| 1 | /* Copyright (C) 1995,1996,1997,1998,2000,2001, 2002 Free Software Foundation, Inc. |
| 2 | * |
| 3 | * This library is free software; you can redistribute it and/or |
| 4 | * modify it under the terms of the GNU Lesser General Public |
| 5 | * License as published by the Free Software Foundation; either |
| 6 | * version 2.1 of the License, or (at your option) any later version. |
| 7 | * |
| 8 | * This library 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 GNU |
| 11 | * Lesser General Public License for more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU Lesser General Public |
| 14 | * License along with this library; if not, write to the Free Software |
| 15 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 16 | */ |
| 17 | |
| 18 | |
| 19 | \f |
| 20 | |
| 21 | #include "libguile/_scm.h" /* config.h, _scm.h, __scm.h should be first */ |
| 22 | |
| 23 | #include <unistd.h> |
| 24 | #include <stdio.h> |
| 25 | #include <assert.h> |
| 26 | #include <sys/time.h> |
| 27 | |
| 28 | #include "libguile/validate.h" |
| 29 | #include "libguile/coop-pthreads.h" |
| 30 | #include "libguile/root.h" |
| 31 | #include "libguile/eval.h" |
| 32 | #include "libguile/async.h" |
| 33 | #include "libguile/ports.h" |
| 34 | |
| 35 | #undef DEBUG |
| 36 | |
| 37 | /*** Queues */ |
| 38 | |
| 39 | static SCM |
| 40 | make_queue () |
| 41 | { |
| 42 | return scm_cons (SCM_EOL, SCM_EOL); |
| 43 | } |
| 44 | |
| 45 | static void |
| 46 | enqueue (SCM q, SCM t) |
| 47 | { |
| 48 | SCM c = scm_cons (t, SCM_EOL); |
| 49 | if (SCM_NULLP (SCM_CAR (q))) |
| 50 | SCM_SETCAR (q, c); |
| 51 | else |
| 52 | SCM_SETCDR (SCM_CDR (q), c); |
| 53 | SCM_SETCDR (q, c); |
| 54 | } |
| 55 | |
| 56 | static SCM |
| 57 | dequeue (SCM q) |
| 58 | { |
| 59 | SCM c = SCM_CAR (q); |
| 60 | if (SCM_NULLP (c)) |
| 61 | return SCM_BOOL_F; |
| 62 | else |
| 63 | { |
| 64 | SCM_SETCAR (q, SCM_CDR (c)); |
| 65 | if (SCM_NULLP (SCM_CAR (q))) |
| 66 | SCM_SETCDR (q, SCM_EOL); |
| 67 | return SCM_CAR (c); |
| 68 | } |
| 69 | } |
| 70 | |
| 71 | |
| 72 | /*** Threads */ |
| 73 | |
| 74 | typedef struct scm_copt_thread { |
| 75 | |
| 76 | /* A condition variable for sleeping on. |
| 77 | */ |
| 78 | pthread_cond_t sleep_cond; |
| 79 | |
| 80 | /* A link for waiting queues. |
| 81 | */ |
| 82 | struct scm_copt_thread *next_waiting; |
| 83 | |
| 84 | scm_root_state *root; |
| 85 | SCM handle; |
| 86 | pthread_t pthread; |
| 87 | SCM result; |
| 88 | |
| 89 | SCM joining_threads; |
| 90 | |
| 91 | /* For keeping track of the stack and registers. */ |
| 92 | SCM_STACKITEM *base; |
| 93 | SCM_STACKITEM *top; |
| 94 | jmp_buf regs; |
| 95 | |
| 96 | } scm_copt_thread; |
| 97 | |
| 98 | static SCM |
| 99 | make_thread (SCM creation_protects) |
| 100 | { |
| 101 | SCM z; |
| 102 | scm_copt_thread *t = scm_gc_malloc (sizeof(*t), "thread"); |
| 103 | z = scm_cell (scm_tc16_thread, (scm_t_bits)t); |
| 104 | t->handle = z; |
| 105 | t->result = creation_protects; |
| 106 | t->base = NULL; |
| 107 | t->joining_threads = make_queue (); |
| 108 | pthread_cond_init (&t->sleep_cond, NULL); |
| 109 | return z; |
| 110 | } |
| 111 | |
| 112 | static void |
| 113 | init_thread_creator (SCM thread, pthread_t th, scm_root_state *r) |
| 114 | { |
| 115 | scm_copt_thread *t = SCM_THREAD_DATA(thread); |
| 116 | t->root = r; |
| 117 | t->pthread = th; |
| 118 | #ifdef DEBUG |
| 119 | // fprintf (stderr, "%ld created %ld\n", pthread_self (), th); |
| 120 | #endif |
| 121 | } |
| 122 | |
| 123 | static void |
| 124 | init_thread_creatant (SCM thread, SCM_STACKITEM *base) |
| 125 | { |
| 126 | scm_copt_thread *t = SCM_THREAD_DATA(thread); |
| 127 | t->base = base; |
| 128 | t->top = NULL; |
| 129 | } |
| 130 | |
| 131 | static SCM |
| 132 | thread_mark (SCM obj) |
| 133 | { |
| 134 | scm_copt_thread *t = SCM_THREAD_DATA (obj); |
| 135 | scm_gc_mark (t->result); |
| 136 | scm_gc_mark (t->joining_threads); |
