79 lines
2.4 KiB
Go
79 lines
2.4 KiB
Go
/*
|
|
* Copyright (c) 2021 IBM Corp and others.
|
|
*
|
|
* All rights reserved. This program and the accompanying materials
|
|
* are made available under the terms of the Eclipse Public License v2.0
|
|
* and Eclipse Distribution License v1.0 which accompany this distribution.
|
|
*
|
|
* The Eclipse Public License is available at
|
|
* https://www.eclipse.org/legal/epl-2.0/
|
|
* and the Eclipse Distribution License is available at
|
|
* http://www.eclipse.org/org/documents/edl-v10.php.
|
|
*
|
|
* Contributors:
|
|
* Seth Hoenig
|
|
* Allan Stockdill-Mander
|
|
* Mike Robertson
|
|
*/
|
|
|
|
package mqtt
|
|
|
|
import (
|
|
"errors"
|
|
"io"
|
|
"sync/atomic"
|
|
"time"
|
|
|
|
"github.com/eclipse/paho.mqtt.golang/packets"
|
|
)
|
|
|
|
// keepalive - Send ping when connection unused for set period
|
|
// connection passed in to avoid race condition on shutdown
|
|
func keepalive(c *client, conn io.Writer) {
|
|
defer c.workers.Done()
|
|
DEBUG.Println(PNG, "keepalive starting")
|
|
var checkInterval int64
|
|
var pingSent time.Time
|
|
|
|
if c.options.KeepAlive > 10 {
|
|
checkInterval = 5
|
|
} else {
|
|
checkInterval = c.options.KeepAlive / 2
|
|
}
|
|
|
|
intervalTicker := time.NewTicker(time.Duration(checkInterval * int64(time.Second)))
|
|
defer intervalTicker.Stop()
|
|
|
|
for {
|
|
select {
|
|
case <-c.stop:
|
|
DEBUG.Println(PNG, "keepalive stopped")
|
|
return
|
|
case <-intervalTicker.C:
|
|
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)
|
|
if err := ping.Write(conn); err != nil {
|
|
ERROR.Println(PNG, err)
|
|
}
|
|
c.lastSent.Store(time.Now())
|
|
pingSent = time.Now()
|
|
}
|
|
}
|
|
if atomic.LoadInt32(&c.pingOutstanding) > 0 && time.Since(pingSent) >= c.options.PingTimeout {
|
|
CRITICAL.Println(PNG, "pingresp not received, disconnecting")
|
|
c.internalConnLost(errors.New("pingresp not received, disconnecting")) // no harm in calling this if the connection is already down (or shutdown is in progress)
|
|
return
|
|
}
|
|
}
|
|
}
|
|
}
|