Semaphore example in python

Semaphore in python

import threading

sem = threading.Semaphore() # or sem = threading.Semaphore(value=n)
sem.acquire()
# Your code here
sem.release()

Semaphore example in 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()

Source: bogotobogo.com

Similar codes

4 votes165 views3 answers
Display prime numbers between two intervals in python
Python
2 votes228 views1 answer
Run flask application in development mode stack overflow
Python
0 vote172 views1 answer
Jaccard distance python
Python
0 vote159 views1 answer
Conda cassandra
Python
1 vote167 views2 answers
Java Array objects
Python
0 vote173 views1 answer
Pyqt5 close event
Python
0 vote152 views1 answer
Python sum 1-50
Python
0 vote204 views1 answer
Pass in 2 numbers, A and B. You should create a list with A rows and B columns, then populate each cell
Python
2 votes189 views1 answer
Python bisect
Python
0 vote186 views1 answer
How to config django templates with pathlib
Python