Merge lp:~chipaca/ubuntu-push/flapping-fix-more-tweaks into lp:ubuntu-push/automatic

[John Lenton]

add SIGQUIT handler to spit out stack dumps; logging tweaks.

This is lp:~noise/ubuntu-push/flapping-fix-more-tweaks with a conflict resolved.

[John Lenton (chipaca)]

review: Approve

=== modified file 'bus/connectivity/connectivity.go'
--- bus/connectivity/connectivity.go	2015-01-22 09:54:10 +0000
+++ bus/connectivity/connectivity.go	2015-01-22 11:12:24 +0000
@@ -120,44 +120,51 @@
 		case <-cs.networkConCh:
 			cs.webgetCh = nil
 			cs.timer.Reset(stabilizingTimeout)
-			log.Debugf("PrimaryConnection changed. Assuming disconnect.")
 			if cs.lastSent == true {
+				log.Debugf("connectivity: PrimaryConnection changed. lastSent: %v, sending 'disconnected'.", cs.lastSent)
 				cs.lastSent = false
 				break Loop
+			} else {
+				log.Debugf("connectivity: PrimaryConnection changed. lastSent: %v, Ignoring.", cs.lastSent)
 			}
 
 		case v, ok := <-cs.networkStateCh:
+			// Handle only disconnecting here, connecting handled under the timer below
 			if !ok {
 				// tear it all down and start over
 				return false, errors.New("got not-OK from StateChanged watch")
 			}
 			cs.webgetCh = nil
-			if v != networkmanager.Connecting && cs.currentState != v {
-				cs.currentState = v
+			lastState := cs.currentState
+			cs.currentState = v
+			// ignore Connecting (followed immediately by "Connected Global") and repeats
+			if v != networkmanager.Connecting && lastState != v {
 				cs.timer.Reset(stabilizingTimeout)
 				log.Debugf("state changed to %s. Assuming disconnect.", v)
 				if cs.lastSent == true {
-					log.Debugf("sending 'disconnected'.")
+					log.Debugf("connectivity: %s -> %s. lastSent: %v, sending 'disconnected'", lastState, v, cs.lastSent)
 					cs.lastSent = false
 					break Loop
+				} else {
+					log.Debugf("connectivity: %s -> %s. lastSent: %v, Ignoring.", lastState, v, cs.lastSent)
 				}
 			} else {
-				log.Debugf("got State of %s, current is %s, ignoring.", v, cs.currentState)
+				log.Debugf("connectivity: %s -> %s. lastSent: %v, Ignoring.", lastState, v, cs.lastSent)
 			}
 
 		case <-cs.timer.C:
 			if cs.currentState == networkmanager.ConnectedGlobal {
-				log.Debugf("may be connected; checking...")
+				log.Debugf("connectivity: timer signal, state: ConnectedGlobal, checking...")
 				cs.webgetCh = make(chan bool)
 				go cs.webget(cs.webgetCh)
 			}
 
 		case connected := <-cs.webgetCh:
 			cs.timer.Reset(recheckTimeout)
-			log.Debugf("connection check says: %t", connected)
+			log.Debugf("connectivity: connection check says: %t", connected)
 			cs.webgetCh = nil
 			if connected && cs.lastSent == false {
-				log.Debugf("sending 'connected'.")
+				log.Debugf("connectivity: connection check ok, lastSent: %v, sending 'connected'.", cs.lastSent)
 				cs.lastSent = true
 				break Loop
 			}

=== modified file 'client/client.go'
--- client/client.go	2015-01-22 09:54:10 +0000
+++ client/client.go	2015-01-22 11:12:24 +0000
@@ -376,6 +376,7 @@
 
 // handleConnState deals with connectivity events
 func (client *PushClient) handleConnState(hasConnectivity bool) {
+	client.log.Debugf("handleConnState: %v", hasConnectivity)
 	if client.hasConnectivity == hasConnectivity {
 		// nothing to do!
 		return

=== modified file 'client/session/session.go'
--- client/session/session.go	2015-01-22 10:30:42 +0000
+++ client/session/session.go	2015-01-22 11:12:24 +0000
@@ -235,6 +235,7 @@
 }
 
 func (sess *ClientSession) setState(state ClientSessionState) {
+	sess.Log.Debugf("session.setState: %s -> %s", ClientSessionState(atomic.LoadUint32(sess.stateP)), state)
 	atomic.StoreUint32(sess.stateP, uint32(state))
 }
 
@@ -392,6 +393,7 @@
 			sess.Log.Debugf("session autoredialer skipping retry: retrier has been set to nil.")
 			return
 		}
+		sess.Log.Debugf("session autoredialier launching Redial goroutine")
 		doneCh <- retrier.Redial()
 	}()
 }

=== modified file 'ubuntu-push-client.go'
--- ubuntu-push-client.go	2014-05-08 22:29:26 +0000
+++ ubuntu-push-client.go	2015-01-22 11:12:24 +0000
@@ -18,13 +18,31 @@
 
 import (
 	"log"
+	"os"
+	"os/signal"
+	"runtime"
+	"syscall"
 
 	"launchpad.net/go-xdg/v0"
 
 	"launchpad.net/ubuntu-push/client"
 )
 
+func installSigQuitHandler() {
+	go func() {
+		sigs := make(chan os.Signal, 1)
+		signal.Notify(sigs, syscall.SIGQUIT)
+		buf := make([]byte, 1<<20)
+		for {
+			<-sigs
+			runtime.Stack(buf, true)
+			log.Printf("=== received SIGQUIT ===\n*** goroutine dump...\n%s\n*** end\n", buf)
+		}
+	}()
+}
+
 func main() {
+	installSigQuitHandler()
 	cfgFname, err := xdg.Config.Find("ubuntu-push-client/config.json")
 	if err != nil {
 		log.Fatalf("unable to find a configuration file: %v", err)