Fix dispatcher not closed

mobile/src/main/java/be/mygod/vpnhotspot/LocalOnlyHotspotService.kt

@@ -46,7 +46,8 @@ class LocalOnlyHotspotService : IpNeighbourMonitoringService(), CoroutineScope {
     /**
      * Writes and critical reads to routingManager should be protected with this context.
      */
-    override val coroutineContext = newSingleThreadContext("LocalOnlyHotspotService") + Job()
+    private val dispatcher = newSingleThreadContext("LocalOnlyHotspotService")
+    override val coroutineContext = dispatcher + Job()
     private var routingManager: RoutingManager? = null
     private val handler = Handler()
     @RequiresApi(28)
@@ -158,7 +159,10 @@ class LocalOnlyHotspotService : IpNeighbourMonitoringService(), CoroutineScope {
         launch {
             routingManager?.destroy()
             routingManager = null
-            if (exