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Date: Mon, 23 May 2016 15:38:42 +0200
From: Joerg Sonnenberger <joerg@bec.de>
To: freebsd-hackers@freebsd.org
Subject: Re: read(2) and thus bsdiff is limited to 2^31 bytes
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On Mon, May 23, 2016 at 02:36:58PM +0200, Dirk Engling wrote:
> On 23.05.16 14:21, Joerg Sonnenberger wrote:
> 
> > Atomic meaning in this context that the read can be observed either
> > completely or not at all. This still doesn't mean that read must
> > execute the full size. Other cases for short read/writes are socket,
> > pipes etc.
> 
> On linux I found read() returning a short read, however I wonder if any
> user land application developer ever expects a read from local file to
> yield a short read and continue reading. Maybe I should scan base system
> sources for all occurrences of read.

They have to. Consider a signal interrupting the read.

Joerg