alarm.cc revision 1a7856018ab1608a3d681caab4eecd2185ff51f2
1/****************************************************************************** 2 * 3 * Copyright (C) 2014 Google, Inc. 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at: 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 ******************************************************************************/ 18 19#include "include/bt_target.h" 20 21#define LOG_TAG "bt_osi_alarm" 22 23#include "osi/include/alarm.h" 24 25#include <base/cancelable_callback.h> 26#include <base/logging.h> 27#include <base/message_loop/message_loop.h> 28#include <errno.h> 29#include <fcntl.h> 30#include <inttypes.h> 31#include <malloc.h> 32#include <pthread.h> 33#include <signal.h> 34#include <string.h> 35#include <time.h> 36 37#include <hardware/bluetooth.h> 38 39#include <mutex> 40 41#include "osi/include/allocator.h" 42#include "osi/include/fixed_queue.h" 43#include "osi/include/list.h" 44#include "osi/include/log.h" 45#include "osi/include/osi.h" 46#include "osi/include/semaphore.h" 47#include "osi/include/thread.h" 48#include "osi/include/wakelock.h" 49 50using base::Bind; 51using base::CancelableClosure; 52using base::MessageLoop; 53 54extern base::MessageLoop* get_message_loop(); 55 56// Callback and timer threads should run at RT priority in order to ensure they 57// meet audio deadlines. Use this priority for all audio/timer related thread. 58static const int THREAD_RT_PRIORITY = 1; 59 60typedef struct { 61 size_t count; 62 period_ms_t total_ms; 63 period_ms_t max_ms; 64} stat_t; 65 66// Alarm-related information and statistics 67typedef struct { 68 const char* name; 69 size_t scheduled_count; 70 size_t canceled_count; 71 size_t rescheduled_count; 72 size_t total_updates; 73 period_ms_t last_update_ms; 74 stat_t overdue_scheduling; 75 stat_t premature_scheduling; 76} alarm_stats_t; 77 78/* Wrapper around CancellableClosure that let it be embedded in structs, without 79 * need to define copy operator. */ 80struct CancelableClosureInStruct { 81 base::CancelableClosure i; 82 83 CancelableClosureInStruct& operator=(const CancelableClosureInStruct& in) { 84 if (!in.i.callback().is_null()) i.Reset(in.i.callback()); 85 return *this; 86 } 87}; 88 89struct alarm_t { 90 // The mutex is held while the callback for this alarm is being executed. 91 // It allows us to release the coarse-grained monitor lock while a 92 // potentially long-running callback is executing. |alarm_cancel| uses this 93 // mutex to provide a guarantee to its caller that the callback will not be 94 // in progress when it returns. 95 std::recursive_mutex* callback_mutex; 96 period_ms_t creation_time; 97 period_ms_t period; 98 period_ms_t deadline; 99 period_ms_t prev_deadline; // Previous deadline - used for accounting of 100 // periodic timers 101 bool is_periodic; 102 fixed_queue_t* queue; // The processing queue to add this alarm to 103 alarm_callback_t callback; 104 void* data; 105 alarm_stats_t stats; 106 107 bool for_msg_loop; // True, if the alarm should be processed on message loop 108 CancelableClosureInStruct closure; // posted to message loop for processing 109}; 110 111// If the next wakeup time is less than this threshold, we should acquire 112// a wakelock instead of setting a wake alarm so we're not bouncing in 113// and out of suspend frequently. This value is externally visible to allow 114// unit tests to run faster. It should not be modified by production code. 115int64_t TIMER_INTERVAL_FOR_WAKELOCK_IN_MS = 3000; 116static const clockid_t CLOCK_ID = CLOCK_BOOTTIME; 117 118#if (KERNEL_MISSING_CLOCK_BOOTTIME_ALARM == TRUE) 119static const clockid_t CLOCK_ID_ALARM = CLOCK_BOOTTIME; 