); | |
d823b11b MV |
668 | } |
669 | else | |
670 | m->owner = SCM_BOOL_F; | |
671 | } | |
9bc4701c MD |
672 | scm_i_plugin_mutex_unlock (&m->lock); |
673 | return 0; | |
5f05c406 MV |
674 | } |
675 | ||
9bc4701c | 676 | /*** Fair condition variables */ |
7bfd3b9e | 677 | |
d823b11b MV |
678 | /* Like mutexes, we implement our own condition variables using the |
679 | primitives above. | |
680 | */ | |
5f05c406 | 681 | |
9bc4701c MD |
682 | typedef struct fair_cond { |
683 | scm_t_mutex lock; | |
d823b11b MV |
684 | /* the threads waiting for this condition. */ |
685 | SCM waiting; | |
9bc4701c | 686 | } fair_cond; |
5f05c406 | 687 | |
d823b11b | 688 | static SCM |
9bc4701c | 689 | fair_cond_mark (SCM cv) |
5f05c406 | 690 | { |
9bc4701c | 691 | fair_cond *c = SCM_CONDVAR_DATA (cv); |
d823b11b | 692 | return c->waiting; |
5f05c406 MV |
693 | } |
694 | ||
9bc4701c MD |
695 | SCM_DEFINE (scm_make_fair_condition_variable, "make-fair-condition-variable", 0, 0, 0, |
696 | (void), | |
697 | "Make a new fair condition variable.") | |
698 | #define FUNC_NAME s_scm_make_fair_condition_variable | |
699 | { | |
700 | SCM cv = scm_make_smob (scm_tc16_fair_condvar); | |
701 | fair_cond *c = SCM_CONDVAR_DATA (cv); | |
702 | scm_i_plugin_mutex_init (&c->lock, 0); | |
703 | c->waiting = make_queue (); | |
704 | return cv; | |
705 | } | |
706 | #undef FUNC_NAME | |
707 | ||
708 | static int | |
709 | fair_cond_timedwait (fair_cond *c, | |
710 | fair_mutex *m, | |
711 | const struct timespec *waittime) | |
712 | { | |
713 | int err; | |
714 | scm_i_plugin_mutex_lock (&c->lock); | |
715 | ||
716 | while (1) | |
717 | { | |
718 | enqueue (c->waiting, cur_thread); | |
719 | scm_i_plugin_mutex_unlock (&c->lock); | |
720 | fair_mutex_unlock (m); /*fixme* - not thread safe */ | |
721 | if (waittime == NULL) | |
722 | err = block (); | |
723 | else | |
724 | err = timed_block (waittime); | |
725 | fair_mutex_lock (m); | |
726 | if (err) | |
727 | return err; | |
728 | /* XXX - check whether we have been signalled. */ | |
729 | break; | |
730 | } | |
731 | return err; | |
732 | } | |
733 | ||
734 | static int | |
735 | fair_cond_signal (fair_cond *c) | |
736 | { | |
737 | SCM th; | |
738 | scm_i_plugin_mutex_lock (&c->lock); | |
739 | if (!SCM_FALSEP (th = dequeue (c->waiting))) | |
740 | unblock (SCM_THREAD_DATA (th)); | |
741 | scm_i_plugin_mutex_unlock (&c->lock); | |
742 | return 0; | |
743 | } | |
744 | ||
745 | static int | |
746 | fair_cond_broadcast (fair_cond *c) | |
747 | { | |
748 | SCM th; | |
749 | scm_i_plugin_mutex_lock (&c->lock); | |
750 | while (!SCM_FALSEP (th = dequeue (c->waiting))) | |
751 | unblock (SCM_THREAD_DATA (th)); | |
752 | scm_i_plugin_mutex_unlock (&c->lock); | |
753 | return 0; | |
754 | } | |
755 | ||
756 | /*** Mutexes */ | |
757 | ||
758 | SCM_DEFINE (scm_make_mutex, "make-mutex", 0, 0, 0, | |
759 | (void), | |
760 | "Create a new mutex object. ") | |
761 | #define FUNC_NAME s_scm_make_mutex | |
762 | { | |
763 | SCM mx = scm_make_smob (scm_tc16_mutex); | |
dea5539e | 764 | scm_i_plugin_mutex_init (SCM_MUTEX_DATA (mx), &scm_i_plugin_mutex); |
9bc4701c MD |
765 | return mx; |
766 | } | |
767 | #undef FUNC_NAME | |
768 | ||
769 | /*fixme* change documentation */ | |
770 | SCM_DEFINE (scm_lock_mutex, "lock-mutex", 1, 0, 0, | |
771 | (SCM mx), | |
772 | "Lock @var{mutex}. If the mutex is already locked, the calling thread " | |
773 | "blocks until the mutex becomes available. The function returns when " | |
