[libcamera-devel] [PATCH v3 11/11] android: Remove CameraWorker

Laurent Pinchart laurent.pinchart at ideasonboard.com
Wed Dec 1 03:15:58 CET 2021


Hi Jacopo,

Thank you for the patch.

On Wed, Dec 01, 2021 at 12:36:34AM +0100, Jacopo Mondi wrote:
> The CameraWorker class purpose was to handle acquire fences for incoming
> capture requests directed to libcamera.
> 
> Now that fences are handled by the core library, it is not required to
> handle them in the HAL and the CameraWorker and CaptureRequest classes
> can be dropped.
> 
> Update the core in CameraDevice class accordingly to queue Requests
> directly to the libcamera::Camera and set the release_fence to the
> value of the FrameBuffer::fence() for streams of type ::Direct.
> 
> While at it make CameraRequest::StreamBuffer::fence a UniqueFD to ease
> the management of the fences file descriptor values.
> 
> Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
> ---
>  src/android/camera_device.cpp  |  46 ++++++------
>  src/android/camera_device.h    |   3 -
>  src/android/camera_request.cpp |   8 +-
>  src/android/camera_request.h   |   6 +-
>  src/android/camera_stream.cpp  |  10 +--
>  src/android/camera_worker.cpp  | 129 ---------------------------------
>  src/android/camera_worker.h    |  70 ------------------
>  src/android/meson.build        |   1 -
>  8 files changed, 36 insertions(+), 237 deletions(-)
>  delete mode 100644 src/android/camera_worker.cpp
>  delete mode 100644 src/android/camera_worker.h
> 
> diff --git a/src/android/camera_device.cpp b/src/android/camera_device.cpp
> index 1938b10509fa..b7114c615733 100644
> --- a/src/android/camera_device.cpp
> +++ b/src/android/camera_device.cpp
> @@ -15,10 +15,12 @@
>  
>  #include <libcamera/base/log.h>
>  #include <libcamera/base/thread.h>
> +#include <libcamera/base/unique_fd.h>
>  #include <libcamera/base/utils.h>
>  
>  #include <libcamera/control_ids.h>
>  #include <libcamera/controls.h>
> +#include <libcamera/fence.h>
>  #include <libcamera/formats.h>
>  #include <libcamera/property_ids.h>
>  
> @@ -406,7 +408,6 @@ void CameraDevice::flush()
>  		state_ = State::Flushing;
>  	}
>  
> -	worker_.stop();
>  	camera_->stop();
>  
>  	MutexLocker stateLock(stateMutex_);
> @@ -419,7 +420,6 @@ void CameraDevice::stop()
>  	if (state_ == State::Stopped)
>  		return;
>  
> -	worker_.stop();
>  	camera_->stop();
>  
>  	descriptors_ = {};
> @@ -912,13 +912,9 @@ int CameraDevice::processCaptureRequest(camera3_capture_request_t *camera3Reques
>  
>  		/*
>  		 * Inspect the camera stream type, create buffers opportunely
> -		 * and add them to the Request if required. Only acquire fences
> -		 * for streams of type Direct are handled by the CameraWorker,
