Use monotonic time for keep alive

client.go

@@ -95,8 +95,8 @@ type Client interface {
 
 // client implements the Client interface
 type client struct {
-	lastSent        int64
-	lastReceived    int64
+	lastSent        atomic.Value
+	lastReceived    atomic.Value
 	pingOutstanding int32
 	status          uint32
 	sync.RWMutex
@@ -300,8 +300,8 @@ func (c *client) Connect() Token {
 
 		if c.options.KeepAlive != 0 {
 			atomic.StoreInt32(&c.pingOutstanding, 0)
-			atomic.StoreInt64(&c.lastReceived, time.Now().Unix())
-			atomic.StoreInt64(&c.lastSent, time.Now().Unix())
+			c.lastReceived.Store(time.Now())
+			c.lastSent.Store(time.Now())
 			c.workers.Add(1)
 			go keepalive(c)
 		}
@@ -412,8 +412,8 @@ func (c *client) reconnect() {
 
 	if c.options.KeepAlive != 0 {
 		atomic.StoreInt32(&c.pingOutstanding, 0)
-		atomic.StoreInt64(&c.lastReceived, time.Now().Unix())
-		atomic.StoreInt64(&c.lastSent, time.Now().Unix())
+		c.lastReceived.Store(time.Now())
+		c.lastSent.Store(time.Now())
 		c.workers.Add(1)
 		go keepalive(c)
 	}

net.go

@@ -137,7 +137,7 @@ func incoming(c *client) {
 		case c.ibound <- cp:
 			// Notify keepalive logic that we recently received a packet
 			if c.options.KeepAlive != 0 {
-				atomic.StoreInt64(&c.lastReceived, time.Now().Unix())
+				c.lastReceived.Store(time.Now())
 			}
 		case <-c.stop:
 			// This avoids a deadlock should a message arrive while shutting down.
@@ -221,7 +221,7 @@ func outgoing(c *client) {
 		}
 		// Reset ping timer after sending control packet.
 		if c.options.KeepAlive != 0 {
-			atomic.StoreInt64(&c.lastSent, time.Now().Unix())
+			c.lastSent.Store(time.Now())
 		}
 	}
 }

ping.go

@@ -43,16 +43,19 @@ func keepalive(c *client) {
 			DEBUG.Println(PNG, "keepalive stopped")
 			return
 		case <-intervalTicker.C:
-			DEBUG.Println(PNG, "ping check", time.Now().Unix()-atomic.LoadInt64(&c.lastSent))
-			if time.Now().Unix()-atomic.LoadInt64(&c.lastSent) >= c.options.KeepAlive || time.Now().Unix()-atomic.LoadInt64(&c.lastReceived) >= c.options.KeepAlive {
+			lastSent := c.lastSent.Load().(time.Time)
+			lastReceived := c.lastReceived.Load().(time.Time)
+
+			DEBUG.Println(PNG, "ping check", time.Since(lastSent).Seconds())
+			if time.Since(lastSent) >= time.Duration(c.options.KeepAlive*int64(time.Second)) || time.Since(lastReceived) >= time.Duration(c.options.KeepAlive*int64(time.Second)) {
 				if atomic.LoadInt32(&c.pingOutstanding) == 0 {
 					DEBUG.Println(PNG, "keepalive sending ping")
 					ping := packets.NewControlPacket(packets.Pingreq).(*packets.PingreqPacket)
 					//We don't want to wait behind large messages being sent, the Write call
 					//will block until it it able to send the packet.
 					atomic.StoreInt32(&c.pingOutstanding, 1)
 					ping.Write(c.conn)
-					atomic.StoreInt64(&c.lastSent, time.Now().Unix())
+					c.lastSent.Store(time.Now())
 					pingSent = time.Now()
 				}
 			}