774 | "the calling thread owns the lock on @var{mutex}. Locking a mutex that " | |
775 | "a thread already owns will succeed right away and will not block the " | |
776 | "thread. That is, Guile's mutexes are @emph{recursive}. ") | |
777 | #define FUNC_NAME s_scm_lock_mutex | |
778 | { | |
779 | int err; | |
780 | SCM_VALIDATE_MUTEX (1, mx); | |
781 | ||
782 | if (SCM_TYP16 (mx) == scm_tc16_fair_mutex) | |
783 | err = fair_mutex_lock (SCM_MUTEX_DATA (mx)); | |
784 | else | |
785 | { | |
786 | scm_t_mutex *m = SCM_MUTEX_DATA (mx); | |
787 | scm_thread *t = scm_i_leave_guile (); | |
788 | err = scm_i_plugin_mutex_lock (m); | |
789 | scm_i_enter_guile (t); | |
790 | } | |
791 | ||
792 | if (err) | |
793 | { | |
794 | errno = err; | |
795 | SCM_SYSERROR; | |
796 | } | |
797 | return SCM_BOOL_T; | |
798 | } | |
799 | #undef FUNC_NAME | |
800 | ||
801 | SCM_DEFINE (scm_try_mutex, "try-mutex", 1, 0, 0, | |
802 | (SCM mx), | |
803 | "Try to lock @var{mutex}. If the mutex is already locked by someone " | |
804 | "else, return @code{#f}. Else lock the mutex and return @code{#t}. ") | |
805 | #define FUNC_NAME s_scm_try_mutex | |
806 | { | |
807 | int err; | |
808 | SCM_VALIDATE_MUTEX (1, mx); | |
809 | ||
810 | if (SCM_TYP16 (mx) == scm_tc16_fair_mutex) | |
811 | err = fair_mutex_trylock (SCM_MUTEX_DATA (mx)); | |
812 | else | |
813 | { | |
814 | scm_t_mutex *m = SCM_MUTEX_DATA (mx); | |
815 | scm_thread *t = scm_i_leave_guile (); | |
816 | err = scm_i_plugin_mutex_trylock (m); | |
817 | scm_i_enter_guile (t); | |
818 | } | |
819 | ||
820 | if (err == EBUSY) | |
821 | return SCM_BOOL_F; | |
822 | ||
823 | if (err) | |
824 | { | |
825 | errno = err; | |
826 | SCM_SYSERROR; | |
827 | } | |
828 | ||
829 | return SCM_BOOL_T; | |
830 | } | |
831 | #undef FUNC_NAME | |
832 | ||
833 | SCM_DEFINE (scm_unlock_mutex, "unlock-mutex", 1, 0, 0, | |
834 | (SCM mx), | |
835 | "Unlocks @var{mutex} if the calling thread owns the lock on " | |
836 | "@var{mutex}. Calling unlock-mutex on a mutex not owned by the current " | |
837 | "thread results in undefined behaviour. Once a mutex has been unlocked, " | |
838 | "one thread blocked on @var{mutex} is awakened and grabs the mutex " | |
839 | "lock. Every call to @code{lock-mutex} by this thread must be matched " | |
840 | "with a call to @code{unlock-mutex}. Only the last call to " | |
841 | "@code{unlock-mutex} will actually unlock the mutex. ") | |
842 | #define FUNC_NAME s_scm_unlock_mutex | |
843 | { | |
844 | int err; | |
845 | SCM_VALIDATE_MUTEX (1, mx); | |
846 | ||
847 | if (SCM_TYP16 (mx) == scm_tc16_fair_mutex) | |
848 | { | |
849 | err = fair_mutex_unlock (SCM_MUTEX_DATA (mx)); | |
850 | if (err == EPERM) | |
851 | { | |
852 | fair_mutex *m = SCM_MUTEX_DATA (mx); | |
853 | if (m->owner != cur_thread) | |
854 | { | |
855 | if (m->owner == SCM_BOOL_F) | |
856 | SCM_MISC_ERROR ("mutex not locked", SCM_EOL); | |
857 | else | |
858 | SCM_MISC_ERROR ("mutex not locked by this thread", SCM_EOL); | |
859 | } | |
860 | } | |
861 | } | |
862 | else | |
863 | { | |
864 | scm_t_mutex *m = SCM_MUTEX_DATA (mx); | |
865 | err = scm_i_plugin_mutex_unlock (m); | |
866 | } | |
867 | ||
868 | if (err) | |
869 | { | |
870 | errno = err; | |
871 | SCM_SYSERROR; | |
872 | } | |
873 | return SCM_BOOL_T; | |
874 | } | |
875 | #undef FUNC_NAME | |
876 | ||
877 | /*** Condition variables */ | |
878 | ||
d823b11b MV |
879 | SCM_DEFINE (scm_make_condition_variable, "make-condition-variable", 0, 0, 0, |
