[libcamera-devel] [PATCH v3 2/3] android: camera_device: Transform descriptors_ map to queue
Jacopo Mondi
jacopo at jmondi.org
Wed Sep 29 10:00:17 CEST 2021
Hi Umang,
On Wed, Sep 29, 2021 at 12:47:07PM +0530, Umang Jain wrote:
> The descriptors_ map holds Camera3RequestDescriptor(s) which are
> per-capture requests placed by the framework to libcamera HAL.
> CameraDevice::requestComplete() looks for the descriptor for which the
> camera request has been completed and removes it from the map.
> Since the requests are placed in form of FIFO and the framework expects
> the order of completion to be FIFO as well, this calls for a need of
> a queue rather than a std::map.
>
> This patch still keeps the same lifetime of Camera3RequestDescriptor as
> before i.e. in the requestComplete(). Previously, a descriptor was
> extracted from the map and its lifetime was bound to requestComplete().
> The lifetime is kept same by manually calling .pop_front() on the
> queue. In the subsequent commit, this is likely to change with a
> centralized location of dropping descriptors from the queue for request
> completion.
>
> Signed-off-by: Umang Jain <umang.jain at ideasonboard.com>
> Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---
> src/android/camera_device.cpp | 91 +++++++++++++++++++----------------
> src/android/camera_device.h | 3 +-
> 2 files changed, 51 insertions(+), 43 deletions(-)
>
> diff --git a/src/android/camera_device.cpp b/src/android/camera_device.cpp
> index 9287ea07..499baec8 100644
> --- a/src/android/camera_device.cpp
> +++ b/src/android/camera_device.cpp
> @@ -457,7 +457,8 @@ void CameraDevice::stop()
> worker_.stop();
> camera_->stop();
>
> - descriptors_.clear();
> + descriptors_ = {};
> +
> state_ = State::Stopped;
> }
>
> @@ -955,7 +956,9 @@ int CameraDevice::processCaptureRequest(camera3_capture_request_t *camera3Reques
> * The descriptor and the associated memory reserved here are freed
> * at request complete time.
> */
> - Camera3RequestDescriptor descriptor(camera_.get(), camera3Request);
> + auto descriptor =
> + std::make_unique<Camera3RequestDescriptor>(camera_.get(),
> + camera3Request);
Fits on the previous line ?
>
> /*
> * \todo The Android request model is incremental, settings passed in
> @@ -966,12 +969,12 @@ 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";
Thanks!
>
> - 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];
> + for (const auto &[i, camera3Buffer] : utils::enumerate(descriptor->buffers_)) {
Nicer!
> camera3_stream *camera3Stream = camera3Buffer.stream;
> CameraStream *cameraStream = static_cast<CameraStream *>(camera3Stream->priv);
>
> @@ -1007,12 +1010,12 @@ int CameraDevice::processCaptureRequest(camera3_capture_request_t *camera3Reques
> * associate it with the Camera3RequestDescriptor for
> * lifetime management only.
> */
> - descriptor.frameBuffers_.push_back(
> + descriptor->frameBuffers_.push_back(
> createFrameBuffer(*camera3Buffer.buffer,
> cameraStream->configuration().pixelFormat,
> cameraStream->configuration().size));
>
> - buffer = descriptor.frameBuffers_.back().get();
> + buffer = descriptor->frameBuffers_.back().get();
> acquireFence = camera3Buffer.acquire_fence;
> LOG(HAL, Debug) << ss.str() << " (direct)";
> break;
> @@ -1035,7 +1038,7 @@ int CameraDevice::processCaptureRequest(camera3_capture_request_t *camera3Reques
> return -ENOMEM;
> }
>
> - descriptor.request_->addBuffer(cameraStream->stream(), buffer,
> + descriptor->request_->addBuffer(cameraStream->stream(), buffer,
> acquireFence);
> }
>
> @@ -1043,7 +1046,7 @@ 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.get());
> if (ret)
> return ret;
>
> @@ -1071,11 +1074,11 @@ int CameraDevice::processCaptureRequest(camera3_capture_request_t *camera3Reques
> state_ = State::Running;
> }
>
> - CaptureRequest *request = descriptor.request_.get();
> + CaptureRequest *request = descriptor->request_.get();
>
> {
> MutexLocker descriptorsLock(descriptorsMutex_);
> - descriptors_[descriptor.request_->cookie()] = std::move(descriptor);
> + descriptors_.push(std::move(descriptor));
> }
>
> worker_.queueRequest(request);
> @@ -1085,26 +1088,26 @@ int CameraDevice::processCaptureRequest(camera3_capture_request_t *camera3Reques
>
> void CameraDevice::requestComplete(Request *request)
> {
> - decltype(descriptors_)::node_type node;
> + Camera3RequestDescriptor *descriptor;
> {
> MutexLocker descriptorsLock(descriptorsMutex_);
> - auto it = descriptors_.find(request->cookie());
> - if (it == descriptors_.end()) {
> - /*
> - * \todo Clarify if the Camera has to be closed on
> - * ERROR_DEVICE and possibly demote the Fatal to simple
> - * Error.
