Proper use of mutexes in Python

I don’t know why you’re using the Window’s Mutex instead of Python’s. Using the Python methods, this is pretty simple:

from threading import Thread, Lock

mutex = Lock()

def processData(data):
    mutex.acquire()
    try:
        print('Do some stuff')
    finally:
        mutex.release()

while True:
    t = Thread(target = processData, args = (some_data,))
    t.start()

But note, because of the architecture of CPython (namely the Global Interpreter Lock) you’ll effectively only have one thread running at a time anyway–this is fine if a number of them are I/O bound, although you’ll want to release the lock as much as possible so the I/O bound thread doesn’t block other threads from running.

An alternative, for Python 2.6 and later, is to use Python’s multiprocessing package. It mirrors the threading package, but will create entirely new processes which can run simultaneously. It’s trivial to update your example:

from multiprocessing import Process, Lock

mutex = Lock()

def processData(data):
    with mutex:
        print('Do some stuff')

if __name__ == '__main__':
    while True:
        p = Process(target = processData, args = (some_data,))
        p.start()