880 | (void), | |
881 | "Make a new condition variable.") | |
882 | #define FUNC_NAME s_scm_make_condition_variable | |
5f05c406 | 883 | { |
d823b11b | 884 | SCM cv = scm_make_smob (scm_tc16_condvar); |
9bc4701c | 885 | scm_i_plugin_cond_init (SCM_CONDVAR_DATA (cv), 0); |
d823b11b | 886 | return cv; |
5f05c406 | 887 | } |
d823b11b | 888 | #undef FUNC_NAME |
5f05c406 | 889 | |
d823b11b MV |
890 | SCM_DEFINE (scm_timed_wait_condition_variable, "wait-condition-variable", 2, 1, 0, |
891 | (SCM cv, SCM mx, SCM t), | |
892 | "Wait until @var{cond-var} has been signalled. While waiting, " | |
893 | "@var{mutex} is atomically unlocked (as with @code{unlock-mutex}) and " | |
894 | "is locked again when this function returns. When @var{time} is given, " | |
895 | "it specifies a point in time where the waiting should be aborted. It " | |
896 | "can be either a integer as returned by @code{current-time} or a pair " | |
897 | "as returned by @code{gettimeofday}. When the waiting is aborted the " | |
898 | "mutex is locked and @code{#f} is returned. When the condition " | |
899 | "variable is in fact signalled, the mutex is also locked and @code{#t} " | |
900 | "is returned. ") | |
901 | #define FUNC_NAME s_scm_timed_wait_condition_variable | |
5f05c406 | 902 | { |
d823b11b MV |
903 | struct timespec waittime; |
904 | int err; | |
905 | ||
906 | SCM_VALIDATE_CONDVAR (1, cv); | |
907 | SCM_VALIDATE_MUTEX (2, mx); | |
9bc4701c MD |
908 | if (!((SCM_TYP16 (cv) == scm_tc16_condvar |
909 | && SCM_TYP16 (mx) == scm_tc16_mutex) | |
910 | || (SCM_TYP16 (cv) == scm_tc16_fair_condvar | |
911 | && SCM_TYP16 (mx) == scm_tc16_fair_mutex))) | |
912 | SCM_MISC_ERROR ("Condition variable and mutex are of different kinds.", | |
913 | SCM_EOL); | |
914 | ||
d823b11b MV |
915 | if (!SCM_UNBNDP (t)) |
916 | { | |
917 | if (SCM_CONSP (t)) | |
918 | { | |
9bc4701c MD |
919 | SCM_VALIDATE_UINT_COPY (3, SCM_CAR (t), waittime.tv_sec); |
920 | SCM_VALIDATE_UINT_COPY (3, SCM_CDR (t), waittime.tv_nsec); | |
d823b11b MV |
921 | waittime.tv_nsec *= 1000; |
922 | } | |
923 | else | |
924 | { | |
925 | SCM_VALIDATE_UINT_COPY (3, t, waittime.tv_sec); | |
926 | waittime.tv_nsec = 0; | |
927 | } | |
928 | } | |
929 | ||
9bc4701c MD |
930 | if (SCM_TYP16 (cv) == scm_tc16_fair_condvar) |
931 | err = fair_cond_timedwait (SCM_CONDVAR_DATA (cv), | |
932 | SCM_MUTEX_DATA (mx), | |
933 | SCM_UNBNDP (t) ? NULL : &waittime); | |
934 | else | |
935 | { | |
936 | scm_t_cond *c = SCM_CONDVAR_DATA (cv); | |
937 | scm_t_mutex *m = SCM_MUTEX_DATA (mx); | |
938 | scm_thread *t = scm_i_leave_guile (); | |
939 | err = scm_i_plugin_cond_wait (c, m); | |
940 | scm_i_enter_guile (t); | |
941 | } | |
d823b11b | 942 | |
9bc4701c | 943 | if (err) |
d823b11b | 944 | { |
9bc4701c MD |
945 | errno = err; |
946 | SCM_SYSERROR; | |
d823b11b | 947 | } |
9bc4701c | 948 | return SCM_BOOL_T; |
5f05c406 | 949 | } |
d823b11b | 950 | #undef FUNC_NAME |
5f05c406 | 951 | |
d823b11b MV |
952 | SCM_DEFINE (scm_signal_condition_variable, "signal-condition-variable", 1, 0, 0, |
953 | (SCM cv), | |
954 | "Wake up one thread that is waiting for @var{cv}") | |
955 | #define FUNC_NAME s_scm_signal_condition_variable | |
5f05c406 | 956 | { |
d823b11b | 957 | SCM_VALIDATE_CONDVAR (1, cv); |
9bc4701c MD |
958 | if (SCM_TYP16 (cv) == scm_tc16_fair_condvar) |
959 | fair_cond_signal (SCM_CONDVAR_DATA (cv)); | |
960 | else | |
961 | { | |
962 | scm_t_cond *c = SCM_CONDVAR_DATA (cv); | |
