[libcamera-devel] [PATCH v2 06/12] libcamera: pipeline_handler: Split request queueing

[Jacopo Mondi]

In order to prepare to handle synchronization fences at Request
queueing time, split the PipelineHandler::queueRequest() function in
two, by creating a list of waiting requests and introducing the
doQueueRequest() function that queues requests to the device in the
order the pipeline has received them.

Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
---
 include/libcamera/internal/pipeline_handler.h |  6 +++++
 .../libcamera/internal/tracepoints/request.tp |  9 +++++++
 src/libcamera/pipeline_handler.cpp            | 27 +++++++++++++++++++
 3 files changed, 42 insertions(+)

diff --git a/include/libcamera/internal/pipeline_handler.h b/include/libcamera/internal/pipeline_handler.h
index 41cba44d990f..608e6f79039f 100644
--- a/include/libcamera/internal/pipeline_handler.h
+++ b/include/libcamera/internal/pipeline_handler.h
@@ -7,6 +7,7 @@
 #ifndef __LIBCAMERA_INTERNAL_PIPELINE_HANDLER_H__
 #define __LIBCAMERA_INTERNAL_PIPELINE_HANDLER_H__
 
+#include <deque>
 #include <memory>
 #include <set>
 #include <string>
@@ -76,9 +77,14 @@ private:
 	void mediaDeviceDisconnected(MediaDevice *media);
 	virtual void disconnect();
 
+	void doQueueRequest(Request *request);
+	void doQueueRequests();
+
 	std::vector<std::shared_ptr<MediaDevice>> mediaDevices_;
 	std::vector<std::weak_ptr<Camera>> cameras_;
 
+	std::deque<Request *> waitingRequests_;
+
 	const char *name_;
 
 	friend class PipelineHandlerFactory;
diff --git a/include/libcamera/internal/tracepoints/request.tp b/include/libcamera/internal/tracepoints/request.tp
index 37cd2f8864ce..87219b8d8e6f 100644
--- a/include/libcamera/internal/tracepoints/request.tp
+++ b/include/libcamera/internal/tracepoints/request.tp
@@ -58,6 +58,15 @@ TRACEPOINT_EVENT_INSTANCE(
 	)
 )
 
+TRACEPOINT_EVENT_INSTANCE(
+	libcamera,
+	request,
+	request_device_queue,
+	TP_ARGS(
+		libcamera::Request *, req
+	)
+)
+
 TRACEPOINT_EVENT_INSTANCE(
 	libcamera,
 	request,
diff --git a/src/libcamera/pipeline_handler.cpp b/src/libcamera/pipeline_handler.cpp
index 67fdf1d8db01..b8dd03647954 100644
--- a/src/libcamera/pipeline_handler.cpp
+++ b/src/libcamera/pipeline_handler.cpp
@@ -312,6 +312,17 @@ void PipelineHandler::queueRequest(Request *request)
 {
 	LIBCAMERA_TRACEPOINT(request_queue, request);
 
+	waitingRequests_.push_back(request);
+	doQueueRequests();
+}
+
+/**
+ * \brief Queue one requests to the device
+ */
+void PipelineHandler::doQueueRequest(Request *request)
+{
+	LIBCAMERA_TRACEPOINT(request_device_queue, request);
+
 	Camera *camera = request->_d()->camera();
 	Camera::Private *data = camera->_d();
 	data->queuedRequests_.push_back(request);
@@ -325,6 +336,22 @@ void PipelineHandler::queueRequest(Request *request)
 	}
 }
 
+/**
+ * \brief Queue requests to the device
+ */
+void PipelineHandler::doQueueRequests()
+{
+	while (true) {
+		if (waitingRequests_.empty())
+			return;
+
+		Request *request = waitingRequests_.front();
+		waitingRequests_.pop_front();
+
+		doQueueRequest(request);
+	}
+}
+
 /**
  * \fn PipelineHandler::queueRequestDevice()
  * \brief Queue a request to the device
-- 
2.33.1