alarm.cc revision 081e4b67b44a5fd397c2d79a5566e11ae52d4aca
1f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati/****************************************************************************** 2f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati * 3f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati * Copyright (C) 2014 Google, Inc. 4f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati * 5f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati * Licensed under the Apache License, Version 2.0 (the "License"); 6f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati * you may not use this file except in compliance with the License. 7f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati * You may obtain a copy of the License at: 8f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati * 9f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati * http://www.apache.org/licenses/LICENSE-2.0 10f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati * 11f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati * Unless required by applicable law or agreed to in writing, software 12f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati * distributed under the License is distributed on an "AS IS" BASIS, 13f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati * See the License for the specific language governing permissions and 15f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati * limitations under the License. 16f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati * 17f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati ******************************************************************************/ 18f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 19f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati#define LOG_TAG "bt_osi_alarm" 20f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 21f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati#include <assert.h> 22f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati#include <errno.h> 23f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati#include <hardware/bluetooth.h> 241afbe154a89ad462de739704ce70eed0e32cbc00Michael Wright#include <inttypes.h> 25f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati#include <time.h> 26f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 270f9b91e150e153229235c163861198e23600e636Sharvil Nanavati#include "osi/include/alarm.h" 28081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson#include "osi/include/allocator.h" 290f9b91e150e153229235c163861198e23600e636Sharvil Nanavati#include "osi/include/list.h" 3044802768c447ab480d4227b3a852a97d923b816dSharvil Nanavati#include "osi/include/log.h" 31081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson#include "osi/include/osi.h" 32081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson#include "osi/include/semaphore.h" 33081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson#include "osi/include/thread.h" 34f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 35f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavatistruct alarm_t { 36f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati // The lock is held while the callback for this alarm is being executed. 37f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati // It allows us to release the coarse-grained monitor lock while a potentially 38f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati // long-running callback is executing. |alarm_cancel| uses this lock to provide 39f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati // a guarantee to its caller that the callback will not be in progress when it 40f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati // returns. 41f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati pthread_mutex_t callback_lock; 42e2c57aaba4fd0c029a8cb4c519f6ef11f041b4deZach Johnson period_ms_t created; 43e2c57aaba4fd0c029a8cb4c519f6ef11f041b4deZach Johnson period_ms_t period; 44f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati period_ms_t deadline; 45e2c57aaba4fd0c029a8cb4c519f6ef11f041b4deZach Johnson bool is_periodic; 46f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati alarm_callback_t callback; 47f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati void *data; 48f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati}; 49f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 50f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavatiextern bt_os_callouts_t *bt_os_callouts; 51f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 52f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati// If the next wakeup time is less than this threshold, we should acquire 53f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati// a wakelock instead of setting a wake alarm so we're not bouncing in 54f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati// and out of suspend frequently. This value is externally visible to allow 55f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati// unit tests to run faster. It should not be modified by production code. 56f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavatiint64_t TIMER_INTERVAL_FOR_WAKELOCK_IN_MS = 3000; 57f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavatistatic const clockid_t CLOCK_ID = CLOCK_BOOTTIME; 58f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavatistatic const char *WAKE_LOCK_ID = "bluedroid_timer"; 59f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 60f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati// This mutex ensures that the |alarm_set|, |alarm_cancel|, and alarm callback 61f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati// functions execute serially and not concurrently. As a result, this mutex also 62f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati// protects the |alarms| list. 63f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavatistatic pthread_mutex_t monitor; 64f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavatistatic list_t *alarms; 65f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavatistatic timer_t timer; 66f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavatistatic bool timer_set; 67f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 68081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson// All alarm callbacks are dispatched from |callback_thread| 69081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnsonstatic thread_t *callback_thread; 