Question

I start a thread using the following code.

t = thread.start_new_thread(myfunction)

How can I kill the thread t from another thread. So basically speaking in terms of code, I want to be able to do something like this.

t.kill()

Note that I’m using Python 2.4.

Answer 1

If your thread is busy executing Python code, you have a bigger problem than the inability to kill it. The GIL will prevent any other thread from even running whatever instructions you would use to do the killing. (After a bit of research, I’ve learned that the interpreter periodically releases the GIL, so the preceding statement is bogus. The remaining comment stands, however.)

Your thread must be written in a cooperative manner. That is, it must periodically check in with a signalling object such as a semaphore, which the main thread can use to instruct the worker thread to voluntarily exit.

while not sema.acquire(False):
    # Do a small portion of work…

or:

for item in work:
    # Keep working…
        # Somewhere deep in the bowels…
        if sema.acquire(False):
            thread.exit()