[libcamera-devel] [PATCH 7/8] libcamera: pipeline_handler: Return unique_ptr from createInstance

[Jacopo Mondi]

Hi Laurent,

On Tue, Oct 04, 2022 at 12:21:27AM +0300, Laurent Pinchart via libcamera-devel wrote:
> Avoid naked pointer with memory allocation by returning a unique_ptr
> from PipelineHandlerFactory::createInstance(), in order to increase
> memory allocation safety.
>
> This allows iterating over factories in the CameraManager and unit tests
> using const pointers.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

Reviewed-by: Jacopo Mondi <jacopo at jmondi.org>

Thanks
  j

> ---
>  include/libcamera/internal/pipeline_handler.h | 8 +++++---
>  src/libcamera/camera_manager.cpp              | 4 ++--
>  src/libcamera/pipeline_handler.cpp            | 8 ++++----
>  test/ipa/ipa_interface_test.cpp               | 4 ++--
>  4 files changed, 13 insertions(+), 11 deletions(-)
>
> diff --git a/include/libcamera/internal/pipeline_handler.h b/include/libcamera/internal/pipeline_handler.h
> index ebbdf2aa391f..ad74dc823290 100644
> --- a/include/libcamera/internal/pipeline_handler.h
> +++ b/include/libcamera/internal/pipeline_handler.h
> @@ -113,7 +113,8 @@ public:
>  private:
>  	static void registerType(PipelineHandlerFactory *factory);
>
> -	virtual PipelineHandler *createInstance(CameraManager *manager) const = 0;
> +	virtual std::unique_ptr<PipelineHandler>
> +	createInstance(CameraManager *manager) const = 0;
>
>  	std::string name_;
>  };
> @@ -125,9 +126,10 @@ public:									\
>  	handler##Factory() : PipelineHandlerFactory(#handler) {}	\
>  									\
>  private:								\
> -	PipelineHandler *createInstance(CameraManager *manager) const	\
> +	std::unique_ptr<PipelineHandler>				\
> +	createInstance(CameraManager *manager) const			\
>  	{								\
> -		return new handler(manager);				\
> +		return std::make_unique<handler>(manager);		\
>  	}								\
>  };									\
>  static handler##Factory global_##handler##Factory;
> diff --git a/src/libcamera/camera_manager.cpp b/src/libcamera/camera_manager.cpp
> index 7ff4bc6fd019..2c3f2d86c469 100644
> --- a/src/libcamera/camera_manager.cpp
> +++ b/src/libcamera/camera_manager.cpp
> @@ -142,10 +142,10 @@ void CameraManager::Private::createPipelineHandlers()
>  	 * file and only fallback on all handlers if there is no
>  	 * configuration file.
>  	 */
> -	std::vector<PipelineHandlerFactory *> &factories =
> +	const std::vector<PipelineHandlerFactory *> &factories =
>  		PipelineHandlerFactory::factories();
>
> -	for (PipelineHandlerFactory *factory : factories) {
> +	for (const PipelineHandlerFactory *factory : factories) {
>  		LOG(Camera, Debug)
>  			<< "Found registered pipeline handler '"
>  			<< factory->name() << "'";
> diff --git a/src/libcamera/pipeline_handler.cpp b/src/libcamera/pipeline_handler.cpp
> index 4470e9041e8e..488dd8d32cdf 100644
> --- a/src/libcamera/pipeline_handler.cpp
> +++ b/src/libcamera/pipeline_handler.cpp
> @@ -678,9 +678,9 @@ PipelineHandlerFactory::PipelineHandlerFactory(const char *name)
>   */
>  std::shared_ptr<PipelineHandler> PipelineHandlerFactory::create(CameraManager *manager) const
>  {
> -	PipelineHandler *handler = createInstance(manager);
> +	std::unique_ptr<PipelineHandler> handler = createInstance(manager);
>  	handler->name_ = name_.c_str();
> -	return std::shared_ptr<PipelineHandler>(handler);
> +	return std::shared_ptr<PipelineHandler>(std::move(handler));
>  }
>
>  /**
> @@ -727,8 +727,8 @@ std::vector<PipelineHandlerFactory *> &PipelineHandlerFactory::factories()
>   * macro. It creates a pipeline handler instance associated with the camera
>   * \a manager.
>   *
> - * \return a pointer to a newly constructed instance of the PipelineHandler
> - * subclass corresponding to the factory
> + * \return A unique pointer to a newly constructed instance of the
> + * PipelineHandler subclass corresponding to the factory
>   */
>
>  /**
> diff --git a/test/ipa/ipa_interface_test.cpp b/test/ipa/ipa_interface_test.cpp
> index 3c0df843ea61..a629abc28da7 100644
> --- a/test/ipa/ipa_interface_test.cpp
> +++ b/test/ipa/ipa_interface_test.cpp
> @@ -52,9 +52,9 @@ protected:
>  		ipaManager_ = make_unique<IPAManager>();
>
>  		/* Create a pipeline handler for vimc. */
> -		std::vector<PipelineHandlerFactory *> &factories =
> +		const std::vector<PipelineHandlerFactory *> &factories =
>  			PipelineHandlerFactory::factories();
> -		for (PipelineHandlerFactory *factory : factories) {
> +		for (const PipelineHandlerFactory *factory : factories) {
>  			if (factory->name() == "PipelineHandlerVimc") {
>  				pipe_ = factory->create(nullptr);
>  				break;
> --
> Regards,
>
> Laurent Pinchart
>