963 | scm_i_plugin_cond_signal (c); | |
964 | } | |
d823b11b | 965 | return SCM_BOOL_T; |
5f05c406 | 966 | } |
d823b11b | 967 | #undef FUNC_NAME |
5f05c406 | 968 | |
d823b11b MV |
969 | SCM_DEFINE (scm_broadcast_condition_variable, "broadcast-condition-variable", 1, 0, 0, |
970 | (SCM cv), | |
971 | "Wake up all threads that are waiting for @var{cv}. ") | |
972 | #define FUNC_NAME s_scm_broadcast_condition_variable | |
5f05c406 | 973 | { |
d823b11b | 974 | SCM_VALIDATE_CONDVAR (1, cv); |
9bc4701c MD |
975 | if (SCM_TYP16 (cv) == scm_tc16_fair_condvar) |
976 | fair_cond_broadcast (SCM_CONDVAR_DATA (cv)); | |
977 | else | |
978 | { | |
979 | scm_t_cond *c = SCM_CONDVAR_DATA (cv); | |
980 | scm_i_plugin_cond_broadcast (c); | |
981 | } | |
d823b11b | 982 | return SCM_BOOL_T; |
5f05c406 | 983 | } |
d823b11b | 984 | #undef FUNC_NAME |
5f05c406 | 985 | |
d823b11b MV |
986 | /*** Marking stacks */ |
987 | ||
988 | /* XXX - what to do with this? Do we need to handle this for blocked | |
989 | threads as well? | |
990 | */ | |
991 | #ifdef __ia64__ | |
992 | # define SCM_MARK_BACKING_STORE() do { \ | |
993 | ucontext_t ctx; \ | |
994 | SCM_STACKITEM * top, * bot; \ | |
995 | getcontext (&ctx); \ | |
996 | scm_mark_locations ((SCM_STACKITEM *) &ctx.uc_mcontext, \ | |
997 | ((size_t) (sizeof (SCM_STACKITEM) - 1 + sizeof ctx.uc_mcontext) \ | |
998 | / sizeof (SCM_STACKITEM))); \ | |
999 | bot = (SCM_STACKITEM *) __libc_ia64_register_backing_store_base; \ | |
1000 | top = (SCM_STACKITEM *) ctx.uc_mcontext.sc_ar_bsp; \ | |
1001 | scm_mark_locations (bot, top - bot); } while (0) | |
1002 | #else | |
1003 | # define SCM_MARK_BACKING_STORE() | |
1004 | #endif | |
1005 | ||
1006 | void | |
1007 | scm_threads_mark_stacks (void) | |
5f05c406 | 1008 | { |
d823b11b MV |
1009 | volatile SCM c; |
1010 | for (c = all_threads; !SCM_NULLP (c); c = SCM_CDR (c)) | |
1011 | { | |
1012 | scm_thread *t = SCM_THREAD_DATA (SCM_CAR (c)); | |
9bc4701c | 1013 | if (!THREAD_INITIALIZED_P (t)) |
d823b11b MV |
1014 | { |
1015 | /* Not fully initialized yet. */ | |
1016 | continue; | |
1017 | } | |
1018 | if (t->top == NULL) | |
1019 | { | |
9bc4701c MD |
1020 | long stack_len; |
1021 | #ifdef SCM_DEBUG | |
1022 | if (t->thread != scm_thread_self ()) | |
1023 | abort (); | |
1024 | #endif | |
d823b11b MV |
1025 | /* Active thread */ |
1026 | /* stack_len is long rather than sizet in order to guarantee | |
1027 | that &stack_len is long aligned */ | |
1028 | #ifdef STACK_GROWS_UP | |
9bc4701c MD |
1029 | stack_len = ((SCM_STACKITEM *) (&t) - |
1030 | (SCM_STACKITEM *) thread->base); | |
d823b11b MV |
1031 | |
1032 | /* Protect from the C stack. This must be the first marking | |
1033 | * done because it provides information about what objects | |
1034 | * are "in-use" by the C code. "in-use" objects are those | |
1035 | * for which the information about length and base address must | |
1036 | * remain usable. This requirement is stricter than a liveness | |
1037 | * requirement -- in particular, it constrains the implementation | |
1038 | * of scm_resizuve. | |
1039 | */ | |
1040 | SCM_FLUSH_REGISTER_WINDOWS; | |
1041 | /* This assumes that all registers are saved into the jmp_buf */ | |
1042 | setjmp (scm_save_regs_gc_mark); | |
1043 | scm_mark_locations ((SCM_STACKITEM *) scm_save_regs_gc_mark, | |
1044 | ((size_t) sizeof scm_save_regs_gc_mark | |
1045 | / sizeof (SCM_STACKITEM))); | |
1046 | ||
