Travis Geiselbrecht | 1d0df69 | 2008-09-01 02:26:09 -0700 | [diff] [blame] | 1 | /* |
Travis Geiselbrecht | 9045c06 | 2009-06-28 11:20:09 -0700 | [diff] [blame] | 2 | * Copyright (c) 2008-2009 Travis Geiselbrecht |
Travis Geiselbrecht | 1d0df69 | 2008-09-01 02:26:09 -0700 | [diff] [blame] | 3 | * |
| 4 | * Permission is hereby granted, free of charge, to any person obtaining |
| 5 | * a copy of this software and associated documentation files |
| 6 | * (the "Software"), to deal in the Software without restriction, |
| 7 | * including without limitation the rights to use, copy, modify, merge, |
| 8 | * publish, distribute, sublicense, and/or sell copies of the Software, |
| 9 | * and to permit persons to whom the Software is furnished to do so, |
| 10 | * subject to the following conditions: |
| 11 | * |
| 12 | * The above copyright notice and this permission notice shall be |
| 13 | * included in all copies or substantial portions of the Software. |
| 14 | * |
| 15 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| 16 | * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| 17 | * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
| 18 | * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY |
| 19 | * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
| 20 | * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
| 21 | * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
| 22 | */ |
| 23 | #include <debug.h> |
| 24 | #include <list.h> |
| 25 | #include <malloc.h> |
| 26 | #include <string.h> |
| 27 | #include <err.h> |
| 28 | #include <kernel/thread.h> |
| 29 | #include <kernel/timer.h> |
| 30 | #include <kernel/dpc.h> |
| 31 | #include <platform.h> |
| 32 | |
| 33 | #if DEBUGLEVEL > 1 |
| 34 | #define THREAD_CHECKS 1 |
| 35 | #endif |
| 36 | |
| 37 | #if THREAD_STATS |
| 38 | struct thread_stats thread_stats; |
| 39 | #endif |
| 40 | |
| 41 | /* global thread list */ |
| 42 | static struct list_node thread_list; |
| 43 | |
| 44 | /* the current thread */ |
| 45 | thread_t *current_thread; |
| 46 | |
| 47 | /* the global critical section count */ |
| 48 | int critical_section_count = 1; |
| 49 | |
| 50 | /* the run queue */ |
| 51 | static struct list_node run_queue[NUM_PRIORITIES]; |
| 52 | static uint32_t run_queue_bitmap; |
| 53 | |
| 54 | /* the bootstrap thread (statically allocated) */ |
| 55 | static thread_t bootstrap_thread; |
| 56 | |
| 57 | /* the idle thread */ |
| 58 | thread_t *idle_thread; |
| 59 | |
| 60 | /* local routines */ |
| 61 | static void thread_resched(void); |
| 62 | static void idle_thread_routine(void) __NO_RETURN; |
| 63 | |
Travis Geiselbrecht | 9045c06 | 2009-06-28 11:20:09 -0700 | [diff] [blame] | 64 | #if PLATFORM_HAS_DYNAMIC_TIMER |
| 65 | /* preemption timer */ |
| 66 | static timer_t preempt_timer; |
| 67 | #endif |
| 68 | |
Travis Geiselbrecht | 1d0df69 | 2008-09-01 02:26:09 -0700 | [diff] [blame] | 69 | /* run queue manipulation */ |
| 70 | static void insert_in_run_queue_head(thread_t *t) |
| 71 | { |
| 72 | #if THREAD_CHECKS |
| 73 | ASSERT(t->magic == THREAD_MAGIC); |
| 74 | ASSERT(t->state == THREAD_READY); |
