media.c2 aidl: Use pipe() based fd for waitable object (f6fe5f71) · Commits · e / os / android_frameworks_av

media/codec2/hal/client/GraphicBufferAllocator.cpp

+5 −7

Original line number	Diff line number	Diff line
		@@ -62,14 +62,12 @@ public:
		return ::ndk::ScopedAStatus::ok();
		}

		::ndk::ScopedAStatus GraphicBufferAllocator::getWaitableFds(
		IGraphicBufferAllocator::WaitableFds* _aidl_return) {
		int allocFd;
		int statusFd;
		c2_status_t ret = mGraphicsTracker->getWaitableFds(&allocFd, &statusFd);
		::ndk::ScopedAStatus GraphicBufferAllocator::getWaitableFd(
		::ndk::ScopedFileDescriptor* _aidl_return) {
		int pipeFd;
		c2_status_t ret = mGraphicsTracker->getWaitableFd(&pipeFd);
		if (ret == C2_OK) {
		_aidl_return->allocEvent.set(allocFd);
		_aidl_return->statusEvent.set(statusFd);
		_aidl_return->set(pipeFd);
		return ::ndk::ScopedAStatus::ok();
		}
		return ::ndk::ScopedAStatus::fromServiceSpecificError(ret);

media/codec2/hal/client/GraphicsTracker.cpp

+83 −79

Original line number	Diff line number	Diff line
		@@ -13,7 +13,8 @@
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/
		#include <sys/eventfd.h>
		#include <fcntl.h>
		#include <unistd.h>

		#include <media/stagefright/foundation/ADebug.h>
		#include <private/android/AHardwareBufferHelpers.h>
		@@ -25,6 +26,9 @@ namespace aidl::android::hardware::media::c2::implementation {

		namespace {

		static constexpr int kMaxDequeueMin = 1;
		static constexpr int kMaxDequeueMax = ::android::BufferQueueDefs::NUM_BUFFER_SLOTS - 2;

		c2_status_t retrieveAHardwareBufferId(const C2ConstGraphicBlock &blk, uint64_t *bid) {
		// TODO
		(void)blk;
		@@ -139,21 +143,26 @@ GraphicsTracker::GraphicsTracker(int maxDequeueCount)
		mDequeueable{maxDequeueCount},
		mTotalDequeued{0}, mTotalCancelled{0}, mTotalDropped{0}, mTotalReleased{0},
		mInConfig{false}, mStopped{false} {
		if (maxDequeueCount <= 0) {
		mMaxDequeue = kDefaultMaxDequeue;
		mMaxDequeueRequested = kDefaultMaxDequeue;
		mMaxDequeueCommitted = kDefaultMaxDequeue;
		mDequeueable = kDefaultMaxDequeue;
		}
		int allocEventFd = ::eventfd(mDequeueable, EFD_CLOEXEC \| EFD_NONBLOCK \| EFD_SEMAPHORE);
		int statusEventFd = ::eventfd(0, EFD_CLOEXEC \| EFD_NONBLOCK);

		mAllocEventFd.reset(allocEventFd);
		mStopEventFd.reset(statusEventFd);
		if (maxDequeueCount < kMaxDequeueMin) {
		mMaxDequeue = kMaxDequeueMin;
		mMaxDequeueRequested = kMaxDequeueMin;
		mMaxDequeueCommitted = kMaxDequeueMin;
		mDequeueable = kMaxDequeueMin;
		} else if(maxDequeueCount > kMaxDequeueMax) {
		mMaxDequeue = kMaxDequeueMax;
		mMaxDequeueRequested = kMaxDequeueMax;
		mMaxDequeueCommitted = kMaxDequeueMax;
		mDequeueable = kMaxDequeueMax;
		}
		int pipefd[2] = { -1, -1};
		int ret = ::pipe2(pipefd, O_CLOEXEC \| O_NONBLOCK);

		mReadPipeFd.reset(pipefd[0]);
		mWritePipeFd.reset(pipefd[1]);

		mEventQueueThread = std::thread([this](){processEvent();});

		CHECK(allocEventFd >= 0 && statusEventFd >= 0);
		CHECK(ret >= 0);
		CHECK(mEventQueueThread.joinable());
		}

		@@ -161,7 +170,6 @@ GraphicsTracker::~GraphicsTracker() {
		stop();
		if (mEventQueueThread.joinable()) {
		std::unique_lock<std::mutex> l(mEventLock);
		mStopEventThread = true;
		l.unlock();
		mEventCv.notify_one();
		mEventQueueThread.join();
		@@ -231,6 +239,11 @@ c2_status_t GraphicsTracker::configureGraphics(
		c2_status_t GraphicsTracker::configureMaxDequeueCount(int maxDequeueCount) {
		std::shared_ptr<BufferCache> cache;

		if (maxDequeueCount < kMaxDequeueMin \|\| maxDequeueCount > kMaxDequeueMax) {
		ALOGE("max dequeue count %d is not valid", maxDequeueCount);
		return C2_BAD_VALUE;
		}

