[zeromq-dev] successive connect/disconnect fails after a while

[Boaz Kelmer]

Many attempts to  connect()/disconnect() will eventually fail with EINVAL.
It seems that the number of successful connect()/disconnect() pairs is somewhat correlated
with the number of allowed open file descriptors for the process, as if some descriptors are
not closed:

$ python dis.py
RLIMIT_NOFILE: soft=100, hard=200000
4623: Error: Invalid argument

$ cat dis.py

import sys
import socket
import resource
import zmq

def main():
    ctx = zmq.Context()
    s = ctx.socket(zmq.SUB)
    s.setsockopt(zmq.SUBSCRIBE, "")
    addr = "tcp://%s:6666" % socket.gethostname()
    soft, hard = resource.getrlimit(resource.RLIMIT_NOFILE)
    resource.setrlimit(resource.RLIMIT_NOFILE, (100, hard))
    soft, hard = resource.getrlimit(resource.RLIMIT_NOFILE)
    print "RLIMIT_NOFILE: soft=%s, hard=%s" % (soft, hard)
    for i in xrange(1000000):
        try:
            s.connect(addr)
            s.disconnect(addr)
        except Exception as ex:
            print >> sys.stderr, "%d: Error: %s" % (i, ex)
            return

if __name__ == '__main__':
    main()