Commit | Line | Data |
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d90ca38d | 1 | /* Copyright (C) 1995, 1996, 1997, 1998 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. */ |
7bfd3b9e JB |
41 | \f |
42 | ||
bccab498 | 43 | /* $Id: coop.c,v 1.16 1999-12-19 18:24:12 gjb Exp $ */ |
7bfd3b9e JB |
44 | |
45 | /* Cooperative thread library, based on QuickThreads */ | |
46 | ||
6d71500e JB |
47 | #ifdef HAVE_UNISTD_H |
48 | #include <unistd.h> | |
49 | #endif | |
50 | ||
7bfd3b9e | 51 | #include <qt.h> |
51d394a1 | 52 | #include "eval.h" |
7bfd3b9e | 53 | |
6d71500e | 54 | \f/* #define COOP_STKSIZE (0x10000) */ |
a74145b8 | 55 | #define COOP_STKSIZE (scm_eval_stack) |
7bfd3b9e JB |
56 | |
57 | /* `alignment' must be a power of 2. */ | |
58 | #define COOP_STKALIGN(sp, alignment) \ | |
59 | ((void *)((((qt_word_t)(sp)) + (alignment) - 1) & ~((alignment)-1))) | |
60 | ||
61 | \f | |
62 | ||
63 | /* Queue access functions. */ | |
64 | ||
7bfd3b9e JB |
65 | static void |
66 | coop_qinit (coop_q_t *q) | |
7bfd3b9e JB |
67 | { |
68 | q->t.next = q->tail = &q->t; | |
69 | ||
70 | q->t.all_prev = NULL; | |
71 | q->t.all_next = NULL; | |
44e8413c MD |
72 | #ifdef GUILE_ISELECT |
73 | q->t.nfds = 0; | |
74 | q->t.readfds = NULL; | |
75 | q->t.writefds = NULL; | |
76 | q->t.exceptfds = NULL; | |
77 | q->t.timeoutp = 0; | |
78 | #endif | |
7bfd3b9e JB |
79 | } |
80 | ||
81 | ||
44e8413c | 82 | coop_t * |
7bfd3b9e | 83 | coop_qget (coop_q_t *q) |
7bfd3b9e JB |
84 | { |
85 | coop_t *t; | |
86 | ||
87 | t = q->t.next; | |
88 | q->t.next = t->next; | |
89 | if (t->next == &q->t) { | |
90 | if (t == &q->t) { /* If it was already empty .. */ | |
91 | return (NULL); /* .. say so. */ | |
92 | } | |
93 | q->tail = &q->t; /* Else now it is empty. */ | |
94 | } | |
95 | return (t); | |
96 | } | |
97 | ||
98 | ||
44e8413c | 99 | void |
7bfd3b9e | 100 | coop_qput (coop_q_t *q, coop_t *t) |
7bfd3b9e JB |
101 | { |
102 | q->tail->next = t; | |
103 | t->next = &q->t; | |
104 | q->tail = t; | |
105 | } | |
106 | ||
7bfd3b9e JB |
107 | static void |
108 | coop_all_qput (coop_q_t *q, coop_t *t) | |
7bfd3b9e JB |
109 | { |
110 | if (q->t.all_next) | |
111 | q->t.all_next->all_prev = t; | |
112 | t->all_prev = NULL; | |
113 | t->all_next = q->t.all_next; | |
114 | q->t.all_next = t; | |
115 | } | |
116 | ||
7bfd3b9e JB |
117 | static void |
118 | coop_all_qremove (coop_q_t *q, coop_t *t) | |
7bfd3b9e JB |
119 | { |
120 | if (t->all_prev) | |
121 | t->all_prev->all_next = t->all_next; | |
122 | else | |
123 | q->t.all_next = t->all_next; | |
124 | if (t->all_next) | |
125 | t->all_next->all_prev = t->all_prev; | |
126 | } | |
127 | ||
128 | ||
129 | \f/* Thread routines. */ | |
130 | ||
44e8413c MD |
131 | coop_q_t coop_global_runq; /* A queue of runable threads. */ |
132 | coop_q_t coop_global_sleepq; /* A queue of sleeping threads. */ | |
133 | coop_q_t coop_tmp_queue; /* A temp working queue */ | |
134 | coop_q_t coop_global_allq; /* A queue of all threads. */ | |
135 | static coop_t coop_global_main; /* Thread for the process. */ | |
136 | coop_t *coop_global_curr; /* Currently-executing thread. */ | |
7bfd3b9e JB |
137 | |
138 | static void *coop_starthelp (qt_t *old, void *ignore0, void *ignore1); | |
139 | static void coop_only (void *pu, void *pt, qt_userf_t *f); | |