1047 | scm_mark_locations (((size_t) t->base, | |
1048 | (sizet) stack_len)); | |
1049 | #else | |
9bc4701c MD |
1050 | stack_len = ((SCM_STACKITEM *) t->base - |
1051 | (SCM_STACKITEM *) (&t)); | |
d823b11b MV |
1052 | |
1053 | /* Protect from the C stack. This must be the first marking | |
1054 | * done because it provides information about what objects | |
1055 | * are "in-use" by the C code. "in-use" objects are those | |
1056 | * for which the information about length and base address must | |
1057 | * remain usable. This requirement is stricter than a liveness | |
1058 | * requirement -- in particular, it constrains the implementation | |
1059 | * of scm_resizuve. | |
1060 | */ | |
1061 | SCM_FLUSH_REGISTER_WINDOWS; | |
1062 | /* This assumes that all registers are saved into the jmp_buf */ | |
1063 | setjmp (scm_save_regs_gc_mark); | |
1064 | scm_mark_locations ((SCM_STACKITEM *) scm_save_regs_gc_mark, | |
1065 | ((size_t) sizeof scm_save_regs_gc_mark | |
1066 | / sizeof (SCM_STACKITEM))); | |
1067 | ||
1068 | scm_mark_locations ((SCM_STACKITEM *) &t, | |
1069 | stack_len); | |
1070 | #endif | |
1071 | } | |
1072 | else | |
1073 | { | |
1074 | /* Suspended thread */ | |
1075 | #ifdef STACK_GROWS_UP | |
1076 | long stack_len = t->top - t->base; | |
1077 | scm_mark_locations (t->base, stack_len); | |
1078 | #else | |
1079 | long stack_len = t->base - t->top; | |
1080 | scm_mark_locations (t->top, stack_len); | |
1081 | #endif | |
1082 | scm_mark_locations ((SCM_STACKITEM *) t->regs, | |
1083 | ((size_t) sizeof(t->regs) | |
1084 | / sizeof (SCM_STACKITEM))); | |
1085 | } | |
1086 | } | |
5f05c406 MV |
1087 | } |
1088 | ||
d823b11b MV |
1089 | /*** Select */ |
1090 | ||
911782b7 | 1091 | int |
d823b11b MV |
1092 | scm_internal_select (int nfds, |
1093 | SELECT_TYPE *readfds, | |
1094 | SELECT_TYPE *writefds, | |
1095 | SELECT_TYPE *exceptfds, | |
1096 | struct timeval *timeout) | |
5f05c406 | 1097 | { |
d823b11b | 1098 | int res, eno; |
9bc4701c MD |
1099 | scm_thread *c = scm_i_leave_guile (); |
1100 | res = scm_i_plugin_select (nfds, readfds, writefds, exceptfds, timeout); | |
d823b11b | 1101 | eno = errno; |
9bc4701c | 1102 | scm_i_enter_guile (c); |
d823b11b MV |
1103 | SCM_ASYNC_TICK; |
1104 | errno = eno; | |
1105 | return res; | |
5f05c406 MV |
1106 | } |
1107 | ||
9bc4701c MD |
1108 | /* Low-level C API */ |
1109 | ||
1110 | SCM | |
1111 | scm_spawn_thread (scm_t_catch_body body, void *body_data, | |
1112 | scm_t_catch_handler handler, void *handler_data) | |
1113 | { | |
1114 | return create_thread (body, body_data, handler, handler_data, SCM_BOOL_F); | |
1115 | } | |
1116 | ||
9bc4701c MD |
1117 | int |
1118 | scm_mutex_lock (scm_t_mutex *m) | |
1119 | { | |
1120 | scm_thread *t = scm_i_leave_guile (); | |
1121 | int res = scm_i_plugin_mutex_lock (m); | |
1122 | scm_i_enter_guile (t); | |
1123 | return res; | |
1124 | } | |
1125 | ||
28d52ebb MD |
1126 | scm_t_rec_mutex * |
1127 | scm_make_rec_mutex () | |
1128 | { | |
1129 | scm_t_rec_mutex *m = scm_malloc (sizeof (scm_t_rec_mutex)); | |
1130 | scm_i_plugin_rec_mutex_init (m, &scm_i_plugin_rec_mutex); | |
1131 | return m; | |
1132 | } | |
1133 | ||
1134 | void | |
1135 | scm_rec_mutex_free (scm_t_rec_mutex *m) | |
1136 | { | |
1137 | scm_i_plugin_rec_mutex_destroy (m); | |
1138 | free (m); | |
1139 | } | |
1140 | ||
1141 | int | |
1142 | scm_rec_mutex_lock (scm_t_rec_mutex *m) | |
1143 | { | |
1144 | scm_thread *t = scm_i_leave_guile (); | |
