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

Jacopo Mondi jacopo at jmondi.org
Wed Dec 1 11:42:49 CET 2021


Hi Laurent

On Wed, Dec 01, 2021 at 04:15:58AM +0200, Laurent Pinchart wrote:
> 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.
>

Ups, I was sure the break was there already, I wen throught too many
versions! Indeed other buffers should be processed (and the buffer
status set!). It's weird this doesn't cause huge issues :/


> > +
> > +			/*
> > +			 * 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 ?

I don't know. There are no requirements about that that I found, but I
thought that not resetting buffer.acquire_fence (which if I'm not
mistaken is owned by the framework) was safer.. Probably it's not an
issue but who knows what the camera service does with it...

>
> >  }
> >
> >  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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