On 2020-04-21 11:01, Antoine Pitrou wrote:
On Mon, 20 Apr 2020 19:21:21 -0600 Eric Snow
Honest question: how many C extensions have process-global state that will cause problems under subinterpreters? In other words, how many already break in mod_wsgi?
A slightly tricky question is what happens if a PyObject survives longer than the subinterpreter that created it.
For example, in PyArrow, we allow passing a Python buffer-like object as a C++ buffer to C++ APIs. The C++ buffer could conceivably be kept around by C++ code for some time. When the C++ buffer is destroyed, Py_DECREF() is called on the Python object (I figure that we would have to switch to the future interpreter-aware PyGILState API -- when will it be available?).
But what happens if the interpreter which created the Python object is already destroyed at this point?
That's a good question. What happens today if someone calls Py_Finalize while the buffer is still around? I don't think you need to treat *sub*interpreters specially.