140 | static void *coop_aborthelp (qt_t *sp, void *old, void *null); | |
141 | static void *coop_yieldhelp (qt_t *sp, void *old, void *blockq); | |
142 | ||
143 | ||
7bfd3b9e JB |
144 | void |
145 | coop_init() | |
7bfd3b9e JB |
146 | { |
147 | coop_qinit (&coop_global_runq); | |
148 | coop_qinit (&coop_global_sleepq); | |
44e8413c | 149 | coop_qinit (&coop_tmp_queue); |
7bfd3b9e JB |
150 | coop_qinit (&coop_global_allq); |
151 | coop_global_curr = &coop_global_main; | |
152 | } | |
153 | ||
154 | ||
155 | /* Return the next runnable thread. If no threads are currently runnable, | |
156 | and there are sleeping threads - wait until one wakes up. Otherwise, | |
157 | return NULL. */ | |
158 | ||
6d71500e | 159 | #ifndef GUILE_ISELECT |
7bfd3b9e JB |
160 | coop_t * |
161 | coop_next_runnable_thread() | |
7bfd3b9e JB |
162 | { |
163 | int sleepers; | |
164 | coop_t *t; | |
165 | time_t now; | |
166 | ||
167 | do { | |
168 | sleepers = 0; | |
169 | now = time(NULL); | |
170 | ||
171 | /* Check the sleeping queue */ | |
172 | while ((t = coop_qget(&coop_global_sleepq)) != NULL) | |
173 | { | |
174 | sleepers++; | |
175 | if (t->wakeup_time <= now) | |
176 | coop_qput(&coop_global_runq, t); | |
177 | else | |
44e8413c | 178 | coop_qput(&coop_tmp_queue, t); |
7bfd3b9e | 179 | } |
44e8413c | 180 | while ((t = coop_qget(&coop_tmp_queue)) != NULL) |
7bfd3b9e JB |
181 | coop_qput(&coop_global_sleepq, t); |
182 | ||
183 | t = coop_qget (&coop_global_runq); | |
184 | ||
185 | } while ((t == NULL) && (sleepers > 0)); | |
186 | ||
187 | return t; | |
188 | } | |
44e8413c | 189 | #endif |
7bfd3b9e | 190 | |
7bfd3b9e JB |
191 | void |
192 | coop_start() | |
7bfd3b9e JB |
193 | { |
194 | coop_t *next; | |
195 | ||
196 | while ((next = coop_qget (&coop_global_runq)) != NULL) { | |
197 | coop_global_curr = next; | |
198 | QT_BLOCK (coop_starthelp, 0, 0, next->sp); | |
199 | } | |
200 | } | |
201 | ||
202 | ||
7bfd3b9e JB |
203 | static void * |
204 | coop_starthelp (qt_t *old, void *ignore0, void *ignore1) | |
7bfd3b9e JB |
205 | { |
206 | coop_global_main.sp = old; | |
207 | coop_global_main.joining = NULL; | |
208 | coop_qput (&coop_global_runq, &coop_global_main); | |
209 | return NULL; /* not used, but keeps compiler happy */ | |
210 | } | |
211 | ||
c8bf4ecd | 212 | int |
7bfd3b9e | 213 | coop_mutex_init (coop_m *m) |
7bfd3b9e JB |
214 | { |
215 | m->owner = NULL; | |
216 | coop_qinit(&(m->waiting)); | |
c8bf4ecd | 217 | return 0; |
7bfd3b9e JB |
218 | } |
219 | ||
c8bf4ecd | 220 | int |
7bfd3b9e | 221 | coop_mutex_lock (coop_m *m) |
7bfd3b9e JB |
222 | { |
223 | if (m->owner == NULL) | |
224 | { | |
225 | m->owner = coop_global_curr; | |
226 | } | |
227 | else | |
228 | { | |
229 | coop_t *old, *newthread; | |
230 | ||
231 | /* Record the current top-of-stack before going to sleep */ | |
232 | coop_global_curr->top = &old; | |
233 | ||
44e8413c MD |
234 | #ifdef GUILE_ISELECT |
235 | newthread = coop_wait_for_runnable_thread(); | |
d186aac6 MD |
236 | if (newthread == coop_global_curr) |
237 | coop_abort (); | |
44e8413c | 238 | #else |
7bfd3b9e | 239 | newthread = coop_next_runnable_thread(); |
44e8413c | 240 | #endif |
7bfd3b9e JB |
241 | old = coop_global_curr; |
242 | coop_global_curr = newthread; | |
