Executor

执行器，真正的调度任务和策略都在这里

Parameters:

Name	Type	Description	Default
xxl_client	XXL	xxl客户端	required
config	ExecutorConfig	配置参数	required
handler	Optional[JobHandler]	Defaults to None.	None
loop	Optional[AbstractEventLoop]	Defaults to None.	None

graceful_close(timeout: int = 60) -> None async

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