#include <assert.h>
#include <errno.h>
-#include <fcntl.h>
#include <inttypes.h>
#include <malloc.h>
#include <pthread.h>
void *data;
};
+extern bt_os_callouts_t *bt_os_callouts;
// If the next wakeup time is less than this threshold, we should acquire
// a wakelock instead of setting a wake alarm so we're not bouncing in
// unit tests to run faster. It should not be modified by production code.
int64_t TIMER_INTERVAL_FOR_WAKELOCK_IN_MS = 3000;
static const clockid_t CLOCK_ID = CLOCK_BOOTTIME;
-static const clockid_t CLOCK_ID_ALARM = CLOCK_BOOTTIME_ALARM;
-static const char *WAKE_LOCK_ID = "bluetooth_timer";
-static const char *WAKE_LOCK_PATH = "/sys/power/wake_lock";
-static const char *WAKE_UNLOCK_PATH = "/sys/power/wake_unlock";
-static ssize_t locked_id_len = -1;
-static pthread_once_t wake_fds_initialized = PTHREAD_ONCE_INIT;
-static int wake_lock_fd = INVALID_FD;
-static int wake_unlock_fd = INVALID_FD;
+static const char *WAKE_LOCK_ID = "bluedroid_timer";
// This mutex ensures that the |alarm_set|, |alarm_cancel|, and alarm callback
// functions execute serially and not concurrently. As a result, this mutex also
static pthread_mutex_t monitor;
static list_t *alarms;
static timer_t timer;
-static timer_t wakeup_timer;
static bool timer_set;
// All alarm callbacks are dispatched from |callback_thread|
static void reschedule_root_alarm(void);
static void timer_callback(void *data);
static void callback_dispatch(void *context);
-static bool timer_create_internal(const clockid_t clock_id, timer_t *timer);
-static void initialize_wake_fds(void);
-static bool acquire_wake_lock(void);
-static bool release_wake_lock(void);
alarm_t *alarm_new(void) {
// Make sure we have a list we can insert alarms into.
- if (!alarms && !lazy_initialize()) {
- assert(false); // if initialization failed, we should not continue
+ if (!alarms && !lazy_initialize())
return NULL;
- }
pthread_mutexattr_t attr;
pthread_mutexattr_init(&attr);
static bool lazy_initialize(void) {
assert(alarms == NULL);
- // timer_t doesn't have an invalid value so we must track whether
- // the |timer| variable is valid ourselves.
- bool timer_initialized = false;
- bool wakeup_timer_initialized = false;
-
pthread_mutex_init(&monitor, NULL);
alarms = list_new(NULL);
if (!alarms) {
LOG_ERROR(LOG_TAG, "%s unable to allocate alarm list.", __func__);
- goto error;
+ return false;
}
- if (!timer_create_internal(CLOCK_ID, &timer))
- goto error;
- timer_initialized = true;
-
- if (!timer_create_internal(CLOCK_ID_ALARM, &wakeup_timer))
- goto error;
- wakeup_timer_initialized = true;
+ struct sigevent sigevent;
+ memset(&sigevent, 0, sizeof(sigevent));
+ sigevent.sigev_notify = SIGEV_THREAD;
+ sigevent.sigev_notify_function = (void (*)(union sigval))timer_callback;
+ if (timer_create(CLOCK_ID, &sigevent, &timer) == -1) {
+ LOG_ERROR(LOG_TAG, "%s unable to create timer: %s", __func__,
+ strerror(errno));
+ return false;
+ }
alarm_expired = semaphore_new(0);
if (!alarm_expired) {
LOG_ERROR(LOG_TAG, "%s unable to create alarm expired semaphore", __func__);
- goto error;
+ return false;
}
callback_thread_active = true;
callback_thread = thread_new("alarm_callbacks");
if (!callback_thread) {
LOG_ERROR(LOG_TAG, "%s unable to create alarm callback thread.", __func__);
- goto error;
+ return false;
}
thread_set_priority(callback_thread, CALLBACK_THREAD_PRIORITY_HIGH);
thread_post(callback_thread, callback_dispatch, NULL);
return true;
-
-error:
- thread_free(callback_thread);
- callback_thread = NULL;
-
- callback_thread_active = false;
-
- semaphore_free(alarm_expired);
- alarm_expired = NULL;
-
- if (wakeup_timer_initialized)
- timer_delete(wakeup_timer);
-
- if (timer_initialized)
- timer_delete(timer);
-
- list_free(alarms);
- alarms = NULL;
-
- pthread_mutex_destroy(&monitor);
-
- return false;
}
static period_ms_t now(void) {
// NOTE: must be called with monitor lock.
