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    <p>A fundamental issue with Python threads is that <strong>you can't just kill them - they have to agree to die</strong>.</p> <p>What you should do is:</p> <ol> <li>Implement the thread as a class</li> <li>Add a <code>threading.Event</code> member which the <code>join</code> method clears and the thread's main loop occasionally checks. If it sees it's cleared, it returns. For this override <code>threading.Thread.join</code> to check the event and then call <code>Thread.join</code> on itself</li> <li>To allow (2), make the read from <code>Queue</code> block with some small timeout. This way your thread's "response time" to the kill request will be the timeout, and OTOH no CPU choking is done</li> </ol> <p>Here's some code from a socket client thread I have that has the same issue with blocking on a queue:</p> <pre><code>class SocketClientThread(threading.Thread): """ Implements the threading.Thread interface (start, join, etc.) and can be controlled via the cmd_q Queue attribute. Replies are placed in the reply_q Queue attribute. """ def __init__(self, cmd_q=Queue.Queue(), reply_q=Queue.Queue()): super(SocketClientThread, self).__init__() self.cmd_q = cmd_q self.reply_q = reply_q self.alive = threading.Event() self.alive.set() self.socket = None self.handlers = { ClientCommand.CONNECT: self._handle_CONNECT, ClientCommand.CLOSE: self._handle_CLOSE, ClientCommand.SEND: self._handle_SEND, ClientCommand.RECEIVE: self._handle_RECEIVE, } def run(self): while self.alive.isSet(): try: # Queue.get with timeout to allow checking self.alive cmd = self.cmd_q.get(True, 0.1) self.handlers[cmd.type](cmd) except Queue.Empty as e: continue def join(self, timeout=None): self.alive.clear() threading.Thread.join(self, timeout) </code></pre> <p>Note <code>self.alive</code> and the loop in <code>run</code>.</p>
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    1. USEli Bendersky
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    1. COI ended up finding the issue in my program (a BASH script far, far away in an external system that was messing with processes [probably a sign that my program is poorly designed, but that is an issue for another time]). However, this is a very good answer and is a lot more elegant than what I ended up doing. Once I understand your code, I will try implementing something similar in mine. I would up this if I had the rep to do so.
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    2. CO@Kededro: np. feel free to ask in a comment if you need help understanding it
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