Files
deb-python-concurrent.futures/python3/moprocessmoproblems.py

59 lines
1.3 KiB
Python

import multiprocessing
import queue
def _process_worker(q):
while True:
try:
something = q.get(block=True, timeout=0.1)
except queue.Empty:
return
else:
print('Grabbed item from queue:', something)
def _make_some_processes(q):
processes = []
for _ in range(10):
p = multiprocessing.Process(target=_process_worker, args=(q,))
p.start()
processes.append(p)
return processes
def _do(i):
print('Run:', i)
q = multiprocessing.Queue()
print('Created queue')
for j in range(30):
q.put(i*30+j)
processes = _make_some_processes(q)
print('Created processes')
while not q.empty():
pass
print('Q is empty')
# Without the two following commented lines, the output on Mac OS 10.5 (the
# output is as expected on Linux) will be:
# Run: 0
# Created queue
# Grabbed item from queue: 0
# ...
# Grabbed item from queue: 29
# Created processes
# Q is empty
# Run: 1
# Created queue
# Grabbed item from queue: 30
# ...
# Grabbed item from queue: 59
# Created processes
# Q is empty
# Run: 2
# Created queue
# Created processes
# <no further output>
# for p in processes:
# p.join()
for i in range(100):
_do(i)