step_hide.go

package main

import (
	"fmt"
	"time"
)

var v int = 99

var s string

func foo(x, y int) (z int) {
	s = fmt.Sprintf("x=%d, y=%d, z=%d\n", x, y, z)
	z = x + y
	return
}

func threads() {
	for j := 0; j < 1000; j++ {
		go func() {
			for k := 0; k < 100000; k++ {
				foo(1, 2)
				time.Sleep(10 * time.Millisecond)
			}
		}()
	}
}

func main() {
	x := v
	y := x * x
	var z int
	threads()
	for i := 0; i < 10000; i++ {
		z = foo(x, y)
	}
	fmt.Printf("z=%d\n", z)
}