[libcamera-devel] [PATCH 08/10] libcamera: pipeline_handler: Add camera disconnection support
Laurent Pinchart
laurent.pinchart at ideasonboard.com
Thu Jan 24 11:16:49 CET 2019
From: Niklas Söderlund <niklas.soderlund at ragnatech.se>
Pipeline handlers are responsible for creating camera instances, but
also for destroying them when devices are unplugged. As camera objects
are reference-counted this isn't a straightforward operation and
involves the camera manager and camera object itself. Add two helper
methods in the PipelineHandler base class to register a camera and to
register a media device with the pipeline handler.
When registering a camera, the registerCamera() helper method will add
it to the camera manager. When registering a media device, the
registerMediaDevice() helper method will listen to device disconnection
events, and disconnect all cameras created by the pipeline handler as a
response.
Under the hood the PipelineHandler class needs to keep track of
registered cameras in order to handle disconnection. They can't be
stored as shared pointers as this would create a circular dependency
(the Camera class owns a shared pointer to the pipeline handler). Store
them as weak pointers instead. This is safe as a reference to the camera
is stored in the camera manager, and doesn't get removed until the
camera is unregistered from the manager by the PipelineHandler.
Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
---
src/libcamera/include/pipeline_handler.h | 10 ++++
src/libcamera/pipeline/ipu3/ipu3.cpp | 3 +-
src/libcamera/pipeline/uvcvideo.cpp | 3 +-
src/libcamera/pipeline/vimc.cpp | 3 +-
src/libcamera/pipeline_handler.cpp | 71 ++++++++++++++++++++++++
5 files changed, 84 insertions(+), 6 deletions(-)
diff --git a/src/libcamera/include/pipeline_handler.h b/src/libcamera/include/pipeline_handler.h
index e1d6369eb0c4..804cce4807ee 100644
--- a/src/libcamera/include/pipeline_handler.h
+++ b/src/libcamera/include/pipeline_handler.h
@@ -16,6 +16,7 @@ namespace libcamera {
class CameraManager;
class DeviceEnumerator;
+class MediaDevice;
class PipelineHandler : public std::enable_shared_from_this<PipelineHandler>
{
@@ -27,6 +28,15 @@ public:
protected:
CameraManager *manager_;
+
+ void registerCamera(std::shared_ptr<Camera> camera);
+ void hotplugMediaDevice(MediaDevice *media);
+
+private:
+ virtual void disconnect();
+ void mediaDeviceDisconnected(MediaDevice *media);
+
+ std::vector<std::weak_ptr<Camera>> cameras_;
};
class PipelineHandlerFactory
diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp
index 9831f74fe53f..3161e71420ed 100644
--- a/src/libcamera/pipeline/ipu3/ipu3.cpp
+++ b/src/libcamera/pipeline/ipu3/ipu3.cpp
@@ -9,7 +9,6 @@
#include <vector>
#include <libcamera/camera.h>
-#include <libcamera/camera_manager.h>
#include "device_enumerator.h"
#include "log.h"
@@ -169,7 +168,7 @@ void PipelineHandlerIPU3::registerCameras()
std::string cameraName = sensor->name() + " " + std::to_string(id);
std::shared_ptr<Camera> camera = Camera::create(this, cameraName);
- manager_->addCamera(std::move(camera));
+ registerCamera(std::move(camera));
LOG(IPU3, Info)
<< "Registered Camera[" << numCameras << "] \""
diff --git a/src/libcamera/pipeline/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo.cpp
index 73bad6714bb4..c8f1bf553bfe 100644
--- a/src/libcamera/pipeline/uvcvideo.cpp
+++ b/src/libcamera/pipeline/uvcvideo.cpp
@@ -6,7 +6,6 @@
*/
#include <libcamera/camera.h>
-#include <libcamera/camera_manager.h>
#include "device_enumerator.h"
#include "media_device.h"
@@ -49,7 +48,7 @@ bool PipelineHandlerUVC::match(DeviceEnumerator *enumerator)
