android: CameraDevice: Fix Camera3RequestDescriptor leakage

CameraDevice creates Camera3RequestDescriptor in
processCaptureRequest() and disallocates in requestComplete().
Camera3RequestDescriptor can never be destroyed if
requestComplete() is never called. This avoid the memory
leakage by storing them in map CameraRequestDescriptor.

Signed-off-by: Hirokazu Honda <hiroh@chromium.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/android/camera_device.cpp

@@ -381,16 +381,12 @@ CameraDevice::Camera3RequestDescriptor::Camera3RequestDescriptor(
 	settings_ = CameraMetadata(camera3Request->settings);
 
 	/*
-	 * Create the libcamera::Request unique_ptr<> to tie its lifetime
-	 * to the descriptor's one. Set the descriptor's address as the
-	 * request's cookie to retrieve it at completion time.
+	 * Create the CaptureRequest, stored as a unique_ptr<> to tie its
+	 * lifetime to the descriptor.
 	 */
-	request_ = std::make_unique<CaptureRequest>(camera,
-						    reinterpret_cast<uint64_t>(this));
+	request_ = std::make_unique<CaptureRequest>(camera);
 }
 
-CameraDevice::Camera3RequestDescriptor::~Camera3RequestDescriptor() = default;
-
 /*
  * \class CameraDevice
  *
@@ -767,6 +763,7 @@ void CameraDevice::stop()
 	worker_.stop();
 	camera_->stop();
 
+	descriptors_.clear();
 	running_ = false;
 }
 
@@ -1933,8 +1930,8 @@ int CameraDevice::processCaptureRequest(camera3_capture_request_t *camera3Reques
 	 * The descriptor and the associated memory reserved here are freed
 	 * at request complete time.
 	 */
-	Camera3RequestDescriptor *descriptor =
-		new Camera3RequestDescriptor(camera_.get(), camera3Request);
+	Camera3RequestDescriptor descriptor(camera_.get(), camera3Request);
+
 	/*
 	 * \todo The Android request model is incremental, settings passed in
 	 * previous requests are to be effective until overridden explicitly in
@@ -1944,12 +1941,12 @@ int CameraDevice::processCaptureRequest(camera3_capture_request_t *camera3Reques
 	if (camera3Request->settings)
 		lastSettings_ = camera3Request->settings;
 	else
-		descriptor->settings_ = lastSettings_;
+		descriptor.settings_ = lastSettings_;
 
-	LOG(HAL, Debug) << "Queueing request " << descriptor->request_->cookie()
-			<< " with " << descriptor->buffers_.size() << " streams";
-	for (unsigned int i = 0; i < descriptor->buffers_.size(); ++i) {
-		const camera3_stream_buffer_t &camera3Buffer = descriptor->buffers_[i];
+	LOG(HAL, Debug) << "Queueing request " << descriptor.request_->cookie()
+			<< " with " << descriptor.buffers_.size() << " streams";
+	for (unsigned int i = 0; i < descriptor.buffers_.size(); ++i) {
+		const camera3_stream_buffer_t &camera3Buffer = descriptor.buffers_[i];
 		camera3_stream *camera3Stream = camera3Buffer.stream;
 		CameraStream *cameraStream = static_cast<CameraStream *>(camera3Stream->priv);
 
@@ -1982,7 +1979,7 @@ int CameraDevice::processCaptureRequest(camera3_capture_request_t *camera3Reques
 			 * lifetime management only.
 			 */
 			buffer = createFrameBuffer(*camera3Buffer.buffer);
-			descriptor->frameBuffers_.emplace_back(buffer);
+			descriptor.frameBuffers_.emplace_back(buffer);
 			LOG(HAL, Debug) << ss.str() << " (direct)";
 			break;
 
@@ -2001,11 +1998,10 @@ int CameraDevice::processCaptureRequest(camera3_capture_request_t *camera3Reques
 
 		if (!buffer) {
 			LOG(HAL, Error) << "Failed to create buffer";
-			delete descriptor;
 			return -ENOMEM;
 		}
 
