Context manager

Kõik acquire() ja release() kasutavad objektid saavad eelnevalt mainitud kutsed asendada with-võtmesõnaga. Selle eelis on puhtam ja turvalisem kood: erindi tekkel automaatne lukkudest vabastamine.

Toetatud objektid

1. Lock:

   lock = threading.Lock()
   with lock:
       print("Lock Shop closed - only one thread at the time")
   

2. RLock:

   rlock = threading.RLock()
   def recursive(n):
       with rlock:
           print(" Inside RLock: ", n)
           if n > 0:
               recursive(n-1)
   recursive(2)
   

3. Condition:

   # Consume one item
   with cv:
       while not an_item_is_available():
           cv.wait()
       get_an_available_item()
   
   # Produce one item
   with cv:
       make_an_item_available()
       cv.notify()
   

4. Semaphore:

   sema = threading.Semaphore(2)  # max 2
   def worker(name):
       with sema:
           print(f"{name} inside semaphore")
   threading.Thread(target=worker, args=("A",)).start()
   threading.Thread(target=worker, args=("B",)).start()
   threading.Thread(target=worker, args=("C",)).start()
   

5. Semaphore:

   bsema = threading.BoundedSemaphore(1)
   with bsema:
       print("BoundedSemaphore shop closed - only one thread at the time")