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am 86ad2037: am 2587c6a2: Merge "Change on handling of SIGEV_THREAD timers."

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* commit '86ad2037793d1f125d59d115ee90f2f105f94f41':
  Change on handling of SIGEV_THREAD timers.
This commit is contained in:
Yabin Cui 2015-04-16 01:59:15 +00:00 committed by Android Git Automerger
commit 459676c3b3
2 changed files with 92 additions and 92 deletions
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42
libc/bionic/posix_timers.cpp
View File

@ -26,14 +26,15 @@
* SUCH DAMAGE.
*/
#include "pthread_internal.h"
#include "private/bionic_futex.h"
#include "private/kernel_sigset_t.h"
#include <errno.h>
#include <malloc.h>
#include <pthread.h>
#include <stdatomic.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
// System calls.
extern "C" int __rt_sigtimedwait(const sigset_t*, siginfo_t*, const struct timespec*, size_t);
@ -59,11 +60,11 @@ struct PosixTimer {
int sigev_notify;
// These fields are only needed for a SIGEV_THREAD timer.
// The fields below are only needed for a SIGEV_THREAD timer.
pthread_t callback_thread;
void (*callback)(sigval_t);
sigval_t callback_argument;
volatile bool armed;
atomic_bool deleted; // Set when the timer is deleted, to prevent further calling of callback.
};
static __kernel_timer_t to_kernel_timer_id(timer_t timer) {
@ -85,8 +86,13 @@ static void* __timer_thread_start(void* arg) {
continue;
}
if (si.si_code == SI_TIMER && timer->armed) {
if (si.si_code == SI_TIMER) {
// This signal was sent because a timer fired, so call the callback.
// All events to the callback will be ignored when the timer is deleted.
if (atomic_load(&timer->deleted) == true) {
continue;
}
timer->callback(timer->callback_argument);
} else if (si.si_code == SI_TKILL) {
// This signal was sent because someone wants us to exit.
@ -97,9 +103,7 @@ static void* __timer_thread_start(void* arg) {
}
static void __timer_thread_stop(PosixTimer* timer) {
// Immediately mark the timer as disarmed so even if some events
// continue to happen, the callback won't be called.
timer->armed = false;
atomic_store(&timer->deleted, true);
pthread_kill(timer->callback_thread, TIMER_SIGNAL);
}
@ -126,7 +130,7 @@ int timer_create(clockid_t clock_id, sigevent* evp, timer_t* timer_id) {
// Otherwise, this must be SIGEV_THREAD timer...
timer->callback = evp->sigev_notify_function;
timer->callback_argument = evp->sigev_value;
timer->armed = false;
atomic_init(&timer->deleted, false);
// Check arguments that the kernel doesn't care about but we do.
if (timer->callback == NULL) {
@ -199,25 +203,19 @@ int timer_delete(timer_t id) {
return 0;
}
// http://pubs.opengroup.org/onlinepubs/9699919799/functions/timer_getoverrun.html
// http://pubs.opengroup.org/onlinepubs/9699919799/functions/timer_gettime.html
int timer_gettime(timer_t id, itimerspec* ts) {
return __timer_gettime(to_kernel_timer_id(id), ts);
}
// http://pubs.opengroup.org/onlinepubs/9699919799/functions/timer_getoverrun.html
// http://pubs.opengroup.org/onlinepubs/9699919799/functions/timer_settime.html
// When using timer_settime to disarm a repeatable SIGEV_THREAD timer with a very small
// period (like below 1ms), the kernel may continue to send events to the callback thread
// for a few extra times. This behavior is fine because in POSIX standard: The effect of
// disarming or resetting a timer with pending expiration notifications is unspecified.
int timer_settime(timer_t id, int flags, const itimerspec* ts, itimerspec* ots) {
PosixTimer* timer= reinterpret_cast<PosixTimer*>(id);
int rc = __timer_settime(timer->kernel_timer_id, flags, ts, ots);
if (rc == 0) {
// Mark the timer as either being armed or disarmed. This avoids the
// callback being called after the disarm for SIGEV_THREAD timers only.