-		descriptor->request_->addBuffer(cameraStream->stream(), buffer,
+		descriptor.request_->addBuffer(cameraStream->stream(), buffer,
 						camera3Buffer.acquire_fence);
 	}
 
@@ -2013,11 +2009,16 @@ int CameraDevice::processCaptureRequest(camera3_capture_request_t *camera3Reques
 	 * Translate controls from Android to libcamera and queue the request
 	 * to the CameraWorker thread.
 	 */
-	int ret = processControls(descriptor);
+	int ret = processControls(&descriptor);
 	if (ret)
 		return ret;
 
-	worker_.queueRequest(descriptor->request_.get());
+	worker_.queueRequest(descriptor.request_.get());
+
+	{
+		std::scoped_lock<std::mutex> lock(mutex_);
+		descriptors_[descriptor.request_->cookie()] = std::move(descriptor);
+	}
 
 	return 0;
 }
@@ -2027,8 +2028,21 @@ void CameraDevice::requestComplete(Request *request)
 	const Request::BufferMap &buffers = request->buffers();
 	camera3_buffer_status status = CAMERA3_BUFFER_STATUS_OK;
 	std::unique_ptr<CameraMetadata> resultMetadata;
-	Camera3RequestDescriptor *descriptor =
-		reinterpret_cast<Camera3RequestDescriptor *>(request->cookie());
+
+	decltype(descriptors_)::node_type node;
+	{
+		std::scoped_lock<std::mutex> lock(mutex_);
+		auto it = descriptors_.find(request->cookie());
+		if (it == descriptors_.end()) {
+			LOG(HAL, Fatal)
+				<< "Unknown request: " << request->cookie();
+			status = CAMERA3_BUFFER_STATUS_ERROR;
+			return;
+		}
+
+		node = descriptors_.extract(it);
+	}
+	Camera3RequestDescriptor &descriptor = node.mapped();
 
 	if (request->status() != Request::RequestComplete) {
 		LOG(HAL, Error) << "Request not successfully completed: "
@@ -2037,7 +2051,7 @@ void CameraDevice::requestComplete(Request *request)
 	}
 
 	LOG(HAL, Debug) << "Request " << request->cookie() << " completed with "
-			<< descriptor->buffers_.size() << " streams";
+			<< descriptor.buffers_.size() << " streams";
 
 	/*
 	 * \todo The timestamp used for the metadata is currently always taken
@@ -2046,10 +2060,10 @@ void CameraDevice::requestComplete(Request *request)
 	 * pipeline handlers) timestamp in the Request itself.
 	 */
 	uint64_t timestamp = buffers.begin()->second->metadata().timestamp;
-	resultMetadata = getResultMetadata(*descriptor, timestamp);
+	resultMetadata = getResultMetadata(descriptor, timestamp);
 
 	/* Handle any JPEG compression. */
-	for (camera3_stream_buffer_t &buffer : descriptor->buffers_) {
+	for (camera3_stream_buffer_t &buffer : descriptor.buffers_) {
 		CameraStream *cameraStream =
 			static_cast<CameraStream *>(buffer.stream->priv);
 
@@ -2064,7 +2078,7 @@ void CameraDevice::requestComplete(Request *request)
 
 		int ret = cameraStream->process(*src,
 						*buffer.buffer,
-						descriptor->settings_,
+						descriptor.settings_,
 						resultMetadata.get());
 		if (ret) {
 			status = CAMERA3_BUFFER_STATUS_ERROR;
@@ -2081,17 +2095,17 @@ void CameraDevice::requestComplete(Request *request)
 
