[libcamera-devel] [PATCH 5/5] libcamera: pipeline: Refuse to substitute camera data

[Jacopo Mondi]

Once a pipeline-specific data has been associated with a camera, refuse
to update it in order to avoid invalidating the previously set
reference, which might still be owned by the caller.

Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
---
 src/libcamera/include/pipeline_handler.h |  2 +-
 src/libcamera/pipeline_handler.cpp       | 23 ++++++++++++++---------
 2 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/src/libcamera/include/pipeline_handler.h b/src/libcamera/include/pipeline_handler.h
index ca77a40..01a0f0b 100644
--- a/src/libcamera/include/pipeline_handler.h
+++ b/src/libcamera/include/pipeline_handler.h
@@ -47,7 +47,7 @@ protected:
 	void hotplugMediaDevice(MediaDevice *media);
 
 	CameraData *cameraData(const Camera *camera);
-	void setCameraData(const Camera *camera, std::unique_ptr<CameraData> data);
+	int setCameraData(const Camera *camera, std::unique_ptr<CameraData> data);
 
 private:
 	virtual void disconnect();
diff --git a/src/libcamera/pipeline_handler.cpp b/src/libcamera/pipeline_handler.cpp
index dc55f8f..7e927a7 100644
--- a/src/libcamera/pipeline_handler.cpp
+++ b/src/libcamera/pipeline_handler.cpp
@@ -212,21 +212,26 @@ CameraData *PipelineHandler::cameraData(const Camera *camera)
  * information with \a camera. Ownership of \a data is transferred to
  * the PipelineHandler.
  *
- * If pipeline-specific data has already been associated with the camera by a
- * previous call to this method, is it replaced by \a data and the previous data
- * are deleted, rendering all references to them invalid.
+ * Once pipeline-specific data has already been associated with the camera
+ * by a previous call to this method it cannot be changed later on.
  *
  * The data can be retrieved by pipeline handlers using the cameraData() method.
+ *
+ * \return 0 on success, or a negative error code if camera specific data have
+ * already been set
  */
-void PipelineHandler::setCameraData(const Camera *camera,
-				    std::unique_ptr<CameraData> data)
+int PipelineHandler::setCameraData(const Camera *camera,
+				   std::unique_ptr<CameraData> data)
 {
-	if (cameraData_.count(camera))
-		LOG(Pipeline, Debug)
-			<< "Replacing data associated with "
-			<< camera->name();
+	if (cameraData_.find(camera) != cameraData_.end()) {
+		LOG(Pipeline, Error)
+			<< "Replacing data associated with a camera is forbidden ";
+		return -EINVAL;
+	}
 
 	cameraData_[camera] = std::move(data);
+
+	return 0;
 }
 
 /**
-- 
2.20.1