创建 goroutines

任何函数都可以通过在其调用前加上关键字 go 作为 goroutine 来调用：

func DoMultiply(x,y int) {
    // Simulate some hard work
    time.Sleep(time.Second * 1)
    fmt.Printf("Result: %d\n", x * y)
}

go DoMultiply(1,2) // first execution, non-blocking
go DoMultiply(3,4) // second execution, also non-blocking

// Results are printed after a single second only, 
// not 2 seconds because they execute concurrently:
// Result: 2
// Result: 12

请注意，忽略该函数的返回值。