libcamera: camera: Handle camera objects through shared pointers

The Camera class is explicitly reference-counted to manage the lifetime
of camera objects. Replace this open-coded implementation with usage of
the std::shared_ptr<> class.

This API change prevents pipeline handlers from subclassing the Camera
class. This isn't deemed to be an issue. Mark the class final to make
this explicit.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>

2 files changed, 13 insertions, 10 deletions

diff --git a/include/libcamera/camera.h b/include/libcamera/camera.h
index 9a7579d6..2ea1a688 100644
--- a/include/libcamera/camera.h
+++ b/include/libcamera/camera.h
@@ -7,22 +7,25 @@
 #ifndef __LIBCAMERA_CAMERA_H__
 #define __LIBCAMERA_CAMERA_H__
 
+#include <memory>
 #include <string>
 
 namespace libcamera {
 
-class Camera
+class Camera final
 {
 public:
-	Camera(const std::string &name);
+	static std::shared_ptr<Camera> create(const std::string &name);
+
+	Camera(const Camera &) = delete;
+	void operator=(const Camera &) = delete;
 
 	const std::string &name() const;
-	void get();
-	void put();
 
 private:
-	virtual ~Camera() { };
-	int ref_;
+	explicit Camera(const std::string &name);
+	~Camera();
+
 	std::string name_;
 };
 
diff --git a/include/libcamera/camera_manager.h b/include/libcamera/camera_manager.h
index 4b941fd9..9ade29d7 100644
--- a/include/libcamera/camera_manager.h
+++ b/include/libcamera/camera_manager.h
@@ -24,10 +24,10 @@ public:
 	int start();
 	void stop();
 
-	const std::vector<Camera *> &cameras() const { return cameras_; }
-	Camera *get(const std::string &name);
+	const std::vector<std::shared_ptr<Camera>> &cameras() const { return cameras_; }
+	std::shared_ptr<Camera> get(const std::string &name);
 
-	void addCamera(Camera *camera);
+	void addCamera(std::shared_ptr<Camera> camera);
 
 	static CameraManager *instance();
 
@@ -42,7 +42,7 @@ private:
 
 	std::unique_ptr<DeviceEnumerator> enumerator_;
 	std::vector<PipelineHandler *> pipes_;
-	std::vector<Camera *> cameras_;
+	std::vector<std::shared_ptr<Camera>> cameras_;
 
 	std::unique_ptr<EventDispatcher> dispatcher_;
 };