[Pyobjc-dev] Re: [Pyobjc-checkins] CVS: pyobjc/Modules/objc objc_support.m,1.63,1.64

[Ronald O. <ous...@ci...>]

Hmm,

One of your GIL-related patches completely broke the mcfoo program, it 
now consistently deadlocks. On the bright side, this is a lot better 
than "crashes or deadlocks after a while, most of the time" :-).

What I don't understand is that the deadlock occurs due to a call to 
PyGILState_Ensure in thread 2, *at a location where that thread should 
already own the GIL*:

#0  0x90017048 in semaphore_wait_signal_trap ()
#1  0x9000e890 in _pthread_cond_wait ()
#2  0x95fd0324 in PyThread_acquire_lock ()
#3  0x95fa44f8 in PyEval_RestoreThread ()
#4  0x95fc63fc in PyGILState_Ensure ()
#5  0x004a004c in -[NSObject(PyObjCSupport) __pyobjc_PythonObject__] 
(self=0xa5f62728, _cmd=0x3a03) at Modules/objc/objc_support.m:57
#6  0x004a119c in pythonify_c_value (type=0x3903 "", datum=0xa5f6272c) 
at Modules/objc/objc_support.m:964
#7  0x004b3930 in ObjC_FFICaller (aMeth=0x164e750, self=0x164a350, 
args=0x40) at Modules/objc/libffi_support.m:1102
#8  0x004ad344 in objcsel_call (self=0x164e750, args=0x25c030) at 
Modules/objc/selector.m:575
#9  0x95f4a8d0 in PyObject_Call ()
#10 0x95fa9ba8 in PyEval_GetFuncDesc ()
#11 0x95fa9598 in PyEval_GetFuncDesc ()
#12 0x95fa6c64 in PyEval_EvalCode ()
#13 0x95fa7e30 in PyEval_EvalCodeEx ()
#14 0x95f5f354 in PyFunction_SetClosure ()
#15 0x95f4a8d0 in PyObject_Call ()
#16 0x004adac4 in pysel_call (self=0x164e750, args=0x0, kwargs=0x0) at 
Modules/objc/selector.m:1032
#17 0x95f4a8d0 in PyObject_Call ()
#18 0x95fa91ec in PyEval_CallObjectWithKeywords ()
#19 0x95fd39c0 in _PyObject_GC_Del ()
#20 0x900247e8 in _pthread_body ()

Ronald

P.S. I don't think it is necessary to call PyGILState_Ensure in 
__pyobjc_PythonObject__ (it should only be called when we own the GIL), 
but adding the call should be harmless.