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

0 vote350 views1 answer
TypeError: Direct assignment to the forward side of a many-to-many set is prohibited. Use .set() instead
Python
0 vote346 views1 answer
How to store a int value in django sessions
Python Django
2 votes326 views2 answers
Pandas read excel certain columns
Python
0 vote402 views1 answer
Make button bigger tkinter with grid
Python
11 votes360 views3 answers
Send message to specific channel discord.py
Python
38 votes320 views3 answers
Pil python install
Python
0 vote318 views1 answer
@tf.function
Python
82 votes335 views4 answers
Python read json file array
Python
1 vote306 views2 answers
Save timestamp python
Python
1 vote295 views1 answer
Code to calculate dice score
Python