Home Original page

python thread state

Stefan Schukat SSchukat at dspace.de
Tue Oct 24 07:05:09 EDT 2006 
For this use case the PyGILState API was introduced. 

e.g. try
PyGILState_STATE state = PyGILState_Ensure()
run python code
PyGILState_Release(state) 

	Stefan

> -----Original Message-----
> From: python-list-bounces+sschukat=dspace.de at python.org 
> [mailto:python-list-bounces+sschukat=dspace.de at python.org] On 
> Behalf Of Bryan
> Sent: Monday, October 23, 2006 2:32 PM
> To: python-list at python.org
> Subject: python thread state
> 
> hi,
> 
> i'm trying to write a multithreaded embedded python 
> application and i'm having some trouble.  i found this 
> article "embedding python in multi-threaded c/c++ 
> applications" in the python journal
> (http://www.linuxjournal.com/article/3641) but there still 
> seems to be a step missing for me.
> 
> each time a function in my c module is called, it's called on 
> a different c thread.  i would then like to call a function 
> in an embedded python script.
> from my understanding of the article, you can associate a 
> python script with a c thread by calling PyThreadState_New as 
> in this code:
> 
> // save main thread state
> PyThreadState * mainThreadState = NULL;
> mainThreadState = PyThreadState_Get();
> PyEval_ReleaseLock();
> 
> // setup for each thread
> PyEval_AcquireLock();
> PyInterpreterState * mainInterpreterState = 
> mainThreadState->interp PyThreadState * myThreadState = 
> PyThreadState_New(mainInterpreterState);
> PyEval_ReleaseLock();
> 
> //execute python code
> PyEval_AcquireLock();
> PyThreadState_Swap(myThreadState);
> # execute python code
> PyThreadState_Swap(NULL);
> PyEval_ReleaseLock();
> 
> 
> unfortunately, this doesn't work for me because each time i 
> get called to execute python code, i'm in a new c thread and 
> PyThreadState_Swap seems to want to be executed in the same c 
> thread that PyThreadState_New was executed in.  if this isn't 
> the case, please let know.  
> 
> i then called PyThreadState_New each time i wanted to call a 
> python function in the script, but PyThreadState_New wipes 
> out, or rather gives you a new global dictionary, because i 
> lost all my global variables.  the article assumes you have 
> one c thread per python thread state, but i want multiple c 
> threads per python thread state. Is there a c api function 
> that will associate a c thread without resetting the global 
> dictionary?
> 
> thank you,
> 
> bryan
> 
> --
> http://mail.python.org/mailman/listinfo/python-list
>
More information about the Python-list mailing list