has_events(MPV__Simple* ctx)
    CODE:
    int ret;
    int pipefd = pipes[0];
    if (pipefd < 0)
        ret = -1;
    else {
        struct pollfd pfds[1] = {
            { .fd = pipefd, .events = POLLIN },
        };
        // Wait until there are possibly new mpv events
        poll(pfds,1,0);
        if (pfds[0].revents & POLLIN) {
            // Empty the pipe. Doing this before calling mpv_wait_event()
            // ensures that no wakeups are missed. It's not so important to
            // make sure the pipe is really empty (it will just cause some
            // additional wakeups in unlikely corner cases).
            char unused[256];
            read(pipefd, unused, sizeof(unused));
            ret = 1;
        }
        else {
            ret = 0;
        }
    }
    RETVAL = ret;
    OUTPUT: RETVAL