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7bfd3b9e JB |
1 | /* Copyright (C) 1995, 1996 Free Software Foundation, Inc. |
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 | ||
44e8413c | 43 | /* $Id: coop.c,v 1.3 1997-11-27 18:04:53 mdj Exp $ */ |
7bfd3b9e JB |
44 | |
45 | /* Cooperative thread library, based on QuickThreads */ | |
46 | ||
47 | #include <qt.h> | |
48 | ||
49 | #define COOP_STKSIZE (0x10000) | |
50 | ||
51 | /* `alignment' must be a power of 2. */ | |
52 | #define COOP_STKALIGN(sp, alignment) \ | |
53 | ((void *)((((qt_word_t)(sp)) + (alignment) - 1) & ~((alignment)-1))) | |
54 | ||
55 | \f | |
56 | ||
57 | /* Queue access functions. */ | |
58 | ||
59 | #ifdef __STDC__ | |
60 | static void | |
61 | coop_qinit (coop_q_t *q) | |
62 | #else | |
63 | static void | |
64 | coop_qinit (q) | |
65 | coop_q_t *q; | |
66 | #endif | |
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 | ||
82 | #ifdef __STDC__ | |
44e8413c | 83 | coop_t * |
7bfd3b9e JB |
84 | coop_qget (coop_q_t *q) |
85 | #else | |
44e8413c | 86 | coop_t * |
7bfd3b9e JB |
87 | coop_qget (q) |
88 | coop_q_t *q; | |
89 | #endif | |
90 | { | |
91 | coop_t *t; | |
92 | ||
93 | t = q->t.next; | |
94 | q->t.next = t->next; | |
95 | if (t->next == &q->t) { | |
96 | if (t == &q->t) { /* If it was already empty .. */ | |
97 | return (NULL); /* .. say so. */ | |
98 | } | |
99 | q->tail = &q->t; /* Else now it is empty. */ | |
100 | } | |
101 | return (t); | |
102 | } | |
103 | ||
104 | ||
105 | #ifdef __STDC__ | |
44e8413c | 106 | void |
7bfd3b9e JB |
107 | coop_qput (coop_q_t *q, coop_t *t) |
108 | #else | |
44e8413c | 109 | void |
7bfd3b9e JB |
110 | coop_qput (q, t) |
111 | coop_q_t *q; | |
112 | coop_t *t; | |
113 | #endif | |
114 | { | |
115 | q->tail->next = t; | |
116 | t->next = &q->t; | |
117 | q->tail = t; | |
118 | } | |
119 | ||
120 | #ifdef __STDC__ | |
121 | static void | |
122 | coop_all_qput (coop_q_t *q, coop_t *t) | |
123 | #else | |
124 | static void | |
125 | coop_all_qput (q, t) | |
126 | coop_q_t *q; | |
127 | coop_t *t; | |
128 | #endif | |
129 | { | |
130 | if (q->t.all_next) | |
131 | q->t.all_next->all_prev = t; | |
132 | t->all_prev = NULL; | |
133 | t->all_next = q->t.all_next; | |
134 | q->t.all_next = t; | |
135 | } | |
136 | ||
137 | #ifdef __STDC__ | |
138 | static void | |
139 | coop_all_qremove (coop_q_t *q, coop_t *t) | |
140 | #else | |
141 | static void | |
142 | coop_all_qremove (q, t) | |
143 | coop_q_t *q; | |
144 | coop_t *t; | |
145 | #endif | |
146 | { | |
147 | if (t->all_prev) | |
148 | t->all_prev->all_next = t->all_next; | |
149 | else | |
150 | q->t.all_next = t->all_next; | |
151 | if (t->all_next) | |
152 | t->all_next->all_prev = t->all_prev; | |
153 | } | |
154 | ||
155 | ||
156 | \f/* Thread routines. */ | |
157 | ||
44e8413c MD |
158 | coop_q_t coop_global_runq; /* A queue of runable threads. */ |
159 | coop_q_t coop_global_sleepq; /* A queue of sleeping threads. */ | |
160 | coop_q_t coop_tmp_queue; /* A temp working queue */ | |
161 | coop_q_t coop_global_allq; /* A queue of all threads. */ | |
162 | static coop_t coop_global_main; /* Thread for the process. */ | |
163 | coop_t *coop_global_curr; /* Currently-executing thread. */ | |
7bfd3b9e JB |
164 | |
165 | static void *coop_starthelp (qt_t *old, void *ignore0, void *ignore1); | |
