libcamera, android, cam, gstreamer, qcam, v4l2: Reuse Request

Allow reuse of the Request object by implementing reuse(). This means
the applications now have the responsibility of freeing the Request
objects, so make all libcamera users (cam, qcam, v4l2-compat, gstreamer,
android) do so.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>

1 files changed, 3 insertions, 1 deletions

diff --git a/src/v4l2/v4l2_camera.h b/src/v4l2/v4l2_camera.h
index 1fc5ebef..a6c35a2e 100644
--- a/src/v4l2/v4l2_camera.h
+++ b/src/v4l2/v4l2_camera.h
@@ -76,7 +76,9 @@ private:
 	std::mutex bufferLock_;
 	FrameBufferAllocator *bufferAllocator_;
 
-	std::deque<std::unique_ptr<Request>> pendingRequests_;
+	std::vector<std::unique_ptr<Request>> requestPool_;
+
+	std::deque<Request *> pendingRequests_;
 	std::deque<std::unique_ptr<Buffer>> completedBuffers_;
 
 	int efd_;