1145 | int res = scm_i_plugin_rec_mutex_lock (m); | |
1146 | scm_i_enter_guile (t); | |
1147 | return res; | |
1148 | } | |
1149 | ||
9bc4701c MD |
1150 | int |
1151 | scm_cond_wait (scm_t_cond *c, scm_t_mutex *m) | |
1152 | { | |
1153 | scm_thread *t = scm_i_leave_guile (); | |
1154 | scm_i_plugin_cond_wait (c, m); | |
1155 | scm_i_enter_guile (t); | |
1156 | return 0; | |
1157 | } | |
1158 | ||
1159 | int | |
06babecc | 1160 | scm_cond_timedwait (scm_t_cond *c, scm_t_mutex *m, const struct timespec *wt) |
9bc4701c MD |
1161 | { |
1162 | scm_thread *t = scm_i_leave_guile (); | |
06babecc | 1163 | int res = scm_i_plugin_cond_timedwait (c, m, wt); |
9bc4701c MD |
1164 | scm_i_enter_guile (t); |
1165 | return res; | |
1166 | } | |
9bc4701c MD |
1167 | |
1168 | void | |
1169 | scm_enter_guile () | |
1170 | { | |
1171 | scm_i_enter_guile (SCM_CURRENT_THREAD); | |
1172 | } | |
1173 | ||
1174 | void | |
1175 | scm_leave_guile () | |
1176 | { | |
1177 | scm_i_leave_guile (); | |
1178 | } | |
1179 | ||
d823b11b MV |
1180 | unsigned long |
1181 | scm_thread_usleep (unsigned long usecs) | |
5f05c406 | 1182 | { |
d823b11b MV |
1183 | struct timeval tv; |
1184 | tv.tv_usec = usecs % 1000000; | |
1185 | tv.tv_sec = usecs / 1000000; | |
1186 | scm_internal_select (0, NULL, NULL, NULL, &tv); | |
1187 | return tv.tv_usec + tv.tv_sec*1000000; | |
5f05c406 MV |
1188 | } |
1189 | ||
d823b11b MV |
1190 | unsigned long |
1191 | scm_thread_sleep (unsigned long secs) | |
6c214b62 | 1192 | { |
d823b11b MV |
1193 | struct timeval tv; |
1194 | tv.tv_usec = 0; | |
1195 | tv.tv_sec = secs; | |
1196 | scm_internal_select (0, NULL, NULL, NULL, &tv); | |
1197 | return tv.tv_sec; | |
6c214b62 MD |
1198 | } |
1199 | ||
d823b11b MV |
1200 | /*** Misc */ |
1201 | ||
1202 | SCM_DEFINE (scm_current_thread, "current-thread", 0, 0, 0, | |
1203 | (void), | |
1204 | "Return the thread that called this function.") | |
1205 | #define FUNC_NAME s_scm_current_thread | |
1206 | { | |
1207 | return cur_thread; | |
1208 | } | |
1209 | #undef FUNC_NAME | |
1210 | ||
1211 | SCM_DEFINE (scm_all_threads, "all-threads", 0, 0, 0, | |
1212 | (void), | |
1213 | "Return a list of all threads.") | |
9bc4701c | 1214 | #define FUNC_NAME s_scm_all_threads |
d823b11b MV |
1215 | { |
1216 | return all_threads; | |
1217 | } | |
1218 | #undef FUNC_NAME | |
1219 | ||
1220 | scm_root_state * | |
1221 | scm_i_thread_root (SCM thread) | |
1222 | { | |
9bc4701c | 1223 | return ((scm_thread *) SCM_THREAD_DATA (thread))->root; |
d823b11b MV |
1224 | } |
1225 | ||
1226 | SCM_DEFINE (scm_thread_exited_p, "thread-exited?", 1, 0, 0, | |
1227 | (SCM thread), | |
1228 | "Return @code{#t} iff @var{thread} has exited.\n") | |
1229 | #define FUNC_NAME s_scm_thread_exited_p | |
1230 | { | |
1231 | return SCM_BOOL (scm_c_thread_exited_p (thread)); | |
1232 | } | |
1233 | #undef FUNC_NAME | |
1234 | ||
911782b7 | 1235 | int |
d823b11b MV |
1236 | scm_c_thread_exited_p (SCM thread) |
1237 | #define FUNC_NAME s_scm_thread_exited_p | |
5f05c406 | 1238 | { |
d823b11b MV |
1239 | scm_thread *t; |
1240 | SCM_VALIDATE_THREAD (1, thread); | |
1241 | t = SCM_THREAD_DATA (thread); | |
1242 | return t->exited; | |
5f05c406 | 1243 | } |
d823b11b | 1244 | #undef FUNC_NAME |
5f05c406 | 1245 | |
9bc4701c MD |
1246 | static scm_t_cond wake_up_cond; |
1247 | int scm_i_thread_go_to_sleep; | |
28d52ebb | 1248 | static scm_t_rec_mutex gc_section_mutex; |
9bc4701c MD |
1249 | static int gc_section_count = 0; |
