| 1 | /* Copyright (C) 1995,1996,1997,1998,2000,2001, 2002, 2003 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 | /* This file implements nice Scheme level threads on top of the gastly |
| 22 | C level threads. |
| 23 | */ |
| 24 | |
| 25 | #include "libguile/_scm.h" |
| 26 | |
| 27 | #if HAVE_UNISTD_H |
| 28 | #include <unistd.h> |
| 29 | #endif |
| 30 | #include <stdio.h> |
| 31 | #include <assert.h> |
| 32 | #if HAVE_SYS_TIME_H |
| 33 | #include <sys/time.h> |
| 34 | #endif |
| 35 | |
| 36 | #include "libguile/validate.h" |
| 37 | #include "libguile/root.h" |
| 38 | #include "libguile/eval.h" |
| 39 | #include "libguile/async.h" |
| 40 | #include "libguile/ports.h" |
| 41 | #include "libguile/threads.h" |
| 42 | #include "libguile/dynwind.h" |
| 43 | #include "libguile/iselect.h" |
| 44 | |
| 45 | /*** Queues */ |
| 46 | |
| 47 | static SCM |
| 48 | make_queue () |
| 49 | { |
| 50 | return scm_cons (SCM_EOL, SCM_EOL); |
| 51 | } |
| 52 | |
| 53 | static SCM |
| 54 | enqueue (SCM q, SCM t) |
| 55 | { |
| 56 | SCM c = scm_cons (t, SCM_EOL); |
| 57 | if (SCM_NULLP (SCM_CDR (q))) |
| 58 | SCM_SETCDR (q, c); |
| 59 | else |
| 60 | SCM_SETCDR (SCM_CAR (q), c); |
| 61 | SCM_SETCAR (q, c); |
| 62 | return c; |
| 63 | } |
| 64 | |
| 65 | static void |
| 66 | remqueue (SCM q, SCM c) |
| 67 | { |
| 68 | SCM p, prev = q; |
| 69 | for (p = SCM_CDR (q); !SCM_NULLP (p); p = SCM_CDR (p)) |
| 70 | { |
| 71 | if (SCM_EQ_P (p, c)) |
| 72 | { |
| 73 | if (SCM_EQ_P (c, SCM_CAR (q))) |
| 74 | SCM_SETCAR (q, SCM_CDR (c)); |
| 75 | SCM_SETCDR (prev, SCM_CDR (c)); |
| 76 | return; |
| 77 | } |
| 78 | prev = p; |
| 79 | } |
| 80 | abort (); |
| 81 | } |
| 82 | |
| 83 | static SCM |
| 84 | dequeue (SCM q) |
| 85 | { |
| 86 | SCM c = SCM_CDR (q); |
| 87 | if (SCM_NULLP (c)) |
| 88 | return SCM_BOOL_F; |
| 89 | else |
| 90 | { |
| 91 | SCM_SETCDR (q, SCM_CDR (c)); |
| 92 | if (SCM_NULLP (SCM_CDR (q))) |
| 93 | SCM_SETCAR (q, SCM_EOL); |
| 94 | return SCM_CAR (c); |
| 95 | } |
| 96 | } |
| 97 | |
| 98 | /*** Threads */ |
| 99 | |
| 100 | #define THREAD_INITIALIZED_P(t) (t->base != NULL) |
| 101 | |
| 102 | struct scm_thread { |
| 103 | |
| 104 | /* Blocking. |
| 105 | */ |
| 106 | scm_t_cond sleep_cond; |
| 107 | struct scm_thread *next_waiting; |
| 108 | |
| 109 | /* This mutex represents this threads right to access the heap. |
| 110 | That right can temporarily be taken away by the GC. */ |
| 111 | scm_t_mutex heap_mutex; |
| 112 | int clear_freelists_p; /* set if GC was done while thread was asleep */ |
| 113 | |
| 114 | scm_root_state *root; |
| 115 | SCM handle; |
| 116 | scm_t_thread thread; |
| 117 | SCM result; |
| 118 | int exited; |
| 119 | |
| 120 | /* For keeping track of the stack and registers. */ |
| 121 | SCM_STACKITEM *base; |
| 122 | SCM_STACKITEM *top; |
| 123 | jmp_buf regs; |
| 124 | |
| 125 | }; |
| 126 | |
| 127 | static SCM |
| 128 | make_thread (SCM creation_protects) |
| 129 | { |
| 130 | SCM z; |
| 131 | scm_thread *t; |
| 132 | z = scm_make_smob (scm_tc16_thread); |
| 133 | t = SCM_THREAD_DATA (z); |
| 134 | t->handle = z; |
| 135 | t->result = creation_protects; |
| 136 | t->base = NULL; |
| 137 | scm_i_plugin_cond_init (&t->sleep_cond, 0); |
| 138 | scm_i_plugin_mutex_init (&t->heap_mutex, &scm_i_plugin_mutex); |
| 139 | t->clear_freelists_p = 0; |
| 140 | t->exited = 0; |
| 141 | return z; |
| 142 | } |
| 143 | |
| 144 | static void |
| 145 | init_thread_creatant (SCM thread, |
| 146 | SCM_STACKITEM *base) |
| 147 | { |
| 148 | scm_thread *t = SCM_THREAD_DATA (thread); |
| 149 | t->thread = scm_thread_self (); |
| 150 | t->base = base; |
| 151 | t->top = NULL; |
| 152 | } |
| 153 | |
| 154 | static SCM |
| 155 | thread_mark (SCM obj) |
| 156 | { |
| 157 | scm_thread *t = SCM_THREAD_DATA (obj); |
| 158 | scm_gc_mark (t->result); |
| 159 | return t->root->handle; /* mark root-state of this thread */ |
| 160 | } |
| 161 | |
| 162 | static int |
| 163 | thread_print (SCM exp, SCM port, scm_print_state *pstate SCM_UNUSED) |
| 164 | { |
| 165 | scm_thread *t = SCM_THREAD_DATA (exp); |
| 166 | scm_puts ("#<thread ", port); |
| 167 | scm_intprint ((unsigned long)t->thread, 10, port); |
| 168 | scm_puts (" (", port); |
| 169 | scm_intprint ((unsigned long)t, 16, port); |
| 170 | scm_puts (")>", port); |
| 171 | return 1; |
| 172 | } |
| 173 | |
| 174 | static size_t |
| 175 | thread_free (SCM obj) |
| 176 | { |
| 177 | scm_thread *t = SCM_THREAD_DATA (obj); |
| 178 | if (!t->exited) |
| 179 | abort (); |
| 180 | scm_gc_free (t, sizeof (*t), "thread"); |
| 181 | return 0; |
| 182 | } |
| 183 | |
| 184 | /*** Scheduling */ |
| 185 | |
| 186 | #define cur_thread (SCM_CURRENT_THREAD->handle) |
| 187 | scm_t_key scm_i_thread_key; |
| 188 | scm_t_key scm_i_root_state_key; |
| 189 | |
| 190 | void |
| 191 | scm_i_set_thread_data (void *data) |
| 192 | { |
| 193 | scm_thread *t = SCM_CURRENT_THREAD; |
| 194 | scm_setspecific (scm_i_root_state_key, data); |
| 195 | t->root = (scm_root_state *)data; |
| 196 | } |
| 197 | |
| 198 | static void |
| 199 | resume (scm_thread *t) |
| 200 | { |
| 201 | t->top = NULL; |
| 202 | if (t->clear_freelists_p) |
| 203 | { |
| 204 | *SCM_FREELIST_LOC (scm_i_freelist) = SCM_EOL; |
| 205 | *SCM_FREELIST_LOC (scm_i_freelist2) = SCM_EOL; |
| 206 | t->clear_freelists_p = 0; |
| 207 | } |
| 208 | } |
| 209 | |
| 210 | void |
| 211 | scm_i_enter_guile (scm_thread *t) |
| 212 | { |
| 213 | scm_i_plugin_mutex_lock (&t->heap_mutex); |