| 75 | ASSERT(!list_in_list(&t->queue_node)); |
| 76 | ASSERT(in_critical_section()); |
| 77 | #endif |
| 78 | |
| 79 | list_add_head(&run_queue[t->priority], &t->queue_node); |
| 80 | run_queue_bitmap |= (1<<t->priority); |
| 81 | } |
| 82 | |
| 83 | static void insert_in_run_queue_tail(thread_t *t) |
| 84 | { |
| 85 | #if THREAD_CHECKS |
| 86 | ASSERT(t->magic == THREAD_MAGIC); |
| 87 | ASSERT(t->state == THREAD_READY); |
| 88 | ASSERT(!list_in_list(&t->queue_node)); |
| 89 | ASSERT(in_critical_section()); |
| 90 | #endif |
| 91 | |
| 92 | list_add_tail(&run_queue[t->priority], &t->queue_node); |
| 93 | run_queue_bitmap |= (1<<t->priority); |
| 94 | } |
| 95 | |
| 96 | static void init_thread_struct(thread_t *t, const char *name) |
| 97 | { |
| 98 | memset(t, 0, sizeof(thread_t)); |
| 99 | t->magic = THREAD_MAGIC; |
| 100 | strlcpy(t->name, name, sizeof(t->name)); |
| 101 | } |
| 102 | |
| 103 | thread_t *thread_create(const char *name, thread_start_routine entry, void *arg, int priority, size_t stack_size) |
| 104 | { |
| 105 | thread_t *t; |
| 106 | |
| 107 | t = malloc(sizeof(thread_t)); |
| 108 | if (!t) |
| 109 | return NULL; |
| 110 | |
| 111 | init_thread_struct(t, name); |
| 112 | |
| 113 | t->entry = entry; |
| 114 | t->arg = arg; |
| 115 | t->priority = priority; |
| 116 | t->saved_critical_section_count = 1; /* we always start inside a critical section */ |
| 117 | t->state = THREAD_SUSPENDED; |
| 118 | t->blocking_wait_queue = NULL; |
| 119 | t->wait_queue_block_ret = NO_ERROR; |
| 120 | |
| 121 | /* create the stack */ |
| 122 | t->stack = malloc(stack_size); |
| 123 | if (!t->stack) { |
| 124 | free(t); |
| 125 | return NULL; |
| 126 | } |
| 127 | |
| 128 | t->stack_size = stack_size; |
| 129 | |
travis geiselbrecht | c60a2e6 | 2008-12-22 23:46:26 +0000 | [diff] [blame] | 130 | /* inheirit thread local storage from the parent */ |
| 131 | int i; |
| 132 | for (i=0; i < MAX_TLS_ENTRY; i++) |
| 133 | t->tls[i] = current_thread->tls[i]; |
| 134 | |
Travis Geiselbrecht | 1d0df69 | 2008-09-01 02:26:09 -0700 | [diff] [blame] | 135 | /* set up the initial stack frame */ |
| 136 | arch_thread_initialize(t); |
| 137 | |
| 138 | /* add it to the global thread list */ |
| 139 | enter_critical_section(); |
| 140 | list_add_head(&thread_list, &t->thread_list_node); |
| 141 | exit_critical_section(); |
| 142 | |
| 143 | return t; |
| 144 | } |
| 145 | |
| 146 | status_t thread_resume(thread_t *t) |
| 147 | { |
| 148 | #if THREAD_CHECKS |
| 149 | ASSERT(t->magic == THREAD_MAGIC); |
| 150 | ASSERT(t->state != THREAD_DEATH); |
| 151 | #endif |
| 152 | |
| 153 | if (t->state == THREAD_READY || t->state == THREAD_RUNNING) |
| 154 | return ERR_NOT_SUSPENDED; |
| 155 | |
| 156 | enter_critical_section(); |
| 157 | t->state = THREAD_READY; |
| 158 | insert_in_run_queue_head(t); |
| 159 | thread_yield(); |
| 160 | exit_critical_section(); |
| 161 | |
| 162 | return NO_ERROR; |
| 163 | } |
| 164 | |
| 165 | static void thread_cleanup_dpc(void *thread) |
| 166 | { |
| 167 | thread_t *t = (thread_t *)thread; |
| 168 | |
