main.go

package main

import (
	"bytes"
	"fmt"
	"net/http"
	"strings"
	"sync"
	"sync/atomic"
)

func main() {
	var count int32
	wg := &sync.WaitGroup{}
	for {
		wg.Add(5)
		go doRequest(wg, atomic.AddInt32(&count, 1))
		go doRequest(wg, atomic.AddInt32(&count, 1))
		go doRequest(wg, atomic.AddInt32(&count, 1))
		go doRequest(wg, atomic.AddInt32(&count, 1))
		go doRequest(wg, atomic.AddInt32(&count, 1))
		wg.Wait()
	}
}

func doRequest(wg *sync.WaitGroup, count int32) {
	defer wg.Done()
	path := fmt.Sprintf("http://localhost:9000/foo/%d.txt", count)
	fmt.Printf("PUT %s\n", path)
	req, _ := http.NewRequest("PUT", path, strings.NewReader("test content"))
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		panic(err)
	}
	defer resp.Body.Close()
	// Consuming the body is important; without this, the error never occurs.
	buf := &bytes.Buffer{}
	buf.ReadFrom(resp.Body)
}