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# Copyright (c) 2005 Allan Saddi <allan@saddi.com>
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
#
# $Id$
__author__ = 'Allan Saddi <allan@saddi.com>'
__version__ = '$Revision$'
import sys
import socket
import select
import signal
import errno
try:
import fcntl
except ImportError:
def setCloseOnExec(sock):
pass
else:
def setCloseOnExec(sock):
fcntl.fcntl(sock.fileno(), fcntl.F_SETFD, fcntl.FD_CLOEXEC)
__all__ = ['SingleServer']
class SingleServer(object):
def __init__(self, jobClass=None, jobArgs=(), **kw):
self._jobClass = jobClass
self._jobArgs = jobArgs
def run(self, sock, timeout=1.0):
"""
The main loop. Pass a socket that is ready to accept() client
connections. Return value will be True or False indiciating whether
or not the loop was exited due to SIGHUP.
"""
# Set up signal handlers.
self._keepGoing = True
self._hupReceived = False
# Might need to revisit this?
if not sys.platform.startswith('win'):
self._installSignalHandlers()
# Set close-on-exec
setCloseOnExec(sock)
# Main loop.
while self._keepGoing:
try:
r, w, e = select.select([sock], [], [], timeout)
except select.error, e:
if e[0] == errno.EINTR:
continue
raise
if r:
try:
clientSock, addr = sock.accept()
except socket.error, e:
if e[0] in (errno.EINTR, errno.EAGAIN):
continue
raise
setCloseOnExec(clientSock)
if not self._isClientAllowed(addr):
clientSock.close()
continue
# Hand off to Connection.
conn = self._jobClass(clientSock, addr, *self._jobArgs)
conn.run()
self._mainloopPeriodic()
# Restore signal handlers.
self._restoreSignalHandlers()
# Return bool based on whether or not SIGHUP was received.
return self._hupReceived
def _mainloopPeriodic(self):
"""
Called with just about each iteration of the main loop. Meant to
be overridden.
"""
pass
def _exit(self, reload=False):
"""
Protected convenience method for subclasses to force an exit. Not
really thread-safe, which is why it isn't public.
"""
if self._keepGoing:
self._keepGoing = False
self._hupReceived = reload
def _isClientAllowed(self, addr):
"""Override to provide access control."""
return True
# Signal handlers
def _hupHandler(self, signum, frame):
self._hupReceived = True
self._keepGoing = False
def _intHandler(self, signum, frame):
self._keepGoing = False
def _installSignalHandlers(self):
supportedSignals = [signal.SIGINT, signal.SIGTERM]
if hasattr(signal, 'SIGHUP'):
supportedSignals.append(signal.SIGHUP)
self._oldSIGs = [(x,signal.getsignal(x)) for x in supportedSignals]
for sig in supportedSignals:
if hasattr(signal, 'SIGHUP') and sig == signal.SIGHUP:
signal.signal(sig, self._hupHandler)
else:
signal.signal(sig, self._intHandler)
def _restoreSignalHandlers(self):
for signum,handler in self._oldSIGs:
signal.signal(signum, handler)
if __name__ == '__main__':
class TestJob(object):
def __init__(self, sock, addr):
self._sock = sock
self._addr = addr
def run(self):
print "Client connection opened from %s:%d" % self._addr
self._sock.send('Hello World!\n')
self._sock.setblocking(1)
self._sock.recv(1)
self._sock.close()
print "Client connection closed from %s:%d" % self._addr
sock = socket.socket()
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
sock.bind(('', 8080))
sock.listen(socket.SOMAXCONN)
SingleServer(jobClass=TestJob).run(sock)
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