243 | QT_BLOCK (coop_yieldhelp, old, &(m->waiting), newthread->sp); | |
244 | } | |
c8bf4ecd | 245 | return 0; |
7bfd3b9e JB |
246 | } |
247 | ||
248 | ||
c8bf4ecd | 249 | int |
7bfd3b9e | 250 | coop_mutex_unlock (coop_m *m) |
7bfd3b9e JB |
251 | { |
252 | coop_t *old, *newthread; | |
253 | ||
254 | newthread = coop_qget (&(m->waiting)); | |
255 | if (newthread != NULL) | |
256 | { | |
257 | /* Record the current top-of-stack before going to sleep */ | |
258 | coop_global_curr->top = &old; | |
259 | ||
260 | old = coop_global_curr; | |
261 | coop_global_curr = newthread; | |
b322f09a MD |
262 | /* The new thread came into m->waiting through a lock operation. |
263 | It now owns this mutex. */ | |
7bfd3b9e JB |
264 | m->owner = coop_global_curr; |
265 | QT_BLOCK (coop_yieldhelp, old, &coop_global_runq, newthread->sp); | |
266 | } | |
267 | else | |
268 | { | |
269 | m->owner = NULL; | |
270 | } | |
c8bf4ecd | 271 | return 0; |
7bfd3b9e JB |
272 | } |
273 | ||
274 | ||
c8bf4ecd MD |
275 | int |
276 | coop_mutex_destroy (coop_m *m) | |
c8bf4ecd MD |
277 | { |
278 | return 0; | |
279 | } | |
280 | ||
281 | ||
c8bf4ecd | 282 | int |
7bfd3b9e | 283 | coop_condition_variable_init (coop_c *c) |
7bfd3b9e JB |
284 | { |
285 | coop_qinit(&(c->waiting)); | |
c8bf4ecd | 286 | return 0; |
7bfd3b9e JB |
287 | } |
288 | ||
b322f09a MD |
289 | int |
290 | coop_condition_variable_wait_mutex (coop_c *c, coop_m *m) | |
7bfd3b9e JB |
291 | { |
292 | coop_t *old, *newthread; | |
293 | ||
b322f09a MD |
294 | /* coop_mutex_unlock (m); */ |
295 | newthread = coop_qget (&(m->waiting)); | |
296 | if (newthread != NULL) | |
297 | { | |
298 | m->owner = newthread; | |
299 | } | |
300 | else | |
301 | { | |
302 | m->owner = NULL; | |
44e8413c | 303 | #ifdef GUILE_ISELECT |
b322f09a MD |
304 | newthread = coop_wait_for_runnable_thread(); |
305 | if (newthread == coop_global_curr) | |
306 | coop_abort (); | |
44e8413c | 307 | #else |
b322f09a | 308 | newthread = coop_next_runnable_thread(); |
44e8413c | 309 | #endif |
b322f09a MD |
310 | } |
311 | coop_global_curr->top = &old; | |
7bfd3b9e JB |
312 | old = coop_global_curr; |
313 | coop_global_curr = newthread; | |
314 | QT_BLOCK (coop_yieldhelp, old, &(c->waiting), newthread->sp); | |
c8bf4ecd | 315 | |
c8bf4ecd MD |
316 | coop_mutex_lock (m); |
317 | return 0; | |
7bfd3b9e JB |
318 | } |
319 | ||
c8bf4ecd | 320 | |
c8bf4ecd | 321 | int |
7bfd3b9e | 322 | coop_condition_variable_signal (coop_c *c) |
7bfd3b9e JB |
323 | { |
324 | coop_t *newthread; | |
325 | ||
326 | while ((newthread = coop_qget (&(c->waiting))) != NULL) | |
327 | { | |
328 | coop_qput (&coop_global_runq, newthread); | |
329 | } | |
c8bf4ecd MD |
330 | return 0; |
331 | } | |
332 | ||
333 | ||
c8bf4ecd MD |
334 | int |
335 | coop_condition_variable_destroy (coop_c *c) | |
c8bf4ecd MD |
336 | { |
337 | return 0; | |
7bfd3b9e JB |
338 | } |
339 | ||
340 | ||
7bfd3b9e JB |
341 | coop_t * |
342 | coop_create (coop_userf_t *f, void *pu) | |
7bfd3b9e JB |
343 | { |
344 | coop_t *t; | |
345 | void *sto; | |
346 | ||
347 | t = malloc (sizeof(coop_t)); | |
348 | ||
349 | t->data = NULL; | |
350 | t->sto = malloc (COOP_STKSIZE); | |
351 | sto = COOP_STKALIGN (t->sto, QT_STKALIGN); | |
352 | t->sp = QT_SP (sto, COOP_STKSIZE - QT_STKALIGN); | |
353 | t->base = t->sp; | |