Travis Geiselbrecht | eb94605 | 2008-09-07 22:32:49 -0700 | [diff] [blame] | 169 | // dprintf(SPEW, "thread_cleanup_dpc: thread %p (%s)\n", t, t->name); |
Travis Geiselbrecht | 1d0df69 | 2008-09-01 02:26:09 -0700 | [diff] [blame] | 170 | |
| 171 | #if THREAD_CHECKS |
| 172 | ASSERT(t->state == THREAD_DEATH); |
| 173 | ASSERT(t->blocking_wait_queue == NULL); |
| 174 | ASSERT(!list_in_list(&t->queue_node)); |
| 175 | #endif |
| 176 | |
| 177 | /* remove it from the master thread list */ |
| 178 | enter_critical_section(); |
| 179 | list_delete(&t->thread_list_node); |
| 180 | exit_critical_section(); |
| 181 | |
| 182 | /* free its stack and the thread structure itself */ |
| 183 | if (t->stack) |
| 184 | free(t->stack); |
| 185 | |
| 186 | free(t); |
| 187 | } |
| 188 | |
| 189 | void thread_exit(int retcode) |
| 190 | { |
| 191 | #if THREAD_CHECKS |
| 192 | ASSERT(current_thread->magic == THREAD_MAGIC); |
| 193 | ASSERT(current_thread->state == THREAD_RUNNING); |
| 194 | #endif |
| 195 | |
| 196 | // dprintf("thread_exit: current %p\n", current_thread); |
| 197 | |
| 198 | enter_critical_section(); |
| 199 | |
| 200 | /* enter the dead state */ |
| 201 | current_thread->state = THREAD_DEATH; |
| 202 | current_thread->retcode = retcode; |
| 203 | |
| 204 | /* schedule a dpc to clean ourselves up */ |
| 205 | dpc_queue(thread_cleanup_dpc, (void *)current_thread, DPC_FLAG_NORESCHED); |
| 206 | |
| 207 | /* reschedule */ |
| 208 | thread_resched(); |
| 209 | |
| 210 | panic("somehow fell through thread_exit()\n"); |
| 211 | } |
| 212 | |
| 213 | static void idle_thread_routine(void) |
| 214 | { |
| 215 | for(;;) |
| 216 | arch_idle(); |
| 217 | } |
| 218 | |
| 219 | /* |
| 220 | * Internal reschedule routine. The current thread needs to already be in whatever |
| 221 | * state and queues it needs to be in. This routine simply picks the next thread and |
| 222 | * switches to it. |
| 223 | */ |
| 224 | void thread_resched(void) |
| 225 | { |
| 226 | thread_t *oldthread; |
| 227 | thread_t *newthread; |
| 228 | |
| 229 | // dprintf("thread_resched: current %p: ", current_thread); |
| 230 | // dump_thread(current_thread); |
| 231 | |
| 232 | #if THREAD_CHECKS |
| 233 | ASSERT(in_critical_section()); |
| 234 | #endif |
| 235 | |
| 236 | #if THREAD_STATS |
| 237 | thread_stats.reschedules++; |
| 238 | #endif |
| 239 | |
| 240 | oldthread = current_thread; |
| 241 | |
| 242 | // at the moment, can't deal with more than 32 priority levels |
| 243 | ASSERT(NUM_PRIORITIES <= 32); |
| 244 | |
| 245 | // should at least find the idle thread |
| 246 | #if THREAD_CHECKS |
| 247 | ASSERT(run_queue_bitmap != 0); |
| 248 | #endif |
| 249 | |
| 250 | int next_queue = HIGHEST_PRIORITY - __builtin_clz(run_queue_bitmap) - (32 - NUM_PRIORITIES); |
Travis Geiselbrecht | eb94605 | 2008-09-07 22:32:49 -0700 | [diff] [blame] | 251 | //dprintf(SPEW, "bitmap 0x%x, next %d\n", run_queue_bitmap, next_queue); |
Travis Geiselbrecht | 1d0df69 | 2008-09-01 02:26:09 -0700 | [diff] [blame] | 252 | |
| 253 | newthread = list_remove_head_type(&run_queue[next_queue], thread_t, queue_node); |
| 254 | |