| 137 | return t->root->handle; |
| 138 | } |
| 139 | |
| 140 | static int |
| 141 | thread_print (SCM exp, SCM port, scm_print_state *pstate SCM_UNUSED) |
| 142 | { |
| 143 | scm_copt_thread *t = SCM_THREAD_DATA (exp); |
| 144 | scm_puts ("#<thread ", port); |
| 145 | scm_intprint ((unsigned long)t, 16, port); |
| 146 | if (t->pthread != -1) |
| 147 | { |
| 148 | scm_putc (' ', port); |
| 149 | scm_intprint (t->pthread, 10, port); |
| 150 | } |
| 151 | else |
| 152 | scm_puts (" (exited)", port); |
| 153 | scm_putc ('>', port); |
| 154 | return 1; |
| 155 | } |
| 156 | |
| 157 | static size_t |
| 158 | thread_free (SCM obj) |
| 159 | { |
| 160 | scm_copt_thread *t = SCM_THREAD_DATA (obj); |
| 161 | if (t->pthread != -1) |
| 162 | abort (); |
| 163 | scm_gc_free (t, sizeof (*t), "thread"); |
| 164 | return 0; |
| 165 | } |
| 166 | |
| 167 | /*** Fair mutexes */ |
| 168 | |
| 169 | /* POSIX mutexes are not necessarily fair but since we'd like to use a |
| 170 | mutex for scheduling, we build a fair one on top of POSIX. |
| 171 | */ |
| 172 | |
| 173 | typedef struct fair_mutex { |
| 174 | pthread_mutex_t lock; |
| 175 | scm_copt_thread *owner; |
| 176 | scm_copt_thread *next_waiting, *last_waiting; |
| 177 | } fair_mutex; |
| 178 | |
| 179 | static void |
| 180 | fair_mutex_init (fair_mutex *m) |
| 181 | { |
| 182 | pthread_mutex_init (&m->lock, NULL); |
| 183 | m->owner = NULL; |
| 184 | m->next_waiting = NULL; |
| 185 | m->last_waiting = NULL; |
| 186 | } |
| 187 | |
| 188 | static void |
| 189 | fair_mutex_lock_1 (fair_mutex *m, scm_copt_thread *t) |
| 190 | { |
| 191 | if (m->owner == NULL) |
| 192 | m->owner = t; |
| 193 | else |
| 194 | { |
| 195 | t->next_waiting = NULL; |
| 196 | if (m->last_waiting) |
| 197 | m->last_waiting->next_waiting = t; |
| 198 | else |
| 199 | m->next_waiting = t; |
| 200 | m->last_waiting = t; |
| 201 | do |
| 202 | { |
| 203 | pthread_cond_wait (&t->sleep_cond, &m->lock); |
| 204 | } |
| 205 | while (m->owner != t); |
| 206 | assert (m->next_waiting == t); |
| 207 | m->next_waiting = t->next_waiting; |
| 208 | if (m->next_waiting == NULL) |
| 209 | m->last_waiting = NULL; |
| 210 | } |
| 211 | pthread_mutex_unlock (&m->lock); |
| 212 | } |
| 213 | |
| 214 | static void |
| 215 | fair_mutex_lock (fair_mutex *m, scm_copt_thread *t) |
| 216 | { |
| 217 | pthread_mutex_lock (&m->lock); |
| 218 | fair_mutex_lock_1 (m, t); |
| 219 | } |
| 220 | |
| 221 | static void |
| 222 | fair_mutex_unlock_1 (fair_mutex *m) |
| 223 | { |
| 224 | scm_copt_thread *t; |
| 225 | pthread_mutex_lock (&m->lock); |
| 226 | // fprintf (stderr, "%ld unlocking\n", m->owner->pthread); |
| 227 | if ((t = m->next_waiting) != NULL) |
| 228 | { |
| 229 | m->owner = t; |
| 230 | pthread_cond_signal (&t->sleep_cond); |
| 231 | } |
| 232 | else |
| 233 | m->owner = NULL; |
| 234 | // fprintf (stderr, "%ld unlocked\n", pthread_self ()); |
| 235 | } |
| 236 | |
| 237 | static void |
| 238 | fair_mutex_unlock (fair_mutex *m) |
| 239 | { |
| 240 | fair_mutex_unlock_1 (m); |
| 241 | pthread_mutex_unlock (&m->lock); |
| 242 | } |
| 243 | |
| 244 | /* Temporarily give up the mutex. This function makes sure that we |
| 245 | are on the wait queue before starting the next thread. Otherwise |
| 246 | the next thread might preempt us and we will have a hard time |
| 247 | getting on the wait queue. |
| 248 | */ |
| 249 | #if 0 |
| 250 | static void |
| 251 | fair_mutex_yield (fair_mutex *m) |
| 252 | { |
| 253 | scm_copt_thread *self, *next; |
| 254 | |
| 255 | pthread_mutex_lock (&m->lock); |
| 256 | |
| 257 | /* get next thread |
| 258 | */ |
| 259 | if ((next = m->next_waiting) == NULL) |
| 260 | { |
| 261 | /* No use giving it up. */ |
| 262 | pthread_mutex_unlock (&m->lock); |
| 263 | return; |
| 264 | } |
| 265 | |
| 266 | /* put us on queue |
| 267 | */ |
| 268 | self = m->owner; |
| 269 | self->next_waiting = NULL; |
| 270 | if (m->last_waiting) |
