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 vote185 views1 answer
Pandas reemplazar nan por cero
Python
0 vote275 views1 answer
Aggregation with f() in django rest api
Python Django
0 vote195 views1 answer
Char count in python
Python
0 vote196 views1 answer
Visualizzare csv in pycharm pandas read_csv
Python
6 votes248 views2 answers
Get client ip flask
Python Flask
0 vote201 views1 answer
Raising a new style class which doesn't inherit from baseexception python
Python
5 votes191 views5 answers
Sorted function in python 3
Python
1 vote149 views1 answer
Python ignore return value
Python
0 vote197 views1 answer
How delete element from list python
Python
2 votes197 views1 answer
C:\Users\saverma2>notebook 'notebook' is not recognized as an internal or external command, operable program or batch file.
Python