| 214 | resume (t); |
| 215 | } |
| 216 | |
| 217 | static scm_thread * |
| 218 | suspend () |
| 219 | { |
| 220 | scm_thread *c = SCM_CURRENT_THREAD; |
| 221 | |
| 222 | /* record top of stack for the GC */ |
| 223 | c->top = SCM_STACK_PTR (&c); |
| 224 | /* save registers. */ |
| 225 | SCM_FLUSH_REGISTER_WINDOWS; |
| 226 | setjmp (c->regs); |
| 227 | |
| 228 | return c; |
| 229 | } |
| 230 | |
| 231 | scm_thread * |
| 232 | scm_i_leave_guile () |
| 233 | { |
| 234 | scm_thread *t = suspend (); |
| 235 | scm_i_plugin_mutex_unlock (&t->heap_mutex); |
| 236 | return t; |
| 237 | } |
| 238 | |
| 239 | /* Put the current thread to sleep until it is explicitely unblocked. |
| 240 | */ |
| 241 | static int |
| 242 | block () |
| 243 | { |
| 244 | int err; |
| 245 | scm_thread *t = suspend (); |
| 246 | err = scm_i_plugin_cond_wait (&t->sleep_cond, &t->heap_mutex); |
| 247 | resume (t); |
| 248 | return err; |
| 249 | } |
| 250 | |
| 251 | /* Put the current thread to sleep until it is explicitely unblocked |
| 252 | or until a signal arrives or until time AT (absolute time) is |
| 253 | reached. Return 0 when it has been unblocked; errno otherwise. |
| 254 | */ |
| 255 | static int |
| 256 | timed_block (const scm_t_timespec *at) |
| 257 | { |
| 258 | int err; |
| 259 | scm_thread *t = suspend (); |
| 260 | err = scm_i_plugin_cond_timedwait (&t->sleep_cond, &t->heap_mutex, at); |
| 261 | resume (t); |
| 262 | return err; |
| 263 | } |
| 264 | |
| 265 | /* Unblock a sleeping thread. |
| 266 | */ |
| 267 | static void |
| 268 | unblock (scm_thread *t) |
| 269 | { |
| 270 | scm_i_plugin_cond_signal (&t->sleep_cond); |
| 271 | } |
| 272 | |
| 273 | /*** Thread creation */ |
| 274 | |
| 275 | static scm_t_mutex thread_admin_mutex; |
| 276 | static SCM all_threads; |
| 277 | static int thread_count; |
| 278 | |
| 279 | typedef struct launch_data { |
| 280 | SCM thread; |
| 281 | SCM rootcont; |
| 282 | scm_t_catch_body body; |
| 283 | void *body_data; |
| 284 | scm_t_catch_handler handler; |
| 285 | void *handler_data; |
| 286 | } launch_data; |
| 287 | |
| 288 | static SCM |
| 289 | body_bootstrip (launch_data* data) |
| 290 | { |
| 291 | /* First save the new root continuation */ |
| 292 | data->rootcont = scm_root->rootcont; |
| 293 | return (data->body) (data->body_data); |
| 294 | } |
| 295 | |
| 296 | static SCM |
| 297 | handler_bootstrip (launch_data* data, SCM tag, SCM throw_args) |
| 298 | { |
| 299 | scm_root->rootcont = data->rootcont; |
| 300 | return (data->handler) (data->handler_data, tag, throw_args); |
| 301 | } |
| 302 | |
| 303 | static void |
| 304 | really_launch (SCM_STACKITEM *base, launch_data *data) |
| 305 | { |
| 306 | SCM thread; |
| 307 | scm_thread *t; |
| 308 | thread = data->thread; |
| 309 | t = SCM_THREAD_DATA (thread); |
| 310 | SCM_FREELIST_CREATE (scm_i_freelist); |
| 311 | SCM_FREELIST_CREATE (scm_i_freelist2); |
| 312 | scm_setspecific (scm_i_thread_key, t); |
| 313 | scm_setspecific (scm_i_root_state_key, t->root); |
| 314 | scm_i_plugin_mutex_lock (&t->heap_mutex); /* ensure that we "own" the heap */ |
| 315 | init_thread_creatant (thread, base); /* must own the heap */ |
| 316 | |
| 317 | data->rootcont = SCM_BOOL_F; |
| 318 | t->result = |
| 319 | scm_internal_cwdr ((scm_t_catch_body) body_bootstrip, |
| 320 | data, |
| 321 | (scm_t_catch_handler) handler_bootstrip, |
| 322 | data, base); |
| 323 | scm_i_leave_guile (); /* release the heap */ |
| 324 | free (data); |
| 325 | |
| 326 | scm_i_plugin_mutex_lock (&thread_admin_mutex); |
| 327 | all_threads = scm_delq_x (thread, all_threads); |
| 328 | t->exited = 1; |
| 329 | thread_count--; |
| 330 | /* detach before unlocking in order to not become joined when detached */ |
| 331 | scm_thread_detach (t->thread); |
| 332 | scm_i_plugin_mutex_unlock (&thread_admin_mutex); |
| 333 | } |
| 334 | |
| 335 | static void * |
| 336 | launch_thread (void *p) |
| 337 | { |
| 338 | really_launch (SCM_STACK_PTR (&p), (launch_data *) p); |
| 339 | return 0; |
| 340 | } |
| 341 | |
| 342 | static SCM |
| 343 | create_thread (scm_t_catch_body body, void *body_data, |
| 344 | scm_t_catch_handler handler, void *handler_data, |
| 345 | SCM protects) |
| 346 | { |
| 347 | SCM thread; |
| 348 | |
| 349 | /* Make new thread. The first thing the new thread will do is to |
| 350 | lock guile_mutex. Thus, we can safely complete its |
| 351 | initialization after creating it. While the new thread starts, |
| 352 | all its data is protected via all_threads. |
| 353 | */ |
| 354 | |
| 355 | { |
| 356 | scm_t_thread th; |
| 357 | SCM root; |
| 358 | launch_data *data; |
| 359 | scm_thread *t; |
| 360 | int err; |
| 361 | |
| 362 | /* Allocate thread locals. */ |
| 363 | root = scm_make_root (scm_root->handle); |
| 364 | data = scm_malloc (sizeof (launch_data)); |
| 365 | |
| 366 | /* Make thread. */ |
| 367 | thread = make_thread (protects); |
| 368 | data->thread = thread; |
| 369 | data->body = body; |
| 370 | data->body_data = body_data; |
| 371 | data->handler = handler; |
| 372 | data->handler_data = handler_data; |
| 373 | t = SCM_THREAD_DATA (thread); |
| 374 | /* must initialize root state pointer before the thread is linked |
| 375 | into all_threads */ |
| 376 | t->root = SCM_ROOT_STATE (root); |
| 377 | /* disconnect from parent, to prevent remembering dead threads */ |
| 378 | t->root->parent = SCM_BOOL_F; |
| 379 | /* start with an empty dynwind chain */ |
| 380 | t->root->dynwinds = SCM_EOL; |