| 271 | m->last_waiting->next_waiting = self; |
| 272 | else |
| 273 | m->next_waiting = self; |
| 274 | m->last_waiting = self; |
| 275 | |
| 276 | /* wake up next thread |
| 277 | */ |
| 278 | |
| 279 | m->owner = next; |
| 280 | pthread_cond_signal (&next->sleep_cond); |
| 281 | |
| 282 | /* wait for mutex |
| 283 | */ |
| 284 | do |
| 285 | { |
| 286 | pthread_cond_wait (&self->sleep_cond, &m->lock); |
| 287 | } |
| 288 | while (m->owner != self); |
| 289 | assert (m->next_waiting == self); |
| 290 | m->next_waiting = self->next_waiting; |
| 291 | if (m->next_waiting == NULL) |
| 292 | m->last_waiting = NULL; |
| 293 | |
| 294 | pthread_mutex_unlock (&m->lock); |
| 295 | } |
| 296 | #else |
| 297 | static void |
| 298 | fair_mutex_yield (fair_mutex *m) |
| 299 | { |
| 300 | scm_copt_thread *self = m->owner; |
| 301 | fair_mutex_unlock_1 (m); |
| 302 | fair_mutex_lock_1 (m, self); |
| 303 | } |
| 304 | #endif |
| 305 | |
| 306 | static void |
| 307 | fair_cond_wait (pthread_cond_t *c, fair_mutex *m) |
| 308 | { |
| 309 | scm_copt_thread *t = m->owner; |
| 310 | fair_mutex_unlock_1 (m); |
| 311 | pthread_cond_wait (c, &m->lock); |
| 312 | fair_mutex_lock_1 (m, t); |
| 313 | } |
| 314 | |
| 315 | /* Return 1 when the mutex was signalled and 0 when not. */ |
| 316 | static int |
| 317 | fair_cond_timedwait (pthread_cond_t *c, fair_mutex *m, scm_t_timespec *at) |
| 318 | { |
| 319 | int res; |
| 320 | scm_copt_thread *t = m->owner; |
| 321 | fair_mutex_unlock_1 (m); |
| 322 | res = pthread_cond_timedwait (c, &m->lock, at); /* XXX - signals? */ |
| 323 | fair_mutex_lock_1 (m, t); |
| 324 | return res == 0; |
| 325 | } |
| 326 | |
| 327 | /*** Scheduling */ |
| 328 | |
| 329 | /* When a thread wants to execute Guile functions, it locks the |
| 330 | guile_mutex. |
| 331 | */ |
| 332 | |
| 333 | static fair_mutex guile_mutex; |
| 334 | |
| 335 | static SCM cur_thread; |
| 336 | void *scm_i_copt_thread_data; |
| 337 | |
| 338 | void |
| 339 | scm_i_copt_set_thread_data (void *data) |
| 340 | { |
| 341 | scm_copt_thread *t = SCM_THREAD_DATA (cur_thread); |
| 342 | scm_i_copt_thread_data = data; |
| 343 | t->root = (scm_root_state *)data; |
| 344 | } |
| 345 | |
| 346 | static void |
| 347 | resume (scm_copt_thread *t) |
| 348 | { |
| 349 | cur_thread = t->handle; |
| 350 | scm_i_copt_thread_data = t->root; |
| 351 | t->top = NULL; |
| 352 | } |
| 353 | |
| 354 | static void |
| 355 | enter_guile (scm_copt_thread *t) |
| 356 | { |
| 357 | fair_mutex_lock (&guile_mutex, t); |
| 358 | resume (t); |
| 359 | } |
| 360 | |
| 361 | static scm_copt_thread * |
| 362 | suspend () |
| 363 | { |
| 364 | SCM cur = cur_thread; |
| 365 | scm_copt_thread *c = SCM_THREAD_DATA (cur); |
| 366 | |
| 367 | /* record top of stack for the GC */ |
| 368 | c->top = (SCM_STACKITEM *)&c; |
| 369 | /* save registers. */ |
| 370 | SCM_FLUSH_REGISTER_WINDOWS; |
| 371 | setjmp (c->regs); |
| 372 | |
| 373 | return c; |
| 374 | } |
| 375 | |
| 376 | static scm_copt_thread * |
| 377 | leave_guile () |
| 378 | { |
| 379 | scm_copt_thread *c = suspend (); |
| 380 | fair_mutex_unlock (&guile_mutex); |
| 381 | return c; |
| 382 | } |
| 383 | |
| 384 | int scm_i_switch_counter; |
| 385 | |
| 386 | SCM |
| 387 | scm_yield () |
| 388 | { |
| 389 | /* Testing guile_mutex.next_waiting without locking guile_mutex.lock |
| 390 | is OK since the outcome is not critical. Even when it changes |
| 391 | after the test, we do the right thing. |
| 392 | */ |
| 393 | if (guile_mutex.next_waiting) |
| 394 | { |
| 395 | scm_copt_thread *t = suspend (); |
| 396 | fair_mutex_yield (&guile_mutex); |
| 397 | resume (t); |
| 398 | } |
| 399 | return SCM_BOOL_T; |
| 400 | } |
| 401 | |
| 402 | /* Put the current thread to sleep until it is explicitely unblocked. |
| 403 | */ |
| 404 | static void |
| 405 | block () |
| 406 | { |
| 407 | scm_copt_thread *t = suspend (); |
| 408 | fair_cond_wait (&t->sleep_cond, &guile_mutex); |
