[issue7123] Multiprocess Process does not always exit when run from a thread.

Charles-François Natali added the comment: > I am pretty sure this is another instance of issue 6721. Indeed. Closing as duplicate. -- status: open -> closed superseder: -> Locks in python standard library should be sanitized on fork ___ Python tra

[issue7123] Multiprocess Process does not always exit when run from a thread.

Changes by Antoine Pitrou : -- nosy: +neologix ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.pytho

[issue7123] Multiprocess Process does not always exit when run from a thread.

Tomaž Šolc added the comment: I am pretty sure this is another instance of issue 6721. multiprocessing is forking a new process and if that happens while the other thread is holding the lock for stdout, the process will deadlock because the lock state is replicated in the subprocess while the

[issue7123] Multiprocess Process does not always exit when run from a thread.

Changes by Ask Solem : -- nosy: +asksol ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/m

[issue7123] Multiprocess Process does not always exit when run from a thread.

Peter Saunders added the comment: Tested on Linux, and repeated the issue - just to confirm this isn't a Solaris specific issue. Tested using dummy_threading - bug does not appear when that is used. Added _verbose=True to threads, and log_to_stderr(SUBDEBUG) set for Process. Attached is the o

[issue7123] Multiprocess Process does not always exit when run from a thread.

Peter Saunders added the comment: Sorry for the spam on the updates :) - but, its the same thread printing this out too. I changed the print line to: curThread = threading.current_thread() print("Started subproc: PID: %d : args: %s Thread ID: %s" %(newJob.pid, str(args), str(curThread.ident)))

[issue7123] Multiprocess Process does not always exit when run from a thread.

Antoine Pitrou added the comment: > Notice the Started subprod of the SAME PID and the Same args twice, yet > this print only occurs once in the code, and I can't see how this should > happen? This is a thread-safety issue in sys.stdout/stderr, it will be fixed in 3.1.2 (see issue6750). --

[issue7123] Multiprocess Process does not always exit when run from a thread.

Peter Saunders added the comment: Further oddness: When running the script (i've reduced its size further now, see attached): I get the following output: Reaping PID: 23215 True Started subproc: PID: 23216 : args: data1 Started subproc: PID: 23216 : args: data1 Started subproc: PID: 23217 : a

[issue7123] Multiprocess Process does not always exit when run from a thread.

Peter Saunders added the comment: Same thing occurs, as you would expect, when I do: while True: fail=failureObject() tlist = [] for x in ["data1", "data2"]: t = threading.Thread(target=checkAlive, args = (fail, x), name=x) t.start() tlist.append(t) for

[issue7123] Multiprocess Process does not always exit when run from a thread.

Peter Saunders added the comment: If you mean, in main() instead of doing: while True: q.put(["data1", "data2"]) t = Process(target=popJobs, args=(q, )) t.start() t.join() and doing: while True: q.put(["data1", "data2"]) popJobs(q) instead. Then, the bug does indeed o

[issue7123] Multiprocess Process does not always exit when run from a thread.

Antoine Pitrou added the comment: As for the dtrace output: I'm not a Solaris expert unfortunately, I was just trying to suggest a possible direction for diagnosing this problem. -- ___ Python tracker _

[issue7123] Multiprocess Process does not always exit when run from a thread.

Antoine Pitrou added the comment: Does it not happen if you call your checkAlive() function directly from your main() function? -- ___ Python tracker ___

[issue7123] Multiprocess Process does not always exit when run from a thread.

Peter Saunders added the comment: Well, if it helps, here is the output of the dtrace script from starting of a loop with the failure, and stopping during the failure. -- Added file: http://bugs.python.org/file15126/dtrace.txt ___ Python tracker

[issue7123] Multiprocess Process does not always exit when run from a thread.

Antoine Pitrou added the comment: Acccording to http://blogs.sun.com/chrisg/entry/lwp_park_and_lwp_unpark, the lwp_park() call could point to a mutex which is waiting to be acquired. -- nosy: +pitrou ___ Python tracker

[issue7123] Multiprocess Process does not always exit when run from a thread.

Changes by Antoine Pitrou : -- assignee: -> jnoller components: +Library (Lib) nosy: +jnoller priority: -> normal type: -> behavior versions: +Python 3.2 ___ Python tracker ___

[issue7123] Multiprocess Process does not always exit when run from a thread.

Peter Saunders added the comment: Further information: it doesn't fail everytime in Python 3.1 - usually 1 in 4, or 1 in 5 times. It never fails with Python 2.6.3 Example output from the script when its failing (python 3.1): Starting data1 Starting data2 Started subproc: PID: 20209 : args: dat

[issue7123] Multiprocess Process does not always exit when run from a thread.

New submission from Peter Saunders : I have an example code that works fine on Python 2.6.3, but when run in Python 3.1.1 - after a very short period of time, will go wrong. Summary: We have a queue, and when the queue has something in it (a list), we start a thread to deal with that entry. Th