replacing PyEval_InitThreads with Py_Initialize on python 3.9 and above?

[pauliyobo]

Hello,
It turns out that PyEval_InitThreads which Synthizer uses to obtain the ability to acquire and release the GIL is deprecated in python 3.9 and above.

The PyEval_InitThreads() and PyEval_ThreadsInitialized() functions are now deprecated and will be removed in Python 3.11. Calling PyEval_InitThreads() now does nothing. The GIL is initialized by Py_Initialize() since Python 3.7.

Should we account for this?

[ahicks92]

If you can work out how to get Cython to account for it, send a PR.

[ahicks92]

O actually no wait, you may not need to do anything here: py_initialize will be called by python.exe already. So the only problem is going to be handling the removed call somehow.