		// max dequeue count which can be committed to IGBP.
		// (Sometimes maxDequeueCount cannot be committed if the number of
		// dequeued buffer count is bigger.)
		@@ -347,89 +360,76 @@ void GraphicsTracker::updateDequeueConf() {

		void GraphicsTracker::stop() {
		bool expected = false;
		std::unique_lock<std::mutex> l(mEventLock);
		bool updated = mStopped.compare_exchange_strong(expected, true);
		if (updated) {
		uint64_t val = 1ULL;
		int ret = ::write(mStopEventFd.get(), &val, 8);
		if (ret < 0) {
		// EINTR maybe
		std::unique_lock<std::mutex> l(mEventLock);
		mStopRequest = true;
		l.unlock();
		mEventCv.notify_one();
		ALOGW("stop() status update pending");
		}
		int writeFd = mWritePipeFd.release();
		::close(writeFd);
		}
		}

		void GraphicsTracker::writeIncDequeueable(int inc) {
		uint64_t val = inc;
		int ret = ::write(mAllocEventFd.get(), &val, 8);
		if (ret < 0) {
		// EINTR due to signal handling maybe, this should be rare
		CHECK(inc > 0 && inc < kMaxDequeueMax);
		thread_local char buf[kMaxDequeueMax];
		int diff = 0;
		{
		std::unique_lock<std::mutex> l(mEventLock);
		mIncDequeueable += inc;
		if (mStopped) {
		return;
		}
		CHECK(mWritePipeFd.get() >= 0);
		int ret = ::write(mWritePipeFd.get(), buf, inc);
		if (ret == inc) {
		return;
		}
		diff = ret < 0 ? inc : inc - ret;

		// Partial write or EINTR. This will not happen in a real scenario.
		mIncDequeueable += diff;
		if (mIncDequeueable > 0) {
		l.unlock();
		mEventCv.notify_one();
		ALOGW("updating dequeueable to eventfd pending");
		ALOGW("updating dequeueable to pipefd pending");
		}
		}
		}

		void GraphicsTracker::processEvent() {
		// This is for write() failure of eventfds.
		// write() failure other than EINTR should not happen.
		int64_t acc = 0;
		bool stopRequest = false;
		bool stopCommitted = false;

		// This is for partial/failed writes to the writing end.
		// This may not happen in the real scenario.
		thread_local char buf[kMaxDequeueMax];
		while (true) {
		{
		std::unique_lock<std::mutex> l(mEventLock);
		acc += mIncDequeueable;
		mIncDequeueable = 0;
		stopRequest \|= mStopRequest;
		mStopRequest = false;
		if (acc == 0 && stopRequest == stopCommitted) {
		if (mStopEventThread) {
		if (mStopped) {
		break;
		}
		mEventCv.wait(l);
		continue;
		}
		}

		if (acc > 0) {
		int ret = ::write(mAllocEventFd.get(), &acc, 8);
		if (ret > 0) {
		acc = 0;
		}
		}
		if (stopRequest && !stopCommitted) {
		uint64_t val = 1ULL;
		int ret = ::write(mStopEventFd.get(), &val, 8);
		if (ret > 0) {
		stopCommitted = true;
		if (mIncDequeueable > 0) {
		int inc = mIncDequeueable > kMaxDequeueMax ? kMaxDequeueMax : mIncDequeueable;
		int ret = ::write(mWritePipeFd.get(), buf, inc);
		int written = ret <= 0 ? 0 : ret;
		mIncDequeueable -= written;
		if (mIncDequeueable > 0) {
		l.unlock();
		if (ret < 0) {
		ALOGE("write to writing end failed %d", errno);
		} else {
		ALOGW("partial write %d(%d)", inc, written);
		}
		continue;
		}
		if (mStopEventThread) {
		break;
		}
		mEventCv.wait(l);
		}
		}

		c2_status_t GraphicsTracker::getWaitableFds(int allocFd, int statusFd) {
		*allocFd = ::dup(mAllocEventFd.get());
		*statusFd = ::dup(mStopEventFd.get());

