#!/usr/bin/python
import threading
from socket import gethostbyname_ex

easyadns_debug = True # Enable/disable debugging messages. 

# Allow 50 simultaneous lookups
_lookup_pool = threading.BoundedSemaphore(value=50)

# Ensure data.add() is thread safe
_data_lock = threading.Lock()

def _lookup(name, data):
    if easyadns_debug: print "[%s] - Acquiring semaphore..." % name
    _lookup_pool.acquire() # Acquire semaphore

    if easyadns_debug: print "[%s] - Doing lookup" % name
    try:
        res = gethostbyname_ex(name) # Do lookup
    except:
        _lookup_pool.release()
        return

    _lookup_pool.release() # Release semaphore
    _data_lock.acquire()
    for ip in res[2]: # Add results to dataset
        data.add(ip)
    _data_lock.release()
    if easyadns_debug: print "[%s] - Done" % name

data = set()
threads = list()

for name in open('proxies.txt').readlines():
    name = name.strip()
    if name:
        t = threading.Thread(target=_lookup, args=(name, data))
        t.start()
        threads.append(t)

if easyadns_debug: print "Done starting threads"
for t in threads:
    t.join() # Wait for threads to finish
if easyadns_debug: print "Last thread exited"