multiprocess.py 文件源码

def _import_mp():
    global Process, Queue, Pool, Event, Value, Array
    try:
        from multiprocessing import Manager, Process
        #prevent the server process created in the manager which holds Python 
        #objects and allows other processes to manipulate them using proxies
        #to interrupt on SIGINT (keyboardinterrupt) so that the communication
        #channel between subprocesses and main process is still usable after
        #ctrl+C is received in the main process.
        old=signal.signal(signal.SIGINT, signal.SIG_IGN)
        m = Manager()
        #reset it back so main process will receive a KeyboardInterrupt
        #exception on ctrl+c
        signal.signal(signal.SIGINT, old)
        Queue, Pool, Event, Value, Array = (
                m.Queue, m.Pool, m.Event, m.Value, m.Array
        )
    except ImportError:
        warn("multiprocessing module is not available, multiprocess plugin "
             "cannot be used", RuntimeWarning)