Question

我有以下代码：

from multiprocessing import Process, Manager, Event

manager = Manager()
shared_Queue = manager.Queue(10)
ev = Event()

def do_this(shared_queue, ev):
    while not ev.is_set():
        if not shared_Queue.__getattribute__('empty')():
           item = shared_queue.get()
           print item
    print 'released!'

subprocs = []
for i in xrange(10):
    subproc = Process(target=do_this, args=(shared_Queue, ev, ))
    subprocs.append(subproc)
    subproc.start()

现在，如果我运行它，我会问这些进程是否还活着：

for subproc in subprocs: print subproc.is_alive()

当然，我得到了所有的真理。

经过几次这样做：*如果我不做这些就没有错误！

shared_Queue.put(3)
shared_Queue.put(5)

现在我想使用以下命令设置事件以杀死所有这些：

ev.set()

但后来没有看到＆＃39;发布！＆＃39; 10次，我得到不同数量的这些打印件，大约2到5秒后，我得到了一堆错误：

released!
released!
released!
released!
released!
released!
released!
Process Process-10:
Traceback (most recent call last):
  File 
 "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/
multiprocessing/process.py", line 258, in _bootstrap
    self.run()
  File 
"/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/
multiprocessing/process.py", line 114, in run
    self._target(*self._args, **self._kwargs)
  File "<input>", line 10, in do_this
  File "<string>", line 2, in get
  File 
"/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/
multiprocessing/managers.py", line 759, in _callmethod
    kind, result = conn.recv()
EOFError
Process Process-5:
Traceback (most recent call last):
  File 
"/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/
multiprocessing/process.py", line 258, in _bootstrap
    self.run()
  File 
"/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/
multiprocessing/process.py", line 114, in run
    self._target(*self._args, **self._kwargs)
  File "<input>", line 10, in do_this
  File "<string>", line 2, in get
  File 
"/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/
multiprocessing/managers.py", line 759, in _callmethod
    kind, result = conn.recv()
EOFError
Process Process-7:
Traceback (most recent call last):
  File 
"/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/
multiprocessing/process.py", line 258, in _bootstrap
    self.run()
  File 
"/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/
multiprocessing/process.py", line 114, in run
    self._target(*self._args, **self._kwargs)
  File "<input>", line 10, in do_this
  File "<string>", line 2, in get
  File 
"/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/
multiprocessing/managers.py", line 759, in _callmethod
    kind, result = conn.recv()
EOFError

为什么某些进程无法识别事件集并在以后显示为错误？是否有更好的方式来表明他们死亡？

Answer 1

感谢评论stovfl，你是对的，ev.set（）不会杀死任何我不小心使用这个词的东西。

至于我遇到的问题，我了解到多处理队列是进程和线程安全的，这意味着，如果队列已经满了，我的进程将在写入队列之前暂停。

如果我尝试设置事件，而某些进程仍在等待向完整队列写入内容，则他们将无法识别事件集。

关键是要清空所有队列，让进程写入它，然后到达可以检查事件的第一行！

Python多处理过程：使用Manager Queue时识别事件的延迟

1 个答案: