InputDevice.read() - Recource temporarily unaivalable

[gvalkov]

InputDevice.read() - Recource temporarily unaivalable

[gvalkov]

Hello @Avraamu,

I must admit that the device.read() method must be documented more thoroughly. What this exception is telling you is that there is nothing to be read from the input device at the moment. Since the device is opened in non-blocking mode, you first have to check if there is anything that can be read from it. One way to do that is with select. For example:

from select import select

while True:
    # The select() call will block until there are events on dev_obj.
    r, w, x = select([self.dev_obj], [], [])
    # .read() will surely return a list of events now.
    for event in self.dev_obj.read():
        yield event

This is exactly what the device.read_loop() method does btw. So, your solution might be as simple as modifying your main() function to check if the device is readable:

def main():
    controller = ControllerInput(controller_name)
    while True:
        select([controller.dev_obj], [], [])
        controller.get_axis_pos()

# you may remove the 'if event_gen is not None' line from 'get_axis_pos()'

One issue with this approach is that your program will only be able to do things when there are events from the pad. This can be addressed in several ways (e.g. select has a timeout parameter or you could use a thread for input handling). I think issue #15 also touched on this subject.

Let me know if this helps.

Kind regards,
Georgi

[philipgroet]

Hello Georgi,

Thanks for the quick reply!
I'm surprised the solution was so simple! I got the example working as you said, with the select function.
Sorry for bothering you with such simple questions :)

Regards Avraamu