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Merge "Fix deadlock in timer_delete."

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Christopher Ferris 2014-03-21 17:26:58 +00:00 committed by Gerrit Code Review
commit 998d7b0307
2 changed files with 54 additions and 5 deletions
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13
libc/bionic/posix_timers.cpp
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@ -100,11 +100,14 @@ static void* __timer_thread_start(void* arg) {
static void __timer_thread_stop(PosixTimer* timer) {
pthread_kill(timer->callback_thread, TIMER_SIGNAL);
// We can't pthread_join because POSIX says "the threads created in response to a timer
// expiration are created detached, or in an unspecified way if the thread attribute's
// detachstate is PTHREAD_CREATE_JOINABLE".
while (timer->exiting == 0) {
__futex_wait(&timer->exiting, 0, NULL);
// If this is being called from within the callback thread, do nothing else.
if (pthread_self() != timer->callback_thread) {
// We can't pthread_join because POSIX says "the threads created in response to a timer
// expiration are created detached, or in an unspecified way if the thread attribute's
// detachstate is PTHREAD_CREATE_JOINABLE".
while (timer->exiting == 0) {
__futex_wait(&timer->exiting, 0, NULL);
}
}
}

46
tests/time_test.cpp
View File

@ -341,3 +341,49 @@ TEST(time, timer_create_multiple) {
EXPECT_EQ(1, counter2.value);
EXPECT_EQ(0, counter3.value);
}
struct TimerDeleteData {
timer_t timer_id;
pthread_t thread_id;
volatile bool complete;
};
static void TimerDeleteCallback(sigval_t value) {
TimerDeleteData* tdd = reinterpret_cast<TimerDeleteData*>(value.sival_ptr);
tdd->thread_id = pthread_self();
timer_delete(tdd->timer_id);
tdd->complete = true;
}
TEST(time, timer_delete_from_timer_thread) {
TimerDeleteData tdd;
sigevent_t se;
memset(&se, 0, sizeof(se));
se.sigev_notify = SIGEV_THREAD;
se.sigev_notify_function = TimerDeleteCallback;
se.sigev_value.sival_ptr = &tdd;
tdd.complete = false;
ASSERT_EQ(0, timer_create(CLOCK_REALTIME, &se, &tdd.timer_id));
itimerspec ts;
ts.it_value.tv_sec = 0;
ts.it_value.tv_nsec = 100;
ts.it_interval.tv_sec = 0;
ts.it_interval.tv_nsec = 0;
ASSERT_EQ(0, timer_settime(tdd.timer_id, TIMER_ABSTIME, &ts, NULL));
time_t cur_time = time(NULL);
while (!tdd.complete && (time(NULL) - cur_time) < 5);
ASSERT_TRUE(tdd.complete);
#if defined(__BIONIC__)
// Since bionic timers are implemented by creating a thread to handle the
// callback, verify that the thread actually completes.
cur_time = time(NULL);
while (pthread_detach(tdd.thread_id) != ESRCH && (time(NULL) - cur_time) < 5);
ASSERT_EQ(ESRCH, pthread_detach(tdd.thread_id));
#endif
}