[gdal-dev] Thread Safety question

[Frank Warmerdam]

On Tue, Sep 13, 2011 at 8:12 AM, Christiaan Janssen
<cjanssen at iavo-rs.com> wrote:
> I know this has probably been asked before in some form or another but I'm
> having trouble finding the answer so I'll ask it anyway. Could anyone give
> me a status update on the thread safety of the various parts of GDAL, OGR,
> and Projection Systems. I'm specifically interested in the projection
> functions (ie OCTTransform) that are based on Proj.4. I have a project that
> intends to perform a very large number of projections and any means to
> improve performance in this area is critical. Any information that you could
> provide would be greatly appreciated. Thanks.

Christian,

I haven't reviewed the OCTTransform side for thread safety closely,
but there has been recent work in PROJ.4 on this so getting trunk
of PROJ.4 can be helpful.

I believe if you use a distinct instance of the
OGRCoordinateTransformation for each thread and if
you use PROJ.4 trunk it should be safe to run OCTTransform
operations in different threads at the same time and there
should be very little lock contention.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Software Developer