static void reschedule_root_alarm(void) {
+ bool timer_was_set = timer_set;
assert(alarms != NULL);
- const bool timer_was_set = timer_set;
-
- // If used in a zeroed state, disarms the timer.
- struct itimerspec timer_time;
- memset(&timer_time, 0, sizeof(timer_time));
+ // If used in a zeroed state, disarms the timer
+ struct itimerspec wakeup_time;
+ memset(&wakeup_time, 0, sizeof(wakeup_time));
if (list_is_empty(alarms))
goto done;
- const alarm_t *next = list_front(alarms);
- const int64_t next_expiration = next->deadline - now();
+ alarm_t *next = list_front(alarms);
+ int64_t next_expiration = next->deadline - now();
if (next_expiration < TIMER_INTERVAL_FOR_WAKELOCK_IN_MS) {
if (!timer_set) {
- if (!acquire_wake_lock()) {
- LOG_ERROR(LOG_TAG, "%s unable to acquire wake lock", __func__);
+ int status = bt_os_callouts->acquire_wake_lock(WAKE_LOCK_ID);
+ if (status != BT_STATUS_SUCCESS) {
+ LOG_ERROR(LOG_TAG, "%s unable to acquire wake lock: %d", __func__, status);
goto done;
}
}
- timer_time.it_value.tv_sec = (next->deadline / 1000);
- timer_time.it_value.tv_nsec = (next->deadline % 1000) * 1000000LL;
-
- // It is entirely unsafe to call timer_settime(2) with a zeroed timerspec for
- // timers with *_ALARM clock IDs. Although the man page states that the timer
- // would be canceled, the current behavior (as of Linux kernel 3.17) is that
- // the callback is issued immediately. The only way to cancel an *_ALARM timer
- // is to delete the timer. But unfortunately, deleting and re-creating a timer
- // is rather expensive; every timer_create(2) spawns a new thread. So we simply
- // set the timer to fire at the largest possible time.
- //
- // If we've reached this code path, we're going to grab a wake lock and wait for
- // the next timer to fire. In that case, there's no reason to have a pending wakeup
- // timer so we simply cancel it.
- struct itimerspec end_of_time;
- memset(&end_of_time, 0, sizeof(end_of_time));
- end_of_time.it_value.tv_sec = (time_t)(1LL << (sizeof(time_t) * 8 - 2));
- timer_settime(wakeup_timer, TIMER_ABSTIME, &end_of_time, NULL);
- } else {
- // WARNING: do not attempt to use relative timers with *_ALARM clock IDs
- // in kernels before 3.17 unless you have the following patch:
- // https://lkml.org/lkml/2014/7/7/576
- struct itimerspec wakeup_time;
- memset(&wakeup_time, 0, sizeof(wakeup_time));
-
-
wakeup_time.it_value.tv_sec = (next->deadline / 1000);
wakeup_time.it_value.tv_nsec = (next->deadline % 1000) * 1000000LL;
- if (timer_settime(wakeup_timer, TIMER_ABSTIME, &wakeup_time, NULL) == -1)
- LOG_ERROR(LOG_TAG, "%s unable to set wakeup timer: %s",
- __func__, strerror(errno));
+ } else {
+ if (!bt_os_callouts->set_wake_alarm(next_expiration, true, timer_callback, NULL))
+ LOG_ERROR(LOG_TAG, "%s unable to set wake alarm for %" PRId64 "ms.", __func__, next_expiration);
}
done:
- timer_set = timer_time.it_value.tv_sec != 0 || timer_time.it_value.tv_nsec != 0;
+ timer_set = wakeup_time.it_value.tv_sec != 0 || wakeup_time.it_value.tv_nsec != 0;