if (ts->it_value.tv_sec != 0 || ts->it_value.tv_nsec != 0) {
timer->armed = true;
} else {
timer->armed = false;
}
}
return rc;
return __timer_settime(timer->kernel_timer_id, flags, ts, ots);
}
// http://pubs.opengroup.org/onlinepubs/9699919799/functions/timer_getoverrun.html

142
tests/time_test.cpp
View File

@ -24,6 +24,7 @@
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <atomic>
#include "ScopedSignalHandler.h"
@ -197,7 +198,7 @@ TEST(time, timer_create) {
ASSERT_EQ(0, timer_delete(timer_id));
}
static int timer_create_SIGEV_SIGNAL_signal_handler_invocation_count = 0;
static int timer_create_SIGEV_SIGNAL_signal_handler_invocation_count;
static void timer_create_SIGEV_SIGNAL_signal_handler(int signal_number) {
++timer_create_SIGEV_SIGNAL_signal_handler_invocation_count;
ASSERT_EQ(SIGUSR1, signal_number);
@ -212,6 +213,7 @@ TEST(time, timer_create_SIGEV_SIGNAL) {
timer_t timer_id;
ASSERT_EQ(0, timer_create(CLOCK_MONOTONIC, &se, &timer_id));
timer_create_SIGEV_SIGNAL_signal_handler_invocation_count = 0;
ScopedSignalHandler ssh(SIGUSR1, timer_create_SIGEV_SIGNAL_signal_handler);
ASSERT_EQ(0, timer_create_SIGEV_SIGNAL_signal_handler_invocation_count);
@ -228,25 +230,26 @@ TEST(time, timer_create_SIGEV_SIGNAL) {
}
struct Counter {
volatile int value;
private:
std::atomic<int> value;
timer_t timer_id;
sigevent_t se;
bool timer_valid;
Counter(void (*fn)(sigval_t)) : value(0), timer_valid(false) {
memset(&se, 0, sizeof(se));
se.sigev_notify = SIGEV_THREAD;
se.sigev_notify_function = fn;
se.sigev_value.sival_ptr = this;
Create();
}
void Create() {
ASSERT_FALSE(timer_valid);
ASSERT_EQ(0, timer_create(CLOCK_REALTIME, &se, &timer_id));
timer_valid = true;
}
public:
Counter(void (*fn)(sigval_t)) : value(0), timer_valid(false) {
memset(&se, 0, sizeof(se));
se.sigev_notify = SIGEV_THREAD;
se.sigev_notify_function = fn;
se.sigev_value.sival_ptr = this;
Create();
}
void DeleteTimer() {
ASSERT_TRUE(timer_valid);
ASSERT_EQ(0, timer_delete(timer_id));
@ -259,12 +262,16 @@ struct Counter {
}
}
int Value() const {
return value;
}
void SetTime(time_t value_s, time_t value_ns, time_t interval_s, time_t interval_ns) {
::SetTime(timer_id, value_s, value_ns, interval_s, interval_ns);
}
bool ValueUpdated() {
volatile int current_value = value;
int current_value = value;
time_t start = time(NULL);
while (current_value == value && (time(NULL) - start) < 5) {
}
@ -287,30 +294,29 @@ struct Counter {
TEST(time, timer_settime_0) {
Counter counter(Counter::CountAndDisarmNotifyFunction);
ASSERT_TRUE(counter.timer_valid);
ASSERT_EQ(0, counter.value);
ASSERT_EQ(0, counter.Value());
counter.SetTime(0, 1, 1, 0);
usleep(500000);
// The count should just be 1 because we disarmed the timer the first time it fired.
ASSERT_EQ(1, counter.value);
ASSERT_EQ(1, counter.Value());
}
TEST(time, timer_settime_repeats) {
Counter counter(Counter::CountNotifyFunction);
ASSERT_TRUE(counter.timer_valid);
ASSERT_EQ(0, counter.value);
ASSERT_EQ(0, counter.Value());
counter.SetTime(0, 1, 0, 10);
ASSERT_TRUE(counter.ValueUpdated());
ASSERT_TRUE(counter.ValueUpdated());
ASSERT_TRUE(counter.ValueUpdated());
counter.DeleteTimer();
// Add a sleep as other threads may be calling the callback function when the timer is deleted.