120#else 121static const clockid_t CLOCK_ID_ALARM = CLOCK_BOOTTIME_ALARM; 122#endif 123 124// This mutex ensures that the |alarm_set|, |alarm_cancel|, and alarm callback 125// functions execute serially and not concurrently. As a result, this mutex 126// also protects the |alarms| list. 127static std::mutex alarms_mutex; 128static list_t* alarms; 129static timer_t timer; 130static timer_t wakeup_timer; 131static bool timer_set; 132 133// All alarm callbacks are dispatched from |dispatcher_thread| 134static thread_t* dispatcher_thread; 135static bool dispatcher_thread_active; 136static semaphore_t* alarm_expired; 137 138// Default alarm callback thread and queue 139static thread_t* default_callback_thread; 140static fixed_queue_t* default_callback_queue; 141 142static alarm_t* alarm_new_internal(const char* name, bool is_periodic); 143static bool lazy_initialize(void); 144static period_ms_t now(void); 145static void alarm_set_internal(alarm_t* alarm, period_ms_t period, 146 alarm_callback_t cb, void* data, 147 fixed_queue_t* queue, bool for_msg_loop); 148static void alarm_cancel_internal(alarm_t* alarm); 149static void remove_pending_alarm(alarm_t* alarm); 150static void schedule_next_instance(alarm_t* alarm); 151static void reschedule_root_alarm(void); 152static void alarm_queue_ready(fixed_queue_t* queue, void* context); 153static void timer_callback(void* data); 154static void callback_dispatch(void* context); 155static bool timer_create_internal(const clockid_t clock_id, timer_t* timer); 156static void update_scheduling_stats(alarm_stats_t* stats, period_ms_t now_ms, 157 period_ms_t deadline_ms); 158// Registers |queue| for processing alarm callbacks on |thread|. 159// |queue| may not be NULL. |thread| may not be NULL. 160static void alarm_register_processing_queue(fixed_queue_t* queue, 161 thread_t* thread); 162 163static void update_stat(stat_t* stat, period_ms_t delta) { 164 if (stat->max_ms < delta) stat->max_ms = delta; 165 stat->total_ms += delta; 166 stat->count++; 167} 168 169alarm_t* alarm_new(const char* name) { return alarm_new_internal(name, false); } 170 171alarm_t* alarm_new_periodic(const char* name) { 172 return alarm_new_internal(name, true); 173} 174 175static alarm_t* alarm_new_internal(const char* name, bool is_periodic) { 176 // Make sure we have a list we can insert alarms into. 177 if (!alarms && !lazy_initialize()) { 178 CHECK(false); // if initialization failed, we should not continue 179 return NULL; 180 } 181 182 alarm_t* ret = static_cast<alarm_t*>(osi_calloc(sizeof(alarm_t))); 183 184 ret->callback_mutex = new std::recursive_mutex; 185 ret->is_periodic = is_periodic; 186 ret->stats.name = osi_strdup(name); 187 188 ret->for_msg_loop = false; 189 // placement new 190 new (&ret->closure) CancelableClosureInStruct(); 191 192 // NOTE: The stats were reset by osi_calloc() above 193 194 return ret; 195} 196 197void alarm_free(alarm_t* alarm) { 198 if (!alarm) return; 199 200 alarm_cancel(alarm); 201 delete alarm->callback_mutex; 202 osi_free((void*)alarm->stats.name); 203 alarm->closure.~CancelableClosureInStruct(); 204 osi_free(alarm); 205} 206 207period_ms_t alarm_get_remaining_ms(const alarm_t* alarm) { 208 CHECK(alarm != NULL); 209 period_ms_t remaining_ms = 0; 210 period_ms_t just_now = now(); 211 212 std::lock_guard<std::mutex> lock(alarms_mutex); 213 if (alarm->deadline > just_now) remaining_ms = alarm->deadline - just_now; 214 215 return remaining_ms; 216} 217 218void alarm_set(alarm_t* alarm, period_ms_t interval_ms, alarm_callback_t cb, 219 void* data) { 220 alarm_set_internal(alarm, interval_ms, cb, data, default_callback_queue, 221 false); 222} 223 224void alarm_set_on_mloop(alarm_t* alarm, period_ms_t interval_ms, 225 alarm_callback_t cb, void* data) { 226 alarm_set_internal(alarm, interval_ms, cb, data, NULL, true); 227} 228 229// Runs in exclusion with alarm_cancel and timer_callback. 