SyncThread: Fix issue when network is back and the app was in background: do not restart the thread

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/network/NetworkConnectivityChecker.kt

@@ -36,7 +36,8 @@ internal class NetworkConnectivityChecker @Inject constructor(context: Context)
     private val listeners = Collections.synchronizedSet(LinkedHashSet<Listener>())
 
     // True when internet is available
-    private var hasInternetAccess = false
+    var hasInternetAccess = false
+        private set
 
     init {
         merlin.bind()
@@ -63,7 +64,7 @@ internal class NetworkConnectivityChecker @Inject constructor(context: Context)
     }
 
     suspend fun waitUntilConnected() {
-        if (isConnected()) {
+        if (hasInternetAccess) {
             return
         } else {
             suspendCoroutine<Unit> { continuation ->
@@ -85,10 +86,6 @@ internal class NetworkConnectivityChecker @Inject constructor(context: Context)
         listeners.remove(listener)
     }
 
-    fun isConnected(): Boolean {
-        return hasInternetAccess
-    }
-
     interface Listener {
         fun onConnect() {
 

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/sync/job/SyncService.kt

@@ -93,8 +93,8 @@ open class SyncService : Service() {
     }
 
     fun doSync(once: Boolean = false) {
-        if (!networkConnectivityChecker.isConnected()) {
-            Timber.v("Sync is Paused. Waiting...")
+        if (!networkConnectivityChecker.hasInternetAccess) {
+            Timber.v("No internet access. Waiting...")
             //TODO Retry in ?
             timer.schedule(object : TimerTask() {
                 override fun run() {

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/sync/job/SyncThread.kt

@@ -50,6 +50,8 @@ internal class SyncThread @Inject constructor(private val syncTask: SyncTask,
     private val lock = Object()
     private var cancelableTask: Cancelable? = null
 
+    private var isStarted = false
+
     init {
         updateStateTo(SyncState.IDLE)
     }
@@ -60,19 +62,18 @@ internal class SyncThread @Inject constructor(private val syncTask: SyncTask,
     }
 
     fun restart() = synchronized(lock) {
-        if (state is SyncState.PAUSED) {
+        if (!isStarted) {
             Timber.v("Resume sync...")
-            updateStateTo(SyncState.RUNNING(afterPause = true))
+            isStarted = true
             lock.notify()
         }
     }
 
     fun pause() = synchronized(lock) {
-        if (state is SyncState.RUNNING) {
+        if (isStarted) {
             Timber.v("Pause sync...")
-            updateStateTo(SyncState.PAUSED)
+            isStarted = false
             cancelableTask?.cancel()
-            lock.notify()
         }
     }
 
@@ -87,21 +88,31 @@ internal class SyncThread @Inject constructor(private val syncTask: SyncTask,
         return liveState
     }
 
+    override fun onConnect() {
+        Timber.v("Network is back")
+        synchronized(lock) {
+            lock.notify()
+        }
+    }
+
     override fun run() {
         Timber.v("Start syncing...")
+        isStarted = true
         networkConnectivityChecker.register(this)
         backgroundDetectionObserver.register(this)
 
         while (state != SyncState.KILLING) {
             Timber.v("Entering loop, state: $state")
 
-            if (!networkConnectivityChecker.isConnected() || state == SyncState.PAUSED) {
-                Timber.v("No network or sync is Paused. Waiting...")
+            if (!networkConnectivityChecker.hasInternetAccess) {
+                Timber.v("No network. Waiting...")
                 updateStateTo(SyncState.NO_NETWORK)
-
-                synchronized(lock) {
-                    lock.wait()
-                }
+                synchronized(lock) { lock.wait() }
+                Timber.v("...unlocked")
+            } else if (!isStarted) {
+                Timber.v("Sync is Paused. Waiting...")
+                updateStateTo(SyncState.PAUSED)
+                synchronized(lock) { lock.wait() }
                 Timber.v("...unlocked")
             } else {
                 if (state !is SyncState.RUNNING) {
@@ -169,16 +180,11 @@ internal class SyncThread @Inject constructor(private val syncTask: SyncTask,
     }
 
     private fun updateStateTo(newState: SyncState) {
-        Timber.v("Update state to $newState")
+        Timber.v("Update state from $state to $newState")
         state = newState
         liveState.postValue(newState)
     }
 
-    override fun onConnect() {
-        synchronized(lock) {
-            lock.notify()
-        }
-    }
 
     override fun onMoveToForeground() {
         restart()

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/util/BackgroundDetectionObserver.kt

@@ -33,7 +33,7 @@ internal class BackgroundDetectionObserver @Inject constructor() : LifecycleObse
         private set
 
     private
-    val listeners = ArrayList<Listener>()
+    val listeners = LinkedHashSet<Listener>()
 
     fun register(listener: Listener) {
         listeners.add(listener)

vector/src/main/java/im/vector/riotx/features/sync/widget/SyncStateView.kt

@@ -38,6 +38,6 @@ class SyncStateView @JvmOverloads constructor(context: Context, attrs: Attribute
             is SyncState.RUNNING -> if (newState.afterPause) View.VISIBLE else View.GONE
             else                 -> View.GONE
         }
-        syncStateNoNetwork.isVisible = newState is SyncState.NO_NETWORK
+        syncStateNoNetwork.isVisible = newState == SyncState.NO_NETWORK
     }
 }