if (timer_was_set && !timer_set) {
- release_wake_lock();
+ bt_os_callouts->release_wake_lock(WAKE_LOCK_ID);
}
- if (timer_settime(timer, TIMER_ABSTIME, &timer_time, NULL) == -1)
+ if (timer_settime(timer, TIMER_ABSTIME, &wakeup_time, NULL) == -1)
LOG_ERROR(LOG_TAG, "%s unable to set timer: %s", __func__, strerror(errno));
// If next expiration was in the past (e.g. short timer that got context switched)
LOG_DEBUG(LOG_TAG, "%s Callback thread exited", __func__);
}
-
-static void initialize_wake_fds(void) {
- LOG_DEBUG(LOG_TAG, "%s opening wake locks", __func__);
-
- wake_lock_fd = open(WAKE_LOCK_PATH, O_RDWR | O_CLOEXEC);
- if (wake_lock_fd == INVALID_FD) {
- LOG_ERROR(LOG_TAG, "%s can't open wake lock %s: %s",
- __func__, WAKE_LOCK_PATH, strerror(errno));
- }
-
- wake_unlock_fd = open(WAKE_UNLOCK_PATH, O_RDWR | O_CLOEXEC);
- if (wake_unlock_fd == INVALID_FD) {
- LOG_ERROR(LOG_TAG, "%s can't open wake unlock %s: %s",
- __func__, WAKE_UNLOCK_PATH, strerror(errno));
- }
-}
-
-static bool acquire_wake_lock(void) {
- pthread_once(&wake_fds_initialized, initialize_wake_fds);
-
- if (wake_lock_fd == INVALID_FD) {
- LOG_ERROR(LOG_TAG, "%s lock not acquired, invalid fd", __func__);
- return false;
- }
-
- if (wake_unlock_fd == INVALID_FD) {
- LOG_ERROR(LOG_TAG, "%s not acquiring lock: can't release lock", __func__);
- return false;
- }
-
- long lock_name_len = strlen(WAKE_LOCK_ID);
- locked_id_len = write(wake_lock_fd, WAKE_LOCK_ID, lock_name_len);
- if (locked_id_len == -1) {
- LOG_ERROR(LOG_TAG, "%s wake lock not acquired: %s",
- __func__, strerror(errno));
- return false;
- } else if (locked_id_len < lock_name_len) {
- // TODO (jamuraa): this is weird. maybe we should release and retry.
- LOG_WARN(LOG_TAG, "%s wake lock truncated to %zd chars",
- __func__, locked_id_len);
- }
- return true;
-}
-
-static bool release_wake_lock(void) {
- pthread_once(&wake_fds_initialized, initialize_wake_fds);
-
- if (wake_unlock_fd == INVALID_FD) {
- LOG_ERROR(LOG_TAG, "%s lock not released, invalid fd", __func__);
- return false;
- }
-
- ssize_t wrote_name_len = write(wake_unlock_fd, WAKE_LOCK_ID, locked_id_len);
- if (wrote_name_len == -1) {
- LOG_ERROR(LOG_TAG, "%s can't release wake lock: %s",
- __func__, strerror(errno));
- } else if (wrote_name_len < locked_id_len) {
- LOG_ERROR(LOG_TAG, "%s lock release only wrote %zd, assuming released",
- __func__, wrote_name_len);
- }
- return true;
-}
-
-static bool timer_create_internal(const clockid_t clock_id, timer_t *timer) {
- assert(timer != NULL);
-
- struct sigevent sigevent;
- memset(&sigevent, 0, sizeof(sigevent));
- sigevent.sigev_notify = SIGEV_THREAD;
- sigevent.sigev_notify_function = (void (*)(union sigval))timer_callback;
- if (timer_create(clock_id, &sigevent, timer) == -1) {
- LOG_ERROR(LOG_TAG, "%s unable to create timer with clock %d: %s",
- __func__, clock_id, strerror(errno));
- return false;
- }
-
- return true;
-}
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