> -		 * while fences for streams of type Internal and Mapped are
> -		 * handled at post-processing time.
> +		 * and add them to the Request if required.
>  		 */
>  		FrameBuffer *frameBuffer = nullptr;
> -		int acquireFence = -1;
>  		switch (cameraStream->type()) {
>  		case CameraStream::Type::Mapped:
>  			/*
> @@ -943,7 +939,6 @@ int CameraDevice::processCaptureRequest(camera3_capture_request_t *camera3Reques
>  						  cameraStream->configuration().pixelFormat,
>  						  cameraStream->configuration().size);
>  			frameBuffer = buffer.frameBuffer.get();
> -			acquireFence = buffer.fence;
>  			LOG(HAL, Debug) << ss.str() << " (direct)";
>  			break;
>  
> @@ -970,12 +965,12 @@ int CameraDevice::processCaptureRequest(camera3_capture_request_t *camera3Reques
>  		}
>  
>  		descriptor->request_->addBuffer(cameraStream->stream(),
> -						frameBuffer, acquireFence);
> +			frameBuffer, std::make_unique<Fence>(std::move(buffer.fence)));
>  	}
>  
>  	/*
>  	 * Translate controls from Android to libcamera and queue the request
> -	 * to the CameraWorker thread.
> +	 * to the camera.
>  	 */
>  	int ret = processControls(descriptor.get());
>  	if (ret)
> @@ -1001,26 +996,23 @@ int CameraDevice::processCaptureRequest(camera3_capture_request_t *camera3Reques
>  	}
>  
>  	if (state_ == State::Stopped) {
> -		worker_.start();
> -
>  		ret = camera_->start();
>  		if (ret) {
>  			LOG(HAL, Error) << "Failed to start camera";
> -			worker_.stop();
>  			return ret;
>  		}
>  
>  		state_ = State::Running;
>  	}
>  
> -	CaptureRequest *request = descriptor->request_.get();
> +	Request *request = descriptor->request_.get();
>  
>  	{
>  		MutexLocker descriptorsLock(descriptorsMutex_);
>  		descriptors_.push(std::move(descriptor));
>  	}
>  
> -	worker_.queueRequest(request);
> +	camera_->queueRequest(request);
>  
>  	return 0;
>  }
> @@ -1042,16 +1034,24 @@ void CameraDevice::requestComplete(Request *request)
>  		/*
>  		 * Streams of type Direct have been queued to the
>  		 * libcamera::Camera and their acquire fences have
> -		 * already been waited on by the CameraWorker.
> +		 * already been waited on by the library.
>  		 *
>  		 * Acquire fences of streams of type Internal and Mapped
>  		 * will be handled during post-processing.
> -		 *
> -		 * \todo Instrument the CameraWorker to set the acquire
> -		 * fence to -1 once it has handled it and remove this check.
>  		 */
> -		if (stream->type() == CameraStream::Type::Direct)
> -			buffer.fence = -1;
> +		if (stream->type() == CameraStream::Type::Direct) {
> +			/* If the fence has been closed, send -1 to the framework. */
> +			std::unique_ptr<Fence> fence = buffer.frameBuffer->resetFence();
> +			if (!fence || !fence->isValid())

