proxy testing code with multi-thread

[shore.cloud]

hi all
I'm now meeting some problem when using threading to test whether or
not a proxy is good or not
and the total number of proxies is just 60
but each time my programme stopped just at approaching the end,
say,
for each proxy I made a proxy
but it just stopped working at maybe 58 or 59 or some other similar
number
below is the code
any advice will be greatly appreciated!
-------------------------------------------------------------------------------------------------------------------------------
import urllib2
import threading
import time
import traceback
import sys

class mythread(threading.Thread):
def __init__(self, agent, i):
self.agent = agent
self.index = i
threading.Thread.__init__(self)

def run(self):
tryagent(self.agent, self.index)

def tryagent(agent, i):
global mutex, bad, goodlist, total
proxy_handler = urllib2.ProxyHandler({'http':'http://' + agent})
opener = urllib2.build_opener(proxy_handler)
try:
response = opener.open('http://www.indeed.com/q-Director-Of-
Finance-jobs.html')
data_web = response.read()
if data_web.find('All director finance job') == -1:
#mutex.acquire( )
bad = bad + 1
total = total + 1
print 'agent %d %s is bad in try' %(i, agent,)
print 'bad number: %d total:%d' %(bad,total)
#mutex.release( )

else:
#mutex.acquire( )
total = total + 1
print 'agent %d %s is good' %(i, agent)
goodlist.append(agent)
#mutex.release( )
except:
# mutex.release( )
#mutex.acquire( )
traceback.print_exc()
total = total + 1
bad = bad + 1
print 'agent %d %s is bad in except' %(i, agent,)
print 'bad number: %d total: %d' %(bad,total)
#mutex.release( )


agentlist = open('F:\\Python25\\works\\agent.txt',
'r').read().split('\n')
mutex = threading.Lock()
total = 0
bad = 0
goodlist = []
threads = []
print 'total proxy number:%d' %(len(agentlist))

if len(agentlist) <= 100:
for i, agent in enumerate(agentlist):
threads.append(mythread(agent, i))
for thread in threads:
thread.start()
for thread in threads:
thread.join()
else:
i = 1
while i * 100 < len(agentlist):
i = i + 1
threads = []
for j in range(100):
threads.append(agentlist[j + 100 * i])
for thread in threads:
thread.start()
for thread in threads:
thread.join()
i = i - 1
threads = []
for k in range(len(agentlist) - 100 * i):
threads.append(agentlist[100 * i + k])
for thread in threads:
thread.start()
for thread in threads:
thread.join()


urllib2.socket.setdefaulttimeout(1)
newproxysock = open('F:\\Python25\\works\\proxy.txt', 'w')
saveout = sys.stdout
sys.stdout = newproxysock
for i, proxy in enumerate(goodlist):
print proxy
sys.stdout = saveout
newproxysock.close()