libcamera: base: extensible: Pass private pointer as unique_ptr<>

The Extensible constructor takes a pointer to a Private instance, whose
lifetime it then manages. Make this explicit in the API by passing the
pointer as a std::unique_ptr<Private>.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>

include/libcamera/base/class.h

@@ -87,7 +87,7 @@ public:
 		Extensible *const o_;
 	};
 
-	Extensible(Private *d);
+	Extensible(std::unique_ptr<Private> d);
 
 protected:
 	template<typename T>

src/android/camera_buffer.h

@@ -32,7 +32,7 @@ public:
 
 #define PUBLIC_CAMERA_BUFFER_IMPLEMENTATION				\
 CameraBuffer::CameraBuffer(buffer_handle_t camera3Buffer, int flags)	\
-	: Extensible(new Private(this, camera3Buffer, flags))		\
+	: Extensible(std::make_unique<Private>(this, camera3Buffer, flags)) \
 {									\
 }									\
 CameraBuffer::~CameraBuffer()						\

src/android/camera_hal_config.cpp

@@ -341,7 +341,7 @@ int CameraHalConfig::Private::parseConfigFile(FILE *fh,
 }
 
 CameraHalConfig::CameraHalConfig()
-	: Extensible(new Private()), exists_(false), valid_(false)
+	: Extensible(std::make_unique<Private>()), exists_(false), valid_(false)
 {
 	parseConfigurationFile();
 }

src/libcamera/base/class.cpp

@@ -147,9 +147,12 @@ namespace libcamera {
 /**
  * \brief Construct an instance of an Extensible class
  * \param[in] d Pointer to the private data instance
+ *
+ * The private data lifetime is managed by the Extensible class, which destroys
+ * it when the Extensible instance is destroyed.
  */
-Extensible::Extensible(Extensible::Private *d)
-	: d_(d)
+Extensible::Extensible(std::unique_ptr<Extensible::Private> d)
+	: d_(std::move(d))
 {
 	*const_cast<Extensible **>(&d_->o_) = this;
 }
@@ -163,6 +166,10 @@ Extensible::Extensible(Extensible::Private *d)
  * overriden _d() functions that return the correct pointer type to the
  * corresponding derived Private class.
  *
+ * The lifetime of the private data is tied to the Extensible class. The caller
+ * shall not retain any reference to the returned pointer for longer than it
+ * holds a reference to the Extensible instance.
+ *
  * \return A pointer to the private data instance
  */
 

src/libcamera/camera.cpp

@@ -596,7 +596,7 @@ const std::string &Camera::id() const
 
 Camera::Camera(PipelineHandler *pipe, const std::string &id,
 	       const std::set<Stream *> &streams)
-	: Extensible(new Private(pipe, id, streams))
+	: Extensible(std::make_unique<Private>(pipe, id, streams))
 {
 }
 

src/libcamera/camera_manager.cpp

@@ -258,7 +258,7 @@ void CameraManager::Private::removeCamera(Camera *camera)
 CameraManager *CameraManager::self_ = nullptr;
 
 CameraManager::CameraManager()
-	: Extensible(new CameraManager::Private())
+	: Extensible(std::make_unique<CameraManager::Private>())
 {
 	if (self_)
 		LOG(Camera, Fatal)

src/libcamera/framebuffer.cpp

@@ -181,7 +181,8 @@ FrameBuffer::Private::Private()
  * \param[in] cookie Cookie
  */
 FrameBuffer::FrameBuffer(const std::vector<Plane> &planes, unsigned int cookie)
-	: Extensible(new Private()), planes_(planes), cookie_(cookie)
+	: Extensible(std::make_unique<Private>()), planes_(planes),
+	  cookie_(cookie)
 {
 }