python的SIGIO handler，sigiohandler,On Linux, us

python的SIGIO handler，sigiohandler,On Linux, us

On Linux, use this to manage objects that can cause a SIGIO to be generated.It calls all registered objects.

# this handler manages a chain of registered callback functions. class SIGIOHandler:    def __init__(self):        self.handlers = []        self.on()    def on(self):        signal.signal(signal.SIGIO, self)    def off(self):        signal.signal(signal.SIGIO, signal.SIG_DFL)    def register(self, callback):        self.handlers.append(callback)        return len(self.handlers) - 1 # the handle    def unregister(self, handle=0):        if self.handlers:            del self.handlers[handle]    def __call__(self, sig, frame):        for h in self.handlers:            h(frame)# a singleton instance of the SIGIOHandler. Usually, users of this module only# have to register a DirectoryNotifier object here. Other objects (Dispatcher# objects) are registered with the poller (which is already set up to be called# when SIGIO occurs). But you may add your own hooks to it.try:    managerexcept NameError:    manager = SIGIOHandler()

Use this to register callable objects that need to handle SIGIO events. Thisallows asyncronous operation of various file, socket, and directory events.

Only works with Linux.