Python threading join hangs 2. setDaemon(True)). is_alive() == True; second attempt to join that thread hangs indefinitely Sep 12, 2022 · A thread may call join() on an empty thread. Hello, as title said, when i use join() it stuck my program (my TKinter window get stuck and not responding). Dec 5, 2017 · None of my threads are marked at daemonic so they in fact so raise a KeyboardInterrupt. Sep 9, 2014 · Even worse, I use a semaphore to run that code section one at a time so all other threads are blocked and waiting for this one thread to finish. I tried to use a separate thread, but the join() is hanging the program. 0. Queue. The join() method can be called multiple times. From my current understanding (which may be wrong) if the thread is not completed it's task within 2 seconds of reaching this it should time out. 2, 3. join() OR object_name. start() t. Introduction to Python Threading In software development, a thread is a single sequence of execution within a process. It's like it's in an infinite loop, but I can't figure out why. shutdown method that :. __init__(self) self. The significance of join() method is, if join() is not invoked, the main thread may Apr 4, 2012 · That's nice! Note however that it will not work if the Python GIL is involved in the deadlock. Thread class: # Define the lock threadLock = threading. Queue Mar 10, 2010 · If one threading. Process is created in the same time, the Process hangs and never joins. the do_pause function in the code below seems to execute before the image is rendered). empty doc says:if empty() returns False it doesn’t guarantee that a subsequent call to get() will not block. futures as first result. Sometimes needs to be run a few times to reproduce. Thread): def __init__(self, name, stuff): threading. Threading can help speed up your code and improve overall design clarity. main_thread = threading. name = name self. join(twait) # here I do Ctrl-C except KeyboardInterrupt: pass t. What if Tasks Are Put After a Call to Join? Tasks may be put on the queue after a thread has called join(). join() # this hangs if twork < twait I can observe the following reproduce sequence: 1. Signal the executor that it should free any resources that it is using when the currently pending futures are done executing. Thread prints and a multiprocessing. After some debugging, it looks like the code is stuck waiting for the threading. start another thread that sleeps Mar 10, 2010 · If one threading. currentThread() for thread in threading. Lock() class MyThreadObject (threading. Syntax: object_name. stop_engine(). In that case, once it hangs, no more Python code will be executed. 11. Python 3 has a built-in threading module that allows developers to create and manage threads efficiently. 3 Jun 22, 2020 · Methods for Joining Threads. 10 Jun 21, 2014 · before thread finishes and join returns, hit Ctrl-C to raise KeyboardInterrupt (KI) after T seconds, thread finishes its (Python) code and KI is raised; Process Explorer confirms that thread really terminates (looked at . I'm using Python3 Code: . Main GUI thread continues running without disturbance. Sep 24, 2010 · # In that case, a Thread. Dec 22, 2015 · I tried using locks and semaphores, etc and nothing was working (e. cancel_join_thread), then that process will not terminate until all buffered items have been flushed to the pipe. join(timeout=None) would hang and even not respond to signals # because signals will get delivered to other threads and Python would forward # them for delayed handling to the main thread which hangs. join(timeout) where timeout argument is the timeout value. 9. I have the following mcve: from threading import Thread import queue def Dec 23, 2021 · Read carefully the documentation for `multiprocessing. Each call to put() will increment an internal counter in the queue. 10. My python version is 2. g. In such a situation the calling thread may ask the thread to stop by sending a signal through an event object. Jun 22, 2020 · We can also specify a timeout value to the join() method. Thread join: thread_queue = queue. Through an ill-handled exception. ident()) thread still reports . stuff = stuff # This flag will be True when the thread have to Python threading. 7. For example, when the join() is invoked from a main thread, the main thread waits till the child thread on which join is invoked exits. enumerate(): if thread is main_thread: continue while thread. Read the second warning, which says in part: Warning: As mentioned above, if a child process has put items on a queue (and it has not used JoinableQueue. 16, 3. May 6, 2018 · I was reading about Queue in the Python documentation and this book, and I don't fully understand why my thread hangs. The thread objects can terminate under any one of the following conditions: Either normally. The Queue. All threads which are my own are supposed to die after execution (I deamonized them with mythread. I am not exactly catching the exception, but defined an exit_handler() in __main__ that calls rs. 10, 3. However, it’s important to understand the limitations of Python […] Apr 11, 2022 · The full test script is attached, but the essential code is: def work(t): sleep(t) twork = 3; twait = 4 t = Thread(target=work, args=(twork,)) try: t. Thread. Till the optional timeout occurs. It lists an Executor. Thread join hangs. If a thread calls join() on a queue that is empty, then it will not block and the call will return immediately. Jun 5, 2021 · Searching for ThreadPoolExecutor on a search engine give me the Python library concurrent. . join(2) break. This join operation is where the code hangs. Tested (and occured) on python versions: 3. This method sends stop signals to all the other threads and joins them afterwards. isAlive(): thread. On invoking the join() method, the calling thread gets blocked until the thread object (on which the thread is called) gets terminated. As a minimum you should use get_nowait or risk data loss. Example: When join method is invoked, the calling thread is blocked till the thread object on which it was called is terminated. pjd twdo jkszqx rouhfbvx qhrth xtjoqaj wkpr jhpukm fwpi kvhghsq beuqm ujnxsm dzysy yacdcx vuksd