tracing: pipeline_handler: Queue Requests

Add tracing to the base pipeline handler class to track when requests are queued.

Tracing is already available for other Request operations, but queuing a Request
is not an operation handled by the Request itself.

Add the tracepoint to the PipelineHandler::queueRequest() so the lifetime of a
Request can be viewed when tracing.

Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

include/libcamera/internal/tracepoints/request.tp

@@ -48,6 +48,15 @@ TRACEPOINT_EVENT_INSTANCE(
 	)
 )
 
+TRACEPOINT_EVENT_INSTANCE(
+	libcamera,
+	request,
+	request_queue,
+	TP_ARGS(
+		libcamera::Request *, req
+	)
+)
+
 TRACEPOINT_EVENT_INSTANCE(
 	libcamera,
 	request,

src/libcamera/pipeline_handler.cpp

@@ -16,6 +16,7 @@
 #include "libcamera/internal/device_enumerator.h"
 #include "libcamera/internal/log.h"
 #include "libcamera/internal/media_device.h"
+#include "libcamera/internal/tracepoints.h"
 #include "libcamera/internal/utils.h"
 
 /**
@@ -375,6 +376,8 @@ const ControlList &PipelineHandler::properties(const Camera *camera) const
  */
 int PipelineHandler::queueRequest(Request *request)
 {
+	LIBCAMERA_TRACEPOINT(request_queue, request);
+
 	Camera *camera = request->camera_;
 	CameraData *data = cameraData(camera);
 	data->queuedRequests_.push_back(request);