From: "Ludovic Courtès" <ludo@gnu.org>
To: Brian Cully <bjc@spork.org>
Cc: 63190@debbugs.gnu.org, Bruno Victal <mirai@makinata.eu>
Subject: bug#63190: [Shepherd] Nested calls lead to a hang
Date: Sat, 13 May 2023 11:45:51 +0200 [thread overview]
Message-ID: <87h6sg1s4w.fsf@gnu.org> (raw)
In-Reply-To: <87h6shduaw.fsf@psyduck.jhoto.kublai.com> (Brian Cully's message of "Fri, 12 May 2023 19:01:08 -0400")
Brian Cully <bjc@spork.org> skribis:
> Ludovic Courtès <ludo@gnu.org> writes:
>
>> (Whether that leads to a deadlock depends; at first sight, I’d say
>> there’s no reason for this to deadlock in general, but you can of
>> course
>> end up with a logic bug like A starts B, which spawns a client to
>> start
>> A, which doesn’t start because it’s waiting for B.)
>
> It's been a while since I looked at this, but my rough recollection is
> the deadlock occurs because shepherd can only process one request over
> its socket at a time.
That’s not the case in 0.9: it can process several requests
concurrently. However, as I wrote in a followup message, the client
socket created by (gnu services herd) lacks SOCK_NONBLOCK, which can
thus block the process on reads and writes.
Ludo’.
prev parent reply other threads:[~2023-05-13 9:47 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-30 15:21 bug#63190: [Shepherd] Nested calls lead to a hang Bruno Victal
2023-05-06 17:26 ` Ludovic Courtès
2023-05-08 10:27 ` Ludovic Courtès
2023-05-12 23:01 ` Brian Cully via Bug reports for GNU Guix
2023-05-13 9:45 ` Ludovic Courtès [this message]
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