re-entrant call to PyEval_RestoreThread(context) hangs

[Greg Chapman]

On 26 Feb 2004 03:54:42 -0800, pcaffrey at iel.ie (Paul) wrote:

>following hangs when re-entered
>
>run()
>{
>    PyEval_RestoreThread(context);
> 
>    pName = PyString_FromString(script);
>
>    Py_DECREF(pName);
>
>    context = PyEval_SaveThread();
>}
>
>This invokes a python script (using context[0])
>
>The python script uses "swig" to call back into the run() method
>The run() method now calls PyEval_RestoreThread(context[1])
>
>but this hangs
>
>ie to summarise
>
>C++ run() context0
>    -> .py
>        -> C++ run()  context1 HANGS!
>
>Can anyone suggest a solution for this?

I've never used SWIG, so I'm not sure if your run method is something for which
SWIG generates the actual C code or pseudocode you're using for example.
Anyway, if you're using 2.3, you can use the PyGILState API:

run()
{
    PyGILState_STATE state = PyGILState_Ensure();

    PyObject *pName = PyString_FromString(script);

    Py_XDECREF(pName);
  
    PyGILState_Release(state);
}

---
Greg Chapman