random fail response from server

[smthpickboy]

I'm using fasthttp + fasthttprouter.

Go 1.8.1
fasthttp version: b154429
fasthttprouter version: ade4e2031af3aed7fffd241084aad80a58faf421

After I update fasthttp from some old version to the current version, I get random failure response from server.

curl: (52) Empty reply from server
curl: (56) Failure when receiving data from the peer

fasthttprouter hasn't been updated for quite some time.

[smthpickboy]

After further testing, I found that it's caused by ReadTimeout/WriteTimeout of fasthttp.Server

func main() {
	m := func(ctx *fasthttp.RequestCtx) {
		switch string(ctx.Path()) {
		case "/foo":
			foo(ctx)
		default:
			ctx.Error("not found", fasthttp.StatusNotFound)
		}
	}

	s := fasthttp.Server{
		Handler: m,
		ReadTimeout:  time.Second + 500*time.Millisecond,
		//WriteTimeout: time.Second,
		MaxRequestBodySize: 2 * 1024,
	}

	fmt.Println("testing with ReadTimeout 1.5s")
	err := s.ListenAndServe("127.0.0.1:8000")
	if err != nil {
		fmt.Println(err)
	}
}

func foo(ctx *fasthttp.RequestCtx) {
	ctx.WriteString("Success")
}

If I set ReadTimeout to 1.5 second on my test machine, It's no problem. But if set to less than 1.5 sec, such as 1 sec, there would be some random fail response.

Is there any additional config that I should do to use ReadTimeout/WriteTimeout of fasthttp.Server?

[algorithm-buaa]

func (c *HostClient) doNonNilReqResp(req *Request, resp *Response) (bool, error) {
	if req == nil {
		panic("BUG: req cannot be nil")
	}
	if resp == nil {
		panic("BUG: resp cannot be nil")
	}

	atomic.StoreUint32(&c.lastUseTime, uint32(CoarseTimeNow().Unix()-startTimeUnix))

	// Free up resources occupied by response before sending the request,
	// so the GC may reclaim these resources (e.g. response body).
	resp.Reset()

	cc, err := c.acquireConn()
	if err != nil {
		return false, err
	}
	conn := cc.c

	if c.WriteTimeout > 0 {
		// Optimization: update write deadline only if more than 25%
		// of the last write deadline exceeded.
		// See https://github.com/golang/go/issues/15133 for details.
		currentTime := CoarseTimeNow()
		if currentTime.Sub(cc.lastWriteDeadlineTime) > (c.WriteTimeout >> 2) {
			if err = conn.SetWriteDeadline(currentTime.Add(c.WriteTimeout)); err != nil {
				c.closeConn(cc)
				return true, err
			}
			cc.lastWriteDeadlineTime = currentTime
		}
	}

The op currentTime := CoarseTimeNow() does not get exact current time :

// CoarseTimeNow returns the current time truncated to the nearest second.
//
// This is a faster alternative to time.Now().
func CoarseTimeNow() time.Time {
	tp := coarseTime.Load().(*time.Time)
	return *tp
}

currentTime := time.Now() will be Ok, but I dont kown why to change like that. Maybe for performance.

[erikdubbelboer]

That’s why I removed coarse time from my fork: erikdubbelboer@05f8f96 (which contains many other fixes as well)