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

include/ui/InputDispatcher.h

+2 −0

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

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

		// 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
		// during unregistration which causes the connection's outbound queue to be cleared

libs/ui/InputDispatcher.cpp

+20 −12

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

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

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

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

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

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

		runCommandsLockedInterruptible();
		} // release lock

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

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

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

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

		connection->status = Connection::STATUS_ZOMBIE;

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

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

		runCommandsLockedInterruptible();
		} // release lock

		mPollLoop->removeCallback(receiveFd);

		// Wake the poll loop because removing the connection may have changed the current
		// synchronization state.
		mPollLoop->wake();
		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) {
		for (size_t i = 0; i < mActiveConnections.size(); i++) {
		if (mActiveConnections.itemAt(i) == connection) {