Python multiprocessing Process() 在 Windows 10 上不起作用(即使对于腌制简单字符串也是如此)

Question

我写了一个Python类来并行绘制pylot。它在Linux上运行良好，但是当我在Windows上尝试时，我遇到了问题。它甚至到了我无法腌制一根绳子的程度。我总是最终收到此错误：

Traceback (most recent call last):
  File "test.py", line 50, in <module>
    test()
  File "test.py", line 7, in test
    asyncPlotter.saveLinePlotVec3("test")
  File "test.py", line 41, in saveLinePlotVec3
    args=(test, ))
  File "test.py", line 34, in process
    p.start()
  File "C:UsersadrianAppDataLocalProgramsPythonPython37libmultiprocessingprocess.py", line 112, in start
    self._popen = self._Popen(self)
  File "C:UsersadrianAppDataLocalProgramsPythonPython37libmultiprocessingcontext.py", line 223, in _Popen
    return _default_context.get_context().Process._Popen(process_obj)
  File "C:UsersadrianAppDataLocalProgramsPythonPython37libmultiprocessingcontext.py", line 322, in _Popen
    return Popen(process_obj)
  File "C:UsersadrianAppDataLocalProgramsPythonPython37libmultiprocessingpopen_spawn_win32.py", line 89, in __init__
    reduction.dump(process_obj, to_child)
  File "C:UsersadrianAppDataLocalProgramsPythonPython37libmultiprocessingreduction.py", line 60, in dump
    ForkingPickler(file, protocol).dump(obj)
TypeError: can't pickle weakref objects
C:PythonMonteCarloTools>Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "C:UsersadrianAppDataLocalProgramsPythonPython37libmultiprocessingspawn.py", line 99, in spawn_main
    new_handle = reduction.steal_handle(parent_pid, pipe_handle)
  File "C:UsersadrianAppDataLocalProgramsPythonPython37libmultiprocessingreduction.py", line 82, in steal_handle
    _winapi.PROCESS_DUP_HANDLE, False, source_pid)
OSError: [WinError 87] The parameter is incorrect

我将其缩小到Windows使用的spawn启动方法(https://docs.python.org/3/library/multiprocessing.html#contexts-and-start-methods(，当我在Linux上使用相同的启动方法时，我可以重现错误。

import multiprocessing as mp
def test():
    asyncPlotter = AsyncPlotter()
    asyncPlotter.saveLinePlotVec3("test")
    asyncPlotter.saveLinePlotVec3("test")
    asyncPlotter.saveLinePlotVec3("test")
    asyncPlotter.join()

class AsyncPlotter():
    def __init__(self, processes=mp.cpu_count()):
        self.manager = mp.Manager()
        self.nc = self.manager.Value('i', 0)
        self.pids = []
        self.processes = processes

    def linePlotVec3(self, nc, processes, test):
        self.waitOnPool(nc, processes)
        return None

    def waitOnPool(self, nc, processes):
        while nc.value >= processes:
            time.sleep(0.1)
        nc.value += 1

    def process(self, target, args):
        p = mp.Process(target=target, args=args)
        p.start()
        self.pids.append(p)

    def saveLinePlotVec3(self, test):
        self.process(target=self.linePlotVec3,
                       args=(self.nc, self.processes, test))

    def join(self):
        for p in self.pids:
            p.join()

if __name__=='__main__':
    test()

我希望我也可以在 Windows 上使用此方法腌制任何类型的字符串、列表、字典等。如果有人能找到一种方法在Windows上完成这项工作，我将不胜感激。谢谢！

Answer 1

更改

self.process(target=self.linePlotVec3, args=(test, ))

自

self.process(target=AsyncPlotter.linePlotVec3, args=(test, ))

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进程采用类或全局方法，因此当您尝试向其传递实例方法时它会崩溃