I'm still not thrilled by the fact that we have two checks that both
report the same condition. Let's leave this aside for now, we can
address the issue by improving the API on top (a \todo somewhere would
be good though).

> +				break;

Is this correct, don't you need to process the other buffers ? It seems
that

			/*
			 * If handling of the fence has failed, send to the
			 * framework the acquire_fence fd as release_fence so
			 * it can close it.
			 */
			std::unique_ptr<Fence> fence = buffer.frameBuffer->resetFence();
			if (fence)
				buffer.fence = fence->reset();

should be enough.

> +
> +			/*
> +			 * If handling of the fence has failed, send to the
> +			 * framework the acquire_fence fd as release_fence so
> +			 * it can close it.
> +			 */
> +			buffer.fence = std::move(fence->reset());

No need for std::move().

> +		}
>  		buffer.status = Camera3RequestDescriptor::Status::Success;
>  	}
>  
> @@ -1172,7 +1172,7 @@ void CameraDevice::sendCaptureResults()
>  		std::vector<camera3_stream_buffer_t> resultBuffers;
>  		resultBuffers.reserve(descriptor->buffers_.size());
>  
> -		for (const auto &buffer : descriptor->buffers_) {
> +		for (auto &buffer : descriptor->buffers_) {
>  			camera3_buffer_status status = CAMERA3_BUFFER_STATUS_ERROR;
>  
>  			if (buffer.status == Camera3RequestDescriptor::Status::Success)
> @@ -1186,7 +1186,7 @@ void CameraDevice::sendCaptureResults()
>  			 */
>  			resultBuffers.push_back({ buffer.stream->camera3Stream(),
>  						  buffer.camera3Buffer, status,
> -						  -1, buffer.fence });
> +						  -1, buffer.fence.release() });
>  		}
>  
>  		captureResult.num_output_buffers = resultBuffers.size();
> diff --git a/src/android/camera_device.h b/src/android/camera_device.h
> index 51fe7da2cb47..494d79d2a3ea 100644
> --- a/src/android/camera_device.h
> +++ b/src/android/camera_device.h
> @@ -30,7 +30,6 @@
>  #include "camera_capabilities.h"
>  #include "camera_metadata.h"
>  #include "camera_stream.h"
> -#include "camera_worker.h"
>  #include "jpeg/encoder.h"
>  
>  class Camera3RequestDescriptor;
> @@ -105,8 +104,6 @@ private:
>  	unsigned int id_;
>  	camera3_device_t camera3Device_;
>  
> -	CameraWorker worker_;
> -
>  	libcamera::Mutex stateMutex_; /* Protects access to the camera state. */
>  	State state_;
>  
> diff --git a/src/android/camera_request.cpp b/src/android/camera_request.cpp
> index 8162aa78e953..c46689a52d6d 100644
> --- a/src/android/camera_request.cpp
> +++ b/src/android/camera_request.cpp
> @@ -47,8 +47,7 @@ Camera3RequestDescriptor::Camera3RequestDescriptor(
>  	 * 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_ = camera->createRequest(reinterpret_cast<uint64_t>(this));
>  }
>  
>  Camera3RequestDescriptor::~Camera3RequestDescriptor() = default;
> @@ -57,8 +56,11 @@ Camera3RequestDescriptor::StreamBuffer::StreamBuffer(
>  	CameraStream *cameraStream, const camera3_stream_buffer_t &buffer,
>  	Camera3RequestDescriptor *requestDescriptor)
>  	: stream(cameraStream), camera3Buffer(buffer.buffer),
> -	  fence(buffer.acquire_fence), request(requestDescriptor)
> +	  request(requestDescriptor)
>  {
> +	/* Do not reset buffer.acquire_fence by moving it to fence. */
> +	int fenceFd = buffer.acquire_fence;
> +	fence = UniqueFD(std::move(fenceFd));

Would it be a problem to move buffer.acquire_fence ?

