AttributeError：無法獲取屬性“journalerReader” <module '__mp_main__< div><div id="text_translate"><p> 我嘗試在 python 中實現 Lmax。我嘗試在 4 個進程中處理數據</p><pre>import disruptor import multiprocessing import random if __name__ == '__main__': cb = disruptor.CircularBuffer(5) def receiveWriter(): while(True): n = random.randint(5,20) cb.receive(n) def ReplicatorReader(): while(True): cb.replicator() def journalerReader(): while(True): cb.journaler() def unmarshallerReader(): while(True): cb.unmarshaller() def consumeReader(): while(True): print(cb.consume()) p1 = multiprocessing.Process(name="p1",target=ReplicatorReader) p1.start() p0 = multiprocessing.Process(name="p0",target=receiveWriter) p0.start() p1 = multiprocessing.Process(name="p1",target=ReplicatorReader) p1.start() p2 = multiprocessing.Process(name="p2",target=journalerReader) p2.start() p3 = multiprocessing.Process(name="p3",target=unmarshallerReader) p3.start() p4 = multiprocessing.Process(name="p4",target=consumeReader) p4.start()</pre><p> 但是我的代碼中出現了這個錯誤：</p><pre> Traceback (most recent call last): File "<string>", line 1, in <module> File "<string>", line 1, in <module> File "C:\Program Files\Python39\lib\multiprocessing\spawn.py", line 116, in spawn_main File "C:\Program Files\Python39\lib\multiprocessing\spawn.py", line 116, in spawn_main exitcode = _main(fd, parent_sentinel) exitcode = _main(fd, parent_sentinel) File "C:\Program Files\Python39\lib\multiprocessing\spawn.py", line 126, in _main File "C:\Program Files\Python39\lib\multiprocessing\spawn.py", line 126, in _main self = reduction.pickle.load(from_parent) self = reduction.pickle.load(from_parent) AttributeError: Can't get attribute 'unmarshallerReader' on <module '__mp_main__' from 'd:\\python\\RunDisruptor.py'> AttributeError: Can't get attribute 'consumeReader' on <module '__mp_main__' from 'd:\\python\\RunDisruptor.py'></pre></div></module>

Question

我嘗試在 python 中實現 Lmax。我嘗試在 4 個進程中處理數據

import disruptor  
import multiprocessing
import random

if __name__ == '__main__':

    cb = disruptor.CircularBuffer(5)

    def receiveWriter():
        while(True):
            n = random.randint(5,20)
            cb.receive(n)

    def ReplicatorReader():
        while(True):
            cb.replicator()

    def journalerReader():
        while(True):
            cb.journaler()

    def unmarshallerReader():
        while(True):
            cb.unmarshaller()

    def consumeReader():
        while(True):
            print(cb.consume())
    


  
    p1 = multiprocessing.Process(name="p1",target=ReplicatorReader)
    p1.start()

    p0 = multiprocessing.Process(name="p0",target=receiveWriter)
    p0.start()
    
    p1 = multiprocessing.Process(name="p1",target=ReplicatorReader)
    p1.start()

    p2 = multiprocessing.Process(name="p2",target=journalerReader)
    p2.start()

    p3 = multiprocessing.Process(name="p3",target=unmarshallerReader)
    p3.start()

    p4 = multiprocessing.Process(name="p4",target=consumeReader)
    p4.start()
   

但是我的代碼中出現了這個錯誤：

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "<string>", line 1, in <module>
  File "C:\Program Files\Python39\lib\multiprocessing\spawn.py", line 116, in spawn_main
  File "C:\Program Files\Python39\lib\multiprocessing\spawn.py", line 116, in spawn_main
    exitcode = _main(fd, parent_sentinel)
    exitcode = _main(fd, parent_sentinel)
  File "C:\Program Files\Python39\lib\multiprocessing\spawn.py", line 126, in _main
  File "C:\Program Files\Python39\lib\multiprocessing\spawn.py", line 126, in _main
    self = reduction.pickle.load(from_parent)
    self = reduction.pickle.load(from_parent)
AttributeError: Can't get attribute 'unmarshallerReader' on <module '__mp_main__' from 'd:\\python\\RunDisruptor.py'>
AttributeError: Can't get attribute 'consumeReader' on <module '__mp_main__' from 'd:\\python\\RunDisruptor.py'>

Answer 1

您的第一個問題是Process調用的目標不能在if __name__ == '__main__':塊內。 但：

正如我在你之前的一篇文章中提到的，我看到你可以跨多個進程共享一個CircularBuffer實例的唯一方法是實現一個托管的 class，令人驚訝的是，這並不難做到。 但是，當您創建托管 class 並創建該 class 的實例時，您所擁有的實際上是對 object 的代理引用。這有兩個含義：

1. 每個方法調用更像是對由您將啟動的管理器創建的特殊服務器進程的遠程過程調用，因此比本地方法調用具有更多的開銷。
2. 如果打印引用，類的__str__方法將不會被調用； 您將打印代理指針的表示。 您可能應該將方法__str__重命名為類似dump的名稱，並在需要實例表示時顯式調用它。

您還應該明確地等待正在創建的進程完成，以便管理器服務不會過早關閉，這意味着每個進程都應該分配給一個唯一的變量並具有唯一的名稱。

import disruptor
import multiprocessing
from multiprocessing.managers import BaseManager
import random

class CircularBufferManager(BaseManager):
    pass

def receiveWriter(cb):
    while(True):
        n = random.randint(5,20)
        cb.receive(n)

def ReplicatorReader(cb):
    while(True):
        cb.replicator()

def journalerReader(cb):
    while(True):
        cb.journaler()

def unmarshallerReader(cb):
    while(True):
        cb.unmarshaller()

def consumeReader(cb):
    while(True):
        print(cb.consume())

if __name__ == '__main__':
    # Create managed class
    CircularBufferManager.register('CircularBuffer', disruptor.CircularBuffer)
    # create and start manager:
    with CircularBufferManager() as manager:
        cb = manager.CircularBuffer(5)

        p1 = multiprocessing.Process(name="p1", target=ReplicatorReader, args=(cb,))
        p1.start()

        p0 = multiprocessing.Process(name="p0",target=receiveWriter, args=(cb,))
        p0.start()

        p1a = multiprocessing.Process(name="p1a",target=ReplicatorReader, args=(cb,))
        p1a.start()

        p2 = multiprocessing.Process(name="p2",target=journalerReader, args=(cb,))
        p2.start()

        p3 = multiprocessing.Process(name="p3",target=unmarshallerReader, args=(cb,))
        p3.start()

        p4 = multiprocessing.Process(name="p4",target=consumeReader, args=(cb,))
        p4.start()

        p1.join()
        p0.join()
        p1a.join()
        p2.join()
        p3.join()
        p4.join()