230static void alarm_set_internal(alarm_t* alarm, period_ms_t period, 231 alarm_callback_t cb, void* data, 232 fixed_queue_t* queue, bool for_msg_loop) { 233 CHECK(alarms != NULL); 234 CHECK(alarm != NULL); 235 CHECK(cb != NULL); 236 237 std::lock_guard<std::mutex> lock(alarms_mutex); 238 239 alarm->creation_time = now(); 240 alarm->period = period; 241 alarm->queue = queue; 242 alarm->callback = cb; 243 alarm->data = data; 244 alarm->for_msg_loop = for_msg_loop; 245 246 schedule_next_instance(alarm); 247 alarm->stats.scheduled_count++; 248} 249 250void alarm_cancel(alarm_t* alarm) { 251 CHECK(alarms != NULL); 252 if (!alarm) return; 253 254 { 255 std::lock_guard<std::mutex> lock(alarms_mutex); 256 alarm_cancel_internal(alarm); 257 } 258 259 // If the callback for |alarm| is in progress, wait here until it completes. 260 std::lock_guard<std::recursive_mutex> lock(*alarm->callback_mutex); 261} 262 263// Internal implementation of canceling an alarm. 264// The caller must hold the |alarms_mutex| 265static void alarm_cancel_internal(alarm_t* alarm) { 266 bool needs_reschedule = 267 (!list_is_empty(alarms) && list_front(alarms) == alarm); 268 269 remove_pending_alarm(alarm); 270 271 alarm->deadline = 0; 272 alarm->prev_deadline = 0; 273 alarm->callback = NULL; 274 alarm->data = NULL; 275 alarm->stats.canceled_count++; 276 alarm->queue = NULL; 277 278 if (needs_reschedule) reschedule_root_alarm(); 279} 280 281bool alarm_is_scheduled(const alarm_t* alarm) { 282 if ((alarms == NULL) || (alarm == NULL)) return false; 283 return (alarm->callback != NULL); 284} 285 286void alarm_cleanup(void) { 287 // If lazy_initialize never ran there is nothing else to do 288 if (!alarms) return; 289 290 dispatcher_thread_active = false; 291 semaphore_post(alarm_expired); 292 thread_free(dispatcher_thread); 293 dispatcher_thread = NULL; 294 295 std::lock_guard<std::mutex> lock(alarms_mutex); 296 297 fixed_queue_free(default_callback_queue, NULL); 298 default_callback_queue = NULL; 299 thread_free(default_callback_thread); 300 default_callback_thread = NULL; 301 302 timer_delete(wakeup_timer); 303 timer_delete(timer); 304 semaphore_free(alarm_expired); 305 alarm_expired = NULL; 306 307 list_free(alarms); 308 alarms = NULL; 309} 310 311static bool lazy_initialize(void) { 312 CHECK(alarms == NULL); 313 314 // timer_t doesn't have an invalid value so we must track whether 315 // the |timer| variable is valid ourselves. 316 bool timer_initialized = false; 317 bool wakeup_timer_initialized = false; 318 319 std::lock_guard<std::mutex> lock(alarms_mutex); 320 321 alarms = list_new(NULL); 322 if (!alarms) { 323 LOG_ERROR(LOG_TAG, "%s unable to allocate alarm list.", __func__); 324 goto error; 325 } 326 327 if (!timer_create_internal(CLOCK_ID, &timer)) goto error; 328 timer_initialized = true; 329 330 if (!timer_create_internal(CLOCK_ID_ALARM, &wakeup_timer)) goto error; 331 wakeup_timer_initialized = true; 332 333 alarm_expired = semaphore_new(0); 334 if (!alarm_expired) { 335 LOG_ERROR(LOG_TAG, "%s unable to create alarm expired semaphore", __func__); 336 goto error; 337 } 338 339 default_callback_thread = 340 thread_new_sized("alarm_default_callbacks", SIZE_MAX); 341 if (default_callback_thread == NULL) { 342 LOG_ERROR(LOG_TAG, "%s unable to create default alarm callbacks thread.", 343 __func__); 344 goto error; 345 } 346 thread_set_rt_priority(default_callback_thread, THREAD_RT_PRIORITY); 347 default_callback_queue = fixed_queue_new(SIZE_MAX); 348 if (default_callback_queue == NULL) { 349 LOG_ERROR(LOG_TAG, "%s unable to create default alarm callbacks queue.", 350 __func__); 351 goto error; 352 } 353 alarm_register_processing_queue(default_callback_queue, 354 default_callback_thread); 355 356 dispatcher_thread_active = true; 357 dispatcher_thread = thread_new("alarm_dispatcher"); 358 if (!dispatcher_thread) { 359 LOG_ERROR(LOG_TAG, "%s unable to create alarm callback thread.", __func__); 360 goto error; 361 } 362 thread_set_rt_priority(dispatcher_thread, THREAD_RT_PRIORITY); 363 thread_post(dispatcher_thread, callback_dispatch, NULL); 364 return true; 365 366error: 367 fixed_queue_free(default_callback_queue, NULL); 368 default_callback_queue = NULL; 369 thread_free(default_callback_thread); 370 default_callback_thread = NULL; 371 372 thread_free(dispatcher_thread); 373 dispatcher_thread = NULL; 374 375 dispatcher_thread_active = false; 376 377 semaphore_free(alarm_expired); 378 alarm_expired = NULL; 379 380 if (wakeup_timer_initialized) timer_delete(wakeup_timer); 381 382 if (timer_initialized) timer_delete(timer); 383 384 list_free(alarms); 385 alarms = NULL; 386 387 return false; 388} 389 390static period_ms_t now(void) { 391 CHECK(alarms != NULL); 392 393 struct timespec ts; 394 if (clock_gettime(CLOCK_ID, &ts) == -1) { 395 LOG_ERROR(LOG_TAG, "%s unable to get current time: %s", __func__, 396 strerror(errno)); 397 return 0; 398 } 399 400 return (ts.tv_sec * 1000LL) + (ts.tv_nsec / 1000000LL); 401} 402 403// Remove alarm from internal alarm list and the processing queue 404// The caller must hold the |alarms_mutex| 405static void remove_pending_alarm(alarm_t* alarm) { 406 list_remove(alarms, alarm); 407 408 if (alarm->for_msg_loop) { 409 alarm->closure.i.Cancel(); 410 } else { 411 while (fixed_queue_try_remove_from_queue(alarm->queue, alarm) != NULL) { 412 // Remove all repeated alarm instances from the queue. 413 // NOTE: We are defensive here - we shouldn't have repeated alarm 414 // instances 415 } 416 } 417} 418 419// Must be called with |alarms_mutex| held 420static void schedule_next_instance(alarm_t* alarm) { 421 // If the alarm is currently set and it's at the start of the list, 422 // we'll need to re-schedule since we've adjusted the earliest deadline. 423 bool needs_reschedule = 424 (!list_is_empty(alarms) && list_front(alarms) == alarm); 425 if (alarm->callback) remove_pending_alarm(alarm); 426 427 // Calculate the next deadline for this alarm 428 period_ms_t just_now = now(); 429 period_ms_t ms_into_period = 0; 430 if ((alarm->is_periodic) && (alarm->period != 0)) 431 ms_into_period = ((just_now - alarm->creation_time) % alarm->period); 432 alarm->deadline = just_now + (alarm->period - ms_into_period); 433 434 // Add it into the timer list sorted by deadline (earliest deadline first). 435 if (list_is_empty(alarms) || 436 ((alarm_t*)list_front(alarms))->deadline > alarm->deadline) { 437 list_prepend(alarms, alarm); 438 } else { 439 for (list_node_t* node = list_begin(alarms); node != list_end(alarms); 440 node = list_next(node)) { 441 list_node_t* next = list_next(node); 442 if (next == list_end(alarms) || 443 ((alarm_t*)list_node(next))->deadline > alarm->deadline) { 444 list_insert_after(alarms, node, alarm); 445 break; 446 } 447 } 448 } 449 450 // If the new alarm has the earliest deadline, we need to re-evaluate our 451 // schedule. 452 if (needs_reschedule || 453 (!list_is_empty(alarms) && list_front(alarms) == alarm)) { 454 reschedule_root_alarm(); 455 } 456} 457 458// NOTE: must be called with |alarms_mutex| held 459static void reschedule_root_alarm(void) { 460 CHECK(alarms != NULL); 461 462 const bool timer_was_set = timer_set; 463 alarm_t* next; 464 int64_t next_expiration; 465 466 // If used in a zeroed state, disarms the timer. 