>  }
>  
>  Camera3RequestDescriptor::StreamBuffer::~StreamBuffer() = default;
> diff --git a/src/android/camera_request.h b/src/android/camera_request.h
> index f3cb6d643961..4372ad775c19 100644
> --- a/src/android/camera_request.h
> +++ b/src/android/camera_request.h
> @@ -13,6 +13,7 @@
>  #include <vector>
>  
>  #include <libcamera/base/class.h>
> +#include <libcamera/base/unique_fd.h>
>  
>  #include <libcamera/camera.h>
>  #include <libcamera/framebuffer.h>
> @@ -20,7 +21,6 @@
>  #include <hardware/camera3.h>
>  
>  #include "camera_metadata.h"
> -#include "camera_worker.h"
>  
>  class CameraBuffer;
>  class CameraStream;
> @@ -45,7 +45,7 @@ public:
>  		CameraStream *stream;
>  		buffer_handle_t *camera3Buffer;
>  		std::unique_ptr<libcamera::FrameBuffer> frameBuffer;
> -		int fence;
> +		libcamera::UniqueFD fence;
>  		Status status = Status::Success;
>  		libcamera::FrameBuffer *internalBuffer = nullptr;
>  		const libcamera::FrameBuffer *srcBuffer = nullptr;
> @@ -71,7 +71,7 @@ public:
>  	std::vector<StreamBuffer> buffers_;
>  
>  	CameraMetadata settings_;
> -	std::unique_ptr<CaptureRequest> request_;
> +	std::unique_ptr<libcamera::Request> request_;
>  	std::unique_ptr<CameraMetadata> resultMetadata_;
>  
>  	bool complete_ = false;
> diff --git a/src/android/camera_stream.cpp b/src/android/camera_stream.cpp
> index 9023c13c40f0..08252341e9cf 100644
> --- a/src/android/camera_stream.cpp
> +++ b/src/android/camera_stream.cpp
> @@ -169,16 +169,16 @@ int CameraStream::process(Camera3RequestDescriptor::StreamBuffer *streamBuffer)
>  	ASSERT(type_ != Type::Direct);
>  
>  	/* Handle waiting on fences on the destination buffer. */
> -	if (streamBuffer->fence != -1) {
> -		int ret = waitFence(streamBuffer->fence);
> +	if (streamBuffer->fence.isValid()) {
> +		int ret = waitFence(streamBuffer->fence.get());
>  		if (ret < 0) {
>  			LOG(HAL, Error) << "Failed waiting for fence: "
> -					<< streamBuffer->fence << ": " << strerror(-ret);
> +					<< streamBuffer->fence.get() << ": "
> +					<< strerror(-ret);
>  			return ret;
>  		}
>  
> -		::close(streamBuffer->fence);
> -		streamBuffer->fence = -1;
> +		streamBuffer->fence.reset();
>  	}
>  
>  	const StreamConfiguration &output = configuration();
> diff --git a/src/android/camera_worker.cpp b/src/android/camera_worker.cpp
> deleted file mode 100644
> index dabb305407a2..000000000000
> --- a/src/android/camera_worker.cpp
> +++ /dev/null
> @@ -1,129 +0,0 @@
> -/* SPDX-License-Identifier: LGPL-2.1-or-later */
> -/*
> - * Copyright (C) 2020, Google Inc.
> - *
> - * camera_worker.cpp - Process capture requests on behalf of the Camera HAL
> - */
> -
> -#include "camera_worker.h"
> -
> -#include <errno.h>
> -#include <string.h>
> -#include <sys/poll.h>
> -#include <unistd.h>
> -
> -#include "camera_device.h"
> -
> -using namespace libcamera;
> -
> -LOG_DECLARE_CATEGORY(HAL)
> -
> -/*
> - * \class CaptureRequest
> - * \brief Wrap a libcamera::Request associated with buffers and fences
> - *
> - * A CaptureRequest is constructed by the CameraDevice, filled with
> - * buffers and fences provided by the camera3 framework and then processed
> - * by the CameraWorker which queues it to the libcamera::Camera after handling
> - * fences.
> - */
> -CaptureRequest::CaptureRequest(Camera *camera, uint64_t cookie)
> -	: camera_(camera)
> -{
> -	request_ = camera_->createRequest(cookie);
> -}
> -
> -void CaptureRequest::addBuffer(Stream *stream, FrameBuffer *buffer, int fence)
> -{
> -	request_->addBuffer(stream, buffer);
> -	acquireFences_.push_back(fence);
> -}
> -
> -void CaptureRequest::queue()
> -{
> -	camera_->queueRequest(request_.get());
> -}
> -
> -/*
> - * \class CameraWorker
> - * \brief Process a CaptureRequest on an internal thread
> - *
> - * The CameraWorker class wraps a Worker that runs on an internal thread
> - * and schedules processing of CaptureRequest through it.
> - */
> -CameraWorker::CameraWorker()
> -{
> -	worker_.moveToThread(this);
