[issue28857] SyncManager and Main Process fail to communicate after reboot or stoping with Ctrl - C

Nagarjuna Arigapudi report at bugs.python.org
Fri Dec 2 01:42:52 EST 2016 

New submission from Nagarjuna Arigapudi:

"SyncManager" and "Main Process" and main process look at different directories and fail to communicate, causing shutdown of all process, immediately after start of program. This behavior is seen in both 2.7 and 3.5. The logging of 2.7 is more clear, It tells the file  name it is looking for.

Extract of Program:

manager = Manager()
lst1 = manager.list([[]]*V1)  
lst2 = manager.list(range(v2)) 
lst3 = manager.list([0]*V3)         
lst4 = manager.list([0]*V3) 
lst5 = manager.list([0]*V3)  
initializeData(lst1,lst2,lst3,lst4,lst5)
procs = []
for indx in range(noOfProcs):
    procs.append(Process(target=workerProc, args=(lst1,lst2,lst3,lst4,lst5)))
    procs[indx].start()

bContinueWorking = True
while (bContinueWorking):
    logger.debug("Main thread about to sleep")   
    time.sleep(300)
    globLOCK.acquire()
    if(not lst1):
        bContinueWorking = False
    try:
        doPickle(lst1)
    except Exception, ep:
        logger.error("failed to pickle" +str(ep))
    finally:
        globLOCK.release()

________________________________________________________
The program works well. but if the program is terminated, it will not start back. rebooting or cleaning temporary files does not fix the issue.

below is log when it fails. ( beneath the log is other log where it runs successfully)

FAIL LOG
[DEBUG/MainProcess] Star of Application
[DEBUG/MainProcess] created semlock with handle 139965318860800
[DEBUG/MainProcess] created semlock with handle 139965318856704
[DEBUG/MainProcess] created semlock with handle 139965318852608
[DEBUG/MainProcess] created semlock with handle 139965318848512
[DEBUG/MainProcess] created semlock with handle 139965318844416
[DEBUG/MainProcess] created semlock with handle 139965318840320
[INFO/SyncManager-1] child process calling self.run()

***[INFO/SyncManager-1] created temp directory /tmp/pymp-xTqdkd***

[DEBUG/MainProcess] requesting creation of a shared 'list' object
[INFO/SyncManager-1] manager serving at '/tmp/pymp-xTqdkd/listener-eDG1yJ'
[DEBUG/SyncManager-1] 'list' callable returned object with id '7f4c34316f80'
[DEBUG/MainProcess] INCREF '7f4c34316f80'
[DEBUG/MainProcess] requesting creation of a shared 'list' object
[DEBUG/SyncManager-1] 'list' callable returned object with id '7f4c3432a758'
[DEBUG/MainProcess] INCREF '7f4c3432a758'
[DEBUG/MainProcess] requesting creation of a shared 'list' object
[DEBUG/SyncManager-1] 'list' callable returned object with id '7f4c3432a7a0'
[DEBUG/MainProcess] INCREF '7f4c3432a7a0'
[DEBUG/MainProcess] requesting creation of a shared 'list' object
[DEBUG/SyncManager-1] 'list' callable returned object with id '7f4c3432a7e8'
[DEBUG/MainProcess] INCREF '7f4c3432a7e8'
[DEBUG/MainProcess] requesting creation of a shared 'list' object
[DEBUG/SyncManager-1] 'list' callable returned object with id '7f4c3432a830'
[DEBUG/MainProcess] INCREF '7f4c3432a830'
[DEBUG/MainProcess] thread 'MainThread' does not own a connection
[DEBUG/MainProcess] making connection to manager
[DEBUG/SyncManager-1] starting server thread to service 'MainProcess'

***[DEBUG/MainProcess] failed to connect to address /tmp/pymp-LOMHoT/listener-EbLeup***

[Errno 2] No such file or directory
Initialization failed Exiting
[INFO/MainProcess] process shutting down


