扭曲的回调链不正确地重复最后一次回调

时间:2013-08-05 01:13:24

标签: python twisted

我正在玩扭曲,我正在尝试创建一个简单的主服务器,它将单元测试列表分发给它的从属服务器。以下代码有效,但我的输出很奇怪。从站执行最后一次单元测试n次,而不是执行n次测试中的每一项。

我正在使用twisted的内置放大器协议。以下是相关代码:

class Master(object):

    def __init__(self):
        self.tests = [
            "test1",
            "tests2",
            ... etc
        ]

    def serve(self):
        self.factory = MasterFactory()
        reactor.listenTCP(1234, self.factory)
        d = threads.deferToThread(self.get_cmd)
        d.addCallback(lambda ign: self.run_test())
        print 'Serving on port 1234'

    def get_cmd(self):
        return raw_input('> ')

    def run_test(self):
        while True:
            for slave in self.factory.slaves.values():
                if self.tests == []:
                    break
                slave.tests.append(self.tests.pop(0))
            if self.tests == []:
                break

        for slave in self.factory.slaves.values():
            self.construct_list(slave)

    def construct_list(self, slave):
        d = defer.Deferred()
        for test in slave.tests:
            d.addCallback(lambda ign:
                slave.protocol.callRemote(commands.RunCmd, cmd="python setup.py trial -s " + test))
            d.addCallback(self.cmd_response)
        d.callback(None)

    def cmd_response(self, response):
        print response['output']
        return None


def main():
    m = Master()
    m.serve()
    reactor.run()

if __name__ == "__main__":
    main()

1 个答案:

答案 0 :(得分:3)

这是循环变量和闭包在Python中如何工作的常见问题。考虑这个例子:

>>> def f(n):
...     print n
... 
>>> fs = []
>>> for i in range(3):
...     fs.append(lambda: f(i))
... 
>>> fs[0]()
2
>>> fs[1]()
2
>>> fs[2]()
2
>>>