change timer to public api #525 (#527)

* change acquireTimer and releaseTimer to public api

args.go

@@ -23,7 +23,7 @@ func AcquireArgs() *Args {
 	return argsPool.Get().(*Args)
 }
 
-// ReleaseArgs returns the object acquired via AquireArgs to the pool.
+// ReleaseArgs returns the object acquired via AcquireArgs to the pool.
 //
 // Do not access the released Args object, otherwise data races may occur.
 func ReleaseArgs(a *Args) {

client.go

@@ -750,7 +750,7 @@ func clientGetURLDeadline(dst []byte, url string, deadline time.Time, c clientDo
 		}
 	}()
 
-	tc := acquireTimer(timeout)
+	tc := AcquireTimer(timeout)
 	select {
 	case resp := <-ch:
 		ReleaseRequest(req)
@@ -762,7 +762,7 @@ func clientGetURLDeadline(dst []byte, url string, deadline time.Time, c clientDo
 		body = dst
 		err = ErrTimeout
 	}
-	releaseTimer(tc)
+	ReleaseTimer(tc)
 
 	return statusCode, body, err
 }
@@ -1003,7 +1003,7 @@ func clientDoDeadline(req *Request, resp *Response, deadline time.Time, c client
 		}
 	}()
 
-	tc := acquireTimer(timeout)
+	tc := AcquireTimer(timeout)
 	var err error
 	select {
 	case err = <-ch:
@@ -1019,7 +1019,7 @@ func clientDoDeadline(req *Request, resp *Response, deadline time.Time, c client
 		atomic.StoreInt32(&cleanup, 1)
 		err = ErrTimeout
 	}
-	releaseTimer(tc)
+	ReleaseTimer(tc)
 
 	return err
 }

tcpdialer.go

@@ -206,14 +206,14 @@ func tryDial(network string, addr *net.TCPAddr, deadline time.Time, concurrencyC
 	select {
 	case concurrencyCh <- struct{}{}:
 	default:
-		tc := acquireTimer(timeout)
+		tc := AcquireTimer(timeout)
 		isTimeout := false
 		select {
 		case concurrencyCh <- struct{}{}:
 		case <-tc.C:
 			isTimeout = true
 		}
-		releaseTimer(tc)
+		ReleaseTimer(tc)
 		if isTimeout {
 			return nil, ErrDialTimeout
 		}
@@ -242,7 +242,7 @@ func tryDial(network string, addr *net.TCPAddr, deadline time.Time, concurrencyC
 		err  error
 	)
 
-	tc := acquireTimer(timeout)
+	tc := AcquireTimer(timeout)
 	select {
 	case dr := <-ch:
 		conn = dr.conn
@@ -251,7 +251,7 @@ func tryDial(network string, addr *net.TCPAddr, deadline time.Time, concurrencyC
 	case <-tc.C:
 		err = ErrDialTimeout
 	}
-	releaseTimer(tc)
+	ReleaseTimer(tc)
 
 	return conn, err
 }

timer.go

@@ -26,7 +26,12 @@ func stopTimer(t *time.Timer) {
 	}
 }
 
-func acquireTimer(timeout time.Duration) *time.Timer {
+// AcquireTimer returns a time.Timer from the pool and updates it to
+// send the current time on its channel after at least timeout.
+//
+// The returned Timer may be returned to the pool with ReleaseTimer
+// when no longer needed. This allows reducing GC load.
+func AcquireTimer(timeout time.Duration) *time.Timer {
 	v := timerPool.Get()
 	if v == nil {
 		return time.NewTimer(timeout)
@@ -36,7 +41,12 @@ func acquireTimer(timeout time.Duration) *time.Timer {
 	return t
 }
 
-func releaseTimer(t *time.Timer) {
+// ReleaseTimer returns the time.Timer acquired via AcquireTimer to the pool
+// and prevents the Timer from firing.
+//
+// Do not access the released time.Timer or read from it's channel otherwise
+// data races may occur.
+func ReleaseTimer(t *time.Timer) {
 	stopTimer(t)
 	timerPool.Put(t)
 }