| 255 | #if THREAD_CHECKS |
| 256 | ASSERT(newthread); |
| 257 | #endif |
| 258 | |
| 259 | if (list_is_empty(&run_queue[next_queue])) |
| 260 | run_queue_bitmap &= ~(1<<next_queue); |
| 261 | |
| 262 | #if 0 |
| 263 | // XXX make this more efficient |
| 264 | newthread = NULL; |
| 265 | for (i=HIGHEST_PRIORITY; i >= LOWEST_PRIORITY; i--) { |
| 266 | newthread = list_remove_head_type(&run_queue[i], thread_t, queue_node); |
| 267 | if (newthread) |
| 268 | break; |
| 269 | } |
| 270 | #endif |
| 271 | |
| 272 | // dprintf("newthread: "); |
| 273 | // dump_thread(newthread); |
| 274 | |
| 275 | newthread->state = THREAD_RUNNING; |
| 276 | |
| 277 | if (newthread == oldthread) |
| 278 | return; |
| 279 | |
| 280 | /* set up quantum for the new thread if it was consumed */ |
| 281 | if (newthread->remaining_quantum <= 0) { |
| 282 | newthread->remaining_quantum = 5; // XXX make this smarter |
| 283 | } |
| 284 | |
| 285 | #if THREAD_STATS |
| 286 | thread_stats.context_switches++; |
| 287 | |
| 288 | if (oldthread == idle_thread) { |
| 289 | bigtime_t now = current_time_hires(); |
| 290 | thread_stats.idle_time += now - thread_stats.last_idle_timestamp; |
| 291 | } |
| 292 | if (newthread == idle_thread) { |
| 293 | thread_stats.last_idle_timestamp = current_time_hires(); |
| 294 | } |
| 295 | #endif |
| 296 | |
| 297 | #if THREAD_CHECKS |
| 298 | ASSERT(critical_section_count > 0); |
| 299 | ASSERT(newthread->saved_critical_section_count > 0); |
| 300 | #endif |
| 301 | |
Travis Geiselbrecht | 9045c06 | 2009-06-28 11:20:09 -0700 | [diff] [blame] | 302 | #if PLATFORM_HAS_DYNAMIC_TIMER |
| 303 | /* if we're switching from idle to a real thread, set up a periodic |
| 304 | * timer to run our preemption tick. |
| 305 | */ |
| 306 | if (oldthread == idle_thread) { |
| 307 | timer_set_periodic(&preempt_timer, 10, (timer_callback)thread_timer_tick, NULL); |
| 308 | } else if (newthread == idle_thread) { |
| 309 | timer_cancel(&preempt_timer); |
| 310 | } |
| 311 | #endif |
| 312 | |
Travis Geiselbrecht | 1d0df69 | 2008-09-01 02:26:09 -0700 | [diff] [blame] | 313 | /* do the switch */ |
| 314 | oldthread->saved_critical_section_count = critical_section_count; |
| 315 | current_thread = newthread; |
| 316 | critical_section_count = newthread->saved_critical_section_count; |
| 317 | arch_context_switch(oldthread, newthread); |
| 318 | } |
| 319 | |
| 320 | void thread_yield(void) |
| 321 | { |
| 322 | #if THREAD_CHECKS |
| 323 | ASSERT(current_thread->magic == THREAD_MAGIC); |
| 324 | ASSERT(current_thread->state == THREAD_RUNNING); |
| 325 | #endif |
| 326 | |
| 327 | enter_critical_section(); |
| 328 | |
| 329 | #if THREAD_STATS |
| 330 | thread_stats.yields++; |
| 331 | #endif |
| 332 | |
| 333 | /* we are yielding the cpu, so stick ourselves into the tail of the run queue and reschedule */ |
| 334 | current_thread->state = THREAD_READY; |
| 335 | current_thread->remaining_quantum = 0; |
| 336 | insert_in_run_queue_tail(current_thread); |
| 337 | thread_resched(); |
| 338 | |
| 339 | exit_critical_section(); |
| 340 | } |
| 341 | |
| 342 | void thread_preempt(void) |