dev_->acquire();
std::shared_ptr<Camera> camera = Camera::create(this, dev_->model());
- manager_->addCamera(std::move(camera));
+ registerCamera(std::move(camera));
return true;
}
diff --git a/src/libcamera/pipeline/vimc.cpp b/src/libcamera/pipeline/vimc.cpp
index 521b20d3a120..b714a07688e9 100644
--- a/src/libcamera/pipeline/vimc.cpp
+++ b/src/libcamera/pipeline/vimc.cpp
@@ -6,7 +6,6 @@
*/
#include <libcamera/camera.h>
-#include <libcamera/camera_manager.h>
#include "device_enumerator.h"
#include "media_device.h"
@@ -58,7 +57,7 @@ bool PipeHandlerVimc::match(DeviceEnumerator *enumerator)
dev_->acquire();
std::shared_ptr<Camera> camera = Camera::create(this, "Dummy VIMC Camera");
- manager_->addCamera(std::move(camera));
+ registerCamera(std::move(camera));
return true;
}
diff --git a/src/libcamera/pipeline_handler.cpp b/src/libcamera/pipeline_handler.cpp
index 3850ea8fadb5..f0aa2f8022c2 100644
--- a/src/libcamera/pipeline_handler.cpp
+++ b/src/libcamera/pipeline_handler.cpp
@@ -5,7 +5,11 @@
* pipeline_handler.cpp - Pipeline handler infrastructure
*/
+#include <libcamera/camera.h>
+#include <libcamera/camera_manager.h>
+
#include "log.h"
+#include "media_device.h"
#include "pipeline_handler.h"
/**
@@ -97,6 +101,73 @@ PipelineHandler::~PipelineHandler()
* constant for the whole lifetime of the pipeline handler.
*/
+/**
+ * \brief Register a camera to the camera manager and pipeline handler
+ * \param[in] camera The camera to be added
+ *
+ * This function is called by pipeline handlers to register the cameras they
+ * handle with the camera manager.
+ */
+void PipelineHandler::registerCamera(std::shared_ptr<Camera> camera)
+{
+ cameras_.push_back(camera);
+ manager_->addCamera(std::move(camera));
+}
+
+/**
+ * \brief Handle hotplugging of a media device
+ * \param[in] media The media device
+ *
+ * This function enables hotplug handling, and especially hot-unplug handling,
+ * of the \a media device. It shall be called by pipeline handlers for all the
+ * media devices that can be disconnected.
+ *
+ * When a media device passed to this function is later unplugged, the pipeline
+ * handler gets notified and automatically disconnects all the cameras it has
+ * registered without requiring any manual intervention.
+ */
+void PipelineHandler::hotplugMediaDevice(MediaDevice *media)
+{
+ media->disconnected.connect(this, &PipelineHandler::mediaDeviceDisconnected);
+}
+
+/**
+ * \brief Device disconnection handler
+ *
+ * This virtual function is called to notify the pipeline handler that the
+ * device it handles has been disconnected. It notifies all cameras created by
+ * the pipeline handler that they have been disconnected, and unregisters them
+ * from the camera manager.
+ *
+ * The function can be overloaded by pipeline handlers to perform custom
+ * operations at disconnection time. Any overloaded version shall call the
+ * PipelineHandler::disconnect() base function for proper hot-unplug operation.
+ */
+void PipelineHandler::disconnect()
+{
+ for (std::weak_ptr<Camera> ptr : cameras_) {
+ std::shared_ptr<Camera> camera = ptr.lock();
+ if (!camera)
+ continue;
+
+ camera->disconnect();
+ manager_->removeCamera(camera.get());
+ }
+
+ cameras_.clear();
+}
+
+/**
+ * \brief Slot for the MediaDevice disconnected signal
+ */
+void PipelineHandler::mediaDeviceDisconnected(MediaDevice *media)
+{
+ if (cameras_.empty())
+ return;
+
+ disconnect();
+}
+
/**
* \class PipelineHandlerFactory
* \brief Registration of PipelineHandler classes and creation of instances
--
Regards,
Laurent Pinchart
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