| 409 | resume (t); |
| 410 | } |
| 411 | |
| 412 | /* Put the current thread to sleep until it is explicitely unblocked |
| 413 | or until a signal arrives or until time AT (absolute time) is |
| 414 | reached. Return 1 when it has been unblocked; 0 otherwise. |
| 415 | */ |
| 416 | static int |
| 417 | timed_block (scm_t_timespec *at) |
| 418 | { |
| 419 | int res; |
| 420 | scm_copt_thread *t = suspend (); |
| 421 | res = fair_cond_timedwait (&t->sleep_cond, &guile_mutex, at); |
| 422 | resume (t); |
| 423 | return res; |
| 424 | } |
| 425 | |
| 426 | /* Unblock a sleeping thread. |
| 427 | */ |
| 428 | static void |
| 429 | unblock (scm_copt_thread *t) |
| 430 | { |
| 431 | pthread_cond_signal (&t->sleep_cond); |
| 432 | } |
| 433 | |
| 434 | /*** Thread creation */ |
| 435 | |
| 436 | static SCM all_threads; |
| 437 | static int thread_count; |
| 438 | |
| 439 | typedef struct launch_data { |
| 440 | SCM thread; |
| 441 | SCM rootcont; |
| 442 | scm_t_catch_body body; |
| 443 | void *body_data; |
| 444 | scm_t_catch_handler handler; |
| 445 | void *handler_data; |
| 446 | } launch_data; |
| 447 | |
| 448 | static SCM |
| 449 | body_bootstrip (launch_data* data) |
| 450 | { |
| 451 | /* First save the new root continuation */ |
| 452 | data->rootcont = scm_root->rootcont; |
| 453 | return (data->body) (data->body_data); |
| 454 | // return scm_call_0 (data->body); |
| 455 | } |
| 456 | |
| 457 | static SCM |
| 458 | handler_bootstrip (launch_data* data, SCM tag, SCM throw_args) |
| 459 | { |
| 460 | scm_root->rootcont = data->rootcont; |
| 461 | return (data->handler) (data->handler_data, tag, throw_args); |
| 462 | // return scm_apply_1 (data->handler, tag, throw_args); |
| 463 | } |
| 464 | |
| 465 | static void |
| 466 | really_launch (SCM_STACKITEM *base, launch_data *data) |
| 467 | { |
| 468 | SCM thread = data->thread; |
| 469 | scm_copt_thread *t = SCM_THREAD_DATA (thread); |
| 470 | init_thread_creatant (thread, base); |
| 471 | enter_guile (t); |
| 472 | |
| 473 | data->rootcont = SCM_BOOL_F; |
| 474 | t->result = |
| 475 | scm_internal_cwdr ((scm_t_catch_body) body_bootstrip, |
| 476 | data, |
| 477 | (scm_t_catch_handler) handler_bootstrip, |
| 478 | data, base); |
| 479 | free (data); |
| 480 | |
| 481 | pthread_detach (t->pthread); |
| 482 | all_threads = scm_delq (thread, all_threads); |
| 483 | t->pthread = -1; |
| 484 | thread_count--; |
| 485 | leave_guile (); |
| 486 | } |
| 487 | |
| 488 | static void * |
| 489 | launch_thread (void *p) |
| 490 | { |
| 491 | really_launch ((SCM_STACKITEM *)&p, (launch_data *)p); |
| 492 | return NULL; |
| 493 | } |
| 494 | |
| 495 | static SCM |
| 496 | create_thread (scm_t_catch_body body, void *body_data, |
| 497 | scm_t_catch_handler handler, void *handler_data, |
| 498 | SCM protects) |
| 499 | { |
| 500 | SCM thread; |
| 501 | |
| 502 | /* Make new thread. The first thing the new thread will do is to |
| 503 | lock guile_mutex. Thus, we can safely complete its |
| 504 | initialization after creating it. While the new thread starts, |
| 505 | all its data is protected via all_threads. |
| 506 | */ |
| 507 | |
| 508 | { |
| 509 | pthread_t th; |
| 510 | SCM root, old_winds; |
| 511 | launch_data *data; |
| 512 | |
| 513 | /* Unwind wind chain. */ |
| 514 | old_winds = scm_dynwinds; |
| 515 | scm_dowinds (SCM_EOL, scm_ilength (scm_root->dynwinds)); |
| 516 | |
| 517 | /* Allocate thread locals. */ |
| 518 | root = scm_make_root (scm_root->handle); |
| 519 | data = scm_malloc (sizeof (launch_data)); |
| 520 | |
| 521 | /* Make thread. */ |
| 522 | thread = make_thread (protects); |
| 523 | data->thread = thread; |
| 524 | data->body = body; |
| 525 | data->body_data = body_data; |
| 526 | data->handler = handler; |
| 527 | data->handler_data = handler_data; |
| 528 | pthread_create (&th, NULL, launch_thread, (void *) data); |
| 529 | init_thread_creator (thread, th, SCM_ROOT_STATE (root)); |