| 343 | { |
| 344 | #if THREAD_CHECKS |
| 345 | ASSERT(current_thread->magic == THREAD_MAGIC); |
| 346 | ASSERT(current_thread->state == THREAD_RUNNING); |
| 347 | #endif |
| 348 | |
| 349 | enter_critical_section(); |
| 350 | |
| 351 | #if THREAD_STATS |
| 352 | if (current_thread != idle_thread) |
| 353 | thread_stats.preempts++; /* only track when a meaningful preempt happens */ |
| 354 | #endif |
| 355 | |
| 356 | /* we are being preempted, so we get to go back into the front of the run queue if we have quantum left */ |
| 357 | current_thread->state = THREAD_READY; |
| 358 | if (current_thread->remaining_quantum > 0) |
| 359 | insert_in_run_queue_head(current_thread); |
| 360 | else |
| 361 | insert_in_run_queue_tail(current_thread); /* if we're out of quantum, go to the tail of the queue */ |
| 362 | thread_resched(); |
| 363 | |
| 364 | exit_critical_section(); |
| 365 | } |
| 366 | |
| 367 | void thread_block(void) |
| 368 | { |
| 369 | #if THREAD_CHECKS |
| 370 | ASSERT(current_thread->magic == THREAD_MAGIC); |
| 371 | ASSERT(current_thread->state == THREAD_BLOCKED); |
| 372 | #endif |
| 373 | |
| 374 | enter_critical_section(); |
| 375 | |
| 376 | /* we are blocking on something. the blocking code should have already stuck us on a queue */ |
| 377 | thread_resched(); |
| 378 | |
| 379 | exit_critical_section(); |
| 380 | } |
| 381 | |
| 382 | enum handler_return thread_timer_tick(void) |
| 383 | { |
| 384 | if (current_thread == idle_thread) |
| 385 | return INT_NO_RESCHEDULE; |
| 386 | |
| 387 | current_thread->remaining_quantum--; |
| 388 | if (current_thread->remaining_quantum <= 0) |
| 389 | return INT_RESCHEDULE; |
| 390 | else |
| 391 | return INT_NO_RESCHEDULE; |
| 392 | } |
| 393 | |
| 394 | /* timer callback to wake up a sleeping thread */ |
| 395 | static enum handler_return thread_sleep_handler(timer_t *timer, time_t now, void *arg) |
| 396 | { |
| 397 | thread_t *t = (thread_t *)arg; |
| 398 | |
| 399 | #if THREAD_CHECKS |
| 400 | ASSERT(t->magic == THREAD_MAGIC); |
| 401 | ASSERT(t->state == THREAD_SLEEPING); |
| 402 | #endif |
| 403 | |
| 404 | t->state = THREAD_READY; |
| 405 | insert_in_run_queue_head(t); |
| 406 | |
| 407 | return INT_RESCHEDULE; |
| 408 | } |
| 409 | |
Travis Geiselbrecht | 9045c06 | 2009-06-28 11:20:09 -0700 | [diff] [blame] | 410 | /* Put thread to sleep; delay specified in ms */ |
Travis Geiselbrecht | 1d0df69 | 2008-09-01 02:26:09 -0700 | [diff] [blame] | 411 | void thread_sleep(time_t delay) |
| 412 | { |
| 413 | timer_t timer; |
| 414 | |
| 415 | #if THREAD_CHECKS |
| 416 | ASSERT(current_thread->magic == THREAD_MAGIC); |
| 417 | ASSERT(current_thread->state == THREAD_RUNNING); |
| 418 | #endif |
| 419 | |
| 420 | timer_initialize(&timer); |
| 421 | |
| 422 | enter_critical_section(); |
| 423 | timer_set_oneshot(&timer, delay, thread_sleep_handler, (void *)current_thread); |
| 424 | current_thread->state = THREAD_SLEEPING; |
| 425 | thread_resched(); |
| 426 | exit_critical_section(); |
| 427 | } |
| 428 | |
travis geiselbrecht | 858b1ad | 2008-12-23 21:55:41 +0000 | [diff] [blame] | 429 | void thread_init_early(void) |
