[Python-Dev] deadlock problem (original) (raw)

Harri Pasanen harri.pasanen@trema.com
Thu, 31 Jul 2003 11:53:39 +0200

Hi,

I'm having a deadlock on import in my embedded python 2.3rc2, on Win2000, built with Visual C++ 7.1.

Having spent a fair amount of time going through the code, and various threads, it is still not clear to me if I'm hitting the problem described in the thread: http://mail.python.org/pipermail/python-dev/2003-February/033436.html or if I'm triggering it because of something else alltogether, as I'm only seeing the problem on Win2000, on Linux it works fine.

Basically my code does this in one C level thread:

PyGILState_STATE _tstate = PyGILState_Ensure ();
PyObject* usermod = PyImport_ImportModule ("echo");

Where echo.py is just:

print "ECHO" import time time.sleep(1) print "DONE"

It never prints out "DONE". If I take away the sleep(), it finishes, printing DONE.

running with THREADDEBUG=15, I'm getting the output below, and the last two lines leave me utterly puzzled, as if something would be quite wrong on my machine (Win2000 under VmWare Linux host). Why could the same thread be unable reacquire a lock it just held?

PyThread_init_thread called 1084: PyThread_allocate_lock() -> 01647578 1084: PyThread_acquire_lock(01647578, 1) called 1084: PyThread_acquire_lock(01647578, 1) -> 1 1084: PyThread_release_lock(01647578) called 1084: PyThread_acquire_lock(01647578, 1) called 1084: PyThread_acquire_lock(01647578, 1) -> 1 1084: PyThread_release_lock(01647578) called PyThread_allocate_lock called 1084: PyThread_allocate_lock() -> 0164A280 1084: PyThread_acquire_lock(0164A280, 0) called 1084: PyThread_acquire_lock(0164A280, 0) -> 1 1084: PyThread_release_lock(0164A280) called 1084: PyThread_acquire_lock(0164A280, 0) called 1084: PyThread_acquire_lock(0164A280, 0) -> 1 1084: PyThread_release_lock(0164A280) called 1084: PyThread_acquire_lock(0164A280, 0) called 1084: PyThread_acquire_lock(0164A280, 0) -> 1 1084: PyThread_release_lock(0164A280) called 1084: PyThread_acquire_lock(0164A280, 0) called 1084: PyThread_acquire_lock(0164A280, 0) -> 1 1084: PyThread_release_lock(0164A280) called 1084: PyThread_acquire_lock(0164A280, 0) called 1084: PyThread_acquire_lock(0164A280, 0) -> 1 1084: PyThread_release_lock(0164A280) called 1084: PyThread_acquire_lock(0164A280, 0) called 1084: PyThread_acquire_lock(0164A280, 0) -> 1 1084: PyThread_release_lock(0164A280) called 1084: PyThread_acquire_lock(0164A280, 0) called 1084: PyThread_acquire_lock(0164A280, 0) -> 1 1084: PyThread_release_lock(0164A280) called 1084: PyThread_acquire_lock(0164A280, 0) called 1084: PyThread_acquire_lock(0164A280, 0) -> 1 1084: PyThread_release_lock(0164A280) called PyThread_allocate_lock called 1084: PyThread_allocate_lock() -> 0256DD40 1084: PyThread_acquire_lock(0256DD40, 1) called 1084: PyThread_acquire_lock(0256DD40, 1) -> 1 1084: PyThread_release_lock(0256DD40) called 1084: PyThread_acquire_lock(0164A280, 0) called 1084: PyThread_acquire_lock(0164A280, 0) -> 1 1084: PyThread_release_lock(0164A280) called 1084: PyThread_acquire_lock(0164A280, 0) called 1084: PyThread_acquire_lock(0164A280, 0) -> 1 1084: PyThread_release_lock(0164A280) called PyThread_allocate_lock called 1084: PyThread_allocate_lock() -> 01648DA8 1084: PyThread_acquire_lock(01648DA8, 1) called 1084: PyThread_acquire_lock(01648DA8, 1) -> 1 1084: PyThread_acquire_lock(0164A280, 0) called 1084: PyThread_acquire_lock(0164A280, 0) -> 1 1084: PyThread_release_lock(0164A280) called 1084: PyThread_acquire_lock(0164A280, 0) called 1084: PyThread_acquire_lock(0164A280, 0) -> 1 1084: PyThread_release_lock(0164A280) called 1084: PyThread_release_lock(01648DA8) called 1084: PyThread_acquire_lock(0164A280, 0) called 1084: PyThread_acquire_lock(0164A280, 0) -> 1 1084: PyThread_release_lock(0164A280) called 1084: PyThread_acquire_lock(0164A280, 0) called 1084: PyThread_acquire_lock(0164A280, 0) -> 1 ECHO 1084: PyThread_release_lock(01648DA8) called 1084: PyThread_acquire_lock(01648DA8, 1) called

Harri