 	/* Prepare to call back the Android camera stack. */
 	camera3_capture_result_t captureResult = {};
-	captureResult.frame_number = descriptor->frameNumber_;
-	captureResult.num_output_buffers = descriptor->buffers_.size();
-	for (camera3_stream_buffer_t &buffer : descriptor->buffers_) {
+	captureResult.frame_number = descriptor.frameNumber_;
+	captureResult.num_output_buffers = descriptor.buffers_.size();
+	for (camera3_stream_buffer_t &buffer : descriptor.buffers_) {
 		buffer.acquire_fence = -1;
 		buffer.release_fence = -1;
 		buffer.status = status;
 	}
-	captureResult.output_buffers = descriptor->buffers_.data();
+	captureResult.output_buffers = descriptor.buffers_.data();
 
 	if (status == CAMERA3_BUFFER_STATUS_OK) {
-		notifyShutter(descriptor->frameNumber_, timestamp);
+		notifyShutter(descriptor.frameNumber_, timestamp);
 
 		captureResult.partial_result = 1;
 		captureResult.result = resultMetadata->get();
@@ -2104,13 +2118,11 @@ void CameraDevice::requestComplete(Request *request)
 		 * is here signalled. Make sure the error path plays well with
 		 * the camera stack state machine.
 		 */
-		notifyError(descriptor->frameNumber_,
-			    descriptor->buffers_[0].stream);
+		notifyError(descriptor.frameNumber_,
+			    descriptor.buffers_[0].stream);
 	}
 
 	callbacks_->process_capture_result(callbacks_, &captureResult);
-
-	delete descriptor;
 }
 
 std::string CameraDevice::logPrefix() const

src/android/camera_device.h

@@ -9,6 +9,7 @@
 
 #include <map>
 #include <memory>
+#include <mutex>
 #include <tuple>
 #include <vector>
 
@@ -69,11 +70,13 @@ private:
 	CameraDevice(unsigned int id, std::shared_ptr<libcamera::Camera> camera);
 
 	struct Camera3RequestDescriptor {
+		Camera3RequestDescriptor() = default;
+		~Camera3RequestDescriptor() = default;
 		Camera3RequestDescriptor(libcamera::Camera *camera,
 					 const camera3_capture_request_t *camera3Request);
-		~Camera3RequestDescriptor();
+		Camera3RequestDescriptor &operator=(Camera3RequestDescriptor &&) = default;
 
-		uint32_t frameNumber_;
+		uint32_t frameNumber_ = 0;
 		std::vector<camera3_stream_buffer_t> buffers_;
 		std::vector<std::unique_ptr<libcamera::FrameBuffer>> frameBuffers_;
 		CameraMetadata settings_;
@@ -124,6 +127,9 @@ private:
 	std::map<int, libcamera::PixelFormat> formatsMap_;
 	std::vector<CameraStream> streams_;
 
+	std::mutex mutex_; /* Protect descriptors_ */
+	std::map<uint64_t, Camera3RequestDescriptor> descriptors_;
+
 	std::string maker_;
 	std::string model_;
 

src/android/camera_worker.cpp

@@ -26,10 +26,10 @@ LOG_DECLARE_CATEGORY(HAL)
  * by the CameraWorker which queues it to the libcamera::Camera after handling
  * fences.
  */
-CaptureRequest::CaptureRequest(libcamera::Camera *camera, uint64_t cookie)
+CaptureRequest::CaptureRequest(libcamera::Camera *camera)
 	: camera_(camera)
 {
-	request_ = camera_->createRequest(cookie);
+	request_ = camera_->createRequest(reinterpret_cast<uint64_t>(this));
 }
 
 void CaptureRequest::addBuffer(Stream *stream, FrameBuffer *buffer, int fence)

src/android/camera_worker.h

@@ -22,7 +22,7 @@ class CameraDevice;
 class CaptureRequest
 {
 public:
-	CaptureRequest(libcamera::Camera *camera, uint64_t cookie);
+	CaptureRequest(libcamera::Camera *camera);
 
 	const std::vector<int> &fences() const { return acquireFences_; }
 	libcamera::ControlList &controls() { return request_->controls(); }