[C++-sig] FW: Converting from SWIG to Boost.Python

[BHELLA,OPINDERJIT (HP-Vancouver,ex1)]

In the example below, every function is wrapped with in a
Py_BEGIN_ALLOW_THREADS/
Py_END_ALLOW_THREADS macro. This macro allows each function to be able to
run in 
multiple threads in Python. Because Py_END_ALLOW_THREADS must be called to 
acquire the interpreter lock when the function is completed, 
the PyEval_RestoreThread(_save); is also called before each catch, if an
excepting occurs
and we return NULL.

Thanks for your help David!



"BHELLA,OPINDERJIT (HP-Vancouver,ex1)" < opinderjit.bhella at hp.com
<mailto:opinderjit.bhella at hp.com>> writes:

I have read through the tutorial and was unable
> to figure out how to reproduce the
> following SWIG logic that uses the Py_BEGIN_ALLOW_THREADS and
> Py_END_ALLOW_THREADS macros.
>
<snip>

Can you explain what it does?

-- 
                       David Abrahams
    dave at boost-consulting.com <mailto:dave at boost-consulting.com> *
<http://www.boost-consulting.com>
Boost support, enhancements, training, and commercial distribution

 -----Original Message-----
> From: 	BHELLA,OPINDERJIT (HP-Vancouver,ex1)  
> Sent:	Thursday, January 30, 2003 11:52 AM
> To:	'c++-sig at python.org'
> Subject:	Converting from SWIG to Boost.Python
> 
> 
> Hi, 
> 
> I have been using SWIG 1.5p for about a year with good success. However, I
> was interested in the newer functionality
> that Boost.Python provides. I have read through the tutorial and was
> unable to figure out how to reproduce the
> following SWIG logic that uses the Py_BEGIN_ALLOW_THREADS and
> Py_END_ALLOW_THREADS macros.
> 
> Thanks.
> 
> SWIG example:
> %except(python)
> {
>     Py_BEGIN_ALLOW_THREADS
>     try
>     {
>         $function
>     }
>     catch(BlackstoneErrorObject &e)
>     {
>         PyEval_RestoreThread(_save);
>         switch(e.getCode())
>         {
>             case SUCCESS: ...                 break;
>             case GENERAL_ERROR:        break;
>             default: ...break;
>         }
>         return NULL;
>     }
>     catch (...)
>     {
>         PyEval_RestoreThread(_save);
>         PyErr_SetString(BlackstoneError,"...");
>         return NULL;
>     }
>     Py_END_ALLOW_THREADS
> }