The daemon process is terminated either during normal plug-in termination (message in a named pipe to terminate) or if it is signaled that the parent process has terminated.
当插件正常终止(命名管道中出现终止消息)时，或者在发现父进程已经终止时，这个守护进程就被终止。
2
When a Broker message flow is deleted, or the owning execution group is ended, the Broker does not invoke a termination method on every thread in the pool that has been active.