usleep(500000);
}
static int timer_create_NULL_signal_handler_invocation_count = 0;
static int timer_create_NULL_signal_handler_invocation_count;
static void timer_create_NULL_signal_handler(int signal_number) {
++timer_create_NULL_signal_handler_invocation_count;
ASSERT_EQ(SIGALRM, signal_number);
@ -321,6 +327,7 @@ TEST(time, timer_create_NULL) {
timer_t timer_id;
ASSERT_EQ(0, timer_create(CLOCK_MONOTONIC, NULL, &timer_id));
timer_create_NULL_signal_handler_invocation_count = 0;
ScopedSignalHandler ssh(SIGALRM, timer_create_NULL_signal_handler);
ASSERT_EQ(0, timer_create_NULL_signal_handler_invocation_count);
@ -367,22 +374,59 @@ TEST(time, timer_delete_multiple) {
TEST(time, timer_create_multiple) {
Counter counter1(Counter::CountNotifyFunction);
ASSERT_TRUE(counter1.timer_valid);
Counter counter2(Counter::CountNotifyFunction);
ASSERT_TRUE(counter2.timer_valid);
Counter counter3(Counter::CountNotifyFunction);
ASSERT_TRUE(counter3.timer_valid);
ASSERT_EQ(0, counter1.value);
ASSERT_EQ(0, counter2.value);
ASSERT_EQ(0, counter3.value);
ASSERT_EQ(0, counter1.Value());
ASSERT_EQ(0, counter2.Value());
ASSERT_EQ(0, counter3.Value());
counter2.SetTime(0, 1, 0, 0);
usleep(500000);
EXPECT_EQ(0, counter1.value);
EXPECT_EQ(1, counter2.value);
EXPECT_EQ(0, counter3.value);
EXPECT_EQ(0, counter1.Value());
EXPECT_EQ(1, counter2.Value());
EXPECT_EQ(0, counter3.Value());
}
// Test to verify that disarming a repeatable timer disables the callbacks.
TEST(time, timer_disarm_terminates) {
Counter counter(Counter::CountNotifyFunction);
ASSERT_EQ(0, counter.Value());
counter.SetTime(0, 1, 0, 1);
ASSERT_TRUE(counter.ValueUpdated());
ASSERT_TRUE(counter.ValueUpdated());
ASSERT_TRUE(counter.ValueUpdated());
counter.SetTime(0, 0, 0, 0);
// Add a sleep as the kernel may have pending events when the timer is disarmed.
usleep(500000);
int value = counter.Value();
usleep(500000);
// Verify the counter has not been incremented.
ASSERT_EQ(value, counter.Value());
}
// Test to verify that deleting a repeatable timer disables the callbacks.
TEST(time, timer_delete_terminates) {
Counter counter(Counter::CountNotifyFunction);
ASSERT_EQ(0, counter.Value());
counter.SetTime(0, 1, 0, 1);
ASSERT_TRUE(counter.ValueUpdated());
ASSERT_TRUE(counter.ValueUpdated());
ASSERT_TRUE(counter.ValueUpdated());
counter.DeleteTimer();
// Add a sleep as other threads may be calling the callback function when the timer is deleted.
usleep(500000);
int value = counter.Value();
usleep(500000);
// Verify the counter has not been incremented.
ASSERT_EQ(value, counter.Value());
}
struct TimerDeleteData {
@ -499,45 +543,3 @@ TEST(time, clock_nanosleep) {
timespec out;
ASSERT_EQ(EINVAL, clock_nanosleep(-1, 0, &in, &out));
}
// Test to verify that disarming a repeatable timer disables the
// callbacks.
TEST(time, timer_disarm_terminates) {
Counter counter(Counter::CountNotifyFunction);
ASSERT_TRUE(counter.timer_valid);
ASSERT_EQ(0, counter.value);
counter.SetTime(0, 1, 0, 1);
ASSERT_TRUE(counter.ValueUpdated());
ASSERT_TRUE(counter.ValueUpdated());
ASSERT_TRUE(counter.ValueUpdated());
counter.SetTime(0, 0, 1, 0);
volatile int value = counter.value;
usleep(500000);
// Verify the counter has not been incremented.
ASSERT_EQ(value, counter.value);
}
// Test to verify that deleting a repeatable timer disables the
// callbacks.
TEST(time, timer_delete_terminates) {
Counter counter(Counter::CountNotifyFunction);
ASSERT_TRUE(counter.timer_valid);
ASSERT_EQ(0, counter.value);
counter.SetTime(0, 1, 0, 1);
ASSERT_TRUE(counter.ValueUpdated());
ASSERT_TRUE(counter.ValueUpdated());
ASSERT_TRUE(counter.ValueUpdated());
counter.DeleteTimer();
volatile int value = counter.value;
usleep(500000);
// Verify the counter has not been incremented.
ASSERT_EQ(value, counter.value);
}