1250 | static int threads_initialized_p = 0; | |
1251 | ||
1252 | void | |
1253 | scm_i_thread_put_to_sleep () | |
1254 | { | |
28d52ebb MD |
1255 | scm_rec_mutex_lock (&gc_section_mutex); |
1256 | if (threads_initialized_p && !gc_section_count++) | |
9bc4701c | 1257 | { |
c4c52ebe MD |
1258 | SCM threads; |
1259 | scm_i_plugin_mutex_lock (&thread_admin_mutex); | |
1260 | threads = all_threads; | |
9bc4701c MD |
1261 | /* Signal all threads to go to sleep */ |
1262 | scm_i_thread_go_to_sleep = 1; | |
1263 | for (; !SCM_NULLP (threads); threads = SCM_CDR (threads)) | |
1264 | if (SCM_CAR (threads) != cur_thread) | |
1265 | { | |
1266 | scm_thread *t = SCM_THREAD_DATA (SCM_CAR (threads)); | |
9bc4701c MD |
1267 | scm_i_plugin_mutex_lock (&t->heap_mutex); |
1268 | } | |
9bc4701c | 1269 | scm_i_thread_go_to_sleep = 0; |
c4c52ebe | 1270 | scm_i_plugin_mutex_unlock (&thread_admin_mutex); |
9bc4701c MD |
1271 | } |
1272 | } | |
1273 | ||
b0dc3d71 MD |
1274 | void |
1275 | scm_i_thread_invalidate_freelists () | |
1276 | { | |
c4c52ebe | 1277 | /* Don't need to lock thread_admin_mutex here since we are sinle threaded */ |
b0dc3d71 MD |
1278 | SCM threads = all_threads; |
1279 | for (; !SCM_NULLP (threads); threads = SCM_CDR (threads)) | |
1280 | if (SCM_CAR (threads) != cur_thread) | |
1281 | { | |
1282 | scm_thread *t = SCM_THREAD_DATA (SCM_CAR (threads)); | |
1283 | t->clear_freelists_p = 1; | |
1284 | } | |
1285 | } | |
1286 | ||
9bc4701c MD |
1287 | void |
1288 | scm_i_thread_wake_up () | |
1289 | { | |
28d52ebb | 1290 | if (threads_initialized_p && !--gc_section_count) |
9bc4701c | 1291 | { |
c4c52ebe MD |
1292 | SCM threads; |
1293 | /* Need to lock since woken threads can die and be deleted from list */ | |
1294 | scm_i_plugin_mutex_lock (&thread_admin_mutex); | |
1295 | threads = all_threads; | |
9bc4701c MD |
1296 | scm_i_plugin_cond_broadcast (&wake_up_cond); |
1297 | for (; !SCM_NULLP (threads); threads = SCM_CDR (threads)) | |
1298 | if (SCM_CAR (threads) != cur_thread) | |
1299 | { | |
1300 | scm_thread *t = SCM_THREAD_DATA (SCM_CAR (threads)); | |
1301 | scm_i_plugin_mutex_unlock (&t->heap_mutex); | |
1302 | } | |
c4c52ebe | 1303 | scm_i_plugin_mutex_unlock (&thread_admin_mutex); |
9bc4701c | 1304 | } |
28d52ebb | 1305 | scm_rec_mutex_unlock (&gc_section_mutex); |
9bc4701c MD |
1306 | } |
1307 | ||
1308 | void | |
1309 | scm_i_thread_sleep_for_gc () | |
1310 | { | |
1311 | scm_thread *t; | |
1312 | t = suspend (); | |
9bc4701c | 1313 | scm_i_plugin_cond_wait (&wake_up_cond, &t->heap_mutex); |
b0dc3d71 | 1314 | resume (t); |
9bc4701c MD |
1315 | } |
1316 | ||
9bc4701c | 1317 | scm_t_mutex scm_i_critical_section_mutex; |
28d52ebb MD |
1318 | scm_t_rec_mutex scm_i_defer_mutex; |
1319 | ||
1320 | #ifdef USE_PTHREAD_THREADS | |
1321 | #include "libguile/pthread-threads.c" | |
1322 | #endif | |
9bc4701c | 1323 | |
d823b11b | 1324 | /*** Initialization */ |
7bfd3b9e | 1325 | |
9bc4701c MD |
1326 | void |
1327 | scm_threads_prehistory () | |
1328 | { | |
1329 | scm_thread *t; | |
93cd4dcd MD |
1330 | #ifdef USE_PTHREAD_THREADS |
1331 | /* Must be called before any initialization of a mutex. */ | |
1332 | scm_init_pthread_threads (); | |
1333 | #endif | |
28d52ebb MD |
1334 | scm_i_plugin_mutex_init (&thread_admin_mutex, &scm_i_plugin_mutex); |
1335 | scm_i_plugin_rec_mutex_init (&gc_section_mutex, &scm_i_plugin_rec_mutex); | |
9bc4701c | 1336 | scm_i_plugin_cond_init (&wake_up_cond, 0); |
