[libcamera-devel] [PATCH v6 2/5] lc-compliance: Make SimpleCapture::stop() idempotent

[Laurent Pinchart]

Hello,

On Wed, Jun 09, 2021 at 04:57:01PM -0300, Nícolas F. R. A. Prado wrote:
> On Wed, Jun 09, 2021 at 06:34:28PM +0200, Jacopo Mondi wrote:
> > On Mon, Jun 07, 2021 at 03:15:03PM -0300, Nícolas F. R. A. Prado wrote:
> > > Make SimpleCapture::stop() be able to be called multiple times and at
> > > any point so that it can be called from the destructor and an assert
> > > failure can return immediately.
> > >
> > > Signed-off-by: Nícolas F. R. A. Prado <nfraprado at collabora.com>
> > > Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> > > ---
> > > No changes in v6
> > >
> > > No changes in v5
> > >
> > > No changes in v4
> > >
> > > No changes in v3
> > >
> > > Changes in v2:
> > > - Suggested by Laurent:
> > >   - Fixed code style
> > >
> > >  src/lc-compliance/simple_capture.cpp | 33 +++++++++++-----------------
> > >  1 file changed, 13 insertions(+), 20 deletions(-)
> > >
> > > diff --git a/src/lc-compliance/simple_capture.cpp b/src/lc-compliance/simple_capture.cpp
> > > index 64e862a08e3a..f90fe6d0f9aa 100644
> > > --- a/src/lc-compliance/simple_capture.cpp
> > > +++ b/src/lc-compliance/simple_capture.cpp
> > > @@ -17,6 +17,7 @@ SimpleCapture::SimpleCapture(std::shared_ptr<Camera> camera)
> > >
> > >  SimpleCapture::~SimpleCapture()
> > >  {
> > > +	stop();
> > >  }
> > >
> > >  Results::Result SimpleCapture::configure(StreamRole role)
> > > @@ -55,12 +56,17 @@ Results::Result SimpleCapture::start()
> > >
> > >  void SimpleCapture::stop()
> > >  {
> > > -	Stream *stream = config_->at(0).stream();
> > > +	if (!config_)
> > > +		return;
> > >
> > >  	camera_->stop();
> > >
> > >  	camera_->requestCompleted.disconnect(this, &SimpleCapture::requestComplete);
> > 
> > nit: I think these two can be moved after the allocator_->allocated() check
> > below as in start()
> > 
> > 	ASSERT_GE(allocator_->allocate(stream), 0) << "Failed to allocate buffers";
> > 
> > 	ASSERT_TRUE(!camera_->start()) << "Failed to start camera";
> > 
> > 	camera_->requestCompleted.connect(this, &SimpleCapture::requestComplete);
> 
> Right, makes sense. In that case I'll join both checks for config_ and
> allocator_->allocated() in a single if at the beginning of the function.
> 
> > I would also respect the inverse order and disconnect the signal
> > first, then stop the camera.
> 
> Okay. So I suppose it won't cause any issues if requests complete after we
> disconnect the signal.

It could result in memory leaks, so I wouldn't do so.

> > All minors
> > Reviewed-by: Jacopo Mondi <jacopo at jmondi.org>
> 
> Thanks :)
> 
> > > +	if (!allocator_->allocated())
> > > +		return;
> > > +
> > > +	Stream *stream = config_->at(0).stream();
> > >  	allocator_->free(stream);
> > >  }
> > >
> > > @@ -84,7 +90,6 @@ Results::Result SimpleCaptureBalanced::capture(unsigned int numRequests)
> > >  	if (buffers.size() > numRequests) {
> > >  		/* Cache buffers.size() before we destroy it in stop() */
> > >  		int buffers_size = buffers.size();
> > > -		stop();
> > >
> > >  		return { Results::Skip, "Camera needs " + std::to_string(buffers_size)
> > >  			+ " requests, can't test only " + std::to_string(numRequests) };
> > > @@ -98,20 +103,14 @@ Results::Result SimpleCaptureBalanced::capture(unsigned int numRequests)
> > >  	std::vector<std::unique_ptr<libcamera::Request>> requests;
> > >  	for (const std::unique_ptr<FrameBuffer> &buffer : buffers) {
> > >  		std::unique_ptr<Request> request = camera_->createRequest();
> > > -		if (!request) {
> > > -			stop();
> > > +		if (!request)
> > >  			return { Results::Fail, "Can't create request" };
> > > -		}
> > >
> > > -		if (request->addBuffer(stream, buffer.get())) {
> > > -			stop();
> > > +		if (request->addBuffer(stream, buffer.get()))
> > >  			return { Results::Fail, "Can't set buffer for request" };
> > > -		}
> > >
> > > -		if (queueRequest(request.get()) < 0) {
> > > -			stop();
> > > +		if (queueRequest(request.get()) < 0)
> > >  			return { Results::Fail, "Failed to queue request" };
> > > -		}
> > >
> > >  		requests.push_back(std::move(request));
> > >  	}
> > > @@ -175,20 +174,14 @@ Results::Result SimpleCaptureUnbalanced::capture(unsigned int numRequests)
> > >  	std::vector<std::unique_ptr<libcamera::Request>> requests;
> > >  	for (const std::unique_ptr<FrameBuffer> &buffer : buffers) {
> > >  		std::unique_ptr<Request> request = camera_->createRequest();
> > > -		if (!request) {
> > > -			stop();
> > > +		if (!request)
> > >  			return { Results::Fail, "Can't create request" };
> > > -		}
> > >
> > > -		if (request->addBuffer(stream, buffer.get())) {
> > > -			stop();
> > > +		if (request->addBuffer(stream, buffer.get()))
> > >  			return { Results::Fail, "Can't set buffer for request" };
> > > -		}
> > >
> > > -		if (camera_->queueRequest(request.get()) < 0) {
> > > -			stop();
> > > +		if (camera_->queueRequest(request.get()) < 0)
> > >  			return { Results::Fail, "Failed to queue request" };
> > > -		}
> > >
> > >  		requests.push_back(std::move(request));
> > >  	}

-- 
Regards,

Laurent Pinchart