[libcamera-devel] [PATCH 10/11] libcamera: pipeline_handler: Add functions to lock a whole pipeline

[Niklas Söderlund]

Add lock() and unlock() which backed by the MediaDevice implementation
can will lock all media devices claimed by a pipeline handler instance.

Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
---
 src/libcamera/include/pipeline_handler.h |  3 ++
 src/libcamera/pipeline_handler.cpp       | 38 ++++++++++++++++++++++++
 2 files changed, 41 insertions(+)

diff --git a/src/libcamera/include/pipeline_handler.h b/src/libcamera/include/pipeline_handler.h
index 4c13496246c2251c..019c8f4751a8c2b2 100644
--- a/src/libcamera/include/pipeline_handler.h
+++ b/src/libcamera/include/pipeline_handler.h
@@ -57,6 +57,9 @@ public:
 	MediaDevice *tryAcquire(DeviceEnumerator *enumerator,
 				const DeviceMatch &dm);
 
+	bool lock();
+	void unlock();
+
 	virtual CameraConfiguration
 	streamConfiguration(Camera *camera, const std::vector<StreamUsage> &usages) = 0;
 	virtual int configureStreams(Camera *camera, const CameraConfiguration &config) = 0;
diff --git a/src/libcamera/pipeline_handler.cpp b/src/libcamera/pipeline_handler.cpp
index 702b398a50a18085..119d8980e6fbd75a 100644
--- a/src/libcamera/pipeline_handler.cpp
+++ b/src/libcamera/pipeline_handler.cpp
@@ -182,6 +182,44 @@ out:
 	return media.get();
 }
 
+/**
+ * \brief Lock all media devices acquired by the pipeline
+ *
+ * This method shall not be called from a pipeline handler implementation
+ * directly, as the Camera handles this on the behalf of the specified
+ * implementation.
+ *
+ * \return True if the devices could be locked, false otherwise
+ * \sa unlock()
+ * \sa MediaDevice::lock()
+ */
+bool PipelineHandler::lock()
+{
+	for (std::shared_ptr<MediaDevice> media : mediaDevices_) {
+		if (!media->lock()) {
+			unlock();
+			return false;
+		}
+	}
+
+	return true;
+}
+
+/**
+ * \brief Unlock all media devices acquired by the pipeline
+ *
+ * This method shall not be called from a pipeline handler implementation
+ * directly, as the Camera handles this on the behalf of the specified
+ * implementation.
+ *
+ * \sa lock()
+ */
+void PipelineHandler::unlock()
+{
+	for (std::shared_ptr<MediaDevice> media : mediaDevices_)
+		media->unlock();
+}
+
 /**
  * \fn PipelineHandler::streamConfiguration()
  * \brief Retrieve a group of stream configurations for a specified camera
-- 
2.21.0