From: Peter Stephenson <p.stephenson@samsung.com>
To: "zsh-workers@zsh.org" <zsh-workers@zsh.org>
Cc: Soares Chen <soares.chen@gmail.com>
Subject: Re: Zsh scripts leave defunct processes when running under docker exec
Date: Wed, 11 Feb 2015 10:11:30 +0000 [thread overview]
Message-ID: <20150211101130.2ac4d9b5@pwslap01u.europe.root.pri> (raw)
In-Reply-To: <CAH+w=7YBD6ocsd6+PL-AgpkDt4-O2AHPQa06U2=b7s2LfeORQw@mail.gmail.com>
On Tue, 10 Feb 2015 22:53:13 -0800
Bart Schaefer <schaefer@brasslantern.com> wrote:
> I'm not exactly a docker expert, but my understanding is that docker
> incorporates (is built on?) the relatively recent Linux feature of "PID
> namespaces". Under a PID namespace, the first process started is assigned
> PID 1and is expected to behave like the "init" process in a traditional
> Unix/Linux system, and be the ultimate manager of all the other processes
> spawned within the namespace.
>
> Zsh is not designed to assume that role. In particular, when processing a
> script, it will optimize process handling and perform an implicit "exec" of
> the final command in the script, so that it need not hang around waiting
> for that process to exit, assuming that it's own parent will reap it. In a
> "docker exec" there is no parent to do so.
Yeah, another special case we don't have either the bandwidth or the
expertise to support...
If that *is* it, is it just a case of special-casing PID 1 not to do
"fake" execs? That's not so hard and shouldn't be problematic in other
cases.
pws
next prev parent reply other threads:[~2015-02-11 10:11 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-11 4:43 Soares Chen
2015-02-11 6:53 ` Bart Schaefer
2015-02-11 10:11 ` Peter Stephenson [this message]
2015-02-11 16:13 ` Bart Schaefer
2015-02-13 10:39 ` Daniel Shahaf
2015-02-14 18:58 ` Bart Schaefer
2015-02-15 14:03 ` Soares Chen
2015-02-15 18:20 ` Peter Stephenson
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