354 | t->sp = QT_ARGS (t->sp, pu, t, (qt_userf_t *)f, coop_only); | |
355 | t->joining = NULL; | |
356 | coop_qput (&coop_global_runq, t); | |
357 | coop_all_qput (&coop_global_allq, t); | |
358 | ||
359 | return t; | |
360 | } | |
361 | ||
362 | ||
7bfd3b9e JB |
363 | static void |
364 | coop_only (void *pu, void *pt, qt_userf_t *f) | |
7bfd3b9e JB |
365 | { |
366 | coop_global_curr = (coop_t *)pt; | |
367 | (*(coop_userf_t *)f)(pu); | |
368 | coop_abort(); | |
369 | /* NOTREACHED */ | |
370 | } | |
371 | ||
372 | ||
7bfd3b9e JB |
373 | void |
374 | coop_abort () | |
7bfd3b9e JB |
375 | { |
376 | coop_t *old, *newthread; | |
377 | ||
378 | /* Wake up any threads that are waiting to join this one */ | |
379 | if (coop_global_curr->joining) | |
380 | { | |
381 | while ((newthread = coop_qget ((coop_q_t *)(coop_global_curr->joining))) | |
382 | != NULL) | |
383 | { | |
384 | coop_qput (&coop_global_runq, newthread); | |
385 | } | |
386 | free(coop_global_curr->joining); | |
387 | } | |
388 | ||
44e8413c | 389 | #ifdef GUILE_ISELECT |
d186aac6 MD |
390 | scm_I_am_dead = 1; |
391 | do { | |
392 | newthread = coop_wait_for_runnable_thread(); | |
393 | } while (newthread == coop_global_curr); | |
394 | scm_I_am_dead = 0; | |
44e8413c | 395 | #else |
7bfd3b9e | 396 | newthread = coop_next_runnable_thread(); |
44e8413c | 397 | #endif |
7bfd3b9e JB |
398 | coop_all_qremove(&coop_global_allq, coop_global_curr); |
399 | old = coop_global_curr; | |
400 | coop_global_curr = newthread; | |
401 | QT_ABORT (coop_aborthelp, old, (void *)NULL, newthread->sp); | |
402 | } | |
403 | ||
404 | ||
7bfd3b9e JB |
405 | static void * |
406 | coop_aborthelp (qt_t *sp, void *old, void *null) | |
7bfd3b9e JB |
407 | { |
408 | coop_t *oldthread = (coop_t *) old; | |
409 | ||
410 | free (oldthread->sto); | |
411 | ||
412 | /* "old" is freed in scm_threads_thread_die(). | |
413 | Marking old->base NULL indicates that this thread is dead */ | |
414 | ||
415 | oldthread->base = NULL; | |
416 | ||
417 | return NULL; | |
418 | } | |
419 | ||
420 | ||
7bfd3b9e JB |
421 | void |
422 | coop_join(coop_t *t) | |
7bfd3b9e JB |
423 | { |
424 | coop_t *old, *newthread; | |
425 | ||
426 | /* Check if t is already finished */ | |
427 | if (t->base == NULL) | |
428 | return; | |
429 | ||
430 | /* Create a join list if necessary */ | |
431 | if (t->joining == NULL) | |
432 | { | |
433 | t->joining = malloc(sizeof(coop_q_t)); | |
434 | coop_qinit((coop_q_t *) t->joining); | |
435 | } | |
436 | ||
44e8413c MD |
437 | #ifdef GUILE_ISELECT |
438 | newthread = coop_wait_for_runnable_thread(); | |
d186aac6 MD |
439 | if (newthread == coop_global_curr) |
440 | return; | |
44e8413c | 441 | #else |
7bfd3b9e | 442 | newthread = coop_next_runnable_thread(); |
44e8413c | 443 | #endif |
7bfd3b9e JB |
444 | old = coop_global_curr; |
445 | coop_global_curr = newthread; | |
446 | QT_BLOCK (coop_yieldhelp, old, (coop_q_t *) t->joining, newthread->sp); | |
447 | } | |
448 | ||
7bfd3b9e JB |
449 | void |
450 | coop_yield() | |
7bfd3b9e JB |
451 | { |
452 | coop_t *old = NULL; | |
453 | coop_t *newthread; | |
454 | ||
455 | newthread = coop_next_runnable_thread(); | |
456 | ||
457 | /* There may be no other runnable threads. Return if this is the | |
458 | case. */ | |
d186aac6 MD |
