Does multiprocessing support named pipes （FIFO)?

问题:

Multiprocessing's Pipes and Queue are based on anonymous pipes, does the multiprocessing of Python provide named pipes （FIFO）?

回答1:

There's no built-in support for a cross-platform abstraction of named pipes in multiprocessing.

If you only care about Unix, or only about Windows, you can of course create named pipes manually. For Unix, mkfifo is in the stdlib. For Windows, you have to use ctypes or cffi, or a third-party library like win32api to call CreateFile with the right arguments.

Trying to abstract over the semantic differences between the two is pretty painful, which is probably why the stdlib doesn't attempt to do so. (For example, Windows named pipes are volatile; posix named pipes are permanent.)

Here's a trivial Unix example:

import multiprocessing
import os

def child():
    with open('mypipe', 'rb') as p:
        print(p.read())

def main():
    try:
        os.mkfifo('mypipe')
    except FileExistsError:
        pass
    multiprocessing.Process(target=child).start()
    with open('mypipe', 'wb') as p:
        p.write(b'hi')
    os.remove('mypipe')

if __name__ == '__main__':
    main()

回答2:

class multiprocessing.connection.Listener([address[, family[, backlog[, authkey]]]])

A wrapper for a bound socket or Windows named pipe which is ‘listening’ for connections.address is the address to be used by the bound socket or named pipe of the listener object.