package main

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

var (
    Num  int
    Conn int
    Addr string
)

const RS = 100000

func init() {
    flag.IntVar(&Num, "num", 1, "")
    flag.IntVar(&Conn, "conn", 1, "")
    flag.StringVar(&Addr, "addr", "127.0.0.1", "")
    flag.Parse()
}

func main() {
    clients := make([]*rpc.Client, 0, 10)
    for i := 0; i < Conn; i++ {
        client, err := rpc.Dial("tcp", Addr+":8000")
        if err != nil {
            log.Fatalln(err)
        }
        clients = append(clients, client)
    }
    index := 0

    s1 := "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"

    var wg sync.WaitGroup

    start := time.Now()

    for i := 0; i < Num; i++ {
        wg.Add(1)

        var c *rpc.Client
        if index < len(clients) {
            c = clients[index]
            index++
        } else {
            index = 0
            c = clients[index]
        }

        go func(cli *rpc.Client) {
            defer wg.Done()

            log.Println("goroutine start...")
            st := time.Now()

            for n := 0; n < RS; n++ {
                if err := cli.Call("EchoServer.Echo", &s1, nil); err != nil {
                    log.Println(err)
                }
            }

            log.Println(time.Now().Sub(st))
        }(c)
    }
    wg.Wait()

    total := RS * Num
    secs := time.Now().Sub(start) / 1000000000

    fmt.Printf("concurrency: %d\n", Num)
    fmt.Printf("total: %d\n", total)
    fmt.Printf("seconds: %d\n", secs)
    fmt.Printf("qps: %d\n", total/int(secs))
}