package test38_alternateprint

import (
    "fmt"
    "testing"
    "time"
)

var POOL = 10

//go test -v -test.run TestAlternatePrint
func TestAlternatePrint(t *testing.T) {
    AlternatePrint1()
    AlternatePrint2()
}

//方法1
func AlternatePrint1() {
    fmt.Println("方法1，两个协程的代码不一样")
    msg := make(chan int)
    go func(p chan int) {
        for i := 1; i <= POOL; i++ {
            p <- i
            if i%2 == 1 {
                fmt.Println("groutine-1:", i)
            }
        }
    }(msg)
    go func(p chan int) {
        for i := 1; i <= POOL; i++ {
            <-p
            if i%2 == 0 {
                fmt.Println("groutine-2:", i)
                fmt.Println("")
            }
        }
    }(msg)

    //等待协程执行完成
    time.Sleep(time.Second * 1)
}

//方法2
func AlternatePrint2() {
    fmt.Println("方法2，两个go程的代码完全一样")
    const N = 2
    chs := make([]chan struct{}, N)
    for i := 0; i < N; i++ {
        chs[i] = make(chan struct{}, 0)
    }
    start := 1
    for i := 0; i < N; i++ {
        go func(i int) {
            for start <= POOL-N+1 {
                //获得执行权
                <-chs[i]

                //执行代码
                fmt.Printf("go程%d：%d\r\n", i, start)
                if (i+1)%N == 0 {
                    fmt.Println("")
                }
                start++

                //给其他协程执行权
                chs[(i+1)%N] <- struct{}{}
            }
        }(i)
    }

    //给第1个协程执行权，第1个协程的序号是0
    chs[0] <- struct{}{}

    //等待协程执行完成
    time.Sleep(time.Second * 1)

    //收回最后1个go程的执行权
    <-chs[POOL%N]
}