> -}
> -
> -void CameraWorker::start()
> -{
> -	Thread::start();
> -}
> -
> -void CameraWorker::stop()
> -{
> -	exit();
> -	wait();
> -}
> -
> -void CameraWorker::run()
> -{
> -	exec();
> -	dispatchMessages(Message::Type::InvokeMessage);
> -}
> -
> -void CameraWorker::queueRequest(CaptureRequest *request)
> -{
> -	/* Async process the request on the worker which runs its own thread. */
> -	worker_.invokeMethod(&Worker::processRequest, ConnectionTypeQueued,
> -			     request);
> -}
> -
> -/*
> - * \class CameraWorker::Worker
> - * \brief Process a CaptureRequest handling acquisition fences
> - */
> -int CameraWorker::Worker::waitFence(int fence)
> -{
> -	/*
> -	 * \todo Better characterize the timeout. Currently equal to the one
> -	 * used by the Rockchip Camera HAL on ChromeOS.
> -	 */
> -	constexpr unsigned int timeoutMs = 300;
> -	struct pollfd fds = { fence, POLLIN, 0 };
> -
> -	do {
> -		int ret = poll(&fds, 1, timeoutMs);
> -		if (ret == 0)
> -			return -ETIME;
> -
> -		if (ret > 0) {
> -			if (fds.revents & (POLLERR | POLLNVAL))
> -				return -EINVAL;
> -
> -			return 0;
> -		}
> -	} while (errno == EINTR || errno == EAGAIN);
> -
> -	return -errno;
> -}
> -
> -void CameraWorker::Worker::processRequest(CaptureRequest *request)
> -{
> -	/* Wait on all fences before queuing the Request. */
> -	for (int fence : request->fences()) {
> -		if (fence == -1)
> -			continue;
> -
> -		int ret = waitFence(fence);
> -		close(fence);
> -		if (ret < 0) {
> -			LOG(HAL, Error) << "Failed waiting for fence: "
> -					<< fence << ": " << strerror(-ret);
> -			return;
> -		}
> -	}
> -
> -	request->queue();
> -}
> diff --git a/src/android/camera_worker.h b/src/android/camera_worker.h
> deleted file mode 100644
> index 26ecc2732046..000000000000
> --- a/src/android/camera_worker.h
> +++ /dev/null
> @@ -1,70 +0,0 @@
> -/* SPDX-License-Identifier: LGPL-2.1-or-later */
> -/*
> - * Copyright (C) 2020, Google Inc.
> - *
> - * camera_worker.h - Process capture requests on behalf of the Camera HAL
> - */
> -
> -#pragma once
> -
> -#include <memory>
> -#include <stdint.h>
> -
> -#include <libcamera/base/object.h>
> -#include <libcamera/base/thread.h>
> -
> -#include <libcamera/camera.h>
> -#include <libcamera/framebuffer.h>
> -#include <libcamera/request.h>
> -#include <libcamera/stream.h>
> -
> -class CameraDevice;
> -
> -class CaptureRequest
> -{
> -public:
> -	CaptureRequest(libcamera::Camera *camera, uint64_t cookie);
> -
> -	const std::vector<int> &fences() const { return acquireFences_; }
> -	libcamera::ControlList &controls() { return request_->controls(); }
> -	const libcamera::ControlList &metadata() const
> -	{
> -		return request_->metadata();
> -	}
> -	unsigned long cookie() const { return request_->cookie(); }
> -
> -	void addBuffer(libcamera::Stream *stream,
> -		       libcamera::FrameBuffer *buffer, int fence);
> -	void queue();
> -
> -private:
> -	libcamera::Camera *camera_;
> -	std::vector<int> acquireFences_;
> -	std::unique_ptr<libcamera::Request> request_;
> -};
> -
> -class CameraWorker : private libcamera::Thread
> -{
> -public:
> -	CameraWorker();
> -
> -	void start();
> -	void stop();
> -
> -	void queueRequest(CaptureRequest *request);
> -
> -protected:
> -	void run() override;
> -
> -private:
> -	class Worker : public libcamera::Object
> -	{
> -	public:
> -		void processRequest(CaptureRequest *request);
> -
> -	private:
> -		int waitFence(int fence);
> -	};
> -
> -	Worker worker_;
> -};
> diff --git a/src/android/meson.build b/src/android/meson.build
> index 332b177ca805..75b4bf207085 100644
> --- a/src/android/meson.build
> +++ b/src/android/meson.build
> @@ -47,7 +47,6 @@ android_hal_sources = files([
>      'camera_ops.cpp',
>      'camera_request.cpp',
>      'camera_stream.cpp',
> -    'camera_worker.cpp',
>      'jpeg/encoder_libjpeg.cpp',
>      'jpeg/exif.cpp',
>      'jpeg/post_processor_jpeg.cpp',

-- 
Regards,

Laurent Pinchart


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