GoLang API是一个同步API，这就是GoLang通常的工作方式。你在while true循环中阻塞，直到一个事件发生，然后你继续处理那个事件。至于有更多的线程同时执行请求，我们不在客户端控制。在客户端gRPC之上的应用层，你可以派生更多的Goroutine，服务器端已经为每个接受的连接甚至连接上的流派生了一个goroutine，所以服务器端已经存在固有的多线程。

注意go中没有线程，我们使用goroutine。
所描述的行为已内置到GRC服务器中。例如，请参阅此选项。

// NumStreamWorkers returns a ServerOption that sets the number of worker
// goroutines that should be used to process incoming streams. Setting this to
// zero (default) will disable workers and spawn a new goroutine for each
// stream.
//
// # Experimental
//
// Notice: This API is EXPERIMENTAL and may be changed or removed in a
// later release.
func NumStreamWorkers(numServerWorkers uint32) ServerOption {
    // TODO: If/when this API gets stabilized (i.e. stream workers become the
    // only way streams are processed), change the behavior of the zero value to
    // a sane default. Preliminary experiments suggest that a value equal to the
    // number of CPUs available is most performant; requires thorough testing.
    return newFuncServerOption(func(o *serverOptions) {
        o.numServerWorkers = numServerWorkers
    })
}

工作线程在某个时刻被初始化。

// initServerWorkers creates worker goroutines and channels to process incoming
// connections to reduce the time spent overall on runtime.morestack.
func (s *Server) initServerWorkers() {
    s.serverWorkerChannels = make([]chan *serverWorkerData, s.opts.numServerWorkers)
    for i := uint32(0); i < s.opts.numServerWorkers; i++ {
        s.serverWorkerChannels[i] = make(chan *serverWorkerData)
        go s.serverWorker(s.serverWorkerChannels[i])
    }
}

我建议您自己阅读服务器代码，了解更多信息。