Created by: tonyyang-svail

To use py::call_guard, pybind11 version needs to be at least 2.2.

The current implementation of python exe.run will hold the python GIL and blocks other python threads. Because by default, "When calling a C++ function from Python, the GIL is always held."

One way to release the lock is through py::call_guard<py::gil_scoped_release>().

m.def("call_go", &call_go, py::call_guard<py::gil_scoped_release>());

Links:

1. pybind11 official documentation: https://github.com/pybind/pybind11/blob/master/docs/advanced/misc.rst#global-interpreter-lock-gil
2. Usage in other project:
   1. Pytorch: https://github.com/rsumner31/pytorch/blob/d7a6b2cd1b47793379a42d5b133255c28ae3499c/torch/csrc/cuda/python_comm.cpp#L8-L16