Python中的多处理队列

Question

我正在尝试在Python中的多处理库中使用队列。执行下面的代码后（打印语句起作用），但是在调用Queue上的join之后，这些进程没有退出，并且仍然存在。我如何终止其余过程？

谢谢！

def MultiprocessTest(self):
  print "Starting multiprocess."
  print "Number of CPUs",multiprocessing.cpu_count()

  num_procs = 4
  def do_work(message):
    print "work",message ,"completed"

  def worker():
    while True:
      item = q.get()
      do_work(item)
      q.task_done()

  q = multiprocessing.JoinableQueue()
  for i in range(num_procs):
    p = multiprocessing.Process(target=worker)
    p.daemon = True
    p.start()

  source = ['hi','there','how','are','you','doing']
  for item in source:
    q.put(item)
  print "q close"
  q.join()
  #q.close()
  print "Finished everything...."
  print "num active children:",multiprocessing.active_children()

Answer 1

尝试这个：

import multiprocessing

num_procs = 4
def do_work(message):
  print "work",message ,"completed"

def worker():
  for item in iter( q.get, None ):
    do_work(item)
    q.task_done()
  q.task_done()

q = multiprocessing.JoinableQueue()
procs = []
for i in range(num_procs):
  procs.append( multiprocessing.Process(target=worker) )
  procs[-1].daemon = True
  procs[-1].start()

source = ['hi','there','how','are','you','doing']
for item in source:
  q.put(item)

q.join()

for p in procs:
  q.put( None )

q.join()

for p in procs:
  p.join()

print "Finished everything...."
print "num active children:", multiprocessing.active_children()