70081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnsonstatic semaphore_t *alarm_expired; 71081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson 72f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavatistatic bool lazy_initialize(void); 73f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavatistatic period_ms_t now(void); 7471864f490d4dc31857df0b31924cd62a337e9f1aZach Johnsonstatic void alarm_set_internal(alarm_t *alarm, period_ms_t deadline, alarm_callback_t cb, void *data, bool is_periodic); 75e2c57aaba4fd0c029a8cb4c519f6ef11f041b4deZach Johnsonstatic void schedule_next_instance(alarm_t *alarm); 76e2c57aaba4fd0c029a8cb4c519f6ef11f041b4deZach Johnsonstatic void reschedule_root_alarm(void); 77081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnsonstatic void timer_callback(void *data); 78081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnsonstatic void callback_dispatch(void *context); 79f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 80f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavatialarm_t *alarm_new(void) { 81f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati // Make sure we have a list we can insert alarms into. 82f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati if (!alarms && !lazy_initialize()) 83f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati return NULL; 84f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 85f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati pthread_mutexattr_t attr; 86f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati pthread_mutexattr_init(&attr); 87f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 88ee2aa45def216a3c4d6a23481fa96f1b02a5de8cZach Johnson alarm_t *ret = osi_calloc(sizeof(alarm_t)); 89f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati if (!ret) { 9044802768c447ab480d4227b3a852a97d923b816dSharvil Nanavati LOG_ERROR("%s unable to allocate memory for alarm.", __func__); 91f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati goto error; 92f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati } 93f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 94f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati // Make this a recursive mutex to make it safe to call |alarm_cancel| from 95f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati // within the callback function of the alarm. 96f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati int error = pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE); 97f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati if (error) { 9844802768c447ab480d4227b3a852a97d923b816dSharvil Nanavati LOG_ERROR("%s unable to create a recursive mutex: %s", __func__, strerror(error)); 99f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati goto error; 100f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati } 101f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 102f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati error = pthread_mutex_init(&ret->callback_lock, &attr); 103f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati if (error) { 10444802768c447ab480d4227b3a852a97d923b816dSharvil Nanavati LOG_ERROR("%s unable to initialize mutex: %s", __func__, strerror(error)); 105f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati goto error; 106f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati } 107f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 108f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati pthread_mutexattr_destroy(&attr); 109f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati return ret; 110f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 111f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavatierror:; 112f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati pthread_mutexattr_destroy(&attr); 113ee2aa45def216a3c4d6a23481fa96f1b02a5de8cZach Johnson osi_free(ret); 114f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati return NULL; 115f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati} 116f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 117f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavativoid alarm_free(alarm_t *alarm) { 118f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati if (!alarm) 119f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati return; 120f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 121f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati alarm_cancel(alarm); 122f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati pthread_mutex_destroy(&alarm->callback_lock); 123ee2aa45def216a3c4d6a23481fa96f1b02a5de8cZach Johnson osi_free(alarm); 124f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati} 125f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 126f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavativoid alarm_set(alarm_t *alarm, period_ms_t deadline, alarm_callback_t cb, void *data) { 12771864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson alarm_set_internal(alarm, deadline, cb, data, false); 12871864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson} 12971864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson 13071864f490d4dc31857df0b31924cd62a337e9f1aZach Johnsonvoid alarm_set_periodic(alarm_t *alarm, period_ms_t period, alarm_callback_t cb, void *data) { 13171864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson alarm_set_internal(alarm, period, cb, data, true); 13271864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson} 13371864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson 13471864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson// Runs in exclusion with alarm_cancel and timer_callback. 