jython_select_bug.py

"""
Check out the differences between the select.poll functionality in CPython
and Jython.
"""
import socket
import errno
import threading
import traceback
import logging
import select

logging.basicConfig(level=logging.DEBUG)
logger = logging.getLogger('select_bug')

class SocketPollThread(threading.Thread):
    def __init__(self, address, name):
        threading.Thread.__init__(self, name=name)
        self.address = address
        self.connect_status_results = []
        self.final_result = ""
        self.poller = select.poll()

    def run(self):
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        sock.setblocking(0)

        try:
            connect_errno = sock.connect_ex(self.address)
            if connect_errno != errno.EINPROGRESS:
                self.final_result = "[%s] socket did not enter EINPROGRESS as expected" % (self.getName(),)
                return
            else:
                self.poller.register(sock.fileno())

            fd_map = {sock.fileno(): sock}
            while True:
                events = self.poller.poll()
                for fd, event in events:
                    logger.debug("sock.fileno = " + str(sock.fileno()) + ", fd = " + str(fd))
                    if sock.fileno() == fd:
                        self.final_result = "fd and sock.fileno() values match"
                    else:
                        self.final_result = "FAIL: fd and sock.fileno() values differ"
                    return
        except:
            self.final_result = traceback.format_exc()
        finally:
            try:
                sock.shutdown(0)
                sock.shutdown(1)
                sock.close()
            except:
                pass


if __name__ == "__main__":
    t = SocketPollThread(address=('127.0.0.1', 8000), name="SelectTest-1")
    t.start()
    t.join()
    logger.debug(t.final_result)

vagrant@vagrant-ubuntu-trusty-64:/vagrant_data$ uname -a
Linux vagrant-ubuntu-trusty-64 3.13.0-52-generic #86-Ubuntu SMP Mon May 4 04:32:59 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
vagrant@vagrant-ubuntu-trusty-64:/vagrant_data$ python -m SimpleHTTPServer 8000 &
vagrant@vagrant-ubuntu-trusty-64:/vagrant_data$ Serving HTTP on 0.0.0.0 port 8000 ...
[1] 26047

vagrant@vagrant-ubuntu-trusty-64:/vagrant_data$ python jython_select_bug.py
DEBUG:select_bug:sock.fileno = 3, fd = 3
DEBUG:select_bug:fd and sock.fileno() values match

vagrant@vagrant-ubuntu-trusty-64:/vagrant_data$ java -jar jython-standalone-2.7.1b2.jar jython_select_bug.py
DEBUG:select_bug:sock.fileno = <_realsocket at 0x2 type=client open_count=1 channel=[id: 0x7d79f1d2] timeout=0.0>, fd = <_socket._socketobject object at 0x3>
DEBUG:select_bug:FAIL: fd and sock.fileno() values differ```

NOTE - I originally thought this was a bug in the Jython poll impl but instead was a misuse of the API. poll.register accepts a fd that needs to be obtained by calling fileno() on a socket, file object, etc.