166 | static void coop_only (void *pu, void *pt, qt_userf_t *f); | |
167 | static void *coop_aborthelp (qt_t *sp, void *old, void *null); | |
168 | static void *coop_yieldhelp (qt_t *sp, void *old, void *blockq); | |
169 | ||
170 | ||
171 | #ifdef __STDC__ | |
172 | void | |
173 | coop_init() | |
174 | #else | |
175 | void | |
176 | coop_init() | |
177 | #endif | |
178 | { | |
179 | coop_qinit (&coop_global_runq); | |
180 | coop_qinit (&coop_global_sleepq); | |
44e8413c | 181 | coop_qinit (&coop_tmp_queue); |
7bfd3b9e JB |
182 | coop_qinit (&coop_global_allq); |
183 | coop_global_curr = &coop_global_main; | |
184 | } | |
185 | ||
186 | ||
187 | /* Return the next runnable thread. If no threads are currently runnable, | |
188 | and there are sleeping threads - wait until one wakes up. Otherwise, | |
189 | return NULL. */ | |
190 | ||
44e8413c MD |
191 | #ifdef GUILE_ISELECT |
192 | extern coop_t *coop_next_runnable_thread (); | |
193 | #else | |
7bfd3b9e JB |
194 | #ifdef __STDC__ |
195 | coop_t * | |
196 | coop_next_runnable_thread() | |
197 | #else | |
198 | coop_t * | |
199 | coop_next_runnable_thread() | |
200 | #endif | |
201 | { | |
202 | int sleepers; | |
203 | coop_t *t; | |
204 | time_t now; | |
205 | ||
206 | do { | |
207 | sleepers = 0; | |
208 | now = time(NULL); | |
209 | ||
210 | /* Check the sleeping queue */ | |
211 | while ((t = coop_qget(&coop_global_sleepq)) != NULL) | |
212 | { | |
213 | sleepers++; | |
214 | if (t->wakeup_time <= now) | |
215 | coop_qput(&coop_global_runq, t); | |
216 | else | |
44e8413c | 217 | coop_qput(&coop_tmp_queue, t); |
7bfd3b9e | 218 | } |
44e8413c | 219 | while ((t = coop_qget(&coop_tmp_queue)) != NULL) |
7bfd3b9e JB |
220 | coop_qput(&coop_global_sleepq, t); |
221 | ||
222 | t = coop_qget (&coop_global_runq); | |
223 | ||
224 | } while ((t == NULL) && (sleepers > 0)); | |
225 | ||
226 | return t; | |
227 | } | |
44e8413c | 228 | #endif |
7bfd3b9e JB |
229 | |
230 | #ifdef __STDC__ | |
231 | void | |
232 | coop_start() | |
233 | #else | |
234 | void | |
235 | coop_start() | |
236 | #endif | |
237 | { | |
238 | coop_t *next; | |
239 | ||
240 | while ((next = coop_qget (&coop_global_runq)) != NULL) { | |
241 | coop_global_curr = next; | |
242 | QT_BLOCK (coop_starthelp, 0, 0, next->sp); | |
243 | } | |
244 | } | |
245 | ||
246 | ||
247 | #ifdef __STDC__ | |
248 | static void * | |
249 | coop_starthelp (qt_t *old, void *ignore0, void *ignore1) | |
250 | #else | |
251 | static void * | |
252 | coop_starthelp (old, ignore0, ignore1) | |
253 | qt_t *old; | |
254 | void *ignore0; | |
255 | void *ignore1; | |
256 | #endif | |
257 | { | |
258 | coop_global_main.sp = old; | |
259 | coop_global_main.joining = NULL; | |
260 | coop_qput (&coop_global_runq, &coop_global_main); | |
261 | return NULL; /* not used, but keeps compiler happy */ | |
262 | } | |
263 | ||
264 | #ifdef __STDC__ | |
265 | void | |
266 | coop_mutex_init (coop_m *m) | |
267 | #else | |
268 | void | |
269 | coop_mutex_init (m) | |
270 | coop_m *m; | |
271 | #endif | |
272 | { | |
273 | m->owner = NULL; | |
274 | coop_qinit(&(m->waiting)); | |
275 | } | |
276 | ||
277 | #ifdef __STDC__ | |
278 | void | |
279 | coop_mutex_lock (coop_m *m) | |
280 | #else | |
281 | void | |
282 | coop_mutex_lock () | |
283 | coop_m *m; | |