135e2c57aaba4fd0c029a8cb4c519f6ef11f041b4deZach Johnsonstatic void alarm_set_internal(alarm_t *alarm, period_ms_t period, alarm_callback_t cb, void *data, bool is_periodic) { 136f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati assert(alarms != NULL); 137f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati assert(alarm != NULL); 138f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati assert(cb != NULL); 139f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 140f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati pthread_mutex_lock(&monitor); 141f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 142e2c57aaba4fd0c029a8cb4c519f6ef11f041b4deZach Johnson alarm->created = now(); 143e2c57aaba4fd0c029a8cb4c519f6ef11f041b4deZach Johnson alarm->is_periodic = is_periodic; 144e2c57aaba4fd0c029a8cb4c519f6ef11f041b4deZach Johnson alarm->period = period; 145f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati alarm->callback = cb; 146f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati alarm->data = data; 147f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 148e2c57aaba4fd0c029a8cb4c519f6ef11f041b4deZach Johnson schedule_next_instance(alarm); 149f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 150f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati pthread_mutex_unlock(&monitor); 151f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati} 152f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 153f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavativoid alarm_cancel(alarm_t *alarm) { 154f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati assert(alarms != NULL); 155f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati assert(alarm != NULL); 156f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 157f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati pthread_mutex_lock(&monitor); 158f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 159f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati bool needs_reschedule = (!list_is_empty(alarms) && list_front(alarms) == alarm); 160f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 161f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati list_remove(alarms, alarm); 162f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati alarm->deadline = 0; 163f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati alarm->callback = NULL; 164f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati alarm->data = NULL; 165f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 166f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati if (needs_reschedule) 167e2c57aaba4fd0c029a8cb4c519f6ef11f041b4deZach Johnson reschedule_root_alarm(); 168f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 169f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati pthread_mutex_unlock(&monitor); 170f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 171f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati // If the callback for |alarm| is in progress, wait here until it completes. 172f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati pthread_mutex_lock(&alarm->callback_lock); 173f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati pthread_mutex_unlock(&alarm->callback_lock); 174f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati} 175f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 176f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavatistatic bool lazy_initialize(void) { 177f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati assert(alarms == NULL); 178f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 179f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati pthread_mutex_init(&monitor, NULL); 180f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 181f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati alarms = list_new(NULL); 182f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati if (!alarms) { 18344802768c447ab480d4227b3a852a97d923b816dSharvil Nanavati LOG_ERROR("%s unable to allocate alarm list.", __func__); 184f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati return false; 185f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati } 186f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 187518a94e706a6602ad69245b0d760cd40595109ffZach Johnson struct sigevent sigevent; 188518a94e706a6602ad69245b0d760cd40595109ffZach Johnson memset(&sigevent, 0, sizeof(sigevent)); 189518a94e706a6602ad69245b0d760cd40595109ffZach Johnson sigevent.sigev_notify = SIGEV_THREAD; 190518a94e706a6602ad69245b0d760cd40595109ffZach Johnson sigevent.sigev_notify_function = (void (*)(union sigval))timer_callback; 191518a94e706a6602ad69245b0d760cd40595109ffZach Johnson if (timer_create(CLOCK_ID, &sigevent, &timer) == -1) { 192518a94e706a6602ad69245b0d760cd40595109ffZach Johnson LOG_ERROR("%s unable to create timer: %s", __func__, strerror(errno)); 193518a94e706a6602ad69245b0d760cd40595109ffZach Johnson return false; 194518a94e706a6602ad69245b0d760cd40595109ffZach Johnson } 195518a94e706a6602ad69245b0d760cd40595109ffZach Johnson 196081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson alarm_expired = semaphore_new(0); 197081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson if (!alarm_expired) { 198081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson LOG_ERROR("%s unable to create alarm expired semaphore", __func__); 199081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson return false; 200081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson } 201081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson 202081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson callback_thread = thread_new("alarm_callbacks"); 203081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson if (!callback_thread) { 204081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson LOG_ERROR("%s unable to create alarm callback thread.", __func__); 205081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson return false; 206081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson } 207081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson 208081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson thread_post(callback_thread, callback_dispatch, NULL); 209f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati return true; 210f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati} 211f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 212f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavatistatic period_ms_t now(void) { 213f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati assert(alarms != NULL); 214f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 215f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati struct timespec ts; 216f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati if (clock_gettime(CLOCK_ID, &ts) == -1) { 21744802768c447ab480d4227b3a852a97d923b816dSharvil Nanavati LOG_ERROR("%s unable to get current time: %s", __func__, strerror(errno)); 218f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati return 0; 219f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati } 220f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 221f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati return (ts.tv_sec * 1000LL) + (ts.tv_nsec / 1000000LL); 222f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati} 223f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 22471864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson// Must be called with monitor held 225e2c57aaba4fd0c029a8cb4c519f6ef11f041b4deZach Johnsonstatic void schedule_next_instance(alarm_t *alarm) { 22671864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson // If the alarm is currently set and it's at the start of the list, 22771864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson // we'll need to re-schedule since we've adjusted the earliest deadline. 