gistfile1.txt

package main

import (
	"context"
	"fmt"
	"log"
	"net/http"
	"sync"
	"testing"
	"time"

	"golang.org/x/net/context/ctxhttp"
)

func doReq(wg *sync.WaitGroup) {
	defer wg.Done()

	ctx, _ := context.WithTimeout(context.Background(), time.Millisecond*1000)
	//defer cancel()
	req, err := http.NewRequest("GET", "https://jsonplaceholder.typicode.com/posts", nil)
	if err != nil {
		log.Fatal(err)
	}
	//req = req.WithContext(ctx)
	_, err = ctxhttp.Do(ctx, http.DefaultClient, req)
}

func TestABC(t *testing.T) {
	now := time.Now()
	wg := &sync.WaitGroup{}
	for i := 0; i < 400; i++ {
		wg.Add(1)
		go doReq(wg)
	}
	wg.Wait()
	fmt.Printf("took %d ms\n", time.Since(now).Milliseconds())
}