new thread blocks main thread

Question

from threading import Thread
class MyClass:
    #...
    def method2(self):
        while True:
            try:
                hashes = self.target.bssid.replace(':','') + '.pixie'
                text = open(hashes).read().splitlines()
            except IOError:
                time.sleep(5)
                continue
        # function goes on ...

    def method1(self):
        new_thread = Thread(target=self.method2())
        new_thread.setDaemon(True)
        new_thread.start()  # Main thread will stop there, wait until method 2 

        print "Its continues!" # wont show =(
        # function goes on ...

Is it possible to do like that? After new_thread.start() Main thread waits until its done, why is that happening? i didn't provide new_thread.join() anywhere.

Daemon doesn't solve my problem because my problem is that Main thread stops right after new thread start, not because main thread execution is end.

score 24 · Accepted Answer · answered Jun 08 '15 at 05:59

24

As written, the call to the Thread constructor is invoking self.method2 instead of referring to it. Replace target=self.method2() with target=self.method2 and the threads will run in parallel.

Note that, depending on what your threads do, CPU computations might still be serialized due to the GIL.

answered Jun 08 '15 at 05:59

user4815162342

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Thanks! Sometimes i just cant find some of theese stupid misstipes by myself. – psyskeptic Jun 08 '15 at 06:04

score 0 · Answer 2 · edited May 23 '17 at 12:17

0

IIRC, this is because the program doesn't exit until all non-daemon threads have finished execution. If you use a daemon thread instead, it should fix the issue. This answer gives more details on daemon threads:

Daemon Threads Explanation

edited May 23 '17 at 12:17

Community

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answered Jun 08 '15 at 05:49

Hazok

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new thread blocks main thread

2 Answers2