| 381 | |
| 382 | /* In order to avoid the need of synchronization between parent |
| 383 | and child thread, we need to insert the child into all_threads |
| 384 | before creation. */ |
| 385 | { |
| 386 | SCM new_threads = scm_cons (thread, SCM_BOOL_F); /* could cause GC */ |
| 387 | scm_thread *parent = scm_i_leave_guile (); /* to prevent deadlock */ |
| 388 | scm_i_plugin_mutex_lock (&thread_admin_mutex); |
| 389 | SCM_SETCDR (new_threads, all_threads); |
| 390 | all_threads = new_threads; |
| 391 | thread_count++; |
| 392 | scm_i_plugin_mutex_unlock (&thread_admin_mutex); |
| 393 | |
| 394 | scm_remember_upto_here_1 (root); |
| 395 | |
| 396 | scm_i_enter_guile (parent); |
| 397 | } |
| 398 | |
| 399 | err = scm_i_plugin_thread_create (&th, 0, launch_thread, (void *) data); |
| 400 | if (err != 0) |
| 401 | { |
| 402 | scm_i_plugin_mutex_lock (&thread_admin_mutex); |
| 403 | all_threads = scm_delq_x (thread, all_threads); |
| 404 | ((scm_thread *) SCM_THREAD_DATA(thread))->exited = 1; |
| 405 | thread_count--; |
| 406 | scm_i_plugin_mutex_unlock (&thread_admin_mutex); |
| 407 | } |
| 408 | |
| 409 | if (err) |
| 410 | { |
| 411 | errno = err; |
| 412 | scm_syserror ("create-thread"); |
| 413 | } |
| 414 | } |
| 415 | |
| 416 | return thread; |
| 417 | } |
| 418 | |
| 419 | SCM_DEFINE (scm_call_with_new_thread, "call-with-new-thread", 2, 0, 0, |
| 420 | (SCM thunk, SCM handler), |
| 421 | "Evaluate @code{(@var{thunk})} in a new thread, and new dynamic context, " |
| 422 | "returning a new thread object representing the thread. " |
| 423 | "If an error occurs during evaluation, call error-thunk, passing it an " |
| 424 | "error code describing the condition. " |
| 425 | "If this happens, the error-thunk is called outside the scope of the new " |
| 426 | "root -- it is called in the same dynamic context in which " |
| 427 | "with-new-thread was evaluated, but not in the callers thread. " |
| 428 | "All the evaluation rules for dynamic roots apply to threads.") |
| 429 | #define FUNC_NAME s_scm_call_with_new_thread |
| 430 | { |
| 431 | SCM_ASSERT (SCM_NFALSEP (scm_thunk_p (thunk)), thunk, SCM_ARG1, FUNC_NAME); |
| 432 | SCM_ASSERT (SCM_NFALSEP (scm_procedure_p (handler)), handler, SCM_ARG2, |
| 433 | FUNC_NAME); |
| 434 | |
| 435 | return create_thread ((scm_t_catch_body) scm_call_0, thunk, |
| 436 | (scm_t_catch_handler) scm_apply_1, handler, |
| 437 | scm_cons (thunk, handler)); |
| 438 | } |
| 439 | #undef FUNC_NAME |
| 440 | |
| 441 | SCM_DEFINE (scm_yield, "yield", 0, 0, 0, |
| 442 | (), |
| 443 | "Move the calling thread to the end of the scheduling queue.") |
| 444 | #define FUNC_NAME s_scm_yield |
| 445 | { |
| 446 | return SCM_BOOL (scm_thread_yield); |
| 447 | } |
| 448 | #undef FUNC_NAME |
| 449 | |
| 450 | SCM_DEFINE (scm_join_thread, "join-thread", 1, 0, 0, |
| 451 | (SCM thread), |
| 452 | "Suspend execution of the calling thread until the target @var{thread} " |
| 453 | "terminates, unless the target @var{thread} has already terminated. ") |
| 454 | #define FUNC_NAME s_scm_join_thread |
| 455 | { |
| 456 | scm_thread *t; |
| 457 | SCM res; |
| 458 | |
| 459 | SCM_VALIDATE_THREAD (1, thread); |
| 460 | if (SCM_EQ_P (cur_thread, thread)) |
| 461 | SCM_MISC_ERROR ("can not join the current thread", SCM_EOL); |
| 462 | |
| 463 | t = SCM_THREAD_DATA (thread); |
| 464 | if (!t->exited) |
| 465 | { |
| 466 | scm_thread *c; |
| 467 | c = scm_i_leave_guile (); |
| 468 | while (!THREAD_INITIALIZED_P (t)) |
| 469 | scm_i_plugin_thread_yield (); |
| 470 | scm_thread_join (t->thread, 0); |
| 471 | scm_i_enter_guile (c); |
| 472 | } |
| 473 | res = t->result; |
| 474 | t->result = SCM_BOOL_F; |
| 475 | return res; |
| 476 | } |
| 477 | #undef FUNC_NAME |
| 478 | |
| 479 | /*** Fair mutexes */ |
| 480 | |
| 481 | /* We implement our own mutex type since we want them to be 'fair', we |
| 482 | want to do fancy things while waiting for them (like running |
| 483 | asyncs) and we want to support waiting on many things at once. |
| 484 | Also, we might add things that are nice for debugging. |
| 485 | */ |
| 486 | |
| 487 | typedef struct fair_mutex { |
| 488 | /* the thread currently owning the mutex, or SCM_BOOL_F. */ |
| 489 | scm_t_mutex lock; |
| 490 | int lockedp; |
| 491 | SCM owner; |
| 492 | /* how much the owner owns us. */ |
| 493 | int level; |
| 494 | /* the threads waiting for this mutex. */ |
| 495 | SCM waiting; |
| 496 | } fair_mutex; |
| 497 | |
| 498 | static SCM |
| 499 | fair_mutex_mark (SCM mx) |
| 500 | { |
| 501 | fair_mutex *m = SCM_MUTEX_DATA (mx); |
| 502 | scm_gc_mark (m->owner); |
| 503 | return m->waiting; |
| 504 | } |
| 505 | |
| 506 | SCM_DEFINE (scm_make_fair_mutex, "make-fair-mutex", 0, 0, 0, |
| 507 | (void), |
| 508 | "Create a new fair mutex object. ") |
| 509 | #define FUNC_NAME s_scm_make_fair_mutex |
| 510 | { |
| 511 | SCM mx = scm_make_smob (scm_tc16_fair_mutex); |
| 512 | fair_mutex *m = SCM_MUTEX_DATA (mx); |
| 513 | scm_i_plugin_mutex_init (&m->lock, &scm_i_plugin_mutex); |
| 514 | m->lockedp = 0; |
| 515 | m->owner = SCM_BOOL_F; |
| 516 | m->level = 0; |
| 517 | m->waiting = make_queue (); |
| 518 | return mx; |
| 519 | } |
| 520 | #undef FUNC_NAME |
| 521 | |
| 522 | static int |
| 523 | fair_mutex_lock (fair_mutex *m) |
| 524 | { |
| 525 | scm_i_plugin_mutex_lock (&m->lock); |
| 526 | #if 0 |
| 527 | /* Need to wait if another thread is just temporarily unlocking. |