467 struct itimerspec timer_time; 468 memset(&timer_time, 0, sizeof(timer_time)); 469 470 if (list_is_empty(alarms)) goto done; 471 472 next = static_cast<alarm_t*>(list_front(alarms)); 473 next_expiration = next->deadline - now(); 474 if (next_expiration < TIMER_INTERVAL_FOR_WAKELOCK_IN_MS) { 475 if (!timer_set) { 476 if (!wakelock_acquire()) { 477 LOG_ERROR(LOG_TAG, "%s unable to acquire wake lock", __func__); 478 goto done; 479 } 480 } 481 482 timer_time.it_value.tv_sec = (next->deadline / 1000); 483 timer_time.it_value.tv_nsec = (next->deadline % 1000) * 1000000LL; 484 485 // It is entirely unsafe to call timer_settime(2) with a zeroed timerspec 486 // for timers with *_ALARM clock IDs. Although the man page states that the 487 // timer would be canceled, the current behavior (as of Linux kernel 3.17) 488 // is that the callback is issued immediately. The only way to cancel an 489 // *_ALARM timer is to delete the timer. But unfortunately, deleting and 490 // re-creating a timer is rather expensive; every timer_create(2) spawns a 491 // new thread. So we simply set the timer to fire at the largest possible 492 // time. 493 // 494 // If we've reached this code path, we're going to grab a wake lock and 495 // wait for the next timer to fire. In that case, there's no reason to 496 // have a pending wakeup timer so we simply cancel it. 497 struct itimerspec end_of_time; 498 memset(&end_of_time, 0, sizeof(end_of_time)); 499 end_of_time.it_value.tv_sec = (time_t)(1LL << (sizeof(time_t) * 8 - 2)); 500 timer_settime(wakeup_timer, TIMER_ABSTIME, &end_of_time, NULL); 501 } else { 502 // WARNING: do not attempt to use relative timers with *_ALARM clock IDs 503 // in kernels before 3.17 unless you have the following patch: 504 // https://lkml.org/lkml/2014/7/7/576 505 struct itimerspec wakeup_time; 506 memset(&wakeup_time, 0, sizeof(wakeup_time)); 507 508 wakeup_time.it_value.tv_sec = (next->deadline / 1000); 509 wakeup_time.it_value.tv_nsec = (next->deadline % 1000) * 1000000LL; 510 if (timer_settime(wakeup_timer, TIMER_ABSTIME, &wakeup_time, NULL) == -1) 511 LOG_ERROR(LOG_TAG, "%s unable to set wakeup timer: %s", __func__, 512 strerror(errno)); 513 } 514 515done: 516 timer_set = 517 timer_time.it_value.tv_sec != 0 || timer_time.it_value.tv_nsec != 0; 518 if (timer_was_set && !timer_set) { 519 wakelock_release(); 520 } 521 522 if (timer_settime(timer, TIMER_ABSTIME, &timer_time, NULL) == -1) 523 LOG_ERROR(LOG_TAG, "%s unable to set timer: %s", __func__, strerror(errno)); 524 525 // If next expiration was in the past (e.g. short timer that got context 526 // switched) then the timer might have diarmed itself. Detect this case and 527 // work around it by manually signalling the |alarm_expired| semaphore. 528 // 529 // It is possible that the timer was actually super short (a few 530 // milliseconds) and the timer expired normally before we called 531 // |timer_gettime|. Worst case, |alarm_expired| is signaled twice for that 532 // alarm. Nothing bad should happen in that case though since the callback 533 // dispatch function checks to make sure the timer at the head of the list 534 // actually expired. 