Threading Module Thread lock

by: dimalott, 6 years ago


I'm running the code in the tutorial (with a Mac) with the print lock but still getting scrambled output (as if the thread lock isn't working).  Any advice?  



import queue
import threading
import time
from queue import Queue

print_lock = threading.Lock()

def exampleJob(worker):
    time.sleep(.5) # pretend to do some work.
    with print_lock:
        print(threading.current_thread().name,worker)

# The threader thread pulls an worker from the queue and processes it
def threader():
    while True:
        # gets an worker from the queue
        worker = q.get()

        # Run the example job with the avail worker in queue (thread)
        exampleJob(worker)

        # completed with the job
        q.task_done()

# Create the queue and threader
q = Queue()

# how many threads are we going to allow for
for x in range(10):
     t = threading.Thread(target=threader)

     # classifying as a daemon, so they will die when the main dies
     t.daemon = True

     # begins, must come after daemon definition
     t.start()

start = time.time()
print ("Start time :", time.ctime(start) )

# 20 jobs assigned.
for worker in range(20):
    q.put(worker)

# wait until the thread terminates.
q.join()

# with 10 workers and 20 tasks, with each task being .5 seconds, then the completed job
# is ~1 second using threading. Normally 20 tasks with .5 seconds each would take 10 seconds.

end = time.time()
print ("End time :", time.ctime (end))

print('Entire job took:', (end - start) , "seconds" )





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