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From: "Joris" <joris.at.lebbeke@skynet.be>
To: <pwatkins@crawfordtech.com>, <tiff@lists.maptools.org>
References: <20060922131842.AA2CA6604A@mail.business.allstream.net>
Subject: Re: [Tiff] libjpeg
Date: Fri, 22 Sep 2006 17:20:31 +0200
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Status:   

Philip,

Philip Watkinson wrote:
> Is libjpeg thread safe?

I believe it is. Of course, 'thread safe' is a misleading
classification, in that it seems to indicate calling threads can do
anything they please. They can't, in that things do need to be logically
consistent. For example, if you're spreading a single decoding or
encoding session over multiple threads, you'll need synchronisation
external to the LibJpeg library, either by logical design or by locks.

The same also applies to LibTiff. You can call LibTiff from within any
thread, and any two threads can use LibTiff simultaniously as long as it
makes sense. Just don't do logically inconsistent stuff like using
TIFFReadDirectory in one thread and potentially simultaniously using
TIFFGetField on the same TIFF* in another thread.

Best regards,

Joris Van Damme
info@awaresystems.be
http://www.awaresystems.be/
Download your free TIFF tag viewer for windows here:
http://www.awaresystems.be/imaging/tiff/astifftagviewer.html

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