284 | #endif | |
285 | { | |
286 | if (m->owner == NULL) | |
287 | { | |
288 | m->owner = coop_global_curr; | |
289 | } | |
290 | else | |
291 | { | |
292 | coop_t *old, *newthread; | |
293 | ||
294 | /* Record the current top-of-stack before going to sleep */ | |
295 | coop_global_curr->top = &old; | |
296 | ||
44e8413c MD |
297 | #ifdef GUILE_ISELECT |
298 | newthread = coop_wait_for_runnable_thread(); | |
299 | #else | |
7bfd3b9e | 300 | newthread = coop_next_runnable_thread(); |
44e8413c | 301 | #endif |
7bfd3b9e JB |
302 | old = coop_global_curr; |
303 | coop_global_curr = newthread; | |
304 | QT_BLOCK (coop_yieldhelp, old, &(m->waiting), newthread->sp); | |
305 | } | |
306 | } | |
307 | ||
308 | ||
309 | #ifdef __STDC__ | |
310 | void | |
311 | coop_mutex_unlock (coop_m *m) | |
312 | #else | |
313 | void | |
314 | coop_mutex_unlock (m) | |
315 | coop_m *m; | |
316 | #endif | |
317 | { | |
318 | coop_t *old, *newthread; | |
319 | ||
320 | newthread = coop_qget (&(m->waiting)); | |
321 | if (newthread != NULL) | |
322 | { | |
323 | /* Record the current top-of-stack before going to sleep */ | |
324 | coop_global_curr->top = &old; | |
325 | ||
326 | old = coop_global_curr; | |
327 | coop_global_curr = newthread; | |
328 | m->owner = coop_global_curr; | |
329 | QT_BLOCK (coop_yieldhelp, old, &coop_global_runq, newthread->sp); | |
330 | } | |
331 | else | |
332 | { | |
333 | m->owner = NULL; | |
334 | } | |
335 | } | |
336 | ||
337 | ||
338 | #ifdef __STDC__ | |
339 | void | |
340 | coop_condition_variable_init (coop_c *c) | |
341 | #else | |
342 | void | |
343 | coop_condition_variable_init (c) | |
344 | coop_c *c; | |
345 | #endif | |
346 | { | |
347 | coop_qinit(&(c->waiting)); | |
348 | } | |
349 | ||
350 | #ifdef __STDC__ | |
351 | void | |
352 | coop_condition_variable_wait (coop_c *c) | |
353 | #else | |
354 | void | |
355 | coop_condition_variable_wait (c) | |
356 | coop_c *c; | |
357 | #endif | |
358 | { | |
359 | coop_t *old, *newthread; | |
360 | ||
44e8413c MD |
361 | #ifdef GUILE_ISELECT |
362 | newthread = coop_wait_for_runnable_thread(); | |
363 | #else | |
7bfd3b9e | 364 | newthread = coop_next_runnable_thread(); |
44e8413c | 365 | #endif |
7bfd3b9e JB |
366 | old = coop_global_curr; |
367 | coop_global_curr = newthread; | |
368 | QT_BLOCK (coop_yieldhelp, old, &(c->waiting), newthread->sp); | |
369 | } | |
370 | ||
371 | #ifdef __STDC__ | |
372 | void | |
373 | coop_condition_variable_signal (coop_c *c) | |
374 | #else | |
375 | void | |
376 | coop_condition_variable_signal (c) | |
377 | coop_c *c; | |
378 | #endif | |
379 | { | |
380 | coop_t *newthread; | |
381 | ||
382 | while ((newthread = coop_qget (&(c->waiting))) != NULL) | |
383 | { | |
384 | coop_qput (&coop_global_runq, newthread); | |
385 | } | |
386 | } | |
387 | ||
388 | ||
389 | #ifdef __STDC__ | |
390 | coop_t * | |
391 | coop_create (coop_userf_t *f, void *pu) | |
392 | #else | |
393 | coop_t * | |
394 | coop_create (f, pu) | |
395 | coop_userf_t *f; | |
396 | void *pu; | |
397 | #endif | |
398 | { | |
399 | coop_t *t; | |
400 | void *sto; | |
401 | ||
402 | t = malloc (sizeof(coop_t)); | |
403 | ||
404 | t->data = NULL; | |
405 | t->sto = malloc (COOP_STKSIZE); | |
406 | sto = COOP_STKALIGN (t->sto, QT_STKALIGN); | |
407 | t->sp = QT_SP (sto, COOP_STKSIZE - QT_STKALIGN); | |
