def _event_select(events):
    """Perform a select() over all the Events provided, returning the
    ones ready to be fired. Only WaitableEvents (including SleepEvents)
    matter here; all other events are ignored (and thus postponed).
    """
    # Gather waitables and wakeup times.
    waitable_to_event = {}
    rlist, wlist, xlist = [], [], []
    earliest_wakeup = None
    for event in events:
        if isinstance(event, SleepEvent):
            if not earliest_wakeup:
                earliest_wakeup = event.wakeup_time
            else:
                earliest_wakeup = min(earliest_wakeup, event.wakeup_time)
        elif isinstance(event, WaitableEvent):
            r, w, x = event.waitables()
            rlist += r
            wlist += w
            xlist += x
            for waitable in r:
                waitable_to_event[('r', waitable)] = event
            for waitable in w:
                waitable_to_event[('w', waitable)] = event
            for waitable in x:
                waitable_to_event[('x', waitable)] = event

    # If we have a any sleeping threads, determine how long to sleep.
    if earliest_wakeup:
        timeout = max(earliest_wakeup - time.time(), 0.0)
    else:
        timeout = None

    # Perform select() if we have any waitables.
    if rlist or wlist or xlist:
        rready, wready, xready = select.select(rlist, wlist, xlist, timeout)
    else:
        rready, wready, xready = (), (), ()
        if timeout:
            time.sleep(timeout)

    # Gather ready events corresponding to the ready waitables.
    ready_events = set()
    for ready in rready:
        ready_events.add(waitable_to_event[('r', ready)])
    for ready in wready:
        ready_events.add(waitable_to_event[('w', ready)])
    for ready in xready:
        ready_events.add(waitable_to_event[('x', ready)])

    # Gather any finished sleeps.
    for event in events:
        if isinstance(event, SleepEvent) and event.time_left() == 0.0:
            ready_events.add(event)

    return ready_events
dataset/ETHPy150Open beetbox/beets/beets/util/bluelet.py/_event_select/original