		if (allocFd < 0 \|\| statusFd < 0) {
		if (*allocFd >= 0) {
		::close(*allocFd);
		*allocFd = -1;
		}
		if (*statusFd >= 0) {
		::close(*statusFd);
		*statusFd = -1;
		c2_status_t GraphicsTracker::getWaitableFd(int *pipeFd) {
		*pipeFd = ::dup(mReadPipeFd.get());
		if (*pipeFd < 0) {
		if (mReadPipeFd.get() < 0) {
		return C2_BAD_STATE;
		}
		// dup error
		ALOGE("dup() for the reading end failed %d", errno);
		return C2_NO_MEMORY;
		}
		return C2_OK;
		@@ -438,8 +438,8 @@ c2_status_t GraphicsTracker::getWaitableFds(int allocFd, int statusFd) {
		c2_status_t GraphicsTracker::requestAllocate(std::shared_ptr<BufferCache> *cache) {
		std::lock_guard<std::mutex> l(mLock);
		if (mDequeueable > 0) {
		uint64_t val;
		int ret = ::read(mAllocEventFd.get(), &val, 8);
		char buf[1];
		int ret = ::read(mReadPipeFd.get(), buf, 1);
		if (ret < 0) {
		if (errno == EINTR) {
		// Do we really need to care for cancel due to signal handling?
		@@ -452,6 +452,10 @@ c2_status_t GraphicsTracker::requestAllocate(std::shared_ptr<BufferCache> *cache
		}
		CHECK(errno != 0);
		}
		if (ret == 0) {
		// writing end is closed
		return C2_BAD_STATE;
		}
		mDequeueable--;
		*cache = mBufferCache;
		return C2_OK;

media/codec2/hal/client/include/codec2/aidl/GraphicBufferAllocator.h

+2 −2

Original line number	Diff line number	Diff line
		@@ -38,8 +38,8 @@ public:

		::ndk::ScopedAStatus deallocate(int64_t in_id, bool* _aidl_return) override;

		::ndk::ScopedAStatus getWaitableFds(
		IGraphicBufferAllocator::WaitableFds* _aidl_return) override;
		::ndk::ScopedAStatus getWaitableFd(
		::ndk::ScopedFileDescriptor* _aidl_return) override;

		/**
		* Configuring Surface/BufferQueue for the interface.

media/codec2/hal/client/include/codec2/aidl/GraphicsTracker.h

+22 −15

Original line number	Diff line number	Diff line
		@@ -142,15 +142,15 @@ public:
		void onReleased(uint32_t generation);

		/**
		* Get waitable fds for events.(allocate is ready, end of life cycle)
		* Get waitable fd for events.(allocate is ready, end of life cycle)
		*
		* @param[out] pipeFd a file descriptor created from pipe2()
		* in order for notifying being ready to allocate
		*
		* @param[out] allocFd eventFd which signals being ready to allocate
		* @param[out] statusFd eventFd which signals end of life cycle.
		* When signaled no more allocate is possible.
		* @return C2_OK
		* C2_NO_MEMORY Max # of fd reached.(not really a memory issue)
		*/
		c2_status_t getWaitableFds(int allocFd, int statusFd);
		c2_status_t getWaitableFd(int *pipeFd);

		/**
		* Ends to use the class. after the call, allocate will fail.
		@@ -158,8 +158,6 @@ public:
		void stop();

		private:
		static constexpr int kDefaultMaxDequeue = 2;

		struct BufferCache;

		struct BufferItem {
		@@ -246,21 +244,30 @@ private:
		std::mutex mLock; // locks for data synchronization
		std::mutex mConfigLock; // locks for configuration change.

		std::atomic<bool> mStopped;

		::android::base::unique_fd mAllocEventFd; // eventfd in semaphore mode which
		// mirrors mDqueueable.
		::android::base::unique_fd mStopEventFd; // eventfd which indicates the life
		// cycle of the class being stopped.
		// NOTE: pipe2() creates two file descriptors for allocatable events
		// and irrecoverable error events notification.
		//
		// A byte will be written to the writing end whenever a buffer is ready to
		// dequeue/allocate. A byte will be read from the reading end whenever
		// an allocate/dequeue event happens.
		//
		// The writing end will be closed when the end-of-lifecycle event was met.
		//
		// The reading end will be shared to the remote processes. Remote processes
		// use ::poll() to check whether a buffer is ready to allocate/ready.
		// Also ::poll() will let remote processes know the end-of-lifecycle event
		// by returning POLLHUP event from the reading end.
		::android::base::unique_fd mReadPipeFd; // The reading end file descriptor
		::android::base::unique_fd mWritePipeFd; // The writing end file descriptor

		std::atomic<bool> mStopped;
		std::thread mEventQueueThread; // Thread to handle interrupted
		// writes to eventfd{s}.
		// writes to the writing end.
		std::mutex mEventLock;
		std::condition_variable mEventCv;

		bool mStopEventThread;
		int mIncDequeueable; // pending # of write to increase dequeueable eventfd
		bool mStopRequest; // pending write to statusfd

		private:
		explicit GraphicsTracker(int maxDequeueCount);