CAPI and thread safety

[Lane Brooks]

I am writing an extension module that needs to release the global 
interpreter lock during some blocking I/O calls, but I need a mutex in 
the C code to make some of the shared data in the extension module are 
kept thread safe.  Can anyone recommend a portable way to do this?  I 
could use a pthread mutex, but I do not think that is portable.

Are any of the python mutexes or locks exposed through the C API?  I 
could not find anything.

Thanks,
Lane