[Galene] Re: Frozen videos [was: use of closed network connection]

[Juliusz Chroboczek <jch@irif.fr>]

> Feb 10 20:25:25 video galene[1251625]: 2021/02/10 20:25:25 Replace: file does not exist

> I also have frozen video frame of a user that left stuck in the group
> view now (but he's not in the user list).

This should be fixed now.

We were pushing connections asynchronously, which could cause the push
actions to arrive in the wrong order: if a connection was created and then
deleted, the deletion could arrive before the creation, in which case the
deletion would log a warning (file does not exist) and the creation would
succeed, leaving a frozen video.

Of course, we cannot just replace asynchronous with synchronous, as that
might cause deadlocks.  So I've had to implement an explicit queue of
pending actions, and make communication between threads use unbounded
amounts of buffering.

Personal opinion -- I much prefer the semantics of Erlang's mailboxes
(which implement unbounded buffering) to that of Go's channels (which use
bounded amounts of buffering, and are therefore susceptible to deadlocks).

-- Juliusz