408 | t->base = t->sp; | |
409 | t->sp = QT_ARGS (t->sp, pu, t, (qt_userf_t *)f, coop_only); | |
410 | t->joining = NULL; | |
411 | coop_qput (&coop_global_runq, t); | |
412 | coop_all_qput (&coop_global_allq, t); | |
413 | ||
414 | return t; | |
415 | } | |
416 | ||
417 | ||
418 | #ifdef __STDC__ | |
419 | static void | |
420 | coop_only (void *pu, void *pt, qt_userf_t *f) | |
421 | #else | |
422 | static void | |
423 | coop_only (pu. pt, f) | |
424 | void *pu, | |
425 | void *pt, | |
426 | qt_userf_t *f; | |
427 | #endif | |
428 | { | |
429 | coop_global_curr = (coop_t *)pt; | |
430 | (*(coop_userf_t *)f)(pu); | |
431 | coop_abort(); | |
432 | /* NOTREACHED */ | |
433 | } | |
434 | ||
435 | ||
436 | #ifdef __STDC__ | |
437 | void | |
438 | coop_abort () | |
439 | #else | |
440 | void | |
441 | coop_abort () | |
442 | #endif | |
443 | { | |
444 | coop_t *old, *newthread; | |
445 | ||
446 | /* Wake up any threads that are waiting to join this one */ | |
447 | if (coop_global_curr->joining) | |
448 | { | |
449 | while ((newthread = coop_qget ((coop_q_t *)(coop_global_curr->joining))) | |
450 | != NULL) | |
451 | { | |
452 | coop_qput (&coop_global_runq, newthread); | |
453 | } | |
454 | free(coop_global_curr->joining); | |
455 | } | |
456 | ||
44e8413c MD |
457 | #ifdef GUILE_ISELECT |
458 | newthread = coop_wait_for_runnable_thread(); | |
459 | #else | |
7bfd3b9e | 460 | newthread = coop_next_runnable_thread(); |
44e8413c | 461 | #endif |
7bfd3b9e JB |
462 | coop_all_qremove(&coop_global_allq, coop_global_curr); |
463 | old = coop_global_curr; | |
464 | coop_global_curr = newthread; | |
465 | QT_ABORT (coop_aborthelp, old, (void *)NULL, newthread->sp); | |
466 | } | |
467 | ||
468 | ||
469 | #ifdef __STDC__ | |
470 | static void * | |
471 | coop_aborthelp (qt_t *sp, void *old, void *null) | |
472 | #else | |
473 | static void * | |
474 | coop_aborthelp (sp, old, null) | |
475 | qt_t *sp; | |
476 | void *old; | |
477 | void *null; | |
478 | #endif | |
479 | { | |
480 | coop_t *oldthread = (coop_t *) old; | |
481 | ||
482 | free (oldthread->sto); | |
483 | ||
484 | /* "old" is freed in scm_threads_thread_die(). | |
485 | Marking old->base NULL indicates that this thread is dead */ | |
486 | ||
487 | oldthread->base = NULL; | |
488 | ||
489 | return NULL; | |
490 | } | |
491 | ||
492 | ||
493 | #ifdef __STDC__ | |
494 | void | |
495 | coop_join(coop_t *t) | |
496 | #else | |
497 | void | |
498 | coop_join() | |
499 | coop_t *t; | |
500 | #endif | |
501 | { | |
502 | coop_t *old, *newthread; | |
503 | ||
504 | /* Check if t is already finished */ | |
505 | if (t->base == NULL) | |
506 | return; | |
507 | ||
508 | /* Create a join list if necessary */ | |
509 | if (t->joining == NULL) | |
510 | { | |
511 | t->joining = malloc(sizeof(coop_q_t)); | |
512 | coop_qinit((coop_q_t *) t->joining); | |
513 | } | |
514 | ||
44e8413c MD |
515 | #ifdef GUILE_ISELECT |
516 | newthread = coop_wait_for_runnable_thread(); | |
517 | #else | |
7bfd3b9e | 518 | newthread = coop_next_runnable_thread(); |
44e8413c | 519 | #endif |
7bfd3b9e JB |
520 | old = coop_global_curr; |
521 | coop_global_curr = newthread; | |
522 | QT_BLOCK (coop_yieldhelp, old, (coop_q_t *) t->joining, newthread->sp); | |
523 | } | |
524 | ||
525 | #ifdef __STDC__ | |
526 | void | |
