Exemplo de semáforo em Python
import threading
import time
import logging
logging.basicConfig(level=logging.DEBUG,
format='(%(threadName)-9s) %(message)s',)
class ThreadPool(object):
def __init__(self):
super(ThreadPool, self).__init__()
self.active = []
self.lock = threading.Lock()
def makeActive(self, name):
with self.lock:
self.active.append(name)
logging.debug('Running: %s', self.active)
def makeInactive(self, name):
with self.lock:
self.active.remove(name)
logging.debug('Running: %s', self.active)
def f(s, pool):
logging.debug('Waiting to join the pool')
with s:
name = threading.currentThread().getName()
pool.makeActive(name)
time.sleep(0.5)
pool.makeInactive(name)
if __name__ == '__main__':
pool = ThreadPool()
s = threading.Semaphore(3)
for i in range(10):
t = threading.Thread(target=f, name='thread_'+str(i), args=(s, pool))
t.start()
Weary Weasel