[libcamera-devel] [PATCH 2/2] pipeline: rkisp1: Use utils::Cleaner to simplify error handling in start

[paul.elder at ideasonboard.com]

On Tue, Oct 04, 2022 at 05:18:42AM +0300, Laurent Pinchart via libcamera-devel wrote:
> Error handling in the PipelineHandlerRkISP1::start() function is
> cumbersome. Simplify it using the utils::Cleaner class.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

Reviewed-by: Paul Elder <paul.elder at ideasonboard.com>

> ---
>  src/libcamera/pipeline/rkisp1/rkisp1.cpp | 31 +++++++++---------------
>  1 file changed, 11 insertions(+), 20 deletions(-)
> 
> diff --git a/src/libcamera/pipeline/rkisp1/rkisp1.cpp b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
> index 455ee2a0a711..33f3b0c5ab00 100644
> --- a/src/libcamera/pipeline/rkisp1/rkisp1.cpp
> +++ b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
> @@ -823,69 +823,60 @@ int PipelineHandlerRkISP1::freeBuffers(Camera *camera)
>  int PipelineHandlerRkISP1::start(Camera *camera, [[maybe_unused]] const ControlList *controls)
>  {
>  	RkISP1CameraData *data = cameraData(camera);
> +	utils::Cleaner cleaner;
>  	int ret;
>  
>  	/* Allocate buffers for internal pipeline usage. */
>  	ret = allocateBuffers(camera);
>  	if (ret)
>  		return ret;
> +	cleaner.defer([&]() { freeBuffers(camera); });
>  
>  	ret = data->ipa_->start();
>  	if (ret) {
> -		freeBuffers(camera);
>  		LOG(RkISP1, Error)
>  			<< "Failed to start IPA " << camera->id();
>  		return ret;
>  	}
> +	cleaner.defer([&]() { data->ipa_->stop(); });
>  
>  	data->frame_ = 0;
>  
>  	ret = param_->streamOn();
>  	if (ret) {
> -		data->ipa_->stop();
> -		freeBuffers(camera);
>  		LOG(RkISP1, Error)
>  			<< "Failed to start parameters " << camera->id();
>  		return ret;
>  	}
> +	cleaner.defer([&]() { param_->streamOff(); });
>  
>  	ret = stat_->streamOn();
>  	if (ret) {
> -		param_->streamOff();
> -		data->ipa_->stop();
> -		freeBuffers(camera);
>  		LOG(RkISP1, Error)
>  			<< "Failed to start statistics " << camera->id();
>  		return ret;
>  	}
> +	cleaner.defer([&]() { stat_->streamOff(); });
>  
>  	if (data->mainPath_->isEnabled()) {
>  		ret = mainPath_.start();
> -		if (ret) {
> -			param_->streamOff();
> -			stat_->streamOff();
> -			data->ipa_->stop();
> -			freeBuffers(camera);
> +		if (ret)
>  			return ret;
> -		}
> +		cleaner.defer([&]() { mainPath_.stop(); });
>  	}
>  
>  	if (hasSelfPath_ && data->selfPath_->isEnabled()) {
>  		ret = selfPath_.start();
> -		if (ret) {
> -			mainPath_.stop();
> -			param_->streamOff();
> -			stat_->streamOff();
> -			data->ipa_->stop();
> -			freeBuffers(camera);
> +		if (ret)
>  			return ret;
> -		}
>  	}
>  
>  	isp_->setFrameStartEnabled(true);
>  
>  	activeCamera_ = camera;
> -	return ret;
> +
> +	cleaner.clear();
> +	return 0;
>  }
>  
>  void PipelineHandlerRkISP1::stopDevice(Camera *camera)
> -- 
> Regards,
> 
> Laurent Pinchart
>