From: Pedro Alves <palves@redhat.com>
To: Tom de Vries <tdevries@suse.de>, gdb-patches@sourceware.org
Subject: Re: [gdb/testsuite] Fix hang in fork-running-state.c
Date: Wed, 13 Jun 2018 12:10:00 -0000 [thread overview]
Message-ID: <21cb1f1d-fad1-e9c5-a106-b0b67a1f7a50@redhat.com> (raw)
In-Reply-To: <20180612155134.7fninj4us5lq4hfc@localhost.localdomain>
On 06/12/2018 04:51 PM, Tom de Vries wrote:
> ...
> So, AFAIU, the hanging process is the child process that gdb detaches from.
>
> There's an alarm set in main before the fork, but alarms are not preserved in
> the fork child:
> ...
> $ man alarm
> ...
> NOTES
> Alarms created by alarm() are preserved across execve(2) and are not inherited by children created via fork(2).
Whoops.
> ...
> So, AFAIU, once the parent is killed, there's no alarm to terminate the child.
Indeed.
Your patch is definitely a good idea. Please push.
However, I think that still leaves an unnecessary delay until
the detached child/parent terminate. They used to exit themselves,
but that caused a race, so they no longer do, see here:
https://sourceware.org/ml/gdb-patches/2018-03/msg00588.html
Sounds like the best would be to restore the self-killing,
but make it controlled by a variable that gdb sets, depending
on whether gdb is staying attached to the child/parent.
Thanks,
Pedro Alves
next prev parent reply other threads:[~2018-06-13 12:10 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-12 15:51 Tom de Vries
2018-06-13 12:10 ` Pedro Alves [this message]
2018-06-14 12:59 ` [PATCH] Avoid gdb.base/fork-running-state.exp lingering processes (Re: [gdb/testsuite] Fix hang in fork-running-state.c) Pedro Alves
2018-06-14 16:07 ` Tom de Vries
2018-06-14 16:44 ` Pedro Alves
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