Travis Geiselbrecht | 1d0df69 | 2008-09-01 02:26:09 -0700 | [diff] [blame] | 430 | { |
| 431 | int i; |
| 432 | |
| 433 | /* initialize the run queues */ |
| 434 | for (i=0; i < NUM_PRIORITIES; i++) |
| 435 | list_initialize(&run_queue[i]); |
| 436 | |
| 437 | /* initialize the thread list */ |
| 438 | list_initialize(&thread_list); |
| 439 | |
| 440 | /* create a thread to cover the current running state */ |
| 441 | thread_t *t = &bootstrap_thread; |
| 442 | init_thread_struct(t, "bootstrap"); |
| 443 | |
| 444 | /* half construct this thread, since we're already running */ |
| 445 | t->priority = HIGHEST_PRIORITY; |
| 446 | t->state = THREAD_RUNNING; |
| 447 | t->saved_critical_section_count = 1; |
| 448 | list_add_head(&thread_list, &t->thread_list_node); |
| 449 | current_thread = t; |
| 450 | } |
| 451 | |
travis geiselbrecht | 858b1ad | 2008-12-23 21:55:41 +0000 | [diff] [blame] | 452 | void thread_init(void) |
| 453 | { |
Travis Geiselbrecht | 9045c06 | 2009-06-28 11:20:09 -0700 | [diff] [blame] | 454 | #if PLATFORM_HAS_DYNAMIC_TIMER |
| 455 | timer_initialize(&preempt_timer); |
| 456 | #endif |
travis geiselbrecht | 858b1ad | 2008-12-23 21:55:41 +0000 | [diff] [blame] | 457 | } |
| 458 | |
Travis Geiselbrecht | 1d0df69 | 2008-09-01 02:26:09 -0700 | [diff] [blame] | 459 | void thread_set_name(const char *name) |
| 460 | { |
| 461 | strlcpy(current_thread->name, name, sizeof(current_thread->name)); |
| 462 | } |
| 463 | |
| 464 | void thread_set_priority(int priority) |
| 465 | { |
| 466 | if (priority < LOWEST_PRIORITY) |
| 467 | priority = LOWEST_PRIORITY; |
| 468 | if (priority > HIGHEST_PRIORITY) |
| 469 | priority = HIGHEST_PRIORITY; |
| 470 | current_thread->priority = priority; |
| 471 | } |
| 472 | |
| 473 | void thread_become_idle(void) |
| 474 | { |
| 475 | thread_set_name("idle"); |
| 476 | thread_set_priority(IDLE_PRIORITY); |
| 477 | idle_thread = current_thread; |
| 478 | idle_thread_routine(); |
| 479 | } |
| 480 | |
| 481 | void dump_thread(thread_t *t) |
| 482 | { |
Travis Geiselbrecht | eb94605 | 2008-09-07 22:32:49 -0700 | [diff] [blame] | 483 | dprintf(INFO, "dump_thread: t %p (%s)\n", t, t->name); |
| 484 | dprintf(INFO, "\tstate %d, priority %d, remaining quantum %d, critical section %d\n", t->state, t->priority, t->remaining_quantum, t->saved_critical_section_count); |
| 485 | dprintf(INFO, "\tstack %p, stack_size %zd\n", t->stack, t->stack_size); |
| 486 | dprintf(INFO, "\tentry %p, arg %p\n", t->entry, t->arg); |
| 487 | dprintf(INFO, "\twait queue %p, wait queue ret %d\n", t->blocking_wait_queue, t->wait_queue_block_ret); |
travis geiselbrecht | c60a2e6 | 2008-12-22 23:46:26 +0000 | [diff] [blame] | 488 | dprintf(INFO, "\ttls:"); |
| 489 | int i; |
| 490 | for (i=0; i < MAX_TLS_ENTRY; i++) { |
| 491 | dprintf(INFO, " 0x%x", t->tls[i]); |
| 492 | } |
| 493 | dprintf(INFO, "\n"); |
Travis Geiselbrecht | 1d0df69 | 2008-09-01 02:26:09 -0700 | [diff] [blame] | 494 | } |
| 495 | |
| 496 | void dump_all_threads(void) |
| 497 | { |
| 498 | thread_t *t; |
| 499 | |
| 500 | enter_critical_section(); |
