ch17go语句及其执行规则

package main

import (
    "fmt"
)

func main() {
    for i := 0; i < 10; i++{
        go func() {
            fmt.Println(i)
        }()
    }
}

输出为空-->主goroutine执行完毕，程序就结束运行，不会等待go函数执行完毕

package main

import (
    "fmt"
    "time"
)

func main() {
    for i := 0; i < 10; i++{
        go func(i int) {
            fmt.Println(i)
        }(i)
        time.Sleep(time.Second)
    }
}

package main
import (
    "fmt"
    "sync/atomic"
    "time"
)
func main() {
    var count uint32
    trigger := func(i uint32, fn func()) {
        for {
            if n := atomic.LoadUint32(&count); n == i {
                fn()
                atomic.AddUint32(&count, 1)
                break
            }
            time.Sleep(time.Nanosecond)
        }
    }
    for i := uint32(0); i < 10; i++{
        go func(i uint32) {
            fn := func() {
                //传参可以保证每个goroutine拿到唯一的一个整数
                fmt.Println(i)
            }
            trigger(i, fn)
        }(i)
        time.Sleep(time.Second)
    }
    trigger(10, func() {})
}