test2 for observe num of goroutine running http://v2ex.com/t/73772

gistfile1.txt

ackage main
import (
    "fmt"
    "time"
    "math/rand"
)

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

func report(c chan int) {
    for {
        fmt.Println("目前goroutine数目", len(c))
        time.Sleep(1000*time.Millisecond)
    }
}

func routine(c chan int){
    c <- 1
    n := get_rand_int(10000)
    time.Sleep(time.Duration(n) * time.Millisecond)
    <-c
}

func main() {
    c := make(chan int, 1000000)
    go report(c)
    time.Sleep(1000*time.Millisecond)
    for{
        time.Sleep(500*time.Millisecond)
        go routine(c)
    }
}