box-cost/boxcost/api/print.go

package api

import (
	"fmt"
	"sync"
	"time"

	"github.com/gin-gonic/gin"
)

func Printr(c *gin.Context, apictx *ApiSession) (interface{}, error) {
	c1 := make(chan int)
	var wg sync.WaitGroup

	for i := 0; i < 3; i++ {
		wg.Add(1)
		go work(&wg, c1, i)
	}

	go func() {
		wg.Wait()
		close(c1)
	}()

	for n := range c1 {
		fmt.Println(n)
	}

	return nil, nil

}

func work(wg *sync.WaitGroup, c1 chan<- int, n int) {
	if n == 1 {
		time.Sleep(1 * time.Second)
	}
	c1 <- n
	wg.Done()
}