def inputhook_wx3():
    """Run the wx event loop by processing pending events only.

    This is like inputhook_wx1, but it keeps processing pending events
    until stdin is ready.  After processing all pending events, a call to
    time.sleep is inserted.  This is needed, otherwise, CPU usage is at 100%.
    This sleep time should be tuned though for best performance.
    """
    # We need to protect against a user pressing Control-C when IPython is
    # idle and this is running. We trap KeyboardInterrupt and pass.
    try:
        app = wx.GetApp()  # @UndefinedVariable
        if app is not None:
            assert wx.Thread_IsMain()  # @UndefinedVariable

            # The import of wx on Linux sets the handler for signal.SIGINT
            # to 0.  This is a bug in wx or gtk.  We fix by just setting it
            # back to the Python default.
            if not callable(signal.getsignal(signal.SIGINT)):
                signal.signal(signal.SIGINT, signal.default_int_handler)

            evtloop = wx.EventLoop()  # @UndefinedVariable
            ea = wx.EventLoopActivator(evtloop)  # @UndefinedVariable
            t = clock()
            while not stdin_ready():
                while evtloop.Pending():
                    t = clock()
                    evtloop.Dispatch()
                app.ProcessIdle()
                # We need to sleep at this point to keep the idle CPU load
                # low.  However, if sleep to long, GUI response is poor.  As
                # a compromise, we watch how often GUI events are being processed
                # and switch between a short and long sleep time.  Here are some
                # stats useful in helping to tune this.
                # time    CPU load
                # 0.001   13%
                # 0.005   3%
                # 0.01    1.5%
                # 0.05    0.5%
                used_time = clock() - t
                if used_time > 10.0:
                    # print 'Sleep for 1 s'  # dbg
                    time.sleep(1.0)
                elif used_time > 0.1:
                    # Few GUI events coming in, so we can sleep longer
                    # print 'Sleep for 0.05 s'  # dbg
                    time.sleep(0.05)
                else:
                    # Many GUI events coming in, so sleep only very little
                    time.sleep(0.001)
            del ea
    except KeyboardInterrupt:
        pass
    return 0
Run the wx event loop by processing pending events only.

    This is like inputhook_wx1, but it keeps processing pending events
    until stdin is ready.  After processing all pending events, a call to
    time.sleep is inserted.  This is needed, otherwise, CPU usage is at 100%.
    This sleep time should be tuned though for best performance.