> - */
> - notifyError(0, nullptr, CAMERA3_MSG_ERROR_DEVICE);
> - LOG(HAL, Fatal)
> - << "Unknown request: " << request->cookie();
> + ASSERT(!descriptors_.empty());
> + descriptor = descriptors_.front().get();
> + }
I was about to comment that this is dangerously racy, as stop() clears
the descriptors_ queue. Laurent confirmed me offline that not only
libcamera::Camera::stop() completes all the in-flight requests, but
that the slots connected to the Camera::requestCompleted signal are
invoked in blocking mode. Hence, it is safe to keep the descriptor in
the queue for the duration of the slot
>
> - return;
> - }
> + if (descriptor->request_->cookie() != request->cookie()) {
> + /*
> + * \todo Clarify if the Camera has to be closed on
> + * ERROR_DEVICE and possibly demote the Fatal to simple
> + * Error.
> + */
> + notifyError(0, nullptr, CAMERA3_MSG_ERROR_DEVICE);
> + LOG(HAL, Fatal)
> + << "Out-of-order completion for request "
Fits on the previous line as well ?
> + << utils::hex(request->cookie());
>
> - node = descriptors_.extract(it);
> + return;
In production builds Fatal won't tear down the library. I think after
the framework receives an CAMERA3_MSG_ERROR_DEVICE it will probably
just close the camera, but in any case, shouldn't you pop() the queue
here ?
> }
> - Camera3RequestDescriptor &descriptor = node.mapped();
>
> /*
> * Prepare the capture result for the Android camera stack.
> @@ -1113,9 +1116,9 @@ void CameraDevice::requestComplete(Request *request)
> * post-processing/compression fails.
> */
> 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_) {
> CameraStream *cameraStream =
> static_cast<CameraStream *>(buffer.stream->priv);
>
> @@ -1135,7 +1138,7 @@ void CameraDevice::requestComplete(Request *request)
> buffer.release_fence = -1;
> buffer.status = CAMERA3_BUFFER_STATUS_OK;
> }
> - captureResult.output_buffers = descriptor.buffers_.data();
> + captureResult.output_buffers = descriptor->buffers_.data();
> captureResult.partial_result = 1;
>
> /*
> @@ -1147,11 +1150,11 @@ void CameraDevice::requestComplete(Request *request)
> << " not successfully completed: "
> << request->status();
>
> - notifyError(descriptor.frameNumber_, nullptr,
> + notifyError(descriptor->frameNumber_, nullptr,
> CAMERA3_MSG_ERROR_REQUEST);
>
> captureResult.partial_result = 0;
> - for (camera3_stream_buffer_t &buffer : descriptor.buffers_) {
> + for (camera3_stream_buffer_t &buffer : descriptor->buffers_) {
> /*
> * Signal to the framework it has to handle fences that
> * have not been waited on by setting the release fence
> @@ -1164,6 +1167,7 @@ void CameraDevice::requestComplete(Request *request)
>
> callbacks_->process_capture_result(callbacks_, &captureResult);
>
> + descriptors_.pop();
This should be locked
> return;
> }
>
> @@ -1175,10 +1179,10 @@ void CameraDevice::requestComplete(Request *request)
> */
> uint64_t sensorTimestamp = static_cast<uint64_t>(request->metadata()
> .get(controls::SensorTimestamp));
> - notifyShutter(descriptor.frameNumber_, sensorTimestamp);
> + notifyShutter(descriptor->frameNumber_, sensorTimestamp);
>
> LOG(HAL, Debug) << "Request " << request->cookie() << " completed with "
> - << descriptor.buffers_.size() << " streams";
> + << descriptor->buffers_.size() << " streams";
>
> /*
> * Generate the metadata associated with the captured buffers.