459 | #if GUILE_ISELECT |
460 | if (newthread == coop_global_curr) | |
461 | return; | |
462 | #else | |
7bfd3b9e JB |
463 | if (newthread == NULL) |
464 | return; | |
d186aac6 | 465 | #endif |
7bfd3b9e JB |
466 | |
467 | old = coop_global_curr; | |
468 | ||
469 | coop_global_curr = newthread; | |
470 | QT_BLOCK (coop_yieldhelp, old, &coop_global_runq, newthread->sp); | |
471 | } | |
472 | ||
473 | ||
7bfd3b9e JB |
474 | static void * |
475 | coop_yieldhelp (qt_t *sp, void *old, void *blockq) | |
7bfd3b9e JB |
476 | { |
477 | ((coop_t *)old)->sp = sp; | |
478 | coop_qput ((coop_q_t *)blockq, (coop_t *)old); | |
479 | return NULL; | |
480 | } | |
481 | ||
482 | /* Replacement for the system's sleep() function. Does the right thing | |
483 | for the process - but not for the system (it busy-waits) */ | |
484 | ||
44e8413c | 485 | void * |
7bfd3b9e | 486 | coop_sleephelp (qt_t *sp, void *old, void *blockq) |
7bfd3b9e JB |
487 | { |
488 | ((coop_t *)old)->sp = sp; | |
489 | /* old is already on the sleep queue - so there's no need to | |
490 | do anything extra here */ | |
491 | return NULL; | |
492 | } | |
493 | ||
44e8413c MD |
494 | #ifdef GUILE_ISELECT |
495 | ||
6aa9316d JB |
496 | unsigned long |
497 | scm_thread_usleep (unsigned long usec) | |
44e8413c MD |
498 | { |
499 | struct timeval timeout; | |
500 | timeout.tv_sec = 0; | |
501 | timeout.tv_usec = usec; | |
502 | scm_internal_select (0, NULL, NULL, NULL, &timeout); | |
2c4e1a34 MD |
503 | return 0; /* Maybe we should calculate actual time slept, |
504 | but this is faster... :) */ | |
44e8413c MD |
505 | } |
506 | ||
6aa9316d JB |
507 | unsigned long |
508 | scm_thread_sleep (unsigned long sec) | |
44e8413c MD |
509 | { |
510 | time_t now = time (NULL); | |
511 | struct timeval timeout; | |
6aa9316d | 512 | unsigned long slept; |
44e8413c MD |
513 | timeout.tv_sec = sec; |
514 | timeout.tv_usec = 0; | |
515 | scm_internal_select (0, NULL, NULL, NULL, &timeout); | |
516 | slept = time (NULL) - now; | |
517 | return slept > sec ? 0 : sec - slept; | |
518 | } | |
519 | ||
520 | #else /* GUILE_ISELECT */ | |
521 | ||
6aa9316d JB |
522 | unsigned long |
523 | scm_thread_sleep (unsigned long s) | |
7bfd3b9e JB |
524 | { |
525 | coop_t *newthread, *old; | |
44e8413c | 526 | time_t now = time (NULL); |
7bfd3b9e JB |
527 | coop_global_curr->wakeup_time = now + s; |
528 | ||
529 | /* Put the current thread on the sleep queue */ | |
530 | coop_qput (&coop_global_sleepq, coop_global_curr); | |
531 | ||
532 | newthread = coop_next_runnable_thread(); | |
533 | ||
534 | /* If newthread is the same as the sleeping thread, do nothing */ | |
535 | if (newthread == coop_global_curr) | |
536 | return s; | |
537 | ||
538 | old = coop_global_curr; | |
539 | ||
540 | coop_global_curr = newthread; | |
541 | QT_BLOCK (coop_sleephelp, old, NULL, newthread->sp); | |
542 | ||
543 | return s; | |
544 | } | |
44e8413c | 545 | |
6aa9316d JB |
546 | unsigned long |
547 | scm_thread_usleep (unsigned long usec) | |
548 | { | |
549 | /* We're so cheap. */ | |
550 | scm_thread_sleep (usec / 1000000); | |
551 | struct timeval timeout; | |
552 | return 0; /* Maybe we should calculate actual time slept, | |
553 | but this is faster... :) */ | |
554 | } | |
555 | ||
44e8413c | 556 | #endif /* GUILE_ISELECT */ |