28d52ebb | 1337 | scm_i_plugin_mutex_init (&scm_i_critical_section_mutex, &scm_i_plugin_mutex); |
9bc4701c MD |
1338 | thread_count = 1; |
1339 | scm_i_plugin_key_create (&scm_i_thread_key, 0); | |
1340 | scm_i_plugin_key_create (&scm_i_root_state_key, 0); | |
28d52ebb | 1341 | scm_i_plugin_rec_mutex_init (&scm_i_defer_mutex, &scm_i_plugin_rec_mutex); |
9bc4701c MD |
1342 | /* Allocate a fake thread object to be used during bootup. */ |
1343 | t = malloc (sizeof (scm_thread)); | |
1344 | t->base = NULL; | |
1345 | t->clear_freelists_p = 0; | |
1346 | scm_setspecific (scm_i_thread_key, t); | |
1347 | } | |
1348 | ||
d823b11b | 1349 | scm_t_bits scm_tc16_thread; |
28d52ebb | 1350 | scm_t_bits scm_tc16_future; |
d823b11b | 1351 | scm_t_bits scm_tc16_mutex; |
9bc4701c | 1352 | scm_t_bits scm_tc16_fair_mutex; |
d823b11b | 1353 | scm_t_bits scm_tc16_condvar; |
9bc4701c | 1354 | scm_t_bits scm_tc16_fair_condvar; |
7bfd3b9e | 1355 | |
7bfd3b9e | 1356 | void |
d823b11b | 1357 | scm_init_threads (SCM_STACKITEM *base) |
7bfd3b9e | 1358 | { |
9bc4701c | 1359 | SCM thread; |
d823b11b | 1360 | scm_tc16_thread = scm_make_smob_type ("thread", sizeof (scm_thread)); |
9bc4701c MD |
1361 | scm_tc16_mutex = scm_make_smob_type ("mutex", sizeof (scm_t_mutex)); |
1362 | scm_tc16_fair_mutex = scm_make_smob_type ("fair-mutex", | |
1363 | sizeof (fair_mutex)); | |
d823b11b | 1364 | scm_tc16_condvar = scm_make_smob_type ("condition-variable", |
9bc4701c MD |
1365 | sizeof (scm_t_cond)); |
1366 | scm_tc16_fair_condvar = scm_make_smob_type ("fair-condition-variable", | |
1367 | sizeof (fair_cond)); | |
d823b11b | 1368 | |
9bc4701c MD |
1369 | thread = make_thread (SCM_BOOL_F); |
1370 | /* Replace initial fake thread with a real thread object */ | |
1371 | free (SCM_CURRENT_THREAD); | |
1372 | scm_setspecific (scm_i_thread_key, SCM_THREAD_DATA (thread)); | |
1373 | scm_i_enter_guile (SCM_CURRENT_THREAD); | |
d823b11b | 1374 | |
d823b11b | 1375 | /* root is set later from init.c */ |
9bc4701c | 1376 | init_thread_creatant (thread, base); |
d823b11b MV |
1377 | thread_count = 1; |
1378 | scm_gc_register_root (&all_threads); | |
9bc4701c | 1379 | all_threads = scm_cons (thread, SCM_EOL); |
d823b11b MV |
1380 | |
1381 | scm_set_smob_mark (scm_tc16_thread, thread_mark); | |
1382 | scm_set_smob_print (scm_tc16_thread, thread_print); | |
1383 | scm_set_smob_free (scm_tc16_thread, thread_free); | |
1384 | ||
9bc4701c MD |
1385 | scm_set_smob_mark (scm_tc16_fair_mutex, fair_mutex_mark); |
1386 | ||
1387 | scm_set_smob_mark (scm_tc16_fair_condvar, fair_cond_mark); | |
d823b11b | 1388 | |
28d52ebb MD |
1389 | scm_tc16_future = scm_make_smob_type ("future", 0); |
1390 | scm_set_smob_mark (scm_tc16_future, scm_markcdr); | |
1391 | scm_set_smob_free (scm_tc16_future, future_free); | |
1392 | scm_set_smob_print (scm_tc16_future, future_print); | |
1393 | ||
9bc4701c | 1394 | threads_initialized_p = 1; |
7bfd3b9e | 1395 | } |
89e00824 | 1396 | |
5f05c406 MV |
1397 | void |
1398 | scm_init_thread_procs () | |
1399 | { | |
28d52ebb MD |
1400 | scm_loc_sys_thread_handler |
1401 | = SCM_VARIABLE_LOC (scm_c_define ("%thread-handler", SCM_BOOL_F)); | |
5f05c406 MV |
1402 | #include "libguile/threads.x" |
1403 | } | |
1404 | ||
d823b11b MV |
1405 | /* XXX */ |
1406 | ||
1407 | void | |
1408 | scm_init_iselect () | |
1409 | { | |
1410 | } | |
1411 | ||
89e00824 ML |
1412 | /* |
1413 | Local Variables: | |
1414 | c-file-style: "gnu" | |
1415 | End: | |
1416 | */ |