535 if (timer_set) { 536 struct itimerspec time_to_expire; 537 timer_gettime(timer, &time_to_expire); 538 if (time_to_expire.it_value.tv_sec == 0 && 539 time_to_expire.it_value.tv_nsec == 0) { 540 LOG_DEBUG( 541 LOG_TAG, 542 "%s alarm expiration too close for posix timers, switching to guns", 543 __func__); 544 semaphore_post(alarm_expired); 545 } 546 } 547} 548 549static void alarm_register_processing_queue(fixed_queue_t* queue, 550 thread_t* thread) { 551 CHECK(queue != NULL); 552 CHECK(thread != NULL); 553 554 fixed_queue_register_dequeue(queue, thread_get_reactor(thread), 555 alarm_queue_ready, NULL); 556} 557 558static void alarm_ready_generic(alarm_t* alarm, 559 std::unique_lock<std::mutex>& lock) { 560 if (alarm == NULL) { 561 return; // The alarm was probably canceled 562 } 563 // 564 // If the alarm is not periodic, we've fully serviced it now, and can reset 565 // some of its internal state. This is useful to distinguish between expired 566 // alarms and active ones. 567 // 568 alarm_callback_t callback = alarm->callback; 569 void* data = alarm->data; 570 period_ms_t deadline = alarm->deadline; 571 if (alarm->is_periodic) { 572 // The periodic alarm has been rescheduled and alarm->deadline has been 573 // updated, hence we need to use the previous deadline. 574 deadline = alarm->prev_deadline; 575 } else { 576 alarm->deadline = 0; 577 alarm->callback = NULL; 578 alarm->data = NULL; 579 alarm->queue = NULL; 580 } 581 582 std::lock_guard<std::recursive_mutex> cb_lock(*alarm->callback_mutex); 583 lock.unlock(); 584 585 // Update the statistics 586 update_scheduling_stats(&alarm->stats, now(), deadline); 587 588 // NOTE: Do NOT access "alarm" after the callback, as a safety precaution 589 // in case the callback itself deleted the alarm. 590 callback(data); 591} 592 593static void alarm_ready_mloop(alarm_t* alarm) { 594 std::unique_lock<std::mutex> lock(alarms_mutex); 595 alarm_ready_generic(alarm, lock); 596} 597 598static void alarm_queue_ready(fixed_queue_t* queue, UNUSED_ATTR void* context) { 599 CHECK(queue != NULL); 600 601 std::unique_lock<std::mutex> lock(alarms_mutex); 602 alarm_t* alarm = (alarm_t*)fixed_queue_try_dequeue(queue); 603 alarm_ready_generic(alarm, lock); 604} 605 606// Callback function for wake alarms and our posix timer 607static void timer_callback(UNUSED_ATTR void* ptr) { 608 semaphore_post(alarm_expired); 609} 610 611// Function running on |dispatcher_thread| that performs the following: 612// (1) Receives a signal using |alarm_exired| that the alarm has expired 613// (2) Dispatches the alarm callback for processing by the corresponding 614// thread for that alarm. 615static void callback_dispatch(UNUSED_ATTR void* context) { 616 while (true) { 617 semaphore_wait(alarm_expired); 618 if (!dispatcher_thread_active) break; 619 620 std::lock_guard<std::mutex> lock(alarms_mutex); 621 alarm_t* alarm; 622 623 // Take into account that the alarm may get cancelled before we get to it. 624 // We're done here if there are no alarms or the alarm at the front is in 625 // the future. Exit right away since there's nothing left to do. 626 if (list_is_empty(alarms) || 627 (alarm = static_cast<alarm_t*>(list_front(alarms)))->deadline > now()) { 628 reschedule_root_alarm(); 629 continue; 630 } 631 632 list_remove(alarms, alarm); 633 634 if (alarm->is_periodic) { 635 alarm->prev_deadline = alarm->deadline; 636 schedule_next_instance(alarm); 637 alarm->stats.rescheduled_count++; 638 } 639 reschedule_root_alarm(); 640 641 // Enqueue the alarm for processing 642 if (alarm->for_msg_loop) { 643 if (!get_message_loop()) { 644 LOG_ERROR(LOG_TAG, "%s: message loop already NULL. Alarm: %s", __func__, 645 alarm->stats.name); 646 continue; 647 } 648 649 alarm->closure.i.Reset(Bind(alarm_ready_mloop, alarm)); 650 get_message_loop()->PostTask(FROM_HERE, alarm->closure.i.callback()); 651 } else { 652 fixed_queue_enqueue(alarm->queue, alarm); 653 } 654 } 655 656 LOG_DEBUG(LOG_TAG, "%s Callback thread exited", __func__); 657} 658 659static bool