Xpra: Ticket #2555: smarter udp-control scheduling

Following up #2554.

Instead of calling schedule_control with just a delay, add a callback to check if sending the 'udp-control' packet is still needed. With out of order packets, we can just check if the missing packet has actually been received before sending. Difficulty: need to keep all the delays and callbacks around so that if one is discarded we can check the next one.

Sun, 04 Oct 2020 14:40:55 GMT - Antoine Martin: status, milestone changed

Sat, 23 Jan 2021 05:54:26 GMT - migration script:

this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/2555