libcamera: ipc: unix: Make socket operation asynchronous

Blocking socket operation when receiving messages may lead to long
delays, and possibly a complete deadlock, if the remote side delays
sending of the payload after the header, or doesn't send the payload at
all. To avoid this, make the socket non-blocking and implement a simple
state machine to receive the header synchronously with the socket read
notification. The payload read is still synchronous with the receive()
method to avoid data copies.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>

This commit is contained in:

Laurent Pinchart

2019-07-02 00:58:53 +03:00

parent a00fdabacd

commit f137451817

2 changed files with 63 additions and 27 deletions

									
										src/libcamera/include/ipc_unixsocket.h
									
		+2
		
												View File
												
				@@ -49,6 +49,8 @@ private:

					void dataNotifier(EventNotifier *notifier);

					int fd_;

					bool headerReceived_;

					struct Header header_;

					EventNotifier *notifier_;

				};