libcamera: request: Provide a sequence number

Provide a sequence number on Requests which are added by the pipeline
handler.

Each pipeline handler keeps a requestSequence per CameraData and
increments everytime a request is queued on that camera.

The sequence number is associated with the Request and can be utilised
for assisting with debugging, and printing the queueing sequence of in
flight requests.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/libcamera/pipeline_handler.cpp b/src/libcamera/pipeline_handler.cpp
index d22991d3..e3d4975d 100644
--- a/src/libcamera/pipeline_handler.cpp
+++ b/src/libcamera/pipeline_handler.cpp
@@ -382,6 +382,8 @@ int PipelineHandler::queueRequest(Request *request)
 	CameraData *data = cameraData(camera);
 	data->queuedRequests_.push_back(request);
 
+	request->sequence_ = data->requestSequence_++;
+
 	int ret = queueRequestDevice(camera, request);
 	if (ret)
 		data->queuedRequests_.remove(request);