python: how to terminate a thread when main progra

问题:

If I have a thread in an infinite loop, is there a way to terminate it when the main program ends (for example, when I press Ctrl+C)?

回答1:

Check this question. The correct answer has great explanation on how to terminate threads the right way: Is there any way to kill a Thread in Python?

To make the thread stop on Keyboard Interrupt signal (ctrl+c) you can catch the exception "KeyboardInterrupt" and cleanup before exiting. Like this:

try:
    start_thread()  
except (KeyboardInterrupt, SystemExit):
    cleanup_stop_thread()
    sys.exit()

This way you can control what to do whenever the program is abruptly terminated.

You can also use the built-in signal module that lets you setup signal handlers (in your specific case the SIGINT signal): http://docs.python.org/library/signal.html

回答2:

If you make your worker threads daemon threads, they will die when all your non-daemon threads (e.g. the main thread) have exited.

http://docs.python.org/library/threading.html#threading.Thread.daemon

回答3:

Use the atexit module of Python's standard library to register "termination" functions that get called (on the main thread) on any reasonably "clean" termination of the main thread, including an uncaught exception such as KeyboardInterrupt. Such termination functions may (though inevitably in the main thread!) call any stop function you require; together with the possibility of setting a thread as daemon, that gives you the tools to properly design the system functionality you need.

回答4:

If you spawn a Thread like so - myThread = Thread(target = function) - and then do myThread.start(); myThread.join(). When CTRL-C is initiated, the main thread doesn't exit because it is waiting on that blocking myThread.join() call. To fix this, simply put in a timeout on the .join() call. The timeout can be as long as you wish. If you want it to wait indefinitely, just put in a really long timeout, like 99999. It's also good practice to do myThread.daemon = True so all the threads exit when the main thread(non-daemon) exits.

回答5:

Try with enabling the sub-thread as daemon-thread.

For Example:

from threading import Thread

threaded = Thread(target=<your-method>)
threaded.daemon = True  # This thread dies when main thread (only non-daemon thread) exits.
threaded.start()

Or (in a line):

from threading import Thread

threaded = Thread(target=<your-method>, daemon=True).start()

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When your main thread terminates ("for example, when I press Ctrl+C") that other threads kills with above instruction.