| 530 | all_threads = scm_cons (thread, all_threads); |
| 531 | thread_count++; |
| 532 | |
| 533 | /* Return to old dynamic context. */ |
| 534 | scm_dowinds (old_winds, - scm_ilength (old_winds)); |
| 535 | } |
| 536 | |
| 537 | return thread; |
| 538 | } |
| 539 | |
| 540 | SCM |
| 541 | scm_call_with_new_thread (SCM argl) |
| 542 | #define FUNC_NAME s_call_with_new_thread |
| 543 | { |
| 544 | SCM thunk, handler; |
| 545 | |
| 546 | /* Check arguments. */ |
| 547 | { |
| 548 | register SCM args = argl; |
| 549 | if (!SCM_CONSP (args)) |
| 550 | SCM_WRONG_NUM_ARGS (); |
| 551 | thunk = SCM_CAR (args); |
| 552 | SCM_ASSERT (SCM_NFALSEP (scm_thunk_p (thunk)), |
| 553 | thunk, |
| 554 | SCM_ARG1, |
| 555 | s_call_with_new_thread); |
| 556 | args = SCM_CDR (args); |
| 557 | if (!SCM_CONSP (args)) |
| 558 | SCM_WRONG_NUM_ARGS (); |
| 559 | handler = SCM_CAR (args); |
| 560 | SCM_ASSERT (SCM_NFALSEP (scm_procedure_p (handler)), |
| 561 | handler, |
| 562 | SCM_ARG2, |
| 563 | s_call_with_new_thread); |
| 564 | if (!SCM_NULLP (SCM_CDR (args))) |
| 565 | SCM_WRONG_NUM_ARGS (); |
| 566 | } |
| 567 | |
| 568 | return create_thread ((scm_t_catch_body) scm_call_0, thunk, |
| 569 | (scm_t_catch_handler) scm_apply_1, handler, |
| 570 | argl); |
| 571 | } |
| 572 | #undef FUNC_NAME |
| 573 | |
| 574 | SCM |
| 575 | scm_spawn_thread (scm_t_catch_body body, void *body_data, |
| 576 | scm_t_catch_handler handler, void *handler_data) |
| 577 | { |
| 578 | return create_thread (body, body_data, handler, handler_data, SCM_BOOL_F); |
| 579 | } |
| 580 | |
| 581 | /*** Mutexes */ |
| 582 | |
| 583 | /* We implement our own mutex type since we want them to be 'fair', we |
| 584 | want to do fancy things while waiting for them (like running |
| 585 | asyncs) and we want to support waiting on many things at once. |
| 586 | Also, we might add things that are nice for debugging. |
| 587 | */ |
| 588 | |
| 589 | typedef struct scm_copt_mutex { |
| 590 | /* the thread currently owning the mutex, or SCM_BOOL_F. */ |
| 591 | SCM owner; |
| 592 | /* how much the owner owns us. */ |
| 593 | int level; |
| 594 | /* the threads waiting for this mutex. */ |
| 595 | SCM waiting; |
| 596 | } scm_copt_mutex; |
| 597 | |
| 598 | static SCM |
| 599 | mutex_mark (SCM mx) |
| 600 | { |
| 601 | scm_copt_mutex *m = SCM_MUTEX_DATA (mx); |
| 602 | scm_gc_mark (m->owner); |
| 603 | return m->waiting; |
| 604 | } |
| 605 | |
| 606 | SCM |
| 607 | scm_make_mutex () |
| 608 | { |
| 609 | SCM mx = scm_make_smob (scm_tc16_mutex); |
| 610 | scm_copt_mutex *m = SCM_MUTEX_DATA (mx); |
| 611 | m->owner = SCM_BOOL_F; |
| 612 | m->level = 0; |
| 613 | m->waiting = make_queue (); |
| 614 | return mx; |
| 615 | } |
| 616 | |
| 617 | SCM |
| 618 | scm_lock_mutex (SCM mx) |
| 619 | #define FUNC_NAME s_lock_mutex |
| 620 | { |
| 621 | scm_copt_mutex *m; |
| 622 | SCM_ASSERT (SCM_MUTEXP (mx), mx, SCM_ARG1, FUNC_NAME); |
| 623 | m = SCM_MUTEX_DATA (mx); |
| 624 | |
| 625 | if (m->owner == SCM_BOOL_F) |
| 626 | m->owner = cur_thread; |
| 627 | else if (m->owner == cur_thread) |
| 628 | m->level++; |
| 629 | else |
| 630 | { |
| 631 | while (m->owner != cur_thread) |
| 632 | { |
| 633 | enqueue (m->waiting, cur_thread); |
| 634 | block (); |
| 635 | SCM_ASYNC_TICK; |
| 636 | } |
| 637 | } |
| 638 | return SCM_BOOL_T; |
| 639 | } |
| 640 | #undef FUNC_NAME |
| 641 | |
| 642 | SCM |
| 643 | scm_try_mutex (SCM mx) |
| 644 | #define FUNC_NAME s_try_mutex |
| 645 | { |
| 646 | scm_copt_mutex *m; |
| 647 | SCM_ASSERT (SCM_MUTEXP (mx), mx, SCM_ARG1, FUNC_NAME); |
| 648 | m = SCM_MUTEX_DATA (mx); |
| 649 | |
| 650 | if (m->owner == SCM_BOOL_F) |
| 651 | m->owner = cur_thread; |
| 652 | else if (m->owner == cur_thread) |
| 653 | m->level++; |
| 654 | else |
| 655 | return SCM_BOOL_F; |
| 656 | return SCM_BOOL_T; |
| 657 | } |
| 658 | #undef FUNC_NAME |
| 659 | |
| 660 | SCM |
| 661 | scm_unlock_mutex (SCM mx) |
