libcamera: pipeline_handler: Register requests

Provide a call allowing requests to be registered and associated with
the pipeline handler after being constructed by the camera.

This provides an opportunity for the PipelineHandler to connect any
signals it may be interested in receiving for the request such as
getting notifications when the request is ready for processing when
using a fence.

While here, update the existing usage of the d pointer in
Camera::createRequest() to match the style of other functions.

Bug: https://github.com/raspberrypi/libcamera-apps/issues/217
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

3 files changed, 28 insertions, 6 deletions

diff --git a/include/libcamera/internal/pipeline_handler.h b/include/libcamera/internal/pipeline_handler.h
index e5b8ffb4..c3e4c258 100644
--- a/include/libcamera/internal/pipeline_handler.h
+++ b/include/libcamera/internal/pipeline_handler.h
@@ -59,6 +59,7 @@ public:
 	void stop(Camera *camera);
 	bool hasPendingRequests(const Camera *camera) const;
 
+	void registerRequest(Request *request);
 	void queueRequest(Request *request);
 
 	bool completeBuffer(Request *request, FrameBuffer *buffer);
diff --git a/src/libcamera/camera.cpp b/src/libcamera/camera.cpp
index 86d84ac0..bb856d60 100644
--- a/src/libcamera/camera.cpp
+++ b/src/libcamera/camera.cpp
@@ -1074,12 +1074,19 @@ int Camera::configure(CameraConfiguration *config)
  */
 std::unique_ptr<Request> Camera::createRequest(uint64_t cookie)
 {
-	int ret = _d()->isAccessAllowed(Private::CameraConfigured,
-					Private::CameraRunning);
+	Private *const d = _d();
+
+	int ret = d->isAccessAllowed(Private::CameraConfigured,
+				     Private::CameraRunning);
 	if (ret < 0)
 		return nullptr;
 
-	return std::make_unique<Request>(this, cookie);
+	std::unique_ptr<Request> request = std::make_unique<Request>(this, cookie);
+
+	/* Associate the request with the pipeline handler. */
+	d->pipe_->registerRequest(request.get());
+
+	return request;
 }
 
 /**
diff --git a/src/libcamera/pipeline_handler.cpp b/src/libcamera/pipeline_handler.cpp
index 03e4b9e6..7ebd76ad 100644
--- a/src/libcamera/pipeline_handler.cpp
+++ b/src/libcamera/pipeline_handler.cpp
@@ -338,6 +338,23 @@ bool PipelineHandler::hasPendingRequests(const Camera *camera) const
 }
 
 /**
+ * \fn PipelineHandler::registerRequest()
+ * \brief Register a request for use by the pipeline handler
+ * \param[in] request The request to register
+ *
+ * This function is called when the request is created, and allows the pipeline
+ * handler to perform any one-time initialization it requries for the request.
+ */
+void PipelineHandler::registerRequest(Request *request)
+{
+	/*
+	 * Connect the request prepared signal to notify the pipeline handler
+	 * when a request is ready to be processed.
+	 */
+	request->_d()->prepared.connect(this, &PipelineHandler::doQueueRequests);
+}
+
+/**
  * \fn PipelineHandler::queueRequest()
  * \brief Queue a request
  * \param[in] request The request to queue
@@ -366,9 +383,6 @@ void PipelineHandler::queueRequest(Request *request)
 
 	waitingRequests_.push(request);
 
-	request->_d()->prepared.connect(this, [this]() {
-						doQueueRequests();
-					});
 	request->_d()->prepare(300ms);
 }