Re: blocking file lock functions (lockf,flock,fcntl) do not return after timer signal

["Michael Kerrisk" <mtk-lkml@gmx.net>]

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> Von: "linux-os \(Dick Johnson\)" <linux-os@analogic.com>
> An: "Alex Riesen" <raa.lkml@gmail.com>
> Kopie: "Trond Myklebust" <trond.myklebust@fys.uio.no>, <boi@boi.at>,
> "Linux kernel" <linux-kernel@vger.kernel.org>
> Betreff: Re: blocking file lock functions (lockf,flock,fcntl) do not
> return after timer signal

[...]

> Datum: Wed, 12 Oct 2005 11:20:26 -0400
> As I told you, you use sigaction(). Also flock() will not block
> unless there is another open on the file. The code will run to
> your blocking read(), wait 10 seconds, get your "timeout" from
> the signal handler, then read() will return with -1 and ERESTARTSYS
> in errno as required.

I was just trying to write a message to say the same ;-).

> Also, using a 'C' runtime library call like write() in a signal-
> handler is a bug.

But this is not correct.  write() is async-signal-safe (POSIX 
requires it).

Cheers,

Michael

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