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我需要执行一个只能由主进程执行的操作。奴隶们真的什么都做不了，只能等主人说完。因此，我做了以下事情（伪代码，我包装了大多数例程，所以我很难想出实际的 MPI 代码。我希望评论足够清楚地解释我在做什么）

def routine():

    if not isMaster(): 
        # I am a slave. I just sit here, waiting for the master to finish.
        # wait for a string from the master explaining the state
        string = MPI_Bcast("whatever", 0) 
        return (string == "SUCCESS")

    <master does its long running business>

    string = MPI_Bcast("SUCCESS", 0) # tell the slaves it worked fine.

    return True

这行得通，还是我滥用广播？

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1 回答 1

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如果您制作该伪代码：

def routine():

    if not isMaster(): 
        # I am a slave. I just sit here, waiting for the master to finish.
        # wait for a string from the master explaining the state
        string = MPI_Bcast("whatever", 0) 
        return (string == "SUCCESS")

    else:
        <master does its long running business>
        string = MPI_Bcast("SUCCESS", 0) # tell the slaves it worked fine.

    return True

那你应该没事。（当然，您需要确保为您的语言正确获取特定的 MPI API。）通常，对于广播或任何集体操作，通信器中的每个等级都需要执行相同数量的调用。为了便于理解，重组程序以在同一源代码行上无条件地执行每个等级的 Bcast 可能是有益的，例如

def routine():
    status_code = UNKNOWN
    if isMaster(): 
        #do stuff
        status_code = OK

    MPI_Bcast(&status_code, 0)
    #check status_code on each rank
于 2013-03-11T11:15:30.063 回答