| 528 | This is happens very seldom and only when the other thread is |
| 529 | between scm_mutex_unlock and scm_i_plugin_mutex_lock below. */ |
| 530 | while (m->lockedp) |
| 531 | SCM_TICK; |
| 532 | m->lockedp = 1; |
| 533 | #endif |
| 534 | |
| 535 | if (m->owner == SCM_BOOL_F) |
| 536 | m->owner = cur_thread; |
| 537 | else if (m->owner == cur_thread) |
| 538 | m->level++; |
| 539 | else |
| 540 | { |
| 541 | while (1) |
| 542 | { |
| 543 | SCM c = enqueue (m->waiting, cur_thread); |
| 544 | int err; |
| 545 | /* Note: It's important that m->lock is never locked for |
| 546 | any longer amount of time since that could prevent GC */ |
| 547 | scm_i_plugin_mutex_unlock (&m->lock); |
| 548 | err = block (); |
| 549 | if (m->owner == cur_thread) |
| 550 | return 0; |
| 551 | scm_i_plugin_mutex_lock (&m->lock); |
| 552 | remqueue (m->waiting, c); |
| 553 | scm_i_plugin_mutex_unlock (&m->lock); |
| 554 | if (err) |
| 555 | return err; |
| 556 | SCM_ASYNC_TICK; |
| 557 | scm_i_plugin_mutex_lock (&m->lock); |
| 558 | } |
| 559 | } |
| 560 | scm_i_plugin_mutex_unlock (&m->lock); |
| 561 | return 0; |
| 562 | } |
| 563 | |
| 564 | static int |
| 565 | fair_mutex_trylock (fair_mutex *m) |
| 566 | { |
| 567 | scm_i_plugin_mutex_lock (&m->lock); |
| 568 | if (m->owner == SCM_BOOL_F) |
| 569 | m->owner = cur_thread; |
| 570 | else if (m->owner == cur_thread) |
| 571 | m->level++; |
| 572 | else |
| 573 | { |
| 574 | scm_i_plugin_mutex_unlock (&m->lock); |
| 575 | return EBUSY; |
| 576 | } |
| 577 | scm_i_plugin_mutex_unlock (&m->lock); |
| 578 | return 0; |
| 579 | } |
| 580 | |
| 581 | static int |
| 582 | fair_mutex_unlock (fair_mutex *m) |
| 583 | { |
| 584 | scm_i_plugin_mutex_lock (&m->lock); |
| 585 | if (m->owner != cur_thread) |
| 586 | { |
| 587 | scm_i_plugin_mutex_unlock (&m->lock); |
| 588 | return EPERM; |
| 589 | } |
| 590 | else if (m->level > 0) |
| 591 | m->level--; |
| 592 | else |
| 593 | { |
| 594 | SCM next = dequeue (m->waiting); |
| 595 | if (!SCM_FALSEP (next)) |
| 596 | { |
| 597 | m->owner = next; |
| 598 | unblock (SCM_THREAD_DATA (next)); |
| 599 | } |
| 600 | else |
| 601 | m->owner = SCM_BOOL_F; |
| 602 | } |
| 603 | scm_i_plugin_mutex_unlock (&m->lock); |
| 604 | return 0; |
| 605 | } |
| 606 | |
| 607 | /*** Fair condition variables */ |
| 608 | |
| 609 | /* Like mutexes, we implement our own condition variables using the |
| 610 | primitives above. |
| 611 | */ |
| 612 | |
| 613 | typedef struct fair_cond { |
| 614 | scm_t_mutex lock; |
| 615 | /* the threads waiting for this condition. */ |
| 616 | SCM waiting; |
| 617 | } fair_cond; |
| 618 | |
| 619 | static SCM |
| 620 | fair_cond_mark (SCM cv) |
| 621 | { |
| 622 | fair_cond *c = SCM_CONDVAR_DATA (cv); |
| 623 | return c->waiting; |
| 624 | } |
| 625 | |
| 626 | SCM_DEFINE (scm_make_fair_condition_variable, "make-fair-condition-variable", 0, 0, 0, |
| 627 | (void), |
| 628 | "Make a new fair condition variable.") |
| 629 | #define FUNC_NAME s_scm_make_fair_condition_variable |
| 630 | { |
| 631 | SCM cv = scm_make_smob (scm_tc16_fair_condvar); |
| 632 | fair_cond *c = SCM_CONDVAR_DATA (cv); |
| 633 | scm_i_plugin_mutex_init (&c->lock, 0); |
| 634 | c->waiting = make_queue (); |
| 635 | return cv; |
| 636 | } |
| 637 | #undef FUNC_NAME |
| 638 | |
| 639 | static int |
| 640 | fair_cond_timedwait (fair_cond *c, |
| 641 | fair_mutex *m, |
| 642 | const scm_t_timespec *waittime) |
| 643 | { |
| 644 | int err; |
| 645 | scm_i_plugin_mutex_lock (&c->lock); |
| 646 | |
| 647 | while (1) |
| 648 | { |
| 649 | enqueue (c->waiting, cur_thread); |
| 650 | scm_i_plugin_mutex_unlock (&c->lock); |
| 651 | fair_mutex_unlock (m); /*fixme* - not thread safe */ |
| 652 | if (waittime == NULL) |
| 653 | err = block (); |
| 654 | else |
| 655 | err = timed_block (waittime); |
| 656 | fair_mutex_lock (m); |
| 657 | if (err) |
| 658 | return err; |
| 659 | /* XXX - check whether we have been signalled. */ |
| 660 | break; |
| 661 | } |
| 662 | return err; |
| 663 | } |
| 664 | |
| 665 | static int |
| 666 | fair_cond_signal (fair_cond *c) |
| 667 | { |
| 668 | SCM th; |
| 669 | scm_i_plugin_mutex_lock (&c->lock); |
| 670 | if (!SCM_FALSEP (th = dequeue (c->waiting))) |
| 671 | unblock (SCM_THREAD_DATA (th)); |
| 672 | scm_i_plugin_mutex_unlock (&c->lock); |
| 673 | return 0; |
| 674 | } |
| 675 | |
| 676 | static int |
| 677 | fair_cond_broadcast (fair_cond *c) |
| 678 | { |
| 679 | SCM th; |
| 680 | scm_i_plugin_mutex_lock (&c->lock); |
| 681 | while (!SCM_FALSEP (th = dequeue (c->waiting))) |
| 682 | unblock (SCM_THREAD_DATA (th)); |
| 683 | scm_i_plugin_mutex_unlock (&c->lock); |
| 684 | return 0; |
| 685 | } |
| 686 | |
| 687 | /*** Mutexes */ |
| 688 | |
| 689 | SCM_DEFINE (scm_make_mutex, "make-mutex", 0, 0, 0, |
| 690 | (void), |
| 691 | "Create a new mutex object. ") |
| 692 | #define FUNC_NAME s_scm_make_mutex |
| 693 | { |
| 694 | SCM mx = scm_make_smob (scm_tc16_mutex); |
| 695 | scm_i_plugin_mutex_init (SCM_MUTEX_DATA (mx), &scm_i_plugin_mutex); |
| 696 | return mx; |
| 697 | } |
| 698 | #undef FUNC_NAME |
| 699 | |
| 700 | /*fixme* change documentation */ |
| 701 | SCM_DEFINE (scm_lock_mutex, "lock-mutex", 1, 0, 0, |
| 702 | (SCM mx), |
| 703 | "Lock @var{mutex}. If the mutex is already locked, the calling thread " |
| 704 | "blocks until the mutex becomes available. The function returns when " |
| 705 | "the calling thread owns the lock on @var{mutex}. Locking a mutex that " |