22871864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson bool needs_reschedule = (!list_is_empty(alarms) && list_front(alarms) == alarm); 22971864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson if (alarm->callback) 23071864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson list_remove(alarms, alarm); 23171864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson 232e2c57aaba4fd0c029a8cb4c519f6ef11f041b4deZach Johnson // Calculate the next deadline for this alarm 233e2c57aaba4fd0c029a8cb4c519f6ef11f041b4deZach Johnson period_ms_t just_now = now(); 234e2c57aaba4fd0c029a8cb4c519f6ef11f041b4deZach Johnson period_ms_t ms_into_period = alarm->is_periodic ? ((just_now - alarm->created) % alarm->period) : 0; 235e2c57aaba4fd0c029a8cb4c519f6ef11f041b4deZach Johnson alarm->deadline = just_now + (alarm->period - ms_into_period); 23671864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson 23771864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson // Add it into the timer list sorted by deadline (earliest deadline first). 23871864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson if (list_is_empty(alarms) || ((alarm_t *)list_front(alarms))->deadline >= alarm->deadline) 23971864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson list_prepend(alarms, alarm); 24071864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson else 24171864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson for (list_node_t *node = list_begin(alarms); node != list_end(alarms); node = list_next(node)) { 24271864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson list_node_t *next = list_next(node); 24371864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson if (next == list_end(alarms) || ((alarm_t *)list_node(next))->deadline >= alarm->deadline) { 24471864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson list_insert_after(alarms, node, alarm); 24571864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson break; 24671864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson } 24771864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson } 24871864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson 24971864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson // If the new alarm has the earliest deadline, we need to re-evaluate our schedule. 25071864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson if (needs_reschedule || (!list_is_empty(alarms) && list_front(alarms) == alarm)) 251e2c57aaba4fd0c029a8cb4c519f6ef11f041b4deZach Johnson reschedule_root_alarm(); 25271864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson} 25371864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson 254f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati// NOTE: must be called with monitor lock. 255e2c57aaba4fd0c029a8cb4c519f6ef11f041b4deZach Johnsonstatic void reschedule_root_alarm(void) { 256f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati assert(alarms != NULL); 257f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 258518a94e706a6602ad69245b0d760cd40595109ffZach Johnson // If used in a zeroed state, disarms the timer 259518a94e706a6602ad69245b0d760cd40595109ffZach Johnson struct itimerspec wakeup_time; 260518a94e706a6602ad69245b0d760cd40595109ffZach Johnson memset(&wakeup_time, 0, sizeof(wakeup_time)); 261f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 262518a94e706a6602ad69245b0d760cd40595109ffZach Johnson if (list_is_empty(alarms)) 263518a94e706a6602ad69245b0d760cd40595109ffZach Johnson goto done; 264f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 265f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati alarm_t *next = list_front(alarms); 266518a94e706a6602ad69245b0d760cd40595109ffZach Johnson int64_t next_expiration = next->deadline - now(); 267518a94e706a6602ad69245b0d760cd40595109ffZach Johnson if (next_expiration < TIMER_INTERVAL_FOR_WAKELOCK_IN_MS) { 268518a94e706a6602ad69245b0d760cd40595109ffZach Johnson if (!timer_set) { 26971864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson int status = bt_os_callouts->acquire_wake_lock(WAKE_LOCK_ID); 27071864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson if (status != BT_STATUS_SUCCESS) { 27171864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson LOG_ERROR("%s unable to acquire wake lock: %d", __func__, status); 272518a94e706a6602ad69245b0d760cd40595109ffZach Johnson goto done; 27371864f490d4dc31857df0b31924cd62a337e9f1aZach Johnson } 274f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati } 275f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 276f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati wakeup_time.it_value.tv_sec = (next->deadline / 1000); 277f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati wakeup_time.it_value.tv_nsec = (next->deadline % 1000) * 1000000LL; 278f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati } else { 279518a94e706a6602ad69245b0d760cd40595109ffZach Johnson if (!bt_os_callouts->set_wake_alarm(next_expiration, true, timer_callback, NULL)) 280518a94e706a6602ad69245b0d760cd40595109ffZach Johnson LOG_ERROR("%s unable to set wake alarm for %" PRId64 "ms.", __func__, next_expiration); 281518a94e706a6602ad69245b0d760cd40595109ffZach Johnson } 282f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati 283518a94e706a6602ad69245b0d760cd40595109ffZach Johnsondone: 284518a94e706a6602ad69245b0d760cd40595109ffZach Johnson timer_set = wakeup_time.it_value.tv_sec != 0 || wakeup_time.it_value.tv_nsec != 0; 285518a94e706a6602ad69245b0d760cd40595109ffZach Johnson if (!timer_set) { 286f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati bt_os_callouts->release_wake_lock(WAKE_LOCK_ID); 287f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati } 288518a94e706a6602ad69245b0d760cd40595109ffZach Johnson 289518a94e706a6602ad69245b0d760cd40595109ffZach Johnson if (timer_settime(timer, TIMER_ABSTIME, &wakeup_time, NULL) == -1) 290518a94e706a6602ad69245b0d760cd40595109ffZach Johnson LOG_ERROR("%s unable to set timer: %s", __func__, strerror(errno)); 291081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson 292081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson // If next expiration was in the past (e.g. short timer that got context switched) 293081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson // then the timer might have diarmed itself. Detect this case and work around it 294081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson // by manually signalling the |alarm_expired| semaphore. 