Thanks for the reply. I'm checking this out today. On Wed, 2 Jun 2010 22:30:37 -0700 (PDT), Carl Banks <pavlovevide...@gmail.com> wrote:
>On Jun 2, 1:46 pm, Paul Grunau wrote: >> I have a problem with embedding Python into a C extension in Windows >> Vista. I have implemented a timer routine in C as an extension, which >> I can import into Python 2.6.5 and run. Each timer interval, the >> extension calls a C CALLBACK function. I want to be able to have this >> CALLBACK function call a Python function, so that I can write the >> timer handler in Python. >> >> I can write Python functions and call them from a C extension function >> with no trouble in all cases EXCEPT when the function that calls the >> Python code is the timer's CALLBACK function. That is, if I call >> PyRun_SimpleString or PyRun_SimpleFile, or PyImport_ImportModule, or >> basically any Python-y function in the CALLBACK function, Python >> crashes and I get a window saying "Python has stopped working. Windows >> is searching for a solution to the problem." >> >> The Python code runs fine if I call it from a function in the >> extension that is not the CALLBACK function. And regular C code runs >> in the CALLBACK function properly. It only crashes if I try to run the >> Python code from the timer CALLBACK function (or any C function I call >> from the CALLBACK function). >> >> Does anybody know how to fix this? Is there a workaround of some sort? > >See PEP 311. When an external/uncertain thread calls into Python, it >has to be sure a Python thread state exists for that thread, and that >the thread holds the global interpreter lock. This is done by >surrounding all Python code with the following calls: > >PyGILState_STATE state = PyGILState_Ensure(); > >and > >PyGILState_Release(state); > >Normally, code in extension modules can rely on the current thread >having the global lock at all entry points, so it doesn't have worry >about the thread state. But a callback from a timer can't assume >that. > > >Carl Banks -- http://mail.python.org/mailman/listinfo/python-list