| 706 | "a thread already owns will succeed right away and will not block the " |
| 707 | "thread. That is, Guile's mutexes are @emph{recursive}. ") |
| 708 | #define FUNC_NAME s_scm_lock_mutex |
| 709 | { |
| 710 | int err; |
| 711 | SCM_VALIDATE_MUTEX (1, mx); |
| 712 | |
| 713 | if (SCM_TYP16 (mx) == scm_tc16_fair_mutex) |
| 714 | err = fair_mutex_lock (SCM_MUTEX_DATA (mx)); |
| 715 | else |
| 716 | { |
| 717 | scm_t_mutex *m = SCM_MUTEX_DATA (mx); |
| 718 | err = scm_mutex_lock (m); |
| 719 | } |
| 720 | |
| 721 | if (err) |
| 722 | { |
| 723 | errno = err; |
| 724 | SCM_SYSERROR; |
| 725 | } |
| 726 | return SCM_BOOL_T; |
| 727 | } |
| 728 | #undef FUNC_NAME |
| 729 | |
| 730 | SCM_DEFINE (scm_try_mutex, "try-mutex", 1, 0, 0, |
| 731 | (SCM mx), |
| 732 | "Try to lock @var{mutex}. If the mutex is already locked by someone " |
| 733 | "else, return @code{#f}. Else lock the mutex and return @code{#t}. ") |
| 734 | #define FUNC_NAME s_scm_try_mutex |
| 735 | { |
| 736 | int err; |
| 737 | SCM_VALIDATE_MUTEX (1, mx); |
| 738 | |
| 739 | if (SCM_TYP16 (mx) == scm_tc16_fair_mutex) |
| 740 | err = fair_mutex_trylock (SCM_MUTEX_DATA (mx)); |
| 741 | else |
| 742 | { |
| 743 | scm_t_mutex *m = SCM_MUTEX_DATA (mx); |
| 744 | err = scm_mutex_trylock (m); |
| 745 | } |
| 746 | |
| 747 | if (err == EBUSY) |
| 748 | return SCM_BOOL_F; |
| 749 | |
| 750 | if (err) |
| 751 | { |
| 752 | errno = err; |
| 753 | SCM_SYSERROR; |
| 754 | } |
| 755 | |
| 756 | return SCM_BOOL_T; |
| 757 | } |
| 758 | #undef FUNC_NAME |
| 759 | |
| 760 | SCM_DEFINE (scm_unlock_mutex, "unlock-mutex", 1, 0, 0, |
| 761 | (SCM mx), |
| 762 | "Unlocks @var{mutex} if the calling thread owns the lock on " |
| 763 | "@var{mutex}. Calling unlock-mutex on a mutex not owned by the current " |
| 764 | "thread results in undefined behaviour. Once a mutex has been unlocked, " |
| 765 | "one thread blocked on @var{mutex} is awakened and grabs the mutex " |
| 766 | "lock. Every call to @code{lock-mutex} by this thread must be matched " |
| 767 | "with a call to @code{unlock-mutex}. Only the last call to " |
| 768 | "@code{unlock-mutex} will actually unlock the mutex. ") |
| 769 | #define FUNC_NAME s_scm_unlock_mutex |
| 770 | { |
| 771 | int err; |
| 772 | SCM_VALIDATE_MUTEX (1, mx); |
| 773 | |
| 774 | if (SCM_TYP16 (mx) == scm_tc16_fair_mutex) |
| 775 | { |
| 776 | err = fair_mutex_unlock (SCM_MUTEX_DATA (mx)); |
| 777 | if (err == EPERM) |
| 778 | { |
| 779 | fair_mutex *m = SCM_MUTEX_DATA (mx); |
| 780 | if (m->owner != cur_thread) |
| 781 | { |
| 782 | if (m->owner == SCM_BOOL_F) |
| 783 | SCM_MISC_ERROR ("mutex not locked", SCM_EOL); |
| 784 | else |
| 785 | SCM_MISC_ERROR ("mutex not locked by this thread", SCM_EOL); |
| 786 | } |
| 787 | } |
| 788 | } |
| 789 | else |
| 790 | { |
| 791 | scm_t_mutex *m = SCM_MUTEX_DATA (mx); |
| 792 | err = scm_mutex_unlock (m); |
| 793 | } |
| 794 | |
| 795 | if (err) |
| 796 | { |
| 797 | errno = err; |
| 798 | SCM_SYSERROR; |
| 799 | } |
| 800 | return SCM_BOOL_T; |
| 801 | } |
| 802 | #undef FUNC_NAME |
| 803 | |
| 804 | /*** Condition variables */ |
| 805 | |
| 806 | SCM_DEFINE (scm_make_condition_variable, "make-condition-variable", 0, 0, 0, |
| 807 | (void), |
| 808 | "Make a new condition variable.") |
| 809 | #define FUNC_NAME s_scm_make_condition_variable |
| 810 | { |
| 811 | SCM cv = scm_make_smob (scm_tc16_condvar); |
| 812 | scm_i_plugin_cond_init (SCM_CONDVAR_DATA (cv), 0); |
| 813 | return cv; |
| 814 | } |
| 815 | #undef FUNC_NAME |
| 816 | |
| 817 | SCM_DEFINE (scm_timed_wait_condition_variable, "wait-condition-variable", 2, 1, 0, |
| 818 | (SCM cv, SCM mx, SCM t), |
| 819 | "Wait until @var{cond-var} has been signalled. While waiting, " |
| 820 | "@var{mutex} is atomically unlocked (as with @code{unlock-mutex}) and " |
| 821 | "is locked again when this function returns. When @var{time} is given, " |
| 822 | "it specifies a point in time where the waiting should be aborted. It " |
| 823 | "can be either a integer as returned by @code{current-time} or a pair " |
| 824 | "as returned by @code{gettimeofday}. When the waiting is aborted the " |
| 825 | "mutex is locked and @code{#f} is returned. When the condition " |
| 826 | "variable is in fact signalled, the mutex is also locked and @code{#t} " |
| 827 | "is returned. ") |
| 828 | #define FUNC_NAME s_scm_timed_wait_condition_variable |
| 829 | { |
| 830 | scm_t_timespec waittime; |
| 831 | int err; |
| 832 | |
| 833 | SCM_VALIDATE_CONDVAR (1, cv); |
| 834 | SCM_VALIDATE_MUTEX (2, mx); |
| 835 | if (!((SCM_TYP16 (cv) == scm_tc16_condvar |
| 836 | && SCM_TYP16 (mx) == scm_tc16_mutex) |
| 837 | || (SCM_TYP16 (cv) == scm_tc16_fair_condvar |
| 838 | && SCM_TYP16 (mx) == scm_tc16_fair_mutex))) |
| 839 | SCM_MISC_ERROR ("Condition variable and mutex are of different kinds.", |
| 840 | SCM_EOL); |
| 841 | |
| 842 | if (!SCM_UNBNDP (t)) |
| 843 | { |
| 844 | if (SCM_CONSP (t)) |
| 845 | { |
| 846 | SCM_VALIDATE_UINT_COPY (3, SCM_CAR (t), waittime.tv_sec); |
| 847 | SCM_VALIDATE_UINT_COPY (3, SCM_CDR (t), waittime.tv_nsec); |
| 848 | waittime.tv_nsec *= 1000; |
| 849 | } |
| 850 | else |
| 851 | { |
| 852 | SCM_VALIDATE_UINT_COPY (3, t, waittime.tv_sec); |
| 853 | waittime.tv_nsec = 0; |
| 854 | } |
| 855 | } |
| 856 | |
| 857 | if (SCM_TYP16 (cv) == scm_tc16_fair_condvar) |
| 858 | err = fair_cond_timedwait (SCM_CONDVAR_DATA (cv), |
| 859 | SCM_MUTEX_DATA (mx), |
| 860 | SCM_UNBNDP (t) ? NULL : &waittime); |