295081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson // 296081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson // It is possible that the timer was actually super short (a few milliseconds) 297081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson // and the timer expired normally before we called |timer_gettime|. Worst case, 298081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson // |alarm_expired| is signaled twice for that alarm. Nothing bad should happen in 299081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson // that case though since the callback dispatch function checks to make sure the 300081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson // timer at the head of the list actually expired. 301081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson if (timer_set) { 302081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson struct itimerspec time_to_expire; 303081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson timer_gettime(timer, &time_to_expire); 304081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson if (time_to_expire.it_value.tv_sec == 0 && time_to_expire.it_value.tv_nsec == 0) { 305081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson LOG_ERROR("%s alarm expiration too close for posix timers, switching to guns", __func__); 306081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson semaphore_post(alarm_expired); 307081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson } 308081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson } 309081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson} 310081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson 311081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson// Callback function for wake alarms and our posix timer 312081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnsonstatic void timer_callback(UNUSED_ATTR void *ptr) { 313081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson semaphore_post(alarm_expired); 314081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson} 315081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson 316081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson// Function running on |callback_thread| that dispatches alarm callbacks upon 317081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson// alarm expiration, which is signaled using |alarm_expired|. 318081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnsonstatic void callback_dispatch(UNUSED_ATTR void *context) { 319081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson while (true) { 320081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson semaphore_wait(alarm_expired); 321081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson pthread_mutex_lock(&monitor); 322081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson 323081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson alarm_t *alarm; 324081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson 325081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson // Take into account that the alarm may get cancelled before we get to it. 326081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson // We're done here if there are no alarms or the alarm at the front is in 327081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson // the future. Release the monitor lock and exit right away since there's 328081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson // nothing left to do. 329081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson if (list_is_empty(alarms) || (alarm = list_front(alarms))->deadline > now()) { 330081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson reschedule_root_alarm(); 331081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson pthread_mutex_unlock(&monitor); 332081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson continue; 333081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson } 334081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson 335081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson list_remove(alarms, alarm); 336081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson 337081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson alarm_callback_t callback = alarm->callback; 338081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson void *data = alarm->data; 339081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson 340081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson if (alarm->is_periodic) { 341081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson schedule_next_instance(alarm); 342081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson } else { 343081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson reschedule_root_alarm(); 344081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson 345081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson alarm->deadline = 0; 346081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson alarm->callback = NULL; 347081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson alarm->data = NULL; 348081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson } 349081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson 350081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson // Downgrade lock. 351081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson pthread_mutex_lock(&alarm->callback_lock); 352081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson pthread_mutex_unlock(&monitor); 353081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson 354081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson callback(data); 355081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson 356081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson pthread_mutex_unlock(&alarm->callback_lock); 357081e4b67b44a5fd397c2d79a5566e11ae52d4acaZach Johnson } 358f0e7c8b895c61104ce962b7c5e3705a32943d711Sharvil Nanavati} 359