SUCCESS LOG

[DEBUG/MainProcess] Star of Application
[DEBUG/MainProcess] created semlock with handle 139830888992768
[DEBUG/MainProcess] created semlock with handle 139830888988672
[DEBUG/MainProcess] created semlock with handle 139830888984576
[DEBUG/MainProcess] created semlock with handle 139830888980480
[DEBUG/MainProcess] created semlock with handle 139830888976384
[DEBUG/MainProcess] created semlock with handle 139830888972288
[INFO/SyncManager-1] child process calling self.run()
[INFO/SyncManager-1] created temp directory /tmp/pymp-UiHuij
[DEBUG/MainProcess] requesting creation of a shared 'list' object
[INFO/SyncManager-1] manager serving at '/tmp/pymp-UiHuij/listener-lS7hf5'
[DEBUG/SyncManager-1] 'list' callable returned object with id '7f2ce78c6f80'
[DEBUG/MainProcess] INCREF '7f2ce78c6f80'
[DEBUG/MainProcess] requesting creation of a shared 'list' object
[DEBUG/SyncManager-1] 'list' callable returned object with id '7f2ce78da758'
[DEBUG/MainProcess] INCREF '7f2ce78da758'
[DEBUG/MainProcess] requesting creation of a shared 'list' object
[DEBUG/SyncManager-1] 'list' callable returned object with id '7f2ce78da7a0'
[DEBUG/MainProcess] INCREF '7f2ce78da7a0'
[DEBUG/MainProcess] requesting creation of a shared 'list' object
[DEBUG/SyncManager-1] 'list' callable returned object with id '7f2ce78da7e8'
[DEBUG/MainProcess] INCREF '7f2ce78da7e8'
[DEBUG/MainProcess] requesting creation of a shared 'list' object
[DEBUG/SyncManager-1] 'list' callable returned object with id '7f2ce78da830'
[DEBUG/MainProcess] INCREF '7f2ce78da830'
[DEBUG/MainProcess] thread 'MainThread' does not own a connection
[DEBUG/MainProcess] making connection to manager
[DEBUG/SyncManager-1] starting server thread to service 'MainProcess'
[DEBUG/MainProcess] Main thread about to sleep
[DEBUG/Process-7] INCREF '7f2ce78c6f80'
[DEBUG/Process-6] INCREF '7f2ce78c6f80'
[DEBUG/Process-5] INCREF '7f2ce78c6f80'
[DEBUG/Process-4] INCREF '7f2ce78c6f80'
[DEBUG/Process-3] INCREF '7f2ce78c6f80'
[DEBUG/Process-2] INCREF '7f2ce78c6f80'
[DEBUG/Process-6] INCREF '7f2ce78da758'
[DEBUG/Process-7] INCREF '7f2ce78da758'
[DEBUG/Process-5] INCREF '7f2ce78da758'
[DEBUG/Process-4] INCREF '7f2ce78da758'
[DEBUG/Process-3] INCREF '7f2ce78da758'
[DEBUG/Process-2] INCREF '7f2ce78da758'
[DEBUG/Process-6] INCREF '7f2ce78da7a0'
[DEBUG/Process-7] INCREF '7f2ce78da7a0'
[DEBUG/Process-5] INCREF '7f2ce78da7a0'
[DEBUG/Process-4] INCREF '7f2ce78da7a0'
[DEBUG/Process-3] INCREF '7f2ce78da7a0'
[DEBUG/Process-2] INCREF '7f2ce78da7a0'
[DEBUG/Process-6] INCREF '7f2ce78da7e8'
[DEBUG/Process-7] INCREF '7f2ce78da7e8'
[DEBUG/Process-5] INCREF '7f2ce78da7e8'
[DEBUG/Process-4] INCREF '7f2ce78da7e8'
[DEBUG/Process-3] INCREF '7f2ce78da7e8'
[DEBUG/Process-2] INCREF '7f2ce78da7e8'
[DEBUG/Process-6] INCREF '7f2ce78da830'
[INFO/Process-6] child process calling self.run()
[DEBUG/Process-6] thread 'MainThread' does not own a connection
[DEBUG/Process-6] making connection to manager
[DEBUG/Process-7] INCREF '7f2ce78da830'
[INFO/Process-7] child process calling self.run()

----------
components: Extension Modules, Interpreter Core
messages: 282223
nosy: Nagarjuna Arigapudi
priority: normal
severity: normal
status: open
title: SyncManager and Main Process fail to communicate after reboot or stoping with Ctrl - C
type: crash
versions: Python 2.7, Python 3.5

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue28857>
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