Re: [PATCH] tests: Create fifo for test-io-channel-command

[Daniel P . Berrangé]

CC'ing Marc-André as original author of the change

On Tue, Oct 25, 2022 at 01:57:23PM +0100, Alex Bennée wrote:
> 
> Juan Quintela <quintela@redhat.com> writes:
> 
> > Previous commit removed the creation of the fifo.  Without it, I get
> > random failure during tests with high load, please consider
> > reintroduce it.
> >
> > My guess is that there is a race between the two socats when we leave
> > them to create the channel, better return to the previous behavior.
> >
> > I can't reproduce the problem when I run ./test-io-channel-command
> > test alone, I need to do the make check.  And any (unrelated) change
> > can make it dissapear.
> 
> I was chasing a similar problem with this test although I don't see it
> timeout while running (I don't think our unit tests time out). I'm
> provisionally queuing this to testing/next unless anyone objects.

It won't build on Win32 since that platform lacks mkfifo.

The test normally works since socat will call mknod to create
the fifo.

I think the problem is that we have a race condition where the
client socat runs before the server socat, and so won't see the
fifo. This will be where high load triggers problems.


With regards,
Daniel
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