Nested imports cause deadlock

[lokuz]

Nested imports cause deadlocks. The deadlock is caused by native libraries which are loading (indirectly) other native libraries before calling "LEAVE_JyNI". Then the next JyNI_loadModule (JyNI.c) call will stop at ENTER_JyNI.

One possible solution might be to add LEAVE_JyNI and ENTER_JyNI around the call of the dynamic load function (return value of _PyImport_GetDynLoadFunc) in _PyImport_LoadDynamicModuleJy (importdl.c) i.e. around line (*p)();

Another solution might be to check in loadModule in JyNI.java, if one was called from the native library and then calls LEAVE_JyNI and at the end of the function restores the state by calling ENTER_JyNI.

Stefan, I would be happy to hear your opinion on that, since I do not know what requirements on this locking mechanism exist.

[Stewori]

Probably using RE_ENTER_JyNI and RE_LEAVE_JyNI instead of ENTER_JyNI and LEAVE_JyNI would fix this. I am actually about to replace ENTER_JyNI and LEAVE_JyNI by RE_ENTER_JyNI and RE_LEAVE_JyNI at all; they were made before redesign of thread state handling in JyNI alpha 3.
So far I was not confident enough about this decision yet and only replaced where needed. You can try to apply this in JyNI_loadModule. RE_ENTER_JyNI and RE_LEAVE_JyNI lock per thread state and not per call, so entering JyNI using the same thread state preserves the lock.

[lokuz]

Thanks for your recommendation. I will try this.

[Stewori]

Can you provide a minimal code sample that triggered this issue for you?

[Stewori]

So, I already ran into this issue myself while investigating umath module.
Should be fixed as of 66a74e0