| 861 | else |
| 862 | { |
| 863 | scm_t_cond *c = SCM_CONDVAR_DATA (cv); |
| 864 | scm_t_mutex *m = SCM_MUTEX_DATA (mx); |
| 865 | if (SCM_UNBNDP (t)) |
| 866 | err = scm_cond_wait (c, m); |
| 867 | else |
| 868 | err = scm_cond_timedwait (c, m, &waittime); |
| 869 | } |
| 870 | |
| 871 | if (err) |
| 872 | { |
| 873 | if (err == ETIMEDOUT) |
| 874 | return SCM_BOOL_F; |
| 875 | errno = err; |
| 876 | SCM_SYSERROR; |
| 877 | } |
| 878 | return SCM_BOOL_T; |
| 879 | } |
| 880 | #undef FUNC_NAME |
| 881 | |
| 882 | SCM_DEFINE (scm_signal_condition_variable, "signal-condition-variable", 1, 0, 0, |
| 883 | (SCM cv), |
| 884 | "Wake up one thread that is waiting for @var{cv}") |
| 885 | #define FUNC_NAME s_scm_signal_condition_variable |
| 886 | { |
| 887 | SCM_VALIDATE_CONDVAR (1, cv); |
| 888 | if (SCM_TYP16 (cv) == scm_tc16_fair_condvar) |
| 889 | fair_cond_signal (SCM_CONDVAR_DATA (cv)); |
| 890 | else |
| 891 | { |
| 892 | scm_t_cond *c = SCM_CONDVAR_DATA (cv); |
| 893 | scm_cond_signal (c); |
| 894 | } |
| 895 | return SCM_BOOL_T; |
| 896 | } |
| 897 | #undef FUNC_NAME |
| 898 | |
| 899 | SCM_DEFINE (scm_broadcast_condition_variable, "broadcast-condition-variable", 1, 0, 0, |
| 900 | (SCM cv), |
| 901 | "Wake up all threads that are waiting for @var{cv}. ") |
| 902 | #define FUNC_NAME s_scm_broadcast_condition_variable |
| 903 | { |
| 904 | SCM_VALIDATE_CONDVAR (1, cv); |
| 905 | if (SCM_TYP16 (cv) == scm_tc16_fair_condvar) |
| 906 | fair_cond_broadcast (SCM_CONDVAR_DATA (cv)); |
| 907 | else |
| 908 | { |
| 909 | scm_t_cond *c = SCM_CONDVAR_DATA (cv); |
| 910 | scm_cond_broadcast (c); |
| 911 | } |
| 912 | return SCM_BOOL_T; |
| 913 | } |
| 914 | #undef FUNC_NAME |
| 915 | |
| 916 | /*** Marking stacks */ |
| 917 | |
| 918 | /* XXX - what to do with this? Do we need to handle this for blocked |
| 919 | threads as well? |
| 920 | */ |
| 921 | #ifdef __ia64__ |
| 922 | # define SCM_MARK_BACKING_STORE() do { \ |
| 923 | ucontext_t ctx; \ |
| 924 | SCM_STACKITEM * top, * bot; \ |
| 925 | getcontext (&ctx); \ |
| 926 | scm_mark_locations ((SCM_STACKITEM *) &ctx.uc_mcontext, \ |
| 927 | ((size_t) (sizeof (SCM_STACKITEM) - 1 + sizeof ctx.uc_mcontext) \ |
| 928 | / sizeof (SCM_STACKITEM))); \ |
| 929 | bot = (SCM_STACKITEM *) __libc_ia64_register_backing_store_base; \ |
| 930 | top = (SCM_STACKITEM *) ctx.uc_mcontext.sc_ar_bsp; \ |
| 931 | scm_mark_locations (bot, top - bot); } while (0) |
| 932 | #else |
| 933 | # define SCM_MARK_BACKING_STORE() |
| 934 | #endif |
| 935 | |
| 936 | void |
| 937 | scm_threads_mark_stacks (void) |
| 938 | { |
| 939 | volatile SCM c; |
| 940 | for (c = all_threads; !SCM_NULLP (c); c = SCM_CDR (c)) |
| 941 | { |
| 942 | scm_thread *t = SCM_THREAD_DATA (SCM_CAR (c)); |
| 943 | if (!THREAD_INITIALIZED_P (t)) |
| 944 | { |
| 945 | /* Not fully initialized yet. */ |
| 946 | continue; |
| 947 | } |
| 948 | if (t->top == NULL) |
| 949 | { |
| 950 | long stack_len; |
| 951 | #ifdef SCM_DEBUG |
| 952 | if (t->thread != scm_thread_self ()) |
| 953 | abort (); |
| 954 | #endif |
| 955 | /* Active thread */ |
| 956 | /* stack_len is long rather than sizet in order to guarantee |
| 957 | that &stack_len is long aligned */ |
| 958 | #if SCM_STACK_GROWS_UP |
| 959 | stack_len = SCM_STACK_PTR (&t) - t->base; |
| 960 | |
| 961 | /* Protect from the C stack. This must be the first marking |
| 962 | * done because it provides information about what objects |
| 963 | * are "in-use" by the C code. "in-use" objects are those |
| 964 | * for which the information about length and base address must |
| 965 | * remain usable. This requirement is stricter than a liveness |
| 966 | * requirement -- in particular, it constrains the implementation |
| 967 | * of scm_resizuve. |
| 968 | */ |
| 969 | SCM_FLUSH_REGISTER_WINDOWS; |
| 970 | /* This assumes that all registers are saved into the jmp_buf */ |
| 971 | setjmp (scm_save_regs_gc_mark); |
| 972 | scm_mark_locations ((SCM_STACKITEM *) scm_save_regs_gc_mark, |
| 973 | ((size_t) sizeof scm_save_regs_gc_mark |
| 974 | / sizeof (SCM_STACKITEM))); |
| 975 | |
| 976 | scm_mark_locations (((size_t) t->base, |
| 977 | (sizet) stack_len)); |
| 978 | #else |
| 979 | stack_len = t->base - SCM_STACK_PTR (&t); |
| 980 | |
| 981 | /* Protect from the C stack. This must be the first marking |
| 982 | * done because it provides information about what objects |
| 983 | * are "in-use" by the C code. "in-use" objects are those |
| 984 | * for which the information about length and base address must |
| 985 | * remain usable. This requirement is stricter than a liveness |
| 986 | * requirement -- in particular, it constrains the implementation |
| 987 | * of scm_resizuve. |
| 988 | */ |
| 989 | SCM_FLUSH_REGISTER_WINDOWS; |
| 990 | /* This assumes that all registers are saved into the jmp_buf */ |
| 991 | setjmp (scm_save_regs_gc_mark); |
| 992 | scm_mark_locations ((SCM_STACKITEM *) scm_save_regs_gc_mark, |
| 993 | ((size_t) sizeof scm_save_regs_gc_mark |
| 994 | / sizeof (SCM_STACKITEM))); |
| 995 | |
| 996 | scm_mark_locations (SCM_STACK_PTR (&t), stack_len); |
| 997 | #endif |
| 998 | } |
| 999 | else |
| 1000 | { |
| 1001 | /* Suspended thread */ |
| 1002 | #if SCM_STACK_GROWS_UP |
| 1003 | long stack_len = t->top - t->base; |
| 1004 | scm_mark_locations (t->base, stack_len); |
| 1005 | #else |
| 1006 | long stack_len = t->base - t->top; |
| 1007 | scm_mark_locations (t->top, stack_len); |
| 1008 | #endif |
