[gdal-dev] Multithreading with OGR

[Martin Dobias]

On Fri, Jun 25, 2010 at 5:55 PM, Frank Warmerdam <warmerdam at pobox.com> wrote:
>> My intent is to use two OGRLayer instances of the same layer: one
>> instance for handling various stuff in main thread, the other one in
>> worker thread for rendering. Can I expect the GetNextFeature calls to
>> be reentrant, i.e. can they be called from both threads simultaneously
>> using different instances of layers?
>
> Martin,
>
> Are the different OGRLayer instances coming from distinct OGRDataSource
> instances? If so, yes, you could normally treat them as reentrant though
> there might be a few special cases where that turns out not to be true.
> Certainly this is only a good idea in read-only activities.

Yes, I consider using distinct OGRDataSource instances for the
OGRLayer instances. Could you please elaborate on the special cases
you are referring to?

Thanks
Martin