timer_create_internal(const clockid_t clock_id, timer_t* timer) { 660 CHECK(timer != NULL); 661 662 struct sigevent sigevent; 663 // create timer with RT priority thread 664 pthread_attr_t thread_attr; 665 pthread_attr_init(&thread_attr); 666 pthread_attr_setschedpolicy(&thread_attr, SCHED_FIFO); 667 struct sched_param param; 668 param.sched_priority = THREAD_RT_PRIORITY; 669 pthread_attr_setschedparam(&thread_attr, ¶m); 670 671 memset(&sigevent, 0, sizeof(sigevent)); 672 sigevent.sigev_notify = SIGEV_THREAD; 673 sigevent.sigev_notify_function = (void (*)(union sigval))timer_callback; 674 sigevent.sigev_notify_attributes = &thread_attr; 675 if (timer_create(clock_id, &sigevent, timer) == -1) { 676 LOG_ERROR(LOG_TAG, "%s unable to create timer with clock %d: %s", __func__, 677 clock_id, strerror(errno)); 678 if (clock_id == CLOCK_BOOTTIME_ALARM) { 679 LOG_ERROR(LOG_TAG, 680 "The kernel might not have support for " 681 "timer_create(CLOCK_BOOTTIME_ALARM): " 682 "https://lwn.net/Articles/429925/"); 683 LOG_ERROR(LOG_TAG, 684 "See following patches: " 685 "https://git.kernel.org/cgit/linux/kernel/git/torvalds/" 686 "linux.git/log/?qt=grep&q=CLOCK_BOOTTIME_ALARM"); 687 } 688 return false; 689 } 690 691 return true; 692} 693 694static void update_scheduling_stats(alarm_stats_t* stats, period_ms_t now_ms, 695 period_ms_t deadline_ms) { 696 stats->total_updates++; 697 stats->last_update_ms = now_ms; 698 699 if (deadline_ms < now_ms) { 700 // Overdue scheduling 701 period_ms_t delta_ms = now_ms - deadline_ms; 702 update_stat(&stats->overdue_scheduling, delta_ms); 703 } else if (deadline_ms > now_ms) { 704 // Premature scheduling 705 period_ms_t delta_ms = deadline_ms - now_ms; 706 update_stat(&stats->premature_scheduling, delta_ms); 707 } 708} 709 710static void dump_stat(int fd, stat_t* stat, const char* description) { 711 period_ms_t average_time_ms = 0; 712 if (stat->count != 0) average_time_ms = stat->total_ms / stat->count; 713 714 dprintf(fd, "%-51s: %llu / %llu / %llu\n", description, 715 (unsigned long long)stat->total_ms, (unsigned long long)stat->max_ms, 716 (unsigned long long)average_time_ms); 717} 718 719void alarm_debug_dump(int fd) { 720 dprintf(fd, "\nBluetooth Alarms Statistics:\n"); 721 722 std::lock_guard<std::mutex> lock(alarms_mutex); 723 724 if (alarms == NULL) { 725 dprintf(fd, " None\n"); 726 return; 727 } 728 729 period_ms_t just_now = now(); 730 731 dprintf(fd, " Total Alarms: %zu\n\n", list_length(alarms)); 732 733 // Dump info for each alarm 734 for (list_node_t* node = list_begin(alarms); node != list_end(alarms); 735 node = list_next(node)) { 736 alarm_t* alarm = (alarm_t*)list_node(node); 737 alarm_stats_t* stats = &alarm->stats; 738 739 dprintf(fd, " Alarm : %s (%s)\n", stats->name, 740 (alarm->is_periodic) ? "PERIODIC" : "SINGLE"); 741 742 dprintf(fd, "%-51s: %zu / %zu / %zu / %zu\n", 743 " Action counts (sched/resched/exec/cancel)", 744 stats->scheduled_count, stats->rescheduled_count, 745 stats->total_updates, stats->canceled_count); 746 747 dprintf(fd, "%-51s: %zu / %zu\n", 748 " Deviation counts (overdue/premature)", 749 stats->overdue_scheduling.count, stats->premature_scheduling.count); 750 751 dprintf(fd, "%-51s: %llu / %llu / %lld\n", 752 " Time in ms (since creation/interval/remaining)", 753 (unsigned long long)(just_now - alarm->creation_time), 754 (unsigned long long)alarm->period, 755 (long long)(alarm->deadline - just_now)); 756 757 dump_stat(fd, &stats->overdue_scheduling, 758 " Overdue scheduling time in ms (total/max/avg)"); 759 760 dump_stat(fd, &stats->premature_scheduling, 761 " Premature scheduling time in ms (total/max/avg)"); 762 763 dprintf(fd, "\n"); 764 } 765} 766