| 662 | #define FUNC_NAME s_unlock_mutex |
| 663 | { |
| 664 | scm_copt_mutex *m; |
| 665 | SCM_ASSERT (SCM_MUTEXP (mx), mx, SCM_ARG1, FUNC_NAME); |
| 666 | m = SCM_MUTEX_DATA (mx); |
| 667 | |
| 668 | if (m->owner != cur_thread) |
| 669 | { |
| 670 | if (m->owner == SCM_BOOL_F) |
| 671 | SCM_MISC_ERROR ("mutex not locked", SCM_EOL); |
| 672 | else |
| 673 | SCM_MISC_ERROR ("mutex not locked by this thread", SCM_EOL); |
| 674 | } |
| 675 | else if (m->level > 0) |
| 676 | m->level--; |
| 677 | else |
| 678 | { |
| 679 | SCM next = dequeue (m->waiting); |
| 680 | if (!SCM_FALSEP (next)) |
| 681 | { |
| 682 | m->owner = next; |
| 683 | unblock (SCM_THREAD_DATA (next)); |
| 684 | scm_yield (); |
| 685 | } |
| 686 | else |
| 687 | m->owner = SCM_BOOL_F; |
| 688 | } |
| 689 | return SCM_BOOL_T; |
| 690 | } |
| 691 | #undef FUNC_NAME |
| 692 | |
| 693 | /*** Condition variables */ |
| 694 | |
| 695 | /* Like mutexes, we implement our own condition variables using the |
| 696 | primitives above. |
| 697 | */ |
| 698 | |
| 699 | /* yeah, we don't need a structure for this, but more things (like a |
| 700 | name) will likely follow... */ |
| 701 | |
| 702 | typedef struct scm_copt_cond { |
| 703 | /* the threads waiting for this condition. */ |
| 704 | SCM waiting; |
| 705 | } scm_copt_cond; |
| 706 | |
| 707 | static SCM |
| 708 | cond_mark (SCM cv) |
| 709 | { |
| 710 | scm_copt_cond *c = SCM_CONDVAR_DATA (cv); |
| 711 | return c->waiting; |
| 712 | } |
| 713 | |
| 714 | SCM |
| 715 | scm_make_condition_variable (void) |
| 716 | { |
| 717 | SCM cv = scm_make_smob (scm_tc16_condvar); |
| 718 | scm_copt_cond *c = SCM_CONDVAR_DATA (cv); |
| 719 | c->waiting = make_queue (); |
| 720 | return cv; |
| 721 | } |
| 722 | |
| 723 | SCM |
| 724 | scm_timed_wait_condition_variable (SCM cv, SCM mx, SCM t) |
| 725 | #define FUNC_NAME s_wait_condition_variable |
| 726 | { |
| 727 | scm_copt_cond *c; |
| 728 | scm_t_timespec waittime; |
| 729 | int res; |
| 730 | |
| 731 | SCM_ASSERT (SCM_CONDVARP (cv), |
| 732 | cv, |
| 733 | SCM_ARG1, |
| 734 | s_wait_condition_variable); |
| 735 | SCM_ASSERT (SCM_MUTEXP (mx), |
| 736 | mx, |
| 737 | SCM_ARG2, |
| 738 | s_wait_condition_variable); |
| 739 | if (!SCM_UNBNDP (t)) |
| 740 | { |
| 741 | if (SCM_CONSP (t)) |
| 742 | { |
| 743 | SCM_VALIDATE_UINT_COPY (3, SCM_CAR(t), waittime.tv_sec); |
| 744 | SCM_VALIDATE_UINT_COPY (3, SCM_CDR(t), waittime.tv_nsec); |
| 745 | waittime.tv_nsec *= 1000; |
| 746 | } |
| 747 | else |
| 748 | { |
| 749 | SCM_VALIDATE_UINT_COPY (3, t, waittime.tv_sec); |
| 750 | waittime.tv_nsec = 0; |
| 751 | } |
| 752 | } |
| 753 | |
| 754 | c = SCM_CONDVAR_DATA (cv); |
| 755 | |
| 756 | enqueue (c->waiting, cur_thread); |
| 757 | scm_unlock_mutex (mx); |
| 758 | if (SCM_UNBNDP (t)) |
| 759 | { |
| 760 | block (); |
| 761 | res = 1; |
| 762 | } |
| 763 | else |
| 764 | res = timed_block (&waittime); |
| 765 | scm_lock_mutex (mx); |
| 766 | return SCM_BOOL (res); |
| 767 | } |
| 768 | #undef FUNC_NAME |
| 769 | |
| 770 | SCM |
| 771 | scm_signal_condition_variable (SCM cv) |
| 772 | #define FUNC_NAME s_signal_condition_variable |
| 773 | { |
| 774 | SCM th; |
| 775 | scm_copt_cond *c; |
| 776 | SCM_ASSERT (SCM_CONDVARP (cv), |
| 777 | cv, |
| 778 | SCM_ARG1, |
| 779 | s_signal_condition_variable); |
| 780 | c = SCM_CONDVAR_DATA (cv); |
| 781 | if (!SCM_FALSEP (th = dequeue (c->waiting))) |
| 782 | unblock (SCM_THREAD_DATA (th)); |
| 783 | return SCM_BOOL_T; |
| 784 | } |
| 785 | #undef FUNC_NAME |
| 786 | |
| 787 | SCM |
| 788 | scm_broadcast_condition_variable (SCM cv) |
| 789 | #define FUNC_NAME s_broadcast_condition_variable |
| 790 | { |
| 791 | SCM th; |
| 792 | scm_copt_cond *c; |
| 793 | SCM_ASSERT (SCM_CONDVARP (cv), |
| 794 | cv, |
| 795 | SCM_ARG1, |
| 796 | s_signal_condition_variable); |
| 797 | c = SCM_CONDVAR_DATA (cv); |
| 798 | while (!SCM_FALSEP (th = dequeue (c->waiting))) |
| 799 | unblock (SCM_THREAD_DATA (th)); |