| 1009 | scm_mark_locations ((SCM_STACKITEM *) t->regs, |
| 1010 | ((size_t) sizeof(t->regs) |
| 1011 | / sizeof (SCM_STACKITEM))); |
| 1012 | } |
| 1013 | } |
| 1014 | } |
| 1015 | |
| 1016 | /*** Select */ |
| 1017 | |
| 1018 | int |
| 1019 | scm_internal_select (int nfds, |
| 1020 | SELECT_TYPE *readfds, |
| 1021 | SELECT_TYPE *writefds, |
| 1022 | SELECT_TYPE *exceptfds, |
| 1023 | struct timeval *timeout) |
| 1024 | { |
| 1025 | int res, eno; |
| 1026 | scm_thread *c = scm_i_leave_guile (); |
| 1027 | res = scm_i_plugin_select (nfds, readfds, writefds, exceptfds, timeout); |
| 1028 | eno = errno; |
| 1029 | scm_i_enter_guile (c); |
| 1030 | SCM_ASYNC_TICK; |
| 1031 | errno = eno; |
| 1032 | return res; |
| 1033 | } |
| 1034 | |
| 1035 | /* Low-level C API */ |
| 1036 | |
| 1037 | SCM |
| 1038 | scm_spawn_thread (scm_t_catch_body body, void *body_data, |
| 1039 | scm_t_catch_handler handler, void *handler_data) |
| 1040 | { |
| 1041 | return create_thread (body, body_data, handler, handler_data, SCM_BOOL_F); |
| 1042 | } |
| 1043 | |
| 1044 | int |
| 1045 | scm_mutex_lock (scm_t_mutex *m) |
| 1046 | { |
| 1047 | scm_thread *t = scm_i_leave_guile (); |
| 1048 | int res = scm_i_plugin_mutex_lock (m); |
| 1049 | scm_i_enter_guile (t); |
| 1050 | return res; |
| 1051 | } |
| 1052 | |
| 1053 | scm_t_rec_mutex * |
| 1054 | scm_make_rec_mutex () |
| 1055 | { |
| 1056 | scm_t_rec_mutex *m = scm_malloc (sizeof (scm_t_rec_mutex)); |
| 1057 | scm_i_plugin_rec_mutex_init (m, &scm_i_plugin_rec_mutex); |
| 1058 | return m; |
| 1059 | } |
| 1060 | |
| 1061 | void |
| 1062 | scm_rec_mutex_free (scm_t_rec_mutex *m) |
| 1063 | { |
| 1064 | scm_i_plugin_rec_mutex_destroy (m); |
| 1065 | free (m); |
| 1066 | } |
| 1067 | |
| 1068 | int |
| 1069 | scm_rec_mutex_lock (scm_t_rec_mutex *m) |
| 1070 | { |
| 1071 | scm_thread *t = scm_i_leave_guile (); |
| 1072 | int res = scm_i_plugin_rec_mutex_lock (m); |
| 1073 | scm_i_enter_guile (t); |
| 1074 | return res; |
| 1075 | } |
| 1076 | |
| 1077 | int |
| 1078 | scm_cond_wait (scm_t_cond *c, scm_t_mutex *m) |
| 1079 | { |
| 1080 | scm_thread *t = scm_i_leave_guile (); |
| 1081 | scm_i_plugin_cond_wait (c, m); |
| 1082 | scm_i_enter_guile (t); |
| 1083 | return 0; |
| 1084 | } |
| 1085 | |
| 1086 | int |
| 1087 | scm_cond_timedwait (scm_t_cond *c, scm_t_mutex *m, const scm_t_timespec *wt) |
| 1088 | { |
| 1089 | scm_thread *t = scm_i_leave_guile (); |
| 1090 | int res = scm_i_plugin_cond_timedwait (c, m, wt); |
| 1091 | scm_i_enter_guile (t); |
| 1092 | return res; |
| 1093 | } |
| 1094 | |
| 1095 | void * |
| 1096 | scm_getspecific (scm_t_key k) |
| 1097 | { |
| 1098 | return scm_i_plugin_getspecific (k); |
| 1099 | } |
| 1100 | |
| 1101 | int |
| 1102 | scm_setspecific (scm_t_key k, void *s) |
| 1103 | { |
| 1104 | return scm_i_plugin_setspecific (k, s); |
| 1105 | } |
| 1106 | |
| 1107 | void |
| 1108 | scm_enter_guile () |
| 1109 | { |
| 1110 | scm_i_enter_guile (SCM_CURRENT_THREAD); |
| 1111 | } |
| 1112 | |
| 1113 | void |
| 1114 | scm_leave_guile () |
| 1115 | { |
| 1116 | scm_i_leave_guile (); |
| 1117 | } |
| 1118 | |
| 1119 | unsigned long |
| 1120 | scm_thread_usleep (unsigned long usecs) |
| 1121 | { |
| 1122 | struct timeval tv; |
| 1123 | tv.tv_usec = usecs % 1000000; |
| 1124 | tv.tv_sec = usecs / 1000000; |
| 1125 | scm_internal_select (0, NULL, NULL, NULL, &tv); |
| 1126 | return tv.tv_usec + tv.tv_sec*1000000; |
| 1127 | } |
| 1128 | |
| 1129 | unsigned long |
| 1130 | scm_thread_sleep (unsigned long secs) |
| 1131 | { |
| 1132 | struct timeval tv; |
| 1133 | tv.tv_usec = 0; |
| 1134 | tv.tv_sec = secs; |
| 1135 | scm_internal_select (0, NULL, NULL, NULL, &tv); |
| 1136 | return tv.tv_sec; |
| 1137 | } |
| 1138 | |
| 1139 | /*** Misc */ |
| 1140 | |
| 1141 | SCM_DEFINE (scm_current_thread, "current-thread", 0, 0, 0, |
| 1142 | (void), |
| 1143 | "Return the thread that called this function.") |
| 1144 | #define FUNC_NAME s_scm_current_thread |
| 1145 | { |
| 1146 | return cur_thread; |
| 1147 | } |
| 1148 | #undef FUNC_NAME |
| 1149 | |
| 1150 | SCM_DEFINE (scm_all_threads, "all-threads", 0, 0, 0, |
| 1151 | (void), |
| 1152 | "Return a list of all threads.") |
| 1153 | #define FUNC_NAME s_scm_all_threads |
| 1154 | { |
| 1155 | return scm_list_copy (all_threads); |
| 1156 | } |
| 1157 | #undef FUNC_NAME |
| 1158 | |
| 1159 | scm_root_state * |
| 1160 | scm_i_thread_root (SCM thread) |
| 1161 | { |
| 1162 | return ((scm_thread *) SCM_THREAD_DATA (thread))->root; |
| 1163 | } |
| 1164 | |
| 1165 | SCM_DEFINE (scm_thread_exited_p, "thread-exited?", 1, 0, 0, |
| 1166 | (SCM thread), |
| 1167 | "Return @code{#t} iff @var{thread} has exited.\n") |
| 1168 | #define FUNC_NAME s_scm_thread_exited_p |
| 1169 | { |
| 1170 | return SCM_BOOL (scm_c_thread_exited_p (thread)); |
| 1171 | } |
| 1172 | #undef FUNC_NAME |
| 1173 | |
| 1174 | int |
| 1175 | scm_c_thread_exited_p (SCM thread) |
| 1176 | #define FUNC_NAME s_scm_thread_exited_p |
| 1177 | { |
| 1178 | scm_thread *t; |
| 1179 | SCM_VALIDATE_THREAD (1, thread); |
| 1180 | t = SCM_THREAD_DATA (thread); |
| 1181 | return t->exited; |
| 1182 | } |
| 1183 | #undef FUNC_NAME |
| 1184 | |
| 1185 | static scm_t_cond wake_up_cond; |
| 1186 | int scm_i_thread_go_to_sleep; |
| 1187 | static int gc_section_count = 0; |
| 1188 | static int threads_initialized_p = 0; |
| 1189 | |
| 1190 | void |
| 1191 | scm_i_thread_put_to_sleep () |
| 1192 | { |
| 1193 | if (threads_initialized_p && !gc_section_count++) |
