[issue13992] Segfault in PyTrash_destroy_chain

2012-08-01 Thread Manu Cupcic

Manu Cupcic added the comment:

I am also hitting this issue.

I have been able to reproduce it in python 2.5 and 2.7, on debian 6 (64 bits)
Exactly like the reporter, I am making extensive use of threads. I am also 
using SQLalchemy.

All my threads but one are waiting (probably for the GIL) :
(gdb) info threads
  15 Thread 0x7fffe3ff7700 (LWP 419)  0x77bd03c0 in sem_wait () from 
/lib/libpthread.so.0
  14 Thread 0x7fffe47f8700 (LWP 418)  0x77bd03c0 in sem_wait () from 
/lib/libpthread.so.0
  13 Thread 0x7fffe4ff9700 (LWP 417)  0x77bd03c0 in sem_wait () from 
/lib/libpthread.so.0
  12 Thread 0x7fffe57fa700 (LWP 416)  0x77bd03c0 in sem_wait () from 
/lib/libpthread.so.0
  11 Thread 0x7fffe5ffb700 (LWP 415)  0x77bd03c0 in sem_wait () from 
/lib/libpthread.so.0
* 10 Thread 0x7fffe67fc700 (LWP 414)  0x0046479f in _Py_ForgetReference 
(op=0x4dc7bc0)
at Objects/object.c:
  9 Thread 0x7fffe6ffd700 (LWP 413)  0x77bd03c0 in sem_wait () from 
/lib/libpthread.so.0
  8 Thread 0x7fffe77fe700 (LWP 412)  0x77bd03c0 in sem_wait () from 
/lib/libpthread.so.0
  7 Thread 0x7fffe7fff700 (LWP 411)  0x77bd03c0 in sem_wait () from 
/lib/libpthread.so.0
  6 Thread 0x7fffec81c700 (LWP 410)  0x772a11a3 in select () from 
/lib/libc.so.6
  5 Thread 0x7fffed01d700 (LWP 409)  0x77bd03c0 in sem_wait () from 
/lib/libpthread.so.0
  4 Thread 0x7fffed81e700 (LWP 408)  0x77bd03c0 in sem_wait () from 
/lib/libpthread.so.0
  3 Thread 0x7fffee01f700 (LWP 407)  0x77bd03c0 in sem_wait () from 
/lib/libpthread.so.0
  2 Thread 0x7fffee820700 (LWP 406)  0x7729c9d3 in poll () from 
/lib/libc.so.6
  1 Thread 0x77fec700 (LWP 393)  0x772a11a3 in select () from 
/lib/libc.so.6

And the segfault happens in _Py_ForgetReference :

(gdb) bt
#0  0x0046479f in _Py_ForgetReference (op=0x4dc7bc0) at 
Objects/object.c:
#1  0x00464810 in _Py_Dealloc (op=0x4dc7bc0) at Objects/object.c:2242
#2  0x00559a68 in frame_dealloc (f=0x4997ab0) at 
Objects/frameobject.c:458
#3  0x0046481d in _Py_Dealloc (op=0x4997ab0) at Objects/object.c:2243
...

probably because something else zeroed out the op object :
(gdb) select-frame 0
(gdb) print *op
$6 = {_ob_next = 0x0, _ob_prev = 0x0, ob_refcnt = 0, ob_type = 0x2364020}

Is there something else I can do to help resolve this bug ? I can help 
debugging this, but I am not sure how to proceed. I have a --with-pydebug 
interpreter stopped at the segfault in gdb.

--
nosy: +cupcicm

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[issue13992] Segfault in PyTrash_destroy_chain

2012-08-01 Thread Manu Cupcic

Manu Cupcic added the comment:

(gdb) p op
$12 = (PyObject *) 0x4dc7bc0

thread all apply bt is going to be very long no ? Could you tell me what you 
want to know that is not in info threads maybe ? I can definitely post it here, 
but it's going to be a lot of output.

I can be available on IRC if you want to debug it live.

Thanks !

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[issue13992] Segfault in PyTrash_destroy_chain

2012-08-31 Thread Manu Cupcic

Manu Cupcic added the comment:

I am testing this patch right now. Will report back.

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[issue13992] Segfault in PyTrash_destroy_chain

2012-09-03 Thread Manu Cupcic

Manu Cupcic added the comment:

Hi,

Antoine, thank you for the patch you proposed. It indeed fixed the bug I was 
seeing (I ran a job that usually crashes in one to two hours over the week end 
and it is still running).

I am not sure what we should do now. Can this patch be integrated as is ? What 
can I do to help ?

Thanks

Manu

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