> @@ -1186,16 +1190,16 @@ void CameraDevice::requestComplete(Request *request)
> * Notify if the metadata generation has failed, but continue processing
> * buffers and return an empty metadata pack.
> */
> - std::unique_ptr<CameraMetadata> resultMetadata = getResultMetadata(descriptor);
> + std::unique_ptr<CameraMetadata> resultMetadata = getResultMetadata(*descriptor);
> if (!resultMetadata) {
> - notifyError(descriptor.frameNumber_, nullptr, CAMERA3_MSG_ERROR_RESULT);
> + notifyError(descriptor->frameNumber_, nullptr, CAMERA3_MSG_ERROR_RESULT);
>
> /* The camera framework expects an empty metadata pack on error. */
> resultMetadata = std::make_unique<CameraMetadata>(0, 0);
> }
>
> /* Handle post-processing. */
> - for (camera3_stream_buffer_t &buffer : descriptor.buffers_) {
> + for (camera3_stream_buffer_t &buffer : descriptor->buffers_) {
> CameraStream *cameraStream =
> static_cast<CameraStream *>(buffer.stream->priv);
>
> @@ -1206,13 +1210,13 @@ void CameraDevice::requestComplete(Request *request)
> if (!src) {
> LOG(HAL, Error) << "Failed to find a source stream buffer";
> buffer.status = CAMERA3_BUFFER_STATUS_ERROR;
> - notifyError(descriptor.frameNumber_, buffer.stream,
> + notifyError(descriptor->frameNumber_, buffer.stream,
> CAMERA3_MSG_ERROR_BUFFER);
> continue;
> }
>
> int ret = cameraStream->process(*src, buffer,
> - descriptor.settings_,
> + descriptor->settings_,
> resultMetadata.get());
> /*
> * Return the FrameBuffer to the CameraStream now that we're
> @@ -1223,13 +1227,16 @@ void CameraDevice::requestComplete(Request *request)
>
> if (ret) {
> buffer.status = CAMERA3_BUFFER_STATUS_ERROR;
> - notifyError(descriptor.frameNumber_, buffer.stream,
> + notifyError(descriptor->frameNumber_, buffer.stream,
> CAMERA3_MSG_ERROR_BUFFER);
> }
> }
>
> captureResult.result = resultMetadata->get();
> callbacks_->process_capture_result(callbacks_, &captureResult);
> +
> + MutexLocker descriptorsLock(descriptorsMutex_);
> + descriptors_.pop();
> }
>
> std::string CameraDevice::logPrefix() const
> diff --git a/src/android/camera_device.h b/src/android/camera_device.h
> index 43eb5895..9ec510d5 100644
> --- a/src/android/camera_device.h
> +++ b/src/android/camera_device.h
> @@ -10,6 +10,7 @@
> #include <map>
> #include <memory>
> #include <mutex>
> +#include <queue>
> #include <vector>
>
> #include <hardware/camera3.h>
> @@ -125,7 +126,7 @@ private:
> std::vector<CameraStream> streams_;
>
> libcamera::Mutex descriptorsMutex_; /* Protects descriptors_. */
> - std::map<uint64_t, Camera3RequestDescriptor> descriptors_;
> + std::queue<std::unique_ptr<Camera3RequestDescriptor>> descriptors_;
>
> std::string maker_;
> std::string model_;
> --
> 2.31.0
>
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