#!/usr/bin/env python

# Written By: Avner BenHanoch

# Date: 2011-03-08

"""

epoll server test program, identical to the select server.py test program 

that uses epoll instead of select

can be used with the select client.py test program

NOTE: epoll is only supported in python 2.6 and above

"""

import select

import socket

import sys

import time

HOST = ''         # IP for listening on

if len (sys.argv) > 1: HOST = sys.argv[1]

PPORT = 50007     # pyload port

CPORT = PPORT + 1 # ctrl port

SIZE = 8192      # size of recv buf

backlog = 1

def print_info (msg):

	print "INFO: ", msg

#server for payload channel 

pserver = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

pserver.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) 

pserver.bind((HOST,PPORT))

pserver.listen(backlog)

#server for ctrl channel 

cserver = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

cserver.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) 

cserver.bind((HOST,CPORT))

cserver.listen(backlog)

psocket = None #connected payload socket

csocket = None #connected  ctrl   socket

totalBytes = 0

timeout = 1000

epfd = select.epoll()

epfd.register(pserver.fileno(), select.EPOLLIN)

epfd.register(cserver.fileno(), select.EPOLLIN)

while True:

	print_info ("waiting for traffic; sleeping %d seconds on epoll..." % timeout) #dbg

	events = epfd.poll(timeout)

	print_info ("--------> epoll returned %d input fds" % len(events) ) #dbg

	for fileno, event in events:

		if cserver and fileno == cserver.fileno(): # new connection on ctrl server socket

			if csocket:  raise Exception ("payload socket is already connected")

			csocket, address = cserver.accept()

			epfd.register(csocket.fileno(), select.EPOLLIN)

			print_info ("accepted ctrl socket; peer=%s" % str(address))

		elif pserver and fileno == pserver.fileno(): # new connection on payload server socket

			if psocket:  raise Exception ("payload socket is already connected")

			psocket, address = pserver.accept()

			epfd.register(psocket.fileno(), select.EPOLLIN)

			print_info ("accepted payload socket; peer=%s" % str(address))

		elif csocket and fileno == csocket.fileno(): #data on ctrl socket

			buf = csocket.recv(SIZE)

			if buf:

				print_info ("got instruction on ctrl socket")

				t = float(buf)

				print_info (">>> going to sleep for %f seconds..." % t)

				t1 = time.time()

				time.sleep(t)

				t2 = time.time()

				print_info ("<<< sleep was finished after %f seconds" % (t2-t1))

			else: #EOF

				print_info ("got EOF on ctrl socket")

				epfd.unregister(csocket.fileno())

				csocket.close()

				csocket = None

				if psocket: timeout = 1 # wait for ordinary close of payload socket

		elif psocket and fileno == psocket.fileno() : #data on payload socket

			buf = psocket.recv(SIZE)

			if buf:

				size = len(buf)

				print_info ("got data on payload socket; len is: %d" % size) #dbg

				totalBytes += size

			else: #EOF

				print_info (" ====> got EOF on payload socket; total bytes received: %d <<=====" % totalBytes)

				totalBytes = 0

				epfd.unregister(psocket.fileno())

				psocket.close()

				psocket = None

				if csocket: timeout = 1 # wait for ordinary close of ctrl socket

	if not events: #timeout

		print_info ("epoll (%d seconds) timeout" % timeout)

		if csocket:

			print_info ("closing ctrl socket")

			epfd.unregister(csocket.fileno())

			csocket.close()

			csocket = None

		if psocket:

			print_info (" ====> closing payload socket (without EOF); total bytes received: %d <<=====" % totalBytes)

			totalBytes = 0

			epfd.unregister(psocket.fileno())

			psocket.close()

			psocket = None

		timeout = 1000

if pserver: pserver.close()

if cserver: cserver.close()

if psocket: psocket.close()

if csocket: csocket.close()

if epfd:    epfd.close()