demonstration of deadlock with eventlet.green.subprocess on python 2.7

pipetest.py

import os
import sys
import tempfile

import eventlet
from eventlet.green import subprocess


sock = eventlet.listen(('127.0.0.1', 0))
port = sock.getsockname()[1]


def handler(sock, addr):
    while True:
        d = sock.recv(4096)
        if not d:
            break
        sock.sendall(d)
    sock.close()


def server():
    eventlet.serve(sock, handler)

eventlet.spawn(server)


if __name__ == '__main__':
    modpath = os.path.join(tempfile.mkdtemp('_t'), 'foo.py')
    modcontents = """
import random
import socket
import sys

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect(('127.0.0.1', %d))

def randbytes(numbytes):
    return ''.join(chr(random.getrandbits(8)) for i in xrange(numbytes))

for i in xrange(1000):
    dout = randbytes(256)
    sock.sendall(dout)
    assert sock.recv(4096) == dout
    sys.stderr.write(randbytes(256))
    sys.stdout.write(randbytes(256))
""" % (port, )
    with open(modpath, 'w') as f:
        f.write(modcontents)
    devnull = open(os.devnull, 'wb')
    p = subprocess.Popen([sys.executable, modpath],
        #stdout=devnull,
        #stderr=devnull)
        stdout=subprocess.PIPE,
        stderr=subprocess.PIPE)
    p.communicate()
    print p.returncode