527 | coop_yield() | |
528 | #else | |
529 | void | |
530 | coop_yield() | |
531 | #endif | |
532 | { | |
533 | coop_t *old = NULL; | |
534 | coop_t *newthread; | |
535 | ||
536 | newthread = coop_next_runnable_thread(); | |
537 | ||
538 | /* There may be no other runnable threads. Return if this is the | |
539 | case. */ | |
540 | if (newthread == NULL) | |
541 | return; | |
542 | ||
543 | old = coop_global_curr; | |
544 | ||
545 | coop_global_curr = newthread; | |
546 | QT_BLOCK (coop_yieldhelp, old, &coop_global_runq, newthread->sp); | |
547 | } | |
548 | ||
549 | ||
550 | #ifdef __STDC__ | |
551 | static void * | |
552 | coop_yieldhelp (qt_t *sp, void *old, void *blockq) | |
553 | #else | |
554 | static void * | |
555 | coop_yieldhelp (sp, old, blockq) | |
556 | qt_t *sp; | |
557 | void *old; | |
558 | void *blockq; | |
559 | #endif | |
560 | { | |
561 | ((coop_t *)old)->sp = sp; | |
562 | coop_qput ((coop_q_t *)blockq, (coop_t *)old); | |
563 | return NULL; | |
564 | } | |
565 | ||
566 | /* Replacement for the system's sleep() function. Does the right thing | |
567 | for the process - but not for the system (it busy-waits) */ | |
568 | ||
569 | #ifdef __STDC__ | |
44e8413c | 570 | void * |
7bfd3b9e JB |
571 | coop_sleephelp (qt_t *sp, void *old, void *blockq) |
572 | #else | |
44e8413c | 573 | void * |
7bfd3b9e JB |
574 | coop_sleephelp (sp, old, bolckq) |
575 | qt_t *sp; | |
576 | void *old; | |
577 | void *blockq; | |
578 | #endif | |
579 | { | |
580 | ((coop_t *)old)->sp = sp; | |
581 | /* old is already on the sleep queue - so there's no need to | |
582 | do anything extra here */ | |
583 | return NULL; | |
584 | } | |
585 | ||
44e8413c MD |
586 | #ifdef GUILE_ISELECT |
587 | ||
588 | void | |
589 | usleep (unsigned usec) | |
590 | { | |
591 | struct timeval timeout; | |
592 | timeout.tv_sec = 0; | |
593 | timeout.tv_usec = usec; | |
594 | scm_internal_select (0, NULL, NULL, NULL, &timeout); | |
595 | } | |
596 | ||
597 | unsigned | |
598 | sleep (unsigned sec) | |
599 | { | |
600 | time_t now = time (NULL); | |
601 | struct timeval timeout; | |
602 | int slept; | |
603 | timeout.tv_sec = sec; | |
604 | timeout.tv_usec = 0; | |
605 | scm_internal_select (0, NULL, NULL, NULL, &timeout); | |
606 | slept = time (NULL) - now; | |
607 | return slept > sec ? 0 : sec - slept; | |
608 | } | |
609 | ||
610 | #else /* GUILE_ISELECT */ | |
611 | ||
7bfd3b9e JB |
612 | #ifdef __STDC__ |
613 | unsigned | |
614 | sleep (unsigned s) | |
615 | #else | |
616 | unsigned | |
617 | sleep (s) | |
618 | unsigned s; | |
619 | #endif | |
620 | { | |
621 | coop_t *newthread, *old; | |
44e8413c | 622 | time_t now = time (NULL); |
7bfd3b9e JB |
623 | coop_global_curr->wakeup_time = now + s; |
624 | ||
625 | /* Put the current thread on the sleep queue */ | |
626 | coop_qput (&coop_global_sleepq, coop_global_curr); | |
627 | ||
628 | newthread = coop_next_runnable_thread(); | |
629 | ||
630 | /* If newthread is the same as the sleeping thread, do nothing */ | |
631 | if (newthread == coop_global_curr) | |
632 | return s; | |
633 | ||
634 | old = coop_global_curr; | |
635 | ||
636 | coop_global_curr = newthread; | |
637 | QT_BLOCK (coop_sleephelp, old, NULL, newthread->sp); | |
638 | ||
639 | return s; | |
640 | } | |
44e8413c MD |
641 | |
642 | #endif /* GUILE_ISELECT */ |