From: Anthony Liguori <anthony@codemonkey.ws>
To: "Daniel P. Berrange" <berrange@redhat.com>
Cc: Stuart Brady <stuart.brady@gmail.com>, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH] suppress 'warn_unused_result' warning
Date: Mon, 11 May 2009 11:57:16 -0500 [thread overview]
Message-ID: <4A0858EC.4080509@codemonkey.ws> (raw)
In-Reply-To: <20090511162520.GB1579@redhat.com>
Daniel P. Berrange wrote:
> On Mon, May 11, 2009 at 11:16:24AM -0500, Anthony Liguori wrote:
>
>> Any system call can return EINTR just about. It's not just read/write.
>>
>
> For many system calls you can have them auto-restarted after EINTR
> by using sigaction() with the SA_RESTART flag. IIRC read/write/poll
> won't support restarts in this way though, because of the problem of
> partial data read/writes and partial timeouts for poll meaning you
> can't auto-restart them without app developer help
>
SA_RESTART in theory is supposed to cover everything IIUC. I don't know
that that's true in Linux in practice though. I definitely don't know
about other Unices.
I don't think there's a standard way to know which syscalls would be
restarted and which ones would. If you expect EINTR, I think you pretty
much have to handle it everywhere.
Regards,
Anthony Liguori
> Daniel
>
next prev parent reply other threads:[~2009-05-11 16:57 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-10 19:15 [Qemu-devel] [PATCH] suppress 'warn_unused_result' warning Chih-Min Chao
2009-05-10 22:11 ` Paul Brook
2009-05-10 22:15 ` Stuart Brady
2009-05-10 23:19 ` Anthony Liguori
2009-05-11 1:53 ` M. Warner Losh
2009-05-11 15:42 ` Stuart Brady
2009-05-11 16:02 ` Paul Brook
2009-05-11 16:16 ` Anthony Liguori
2009-05-11 16:25 ` Daniel P. Berrange
2009-05-11 16:57 ` Anthony Liguori [this message]
2009-05-12 12:19 ` Jamie Lokier
2009-05-11 17:02 ` Jamie Lokier
2009-05-11 16:15 ` Daniel P. Berrange
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