学步园

wait_events(int timeout_ms)
{
    if (_handles.empty()) {
        if (WaitMessage()) {
            return process_system_events();
        } else {
            THROW("wait failed %d", GetLastError());
        }
    }
    DWORD wait_res = MsgWaitForMultipleObjectsEx(_handles.size(),  &_handles[0], timeout_ms,
                                                 QS_ALLINPUT, 0);
    if (wait_res == WAIT_TIMEOUT) {
        return false;
    }

    if (wait_res == WAIT_FAILED) {
        THROW("wait failed %d", GetLastError());
    }

    int event_index = wait_res - WAIT_OBJECT_0;
    if (event_index == _handles.size()) {
        return process_system_events();
    } else if ((event_index >= 0) && (event_index < (int)_handles.size())) {
        _events[event_index]->action();
        return false;
    } else {
        THROW("invalid event id");
    }
}