Merge "DO NOT MERGE: osi: Offload mutex pointer to local scope" into oc-dev (7478e201) · Commits · e / os / android_packages_modules_Bluetooth

system/osi/src/alarm.cc

+11 −5

Original line number	Diff line number	Diff line
		@@ -73,7 +73,7 @@ struct alarm_t {
		// potentially long-running callback is executing. \|alarm_cancel\| uses this
		// mutex to provide a guarantee to its caller that the callback will not be
		// in progress when it returns.
		std::recursive_mutex* callback_mutex;
		std::shared_ptr<std::recursive_mutex> callback_mutex;
		period_ms_t creation_time;
		period_ms_t period;
		period_ms_t deadline;
		@@ -155,7 +155,8 @@ static alarm_t* alarm_new_internal(const char* name, bool is_periodic) {

		alarm_t* ret = static_cast<alarm_t*>(osi_calloc(sizeof(alarm_t)));

		ret->callback_mutex = new std::recursive_mutex;
		std::shared_ptr<std::recursive_mutex> ptr(new std::recursive_mutex());
		ret->callback_mutex = ptr;
		ret->is_periodic = is_periodic;
		ret->stats.name = osi_strdup(name);
		// NOTE: The stats were reset by osi_calloc() above
		@@ -167,7 +168,7 @@ void alarm_free(alarm_t* alarm) {
		if (!alarm) return;

		alarm_cancel(alarm);
		delete alarm->callback_mutex;

		osi_free((void*)alarm->stats.name);
		osi_free(alarm);
		}
		@@ -218,13 +219,15 @@ void alarm_cancel(alarm_t* alarm) {
		CHECK(alarms != NULL);
		if (!alarm) return;

		std::shared_ptr<std::recursive_mutex> local_mutex_ref;
		{
		std::lock_guard<std::mutex> lock(alarms_mutex);
		local_mutex_ref = alarm->callback_mutex;
		alarm_cancel_internal(alarm);
		}

		// If the callback for \|alarm\| is in progress, wait here until it completes.
		std::lock_guard<std::recursive_mutex> lock(*alarm->callback_mutex);
		std::lock_guard<std::recursive_mutex> lock(*local_mutex_ref);
		}

		// Internal implementation of canceling an alarm.
		@@ -561,7 +564,10 @@ static void alarm_queue_ready(fixed_queue_t* queue, UNUSED_ATTR void* context) {
		alarm->queue = NULL;
		}

		std::lock_guard<std::recursive_mutex> cb_lock(*alarm->callback_mutex);
		// Increment the reference count of the mutex so it doesn't get freed
		// before the callback gets finished executing.
		std::shared_ptr<std::recursive_mutex> local_mutex_ref = alarm->callback_mutex;
		std::lock_guard<std::recursive_mutex> cb_lock(*local_mutex_ref);
		lock.unlock();

		// Update the statistics

system/osi/test/alarm_test.cc

+14 −0

Original line number	Diff line number	Diff line
		@@ -451,3 +451,17 @@ TEST_F(AlarmTest, test_callback_free_race) {
		}
		alarm_cleanup();
		}

		static void remove_cb(void* data) {
		alarm_free((alarm_t*)data);
		semaphore_post(semaphore);
		}

		TEST_F(AlarmTest, test_delete_during_callback) {
		for (int i = 0; i < 1000; ++i) {
		alarm_t* alarm = alarm_new("alarm_test.test_delete_during_callback");
		alarm_set(alarm, 0, remove_cb, alarm);
		semaphore_wait(semaphore);
		}
		alarm_cleanup();
		}