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.start()不会启动进程并导致程序崩溃

python-multiprocessing python

Amrmsmb · 技术社区 · 4 年前

在下面发布的代码中,我正在对Process进行子类化。正如一些教程中所述,必须调用.start才能启动工作流程。我面临的问题是,我无法调用.start()方法,因为它会导致应用程序崩溃并生成下面发布的错误消息。相反,我调用.run()方法。请告诉我为什么我不能使用.start(),它是如何生成错误消息的,以及如何修复它,这样我就可以使用/start()

笔记 :下面发布的代码位于Web服务中

错误消息 :

File "C:\Python310\lib\multiprocessing\process.py", line 100, in _check_closed
    if self._closed:
AttributeError: 'KeyGridCellsProcessing' object has no attribute '_closed'

密码 :

class KeyGridCellsProcessing(Process):

    @staticmethod
    def newInstance(pNameSuffix,row,col,_pixelsValuesSatisfyThresholdInWindowedSegment,pixelsValuesSatisfyThresholdInTIFFImageDatasetCnt):
        keyGridCellsProcessing = KeyGridCellsProcessing(pNameSuffix,row,col,_pixelsValuesSatisfyThresholdInWindowedSegment,pixelsValuesSatisfyThresholdInTIFFImageDatasetCnt)
        KeyGridCellsProcessing.processesCollector.append(KeyGridCellsProcessing)
        return keyGridCellsProcessing
    
    @staticmethod
    def setDatasetElevationsTIFFInEPSG25832(datasetElevationsTIFFInEPSG25832):
        KeyGridCellsProcessing.datasetElevationsTIFFInEPSG25832 = datasetElevationsTIFFInEPSG25832
    
    @staticmethod
    def setNDVIsTIFFWindowedSegmentContentsInEPSG25832(NDVIsTIFFWindowedSegmentContentsInEPSG25832):
        KeyGridCellsProcessing.NDVIsTIFFWindowedSegmentContentsInEPSG25832 = NDVIsTIFFWindowedSegmentContentsInEPSG25832
        
    @staticmethod
    def setMainTIFFImageDatasetContents(mainTIFFImageDatasetContents):
        KeyGridCellsProcessing.mainTIFFImageDatasetContents = mainTIFFImageDatasetContents
    
    @staticmethod
    def waitForProcessToFinish():
        for p in KeyGridCellsProcessing.processesCollector:
            p.join()  
            # logger.debug(f"process:{p}")
        # exit()
            
    def __init__(self,pNameSuffix,row,col,_pixelsValuesSatisfyThresholdInWindowedSegment,pixelsValuesSatisfyThresholdInTIFFImageDatasetCnt):
        # self.queue = queue
        self.pNameSuffix = pNameSuffix
        self.row = row
        self.col = col
        self._pixelsValuesSatisfyThresholdInWindowedSegment = _pixelsValuesSatisfyThresholdInWindowedSegment
        self.pixelsValuesSatisfyThresholdInTIFFImageDatasetCnt = pixelsValuesSatisfyThresholdInTIFFImageDatasetCnt
        self.fourCornersOfKeyWindowInEPSG4326 = []
        
    def run(self):
        runStartTime = time.time()
        #logic
        ...
        ...
        runEndTime = time.time() - runStartTime
        KeyGridCellsProcessing.runMethodForKeyGridCellsExecutionTimeAccumulator+=runEndTime
    
    @staticmethod
    def enqueue():
        KeyGridCellsProcessing.keyGridCellsQueue.put([KeyGridCellsProcessing.NDVIsPer10mX10mForKeyWindow,
                                ......,
                                ......,
                                ......,
                                ......,
                                ......,
                                ], block=True, timeout=None)
    @staticmethod
    def dequeue():
        deqeueStartTime = time.time()
        item = KeyGridCellsProcessing.keyGridCellsQueue.get(block=True, timeout=None)
        KeyGridCellsProcessing.executionTimeOfDequeueProcess = time.time() - deqeueStartTime
        return item
    
    
    @staticmethod
    def shutdownQueue():
        KeyGridCellsProcessing.keyGridCellsQueue.close()
        KeyGridCellsProcessing.keyGridCellsQueue.join_thread()

    def startProcessing(self):
        #self.start()#<=========== causes the app to crash
        self.run()  #works

0 回复 | 直到 4 年前

Guy 4 年前

start() 第一个动作是打电话 self._check_closed() 在里面 BaseProcess (的基类 Process )

def _check_closed(self):
    if self._closed:
        raise ValueError("process object is closed")

self._closed 在中初始化 基本流程 __init__ ,但既然你没有 super().__init__() 在您的类中,它从未初始化过。添加它应该可以解决问题

class KeyGridCellsProcessing(Process):
    def __init__(self, ...):
        super().__init__()
        ...