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> > my question is</p>
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> > starting from gdal-3.x OGRCoordinateTransformation object (::Transform() in</p>
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> > particular) is not intended to be used by multiple threads? With gdal-2.4</p>
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> > it worked fine.</p>
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> > OGRCoordinateTransformation, as most objects in GDAL, instances have never been</p>
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> intended from being used by multiple threads. That it might have worked in 2.4 was an implementation detail.</p>
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> > Even<br>
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<div>The OGRCoordinateTransformation implementation class defines several (over 20) data members. Some of<br>
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<div>them are altered during a transformation, and hence the implementation is not thread safe. At least the<br>
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<div>variables used for reverse checking the result could be placed into the Transform method instead to improve</div>
<div><span style="font-family: monospace; font-size: 9pt;">thread safety. However, since there were some many member variables I did not check them all.</span></div>
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<div>Mika<br>
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