linux-kernel - RE: PROBLEM: close(fd) doesn't wake up read(fd) or select() in another thread

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Date:	Sat, 15 Jul 2006 23:44:50 -0700
From:	"David Schwartz" <davids@...master.com>
To:	<linux-kernel@...r.kernel.org>
Subject: RE: PROBLEM: close(fd) doesn't wake up read(fd) or select() in another thread


> [1.] One line summary of the problem:
> 	close(fd) doesn't wake up read(fd) or select() in another thread

	If you delete a resource in one thread while another thread is using it,
anything can happen. This is as serious a bug as calling 'free' on a block
of memory while another thread is using it.

	You can never be sure the other thread was in 'read' or 'select' (as
opposed to being about to call it and then being pre-empted), so such code
will always have race conditions.

	DS


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