Merge "Fix possible race conditions during channel unregistration." into gingerbread (f9ad410f) · Commits · e / os / android_frameworks_native

include/ui/InputDispatcher.h

+2 −0

Original line number	Original line	Diff line number	Diff line
	@@ -554,6 +554,8 @@ private:
	// All registered connections mapped by receive pipe file descriptor.		// All registered connections mapped by receive pipe file descriptor.
	KeyedVector<int, sp<Connection> > mConnectionsByReceiveFd;		KeyedVector<int, sp<Connection> > mConnectionsByReceiveFd;

			ssize_t getConnectionIndex(const sp<InputChannel>& inputChannel);

	// Active connections are connections that have a non-empty outbound queue.		// Active connections are connections that have a non-empty outbound queue.
	// We don't use a ref-counted pointer here because we explicitly abort connections		// We don't use a ref-counted pointer here because we explicitly abort connections
	// during unregistration which causes the connection's outbound queue to be cleared		// during unregistration which causes the connection's outbound queue to be cleared

libs/ui/InputDispatcher.cpp

+20 −12

Original line number	Original line	Diff line number	Diff line
	@@ -433,8 +433,7 @@ void InputDispatcher::dispatchEventToCurrentInputTargetsLocked(nsecs_t currentTi
	for (size_t i = 0; i < mCurrentInputTargets.size(); i++) {		for (size_t i = 0; i < mCurrentInputTargets.size(); i++) {
	const InputTarget& inputTarget = mCurrentInputTargets.itemAt(i);		const InputTarget& inputTarget = mCurrentInputTargets.itemAt(i);

	ssize_t connectionIndex = mConnectionsByReceiveFd.indexOfKey(		ssize_t connectionIndex = getConnectionIndex(inputTarget.inputChannel);
	inputTarget.inputChannel->getReceivePipeFd());
	if (connectionIndex >= 0) {		if (connectionIndex >= 0) {
	sp<Connection> connection = mConnectionsByReceiveFd.valueAt(connectionIndex);		sp<Connection> connection = mConnectionsByReceiveFd.valueAt(connectionIndex);
	prepareDispatchCycleLocked(currentTime, connection, eventEntry, & inputTarget,		prepareDispatchCycleLocked(currentTime, connection, eventEntry, & inputTarget,
	@@ -1367,12 +1366,10 @@ status_t InputDispatcher::registerInputChannel(const sp<InputChannel>& inputChan
	LOGD("channel '%s' ~ registerInputChannel", inputChannel->getName().string());		LOGD("channel '%s' ~ registerInputChannel", inputChannel->getName().string());
	#endif		#endif

	int receiveFd;
	{ // acquire lock		{ // acquire lock
	AutoMutex _l(mLock);		AutoMutex _l(mLock);

	receiveFd = inputChannel->getReceivePipeFd();		if (getConnectionIndex(inputChannel) >= 0) {
	if (mConnectionsByReceiveFd.indexOfKey(receiveFd) >= 0) {
	LOGW("Attempted to register already registered input channel '%s'",		LOGW("Attempted to register already registered input channel '%s'",
	inputChannel->getName().string());		inputChannel->getName().string());
	return BAD_VALUE;		return BAD_VALUE;
	@@ -1386,12 +1383,13 @@ status_t InputDispatcher::registerInputChannel(const sp<InputChannel>& inputChan
	return status;		return status;
	}		}

			int32_t receiveFd = inputChannel->getReceivePipeFd();
	mConnectionsByReceiveFd.add(receiveFd, connection);		mConnectionsByReceiveFd.add(receiveFd, connection);

			mPollLoop->setCallback(receiveFd, POLLIN, handleReceiveCallback, this);

	runCommandsLockedInterruptible();		runCommandsLockedInterruptible();
	} // release lock		} // release lock

	mPollLoop->setCallback(receiveFd, POLLIN, handleReceiveCallback, this);
	return OK;		return OK;
	}		}

	@@ -1400,12 +1398,10 @@ status_t InputDispatcher::unregisterInputChannel(const sp<InputChannel>& inputCh
	LOGD("channel '%s' ~ unregisterInputChannel", inputChannel->getName().string());		LOGD("channel '%s' ~ unregisterInputChannel", inputChannel->getName().string());
	#endif		#endif

	int32_t receiveFd;
	{ // acquire lock		{ // acquire lock
	AutoMutex _l(mLock);		AutoMutex _l(mLock);

	receiveFd = inputChannel->getReceivePipeFd();		ssize_t connectionIndex = getConnectionIndex(inputChannel);
	ssize_t connectionIndex = mConnectionsByReceiveFd.indexOfKey(receiveFd);
	if (connectionIndex < 0) {		if (connectionIndex < 0) {
	LOGW("Attempted to unregister already unregistered input channel '%s'",		LOGW("Attempted to unregister already unregistered input channel '%s'",
	inputChannel->getName().string());		inputChannel->getName().string());
	@@ -1417,20 +1413,32 @@ status_t InputDispatcher::unregisterInputChannel(const sp<InputChannel>& inputCh

	connection->status = Connection::STATUS_ZOMBIE;		connection->status = Connection::STATUS_ZOMBIE;

			mPollLoop->removeCallback(inputChannel->getReceivePipeFd());

	nsecs_t currentTime = now();		nsecs_t currentTime = now();
	abortDispatchCycleLocked(currentTime, connection, true /broken/);		abortDispatchCycleLocked(currentTime, connection, true /broken/);

	runCommandsLockedInterruptible();		runCommandsLockedInterruptible();
	} // release lock		} // release lock

	mPollLoop->removeCallback(receiveFd);

	// Wake the poll loop because removing the connection may have changed the current		// Wake the poll loop because removing the connection may have changed the current
	// synchronization state.		// synchronization state.
	mPollLoop->wake();		mPollLoop->wake();
	return OK;		return OK;
	}		}

			ssize_t InputDispatcher::getConnectionIndex(const sp<InputChannel>& inputChannel) {
			ssize_t connectionIndex = mConnectionsByReceiveFd.indexOfKey(inputChannel->getReceivePipeFd());
			if (connectionIndex >= 0) {
			sp<Connection> connection = mConnectionsByReceiveFd.valueAt(connectionIndex);
			if (connection->inputChannel.get() == inputChannel.get()) {
			return connectionIndex;
			}
			}

			return -1;
			}

	void InputDispatcher::activateConnectionLocked(Connection* connection) {		void InputDispatcher::activateConnectionLocked(Connection* connection) {
	for (size_t i = 0; i < mActiveConnections.size(); i++) {		for (size_t i = 0; i < mActiveConnections.size(); i++) {
	if (mActiveConnections.itemAt(i) == connection) {		if (mActiveConnections.itemAt(i) == connection) {