From: Johannes Sixt <j.sixt@viscovery.net>
To: Felipe Contreras <felipe.contreras@gmail.com>
Cc: git@vger.kernel.org, Junio C Hamano <gitster@pobox.com>,
Jeff King <peff@peff.net>,
Sverre Rabbelier <srabbelier@gmail.com>,
"Shawn O. Pearce" <spearce@spearce.org>
Subject: Re: [PATCH] transport-helper: check when helpers fail
Date: Mon, 22 Oct 2012 08:35:29 +0200 [thread overview]
Message-ID: <5084E931.3010809@viscovery.net> (raw)
In-Reply-To: <1350847158-14154-1-git-send-email-felipe.contreras@gmail.com>
Am 10/21/2012 21:19, schrieb Felipe Contreras:
> diff --git a/run-command.c b/run-command.c
> index 1101ef7..2852e9d 100644
> --- a/run-command.c
> +++ b/run-command.c
> @@ -559,6 +559,23 @@ int run_command(struct child_process *cmd)
> return finish_command(cmd);
> }
>
> +int check_command(struct child_process *cmd)
> +{
> + int status;
> + pid_t pid;
> +
> + pid = waitpid(cmd->pid, &status, WNOHANG);
> +
> + if (pid < 0)
> + return -1;
> + if (WIFSIGNALED(status))
> + return WTERMSIG(status);
> + if (WIFEXITED(status))
> + return WEXITSTATUS(status);
> +
> + return 0;
> +}
> +
In this form, the function is not suitable as a public run-command API: If
the child did exit, it does not allow finish_command() to do its thing.
The only thing the caller of this function can do is to die() if it
returns non-zero. It doesn't report treat error cases in the same way as
wait_or_whine().
I would expect the function to be usable in this way:
start_command(&proc);
loop {
if (check_command(&proc))
break;
}
finish_command(&proc);
but it would require a bit more work because it would have to cache the
exit status in struct child_process.
BTW, you should check for return value 0 from waitpid() explicitly.
Another thought: In your use-case, isn't it so that it would be an error
that the process exited for whatever reason? I.e., even if it exited with
code 0 ("success"), it would be an error because it violated the protocol?
-- Hannes
next prev parent reply other threads:[~2012-10-22 6:35 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-21 19:19 [PATCH] transport-helper: check when helpers fail Felipe Contreras
2012-10-21 20:33 ` Junio C Hamano
2012-10-21 22:20 ` Felipe Contreras
2012-10-22 6:35 ` Johannes Sixt [this message]
2012-10-22 11:50 ` Felipe Contreras
2012-10-22 13:46 ` Johannes Sixt
2012-10-22 14:31 ` Felipe Contreras
2012-10-22 17:12 ` Felipe Contreras
2012-10-22 19:35 ` Felipe Contreras
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