| 501 | list_for_every_entry(&thread_list, t, thread_t, thread_list_node) { |
| 502 | dump_thread(t); |
| 503 | } |
| 504 | exit_critical_section(); |
| 505 | } |
| 506 | |
| 507 | /* wait queue */ |
| 508 | void wait_queue_init(wait_queue_t *wait) |
| 509 | { |
| 510 | wait->magic = WAIT_QUEUE_MAGIC; |
| 511 | list_initialize(&wait->list); |
| 512 | wait->count = 0; |
| 513 | } |
| 514 | |
| 515 | static enum handler_return wait_queue_timeout_handler(timer_t *timer, time_t now, void *arg) |
| 516 | { |
| 517 | thread_t *thread = (thread_t *)arg; |
| 518 | |
| 519 | #if THREAD_CHECKS |
| 520 | ASSERT(thread->magic == THREAD_MAGIC); |
| 521 | #endif |
| 522 | |
| 523 | if (thread_unblock_from_wait_queue(thread, false, ERR_TIMED_OUT) >= NO_ERROR) |
| 524 | return INT_RESCHEDULE; |
| 525 | |
| 526 | return INT_NO_RESCHEDULE; |
| 527 | } |
| 528 | |
| 529 | status_t wait_queue_block(wait_queue_t *wait, time_t timeout) |
| 530 | { |
| 531 | timer_t timer; |
| 532 | |
| 533 | #if THREAD_CHECKS |
| 534 | ASSERT(wait->magic == WAIT_QUEUE_MAGIC); |
| 535 | ASSERT(current_thread->state == THREAD_RUNNING); |
| 536 | ASSERT(in_critical_section()); |
| 537 | #endif |
| 538 | |
| 539 | if (timeout == 0) |
| 540 | return ERR_TIMED_OUT; |
| 541 | |
| 542 | list_add_tail(&wait->list, ¤t_thread->queue_node); |
| 543 | wait->count++; |
| 544 | current_thread->state = THREAD_BLOCKED; |
| 545 | current_thread->blocking_wait_queue = wait; |
| 546 | current_thread->wait_queue_block_ret = NO_ERROR; |
| 547 | |
| 548 | /* if the timeout is nonzero or noninfinite, set a callback to yank us out of the queue */ |
| 549 | if (timeout != INFINITE_TIME) { |
| 550 | timer_initialize(&timer); |
| 551 | timer_set_oneshot(&timer, timeout, wait_queue_timeout_handler, (void *)current_thread); |
| 552 | } |
| 553 | |
| 554 | thread_block(); |
| 555 | |
| 556 | /* we don't really know if the timer fired or not, so it's better safe to try to cancel it */ |
| 557 | if (timeout != INFINITE_TIME) { |
| 558 | timer_cancel(&timer); |
| 559 | } |
| 560 | |
| 561 | return current_thread->wait_queue_block_ret; |
| 562 | } |
| 563 | |
| 564 | int wait_queue_wake_one(wait_queue_t *wait, bool reschedule, status_t wait_queue_error) |
| 565 | { |
| 566 | thread_t *t; |
| 567 | int ret = 0; |
| 568 | |
| 569 | #if THREAD_CHECKS |
| 570 | ASSERT(wait->magic == WAIT_QUEUE_MAGIC); |
| 571 | ASSERT(in_critical_section()); |
| 572 | #endif |
| 573 | |
| 574 | t = list_remove_head_type(&wait->list, thread_t, queue_node); |
| 575 | if (t) { |
| 576 | wait->count--; |
| 577 | #if THREAD_CHECKS |
| 578 | ASSERT(t->state == THREAD_BLOCKED); |
| 579 | #endif |
| 580 | t->state = THREAD_READY; |
| 581 | t->wait_queue_block_ret = wait_queue_error; |
| 582 | t->blocking_wait_queue = NULL; |
| 583 | |
| 584 | /* if we're instructed to reschedule, stick the current thread on the head |
| 585 | * of the run queue first, so that the newly awakened thread gets a chance to run |
| 586 | * before the current one, but the current one doesn't get unnecessarilly punished. |
| 587 | */ |
| 588 | if (reschedule) { |
