[Linux/raspi] python threading not working

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Issue #152 resolved
Oliver Schwanke created an issue

following snippet works when issued without itom but breaks itom when run within it…

def bla():
  print("bla")
import threading
t=threading.Thread(target=bla)
t.start()

I verified python to be same executable:

import sys
print(sys.executable)

prints

/usr/bin/python3

Errormessage from crashed itom is

libgcc_s.so.1 must be installed for pthread_cancel to work

Can you reproduce this on another pi?

Comments (3)

  1. M. Gronle

    I also have python under user/bin/python3.

    For me your example works and I get the bla print out in the command line.
    I have a Raspberry Pi 4B with the newest Raspbian (based on Debian Buster).

    However if have the library libgcc_s.so.1 installed under /lib/arm-linux-gnueabihf/libgcc_s.so.1.

    Please tell me if I can make further tests with my device.

  2. Oliver Schwanke reporter

    As always - thank you so much for your help!

    I found this to be unrelated to itom actually, but to be some knoen issue with python multithreading,

    with libgcc_s_so.1 to be unloaded to early.

    A somewhat hacky solution is to make sure this dll does not get unloaded, so adding

    import ctypes
    libgcc_s = ctypes.CDLL("libgcc_s.so.1")
    

    and making sure this variable does not get deleted, before the thread has finished solves the error.

    Check this launchpad thread…

    I am closing this and leaving it here for self reference…

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