| 800 | return SCM_BOOL_T; |
| 801 | } |
| 802 | #undef FUNC_NAME |
| 803 | |
| 804 | /*** Initialization */ |
| 805 | |
| 806 | void |
| 807 | scm_threads_init (SCM_STACKITEM *base) |
| 808 | { |
| 809 | scm_tc16_thread = scm_make_smob_type ("thread", 0); |
| 810 | scm_tc16_mutex = scm_make_smob_type ("mutex", sizeof (scm_copt_mutex)); |
| 811 | scm_tc16_condvar = scm_make_smob_type ("condition-variable", |
| 812 | sizeof (scm_copt_cond)); |
| 813 | |
| 814 | scm_i_switch_counter = SCM_I_THREAD_SWITCH_COUNT; |
| 815 | |
| 816 | fair_mutex_init (&guile_mutex); |
| 817 | |
| 818 | cur_thread = make_thread (SCM_BOOL_F); |
| 819 | enter_guile (SCM_THREAD_DATA (cur_thread)); |
| 820 | /* root is set later from init.c */ |
| 821 | init_thread_creator (cur_thread, pthread_self(), NULL); |
| 822 | init_thread_creatant (cur_thread, base); |
| 823 | |
| 824 | thread_count = 1; |
| 825 | scm_gc_register_root (&all_threads); |
| 826 | all_threads = scm_cons (cur_thread, SCM_EOL); |
| 827 | |
| 828 | scm_set_smob_mark (scm_tc16_thread, thread_mark); |
| 829 | scm_set_smob_print (scm_tc16_thread, thread_print); |
| 830 | scm_set_smob_free (scm_tc16_thread, thread_free); |
| 831 | |
| 832 | scm_set_smob_mark (scm_tc16_mutex, mutex_mark); |
| 833 | |
| 834 | scm_set_smob_mark (scm_tc16_condvar, cond_mark); |
| 835 | } |
| 836 | |
| 837 | /*** Marking stacks */ |
| 838 | |
| 839 | /* XXX - what to do with this? Do we need to handle this for blocked |
| 840 | threads as well? |
| 841 | */ |
| 842 | #ifdef __ia64__ |
| 843 | # define SCM_MARK_BACKING_STORE() do { \ |
| 844 | ucontext_t ctx; \ |
| 845 | SCM_STACKITEM * top, * bot; \ |
| 846 | getcontext (&ctx); \ |
| 847 | scm_mark_locations ((SCM_STACKITEM *) &ctx.uc_mcontext, \ |
| 848 | ((size_t) (sizeof (SCM_STACKITEM) - 1 + sizeof ctx.uc_mcontext) \ |
| 849 | / sizeof (SCM_STACKITEM))); \ |
| 850 | bot = (SCM_STACKITEM *) __libc_ia64_register_backing_store_base; \ |
| 851 | top = (SCM_STACKITEM *) ctx.uc_mcontext.sc_ar_bsp; \ |
| 852 | scm_mark_locations (bot, top - bot); } while (0) |
| 853 | #else |
| 854 | # define SCM_MARK_BACKING_STORE() |
| 855 | #endif |
| 856 | |
| 857 | void |
| 858 | scm_threads_mark_stacks (void) |
| 859 | { |
| 860 | volatile SCM c; |
| 861 | for (c = all_threads; !SCM_NULLP (c); c = SCM_CDR (c)) |
| 862 | { |
| 863 | scm_copt_thread *t = SCM_THREAD_DATA (SCM_CAR (c)); |
| 864 | if (t->base == NULL) |
| 865 | { |
| 866 | /* Not fully initialized yet. */ |
| 867 | continue; |
| 868 | } |
| 869 | if (t->top == NULL) |
| 870 | { |
| 871 | /* Active thread */ |
| 872 | /* stack_len is long rather than sizet in order to guarantee |
| 873 | that &stack_len is long aligned */ |
| 874 | #if SCM_STACK_GROWS_UP |
| 875 | long stack_len = ((SCM_STACKITEM *) (&t) - |
| 876 | (SCM_STACKITEM *) thread->base); |
| 877 | |
| 878 | /* Protect from the C stack. This must be the first marking |
| 879 | * done because it provides information about what objects |
| 880 | * are "in-use" by the C code. "in-use" objects are those |
| 881 | * for which the information about length and base address must |
| 882 | * remain usable. This requirement is stricter than a liveness |
| 883 | * requirement -- in particular, it constrains the implementation |
| 884 | * of scm_resizuve. |
| 885 | */ |
| 886 | SCM_FLUSH_REGISTER_WINDOWS; |
| 887 | /* This assumes that all registers are saved into the jmp_buf */ |
| 888 | setjmp (scm_save_regs_gc_mark); |
| 889 | scm_mark_locations ((SCM_STACKITEM *) scm_save_regs_gc_mark, |
| 890 | ((size_t) sizeof scm_save_regs_gc_mark |
| 891 | / sizeof (SCM_STACKITEM))); |
| 892 | |
| 893 | scm_mark_locations (((size_t) t->base, |
| 894 | (sizet) stack_len)); |
| 895 | #else |
| 896 | long stack_len = ((SCM_STACKITEM *) t->base - |
| 897 | (SCM_STACKITEM *) (&t)); |
| 898 | |
| 899 | /* Protect from the C stack. This must be the first marking |
