#!/usr/bin/env python

# encoding: utf-8

import sys

import threading

import time

io_lock = threading.Lock()

blocker = threading.Lock()

def block(i):

t = threading.current_thread()

with io_lock:

print '%s with ident %s going to sleep' % (t.name, t.ident)

if i:

blocker.acquire() # acquired but never released

time.sleep(0.2)

with io_lock:

print t.name, 'finishing'

return

# Create and start several threads that "block"

threads = [ threading.Thread(target=block, args=(i,)) for i in range(3) ]

for t in threads:

t.setDaemon(True)

t.start()

# Map the threads from their identifier to the thread object

threads_by_ident = dict((t.ident, t) for t in threads)

# Show where each thread is "blocked"

time.sleep(0.01)

with io_lock:

for ident, frame in sys._current_frames().items():

t = threads_by_ident.get(ident)

if not t:

# Main thread

continue

print t.name, 'stopped in', frame.f_code.co_name,

print 'at line', frame.f_lineno, 'of', frame.f_code.co_filename