Until now, if more than one thread in Gaffer wanted the result of the same computation, and that result wasn't in the cache yet, both threads would perform the compute. This can be particularly bad for big computes that do IO, which I believe is a good description of the AtomsCrowdReader.__engine plug.
Gaffer 0.54 provides the option of blocking in this case, so that the computation is only performed on a single thread. Relevant documentation here :
Until now, if more than one thread in Gaffer wanted the result of the same computation, and that result wasn't in the cache yet, both threads would perform the compute. This can be particularly bad for big computes that do IO, which I believe is a good description of the
AtomsCrowdReader.__engineplug.Gaffer 0.54 provides the option of blocking in this case, so that the computation is only performed on a single thread. Relevant documentation here :
https://github.com/GafferHQ/gaffer/blob/master/include/Gaffer/ComputeNode.h#L81-L86 https://github.com/GafferHQ/gaffer/blob/master/include/Gaffer/ValuePlug.h#L105-L129
And an example is here :
https://github.com/GafferHQ/gaffer/blob/master/src/GafferImage/OpenImageIOReader.cpp#L756-L771
Feel free to give me a shout if you have any questions.