Thanks for the reply. I'm looking into the Global Interpreter Lock today. On Thu, 03 Jun 2010 01:07:39 +0100, MRAB <pyt...@mrabarnett.plus.com> wrote:
>p...@mail.python.org 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? > >Here's a quote from the Python docs at: > > http://docs.python.org/c-api/init.html > >"""The Python interpreter is not fully thread safe. In order to support >multi-threaded Python programs, there's a global lock, called the global >interpreter lock or GIL, that must be held by the current thread before >it can safely access Python objects. Without the lock, even the simplest >operations could cause problems in a multi-threaded program: for >example, when two threads simultaneously increment the reference count >of the same object, the reference count could end up being incremented >only once instead of twice.""" > >That's probably what's happening to you. -- http://mail.python.org/mailman/listinfo/python-list