| 589 | current_thread->state = THREAD_READY; |
| 590 | insert_in_run_queue_head(current_thread); |
| 591 | } |
| 592 | insert_in_run_queue_head(t); |
| 593 | if (reschedule) |
| 594 | thread_resched(); |
| 595 | ret = 1; |
| 596 | } |
| 597 | |
| 598 | return ret; |
| 599 | } |
| 600 | |
| 601 | int wait_queue_wake_all(wait_queue_t *wait, bool reschedule, status_t wait_queue_error) |
| 602 | { |
| 603 | thread_t *t; |
| 604 | int ret = 0; |
| 605 | |
| 606 | #if THREAD_CHECKS |
| 607 | ASSERT(wait->magic == WAIT_QUEUE_MAGIC); |
| 608 | ASSERT(in_critical_section()); |
| 609 | #endif |
| 610 | |
| 611 | if (reschedule && wait->count > 0) { |
| 612 | /* if we're instructed to reschedule, stick the current thread on the head |
| 613 | * of the run queue first, so that the newly awakened threads get a chance to run |
| 614 | * before the current one, but the current one doesn't get unnecessarilly punished. |
| 615 | */ |
| 616 | current_thread->state = THREAD_READY; |
| 617 | insert_in_run_queue_head(current_thread); |
| 618 | } |
| 619 | |
| 620 | /* pop all the threads off the wait queue into the run queue */ |
| 621 | while ((t = list_remove_head_type(&wait->list, thread_t, queue_node))) { |
| 622 | wait->count--; |
| 623 | #if THREAD_CHECKS |
| 624 | ASSERT(t->state == THREAD_BLOCKED); |
| 625 | #endif |
| 626 | t->state = THREAD_READY; |
| 627 | t->wait_queue_block_ret = wait_queue_error; |
| 628 | t->blocking_wait_queue = NULL; |
| 629 | |
| 630 | insert_in_run_queue_head(t); |
| 631 | ret++; |
| 632 | } |
| 633 | |
| 634 | #if THREAD_CHECKS |
| 635 | ASSERT(wait->count == 0); |
| 636 | #endif |
| 637 | |
| 638 | if (reschedule && ret > 0) |
| 639 | thread_resched(); |
| 640 | |
| 641 | return ret; |
| 642 | } |
| 643 | |
| 644 | void wait_queue_destroy(wait_queue_t *wait, bool reschedule) |
| 645 | { |
| 646 | #if THREAD_CHECKS |
| 647 | ASSERT(wait->magic == WAIT_QUEUE_MAGIC); |
| 648 | ASSERT(in_critical_section()); |
| 649 | #endif |
| 650 | wait_queue_wake_all(wait, reschedule, ERR_OBJECT_DESTROYED); |
| 651 | wait->magic = 0; |
| 652 | } |
| 653 | |
| 654 | status_t thread_unblock_from_wait_queue(thread_t *t, bool reschedule, status_t wait_queue_error) |
| 655 | { |
| 656 | enter_critical_section(); |
| 657 | |
| 658 | #if THREAD_CHECKS |
| 659 | ASSERT(t->magic == THREAD_MAGIC); |
| 660 | #endif |
| 661 | |
| 662 | if (t->state != THREAD_BLOCKED) |
| 663 | return ERR_NOT_BLOCKED; |
| 664 | |
| 665 | #if THREAD_CHECKS |
| 666 | ASSERT(t->blocking_wait_queue != NULL); |
| 667 | ASSERT(t->blocking_wait_queue->magic == WAIT_QUEUE_MAGIC); |
| 668 | ASSERT(list_in_list(&t->queue_node)); |
| 669 | #endif |
| 670 | |
| 671 | list_delete(&t->queue_node); |
| 672 | t->blocking_wait_queue->count--; |
| 673 | t->blocking_wait_queue = NULL; |
| 674 | t->state = THREAD_READY; |
| 675 | t->wait_queue_block_ret = wait_queue_error; |
| 676 | insert_in_run_queue_head(t); |
| 677 | |
| 678 | if (reschedule) |
| 679 | thread_resched(); |
| 680 | |
| 681 | exit_critical_section(); |
| 682 | |
| 683 | return NO_ERROR; |
| 684 | } |
| 685 | |
| 686 | |