| 1194 | { |
| 1195 | SCM threads; |
| 1196 | scm_i_plugin_mutex_lock (&thread_admin_mutex); |
| 1197 | threads = all_threads; |
| 1198 | /* Signal all threads to go to sleep */ |
| 1199 | scm_i_thread_go_to_sleep = 1; |
| 1200 | for (; !SCM_NULLP (threads); threads = SCM_CDR (threads)) |
| 1201 | if (SCM_CAR (threads) != cur_thread) |
| 1202 | { |
| 1203 | scm_thread *t = SCM_THREAD_DATA (SCM_CAR (threads)); |
| 1204 | scm_i_plugin_mutex_lock (&t->heap_mutex); |
| 1205 | } |
| 1206 | scm_i_thread_go_to_sleep = 0; |
| 1207 | } |
| 1208 | } |
| 1209 | |
| 1210 | void |
| 1211 | scm_i_thread_invalidate_freelists () |
| 1212 | { |
| 1213 | /* Don't need to lock thread_admin_mutex here since we are single threaded */ |
| 1214 | SCM threads = all_threads; |
| 1215 | for (; !SCM_NULLP (threads); threads = SCM_CDR (threads)) |
| 1216 | if (SCM_CAR (threads) != cur_thread) |
| 1217 | { |
| 1218 | scm_thread *t = SCM_THREAD_DATA (SCM_CAR (threads)); |
| 1219 | t->clear_freelists_p = 1; |
| 1220 | } |
| 1221 | } |
| 1222 | |
| 1223 | void |
| 1224 | scm_i_thread_wake_up () |
| 1225 | { |
| 1226 | if (threads_initialized_p && !--gc_section_count) |
| 1227 | { |
| 1228 | SCM threads; |
| 1229 | threads = all_threads; |
| 1230 | scm_i_plugin_cond_broadcast (&wake_up_cond); |
| 1231 | for (; !SCM_NULLP (threads); threads = SCM_CDR (threads)) |
| 1232 | if (SCM_CAR (threads) != cur_thread) |
| 1233 | { |
| 1234 | scm_thread *t = SCM_THREAD_DATA (SCM_CAR (threads)); |
| 1235 | scm_i_plugin_mutex_unlock (&t->heap_mutex); |
| 1236 | } |
| 1237 | scm_i_plugin_mutex_unlock (&thread_admin_mutex); |
| 1238 | } |
| 1239 | } |
| 1240 | |
| 1241 | void |
| 1242 | scm_i_thread_sleep_for_gc () |
| 1243 | { |
| 1244 | scm_thread *t; |
| 1245 | t = suspend (); |
| 1246 | scm_i_plugin_cond_wait (&wake_up_cond, &t->heap_mutex); |
| 1247 | resume (t); |
| 1248 | } |
| 1249 | |
| 1250 | scm_t_mutex scm_i_critical_section_mutex; |
| 1251 | scm_t_rec_mutex scm_i_defer_mutex; |
| 1252 | |
| 1253 | #if SCM_USE_PTHREAD_THREADS |
| 1254 | # include "libguile/pthread-threads.c" |
| 1255 | #endif |
| 1256 | #include "libguile/threads-plugin.c" |
| 1257 | |
| 1258 | /*** Initialization */ |
| 1259 | |
| 1260 | void |
| 1261 | scm_threads_prehistory () |
| 1262 | { |
| 1263 | scm_thread *t; |
| 1264 | #if SCM_USE_PTHREAD_THREADS |
| 1265 | /* Must be called before any initialization of a mutex. */ |
| 1266 | scm_init_pthread_threads (); |
| 1267 | #endif |
| 1268 | scm_i_plugin_mutex_init (&thread_admin_mutex, &scm_i_plugin_mutex); |
| 1269 | scm_i_plugin_cond_init (&wake_up_cond, 0); |
| 1270 | scm_i_plugin_mutex_init (&scm_i_critical_section_mutex, &scm_i_plugin_mutex); |
| 1271 | thread_count = 1; |
| 1272 | scm_i_plugin_key_create (&scm_i_thread_key, 0); |
| 1273 | scm_i_plugin_key_create (&scm_i_root_state_key, 0); |
| 1274 | scm_i_plugin_rec_mutex_init (&scm_i_defer_mutex, &scm_i_plugin_rec_mutex); |
| 1275 | /* Allocate a fake thread object to be used during bootup. */ |
| 1276 | t = malloc (sizeof (scm_thread)); |
| 1277 | t->base = NULL; |
| 1278 | t->clear_freelists_p = 0; |
| 1279 | scm_i_plugin_mutex_init (&t->heap_mutex, &scm_i_plugin_mutex); |
| 1280 | scm_setspecific (scm_i_thread_key, t); |
| 1281 | scm_i_enter_guile (t); |
| 1282 | } |
| 1283 | |
| 1284 | scm_t_bits scm_tc16_thread; |
| 1285 | scm_t_bits scm_tc16_future; |
| 1286 | scm_t_bits scm_tc16_mutex; |
| 1287 | scm_t_bits scm_tc16_fair_mutex; |
| 1288 | scm_t_bits scm_tc16_condvar; |
| 1289 | scm_t_bits scm_tc16_fair_condvar; |
| 1290 | |
| 1291 | void |
| 1292 | scm_init_threads (SCM_STACKITEM *base) |
| 1293 | { |
| 1294 | SCM thread; |
| 1295 | scm_tc16_thread = scm_make_smob_type ("thread", sizeof (scm_thread)); |
| 1296 | scm_tc16_mutex = scm_make_smob_type ("mutex", sizeof (scm_t_mutex)); |
| 1297 | scm_tc16_fair_mutex = scm_make_smob_type ("fair-mutex", |
| 1298 | sizeof (fair_mutex)); |
| 1299 | scm_tc16_condvar = scm_make_smob_type ("condition-variable", |
| 1300 | sizeof (scm_t_cond)); |
| 1301 | scm_tc16_fair_condvar = scm_make_smob_type ("fair-condition-variable", |
| 1302 | sizeof (fair_cond)); |
| 1303 | |
| 1304 | thread = make_thread (SCM_BOOL_F); |
| 1305 | /* Replace initial fake thread with a real thread object */ |
| 1306 | free (SCM_CURRENT_THREAD); |
| 1307 | scm_setspecific (scm_i_thread_key, SCM_THREAD_DATA (thread)); |
| 1308 | scm_i_enter_guile (SCM_CURRENT_THREAD); |
| 1309 | |
| 1310 | /* root is set later from init.c */ |
| 1311 | init_thread_creatant (thread, base); |
| 1312 | thread_count = 1; |
| 1313 | scm_gc_register_root (&all_threads); |
| 1314 | all_threads = scm_cons (thread, SCM_EOL); |
| 1315 | |
| 1316 | scm_set_smob_mark (scm_tc16_thread, thread_mark); |
| 1317 | scm_set_smob_print (scm_tc16_thread, thread_print); |
| 1318 | scm_set_smob_free (scm_tc16_thread, thread_free); |
| 1319 | |
| 1320 | scm_set_smob_mark (scm_tc16_fair_mutex, fair_mutex_mark); |
| 1321 | |
| 1322 | scm_set_smob_mark (scm_tc16_fair_condvar, fair_cond_mark); |
| 1323 | |
| 1324 | threads_initialized_p = 1; |
| 1325 | } |
| 1326 | |
| 1327 | void |
| 1328 | scm_init_thread_procs () |
| 1329 | { |
| 1330 | #include "libguile/threads.x" |
| 1331 | } |
| 1332 | |
| 1333 | /* XXX */ |
| 1334 | |
| 1335 | void |
| 1336 | scm_init_iselect () |
| 1337 | { |
| 1338 | } |
| 1339 | |
| 1340 | /* |
| 1341 | Local Variables: |
| 1342 | c-file-style: "gnu" |
| 1343 | End: |
| 1344 | */ |