test for observe num of goroutine running http://v2ex.com/t/73772#reply1

gistfile1.go

package main
import (
    "fmt"
    "time"
    "math/rand"
    "runtime"
)

func get_rand_int(max int) int {
    rand.Seed( time.Now().UTC().UnixNano())
    return rand.Intn(max)
}

func report() {
    for {
        fmt.Println("目前goroutine数目",  runtime.NumGoroutine())
        time.Sleep(1000*time.Millisecond)
    }
}

func routine(){
    n := get_rand_int(10000)
    time.Sleep(time.Duration(n) * time.Millisecond)
}

func main() {
    go report()
    for{
        time.Sleep(500*time.Millisecond)
        go routine()
    }
}