[PATCH] Python: Release GIL on blocking operations

[John (J5) Palmieri]

Cool thanks.  Do you think you could get your client and server into the
regression tests? 

On Wed, 2006-08-02 at 15:35 +0800, Justin Mazzola Paluska wrote:
> Hi,
> 
> I noticed that the D-Bus Python bindings don't release the global
> interpreter lock (GIL) when they block.  This causes all threads that
> need the Python interpreter to block until the D-Bus call returns.
> The attached patch releases/acquires the GIL around blocking D-Bus
> operations.
> 
> I noticed this in another application I was writing, but have attached
> minimal examples of why it's necessary.  Without the patch, the thread
> printing *'s doesn't run; with the patch, the thread printing *'s runs
> while the D-Bus thread is blocked.
> 
> Should I file a bug in the tracker with the patches?
> 	--Justin
> plain text document attachment (python-release-gil-on-block.patch)
> diff --git a/dbus/dbus_bindings.pyx b/dbus/dbus_bindings.pyx
> index c29dea2..bc0f78a 100644
> --- a/dbus/dbus_bindings.pyx
> +++ b/dbus/dbus_bindings.pyx
> @@ -25,6 +25,9 @@ cdef extern from "Python.h":
>      void PyErr_Clear()
>      PyGILState_STATE PyGILState_Ensure()
>      void PyGILState_Release(PyGILState_STATE)
> +    struct PyThreadState
> +    PyThreadState* PyEval_SaveThread()
> +    void PyEval_RestoreThread(PyThreadState *tstate)
>  
>  ctypedef struct DBusError:
>      char *name
> @@ -438,16 +441,22 @@ cdef class Connection:
>          cdef DBusError error
>          cdef DBusMessage *msg
>          cdef Message m
> +        cdef PyThreadState *_save
> +        cdef int int_timeout_milliseconds
>  
>          dbus_error_init(&error)
>  
>          msg = message._get_msg()
>  
> +        int_timeout_milliseconds = timeout_milliseconds
> +        _save = PyEval_SaveThread()
> +        # NOTE: Don't use Python code until RestoreThread
>          retval = dbus_connection_send_with_reply_and_block(
>              self.conn,
>              msg,
> -            timeout_milliseconds,
> +            int_timeout_milliseconds,
>              &error)
> +        PyEval_RestoreThread(_save)
>  
>          if dbus_error_is_set(&error):
>              errormsg = error.message
> @@ -629,7 +638,11 @@ cdef class PendingCall:
>          return message
>  
>      def block(self):
> +        cdef PyThreadState *_save
> +        _save = PyEval_SaveThread()
> +        # NOTE: Don't use Python code until RestoreThread
>          dbus_pending_call_block(self.pending_call)
> +        PyEval_RestoreThread(_save)
>  
>      def set_notify(self, reply_handler, error_handler):
>          user_data = (reply_handler, error_handler)
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--