package main

import (
    "fmt"
    "log"
    "net"
    "net/rpc"
    "time"
)

func main() {
    log.SetFlags(log.Lshortfile | log.Lmicroseconds)
    log.Println("=======begin====== ")

    testRpc()

    time.Sleep(time.Second * 2)
    log.Println("=======end====== ")
}

type Args struct {
    A,B int
}

type Math int

func (t *Math) Division(args *Args,reply *int) error {
    if args.B == 0 {
        return fmt.Errorf("args.B == 0")
    }

    *reply = args.A / args.B
    //time.Sleep(time.Second * 3)
    return nil
}

func testRpc() {
    newServer := rpc.NewServer()
    newServer.Register(new(Math))
    server,_ := net.Listen("tcp","127.0.0.1:1234") // any available address
    go newServer.Accept(server)

    time.Sleep(1 * time.Second)
    conn,_ := net.DialTimeout("tcp","127.0.0.1:1234",time.Second)
    defer conn.Close()
    conn.SetReadDeadline(time.Now().Add(time.Second * 1))

    client := rpc.NewClient(conn)
    defer client.Close()

    reply := new(int)
    callErr := client.Call("Math.Division",&Args{8,2},reply)
    log.Println("call err:",callErr,"reply:",*reply)
}

• 采用低层次的api，可以设置一些超时时间，比如连接超时、读写超时等
• rpc要对返回值进行判断，不仅仅判断远程调用的错误吗，还有其他一些异常情况的判断，包括调用超时，service没有注册，没有找到相应的method等。
  

args.B == 0 rpc: can’t find service Math_test.Divisio rpc: can’t find method Math.Division_test read tcp 127.0.0.1:30624->127.0.0.1:1234: i/o timeout