| 900 | * done because it provides information about what objects |
| 901 | * are "in-use" by the C code. "in-use" objects are those |
| 902 | * for which the information about length and base address must |
| 903 | * remain usable. This requirement is stricter than a liveness |
| 904 | * requirement -- in particular, it constrains the implementation |
| 905 | * of scm_resizuve. |
| 906 | */ |
| 907 | SCM_FLUSH_REGISTER_WINDOWS; |
| 908 | /* This assumes that all registers are saved into the jmp_buf */ |
| 909 | setjmp (scm_save_regs_gc_mark); |
| 910 | scm_mark_locations ((SCM_STACKITEM *) scm_save_regs_gc_mark, |
| 911 | ((size_t) sizeof scm_save_regs_gc_mark |
| 912 | / sizeof (SCM_STACKITEM))); |
| 913 | |
| 914 | scm_mark_locations ((SCM_STACKITEM *) &t, |
| 915 | stack_len); |
| 916 | #endif |
| 917 | } |
| 918 | else |
| 919 | { |
| 920 | /* Suspended thread */ |
| 921 | #if SCM_STACK_GROWS_UP |
| 922 | long stack_len = t->top - t->base; |
| 923 | scm_mark_locations (t->base, stack_len); |
| 924 | #else |
| 925 | long stack_len = t->base - t->top; |
| 926 | scm_mark_locations (t->top, stack_len); |
| 927 | #endif |
| 928 | scm_mark_locations ((SCM_STACKITEM *) t->regs, |
| 929 | ((size_t) sizeof(t->regs) |
| 930 | / sizeof (SCM_STACKITEM))); |
| 931 | } |
| 932 | } |
| 933 | } |
| 934 | |
| 935 | /*** Select */ |
| 936 | |
| 937 | int |
| 938 | scm_internal_select (int nfds, |
| 939 | SELECT_TYPE *readfds, |
| 940 | SELECT_TYPE *writefds, |
| 941 | SELECT_TYPE *exceptfds, |
| 942 | struct timeval *timeout) |
| 943 | { |
| 944 | int res, eno; |
| 945 | scm_copt_thread *c = leave_guile (); |
| 946 | res = select (nfds, readfds, writefds, exceptfds, timeout); |
| 947 | eno = errno; |
| 948 | enter_guile (c); |
| 949 | SCM_ASYNC_TICK; |
| 950 | errno = eno; |
| 951 | return res; |
| 952 | } |
| 953 | |
| 954 | void |
| 955 | scm_init_iselect () |
| 956 | { |
| 957 | } |
| 958 | |
| 959 | unsigned long |
| 960 | scm_thread_usleep (unsigned long usec) |
| 961 | { |
| 962 | scm_copt_thread *c = leave_guile (); |
| 963 | usleep (usec); |
| 964 | enter_guile (c); |
| 965 | return 0; |
| 966 | } |
| 967 | |
| 968 | unsigned long |
| 969 | scm_thread_sleep (unsigned long sec) |
| 970 | { |
| 971 | unsigned long res; |
| 972 | scm_copt_thread *c = leave_guile (); |
| 973 | res = sleep (sec); |
| 974 | enter_guile (c); |
| 975 | return res; |
| 976 | } |
| 977 | |
| 978 | /*** Misc */ |
| 979 | |
| 980 | SCM |
| 981 | scm_current_thread (void) |
| 982 | { |
| 983 | return cur_thread; |
| 984 | } |
| 985 | |
| 986 | SCM |
| 987 | scm_all_threads (void) |
| 988 | { |
| 989 | return all_threads; |
| 990 | } |
| 991 | |
| 992 | scm_root_state * |
| 993 | scm_i_thread_root (SCM thread) |
| 994 | { |
| 995 | if (thread == cur_thread) |
| 996 | return scm_i_copt_thread_data; |
| 997 | else |
| 998 | return ((scm_copt_thread *)SCM_THREAD_DATA (thread))->root; |
| 999 | } |
| 1000 | |
| 1001 | SCM |
| 1002 | scm_join_thread (SCM thread) |
| 1003 | #define FUNC_NAME s_join_thread |
| 1004 | { |
| 1005 | scm_copt_thread *t; |
| 1006 | SCM res; |
| 1007 | |
| 1008 | SCM_VALIDATE_THREAD (1, thread); |
| 1009 | |
| 1010 | t = SCM_THREAD_DATA (thread); |
| 1011 | if (t->pthread != -1) |
| 1012 | { |
| 1013 | scm_copt_thread *c = leave_guile (); |
| 1014 | pthread_join (t->pthread, NULL); |
| 1015 | enter_guile (c); |
| 1016 | } |
| 1017 | res = t->result; |
| 1018 | t->result = SCM_BOOL_F; |
| 1019 | return res; |
| 1020 | } |
| 1021 | #undef FUNC_NAME |
| 1022 | |
| 1023 | int |
| 1024 | scm_c_thread_exited_p (SCM thread) |
| 1025 | #define FUNC_NAME s_scm_thread_exited_p |
| 1026 | { |
| 1027 | scm_copt_thread *t; |
| 1028 | SCM_VALIDATE_THREAD (1, thread); |
| 1029 | t = SCM_THREAD_DATA (thread); |
| 1030 | return t->pthread == -1; |
| 1031 | } |
| 1032 | #undef FUNC_NAME |
| 1033 | |
| 1034 | /* |
| 1035 | Local Variables: |
| 1036 | c-file-style: "gnu" |
| 1037 | End: |
| 1038 | */ |
| 1039 | |