# Copyright 2018 John-Mark Gurney.
# 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.
#
#	$Id$
#

import Queue
import threading
import time
import random

def sleepfun(q, lngth, extlst, idobj):

	while not extlst:
		#factor = (random.random() + 1) * 4
		factor = 1
		factor = (random.random() * .5 + 1)
		time.sleep(lngth * factor)
		q.put((idobj, time.time()))

def run():
	sleeplength = .5
	exitlist = []
	nthreads = 20

	q = Queue.Queue()

	thds = {}
	lastcheck = {}

	for i in xrange(nthreads):
		obj = object()
		thr = threading.Thread(target=sleepfun, args=(q, sleeplength, exitlist, obj))
		thds[obj] = thr
		lastcheck[obj] = time.time()
		thr.start()

	try:
		while True:
			for i in xrange(nthreads*3):
				obj, tm = q.get()
				lastcheck[obj] = tm

			cur = time.time()
			for i in lastcheck.keys():
				if not thds[i].isAlive():
					print 'thread died.'
					del thds[i]
					del lastcheck[i]
					continue

				print 'last checkin:', cur - lastcheck[i]
				if cur - lastcheck[i] > 2 * sleeplength:
					print 'thread is stuck:', `obj`, 'since:', time.ctime(lastcheck[i])
	except KeyboardInterrupt:
		print 'trying to exit...'
		print time.ctime(time.time())
		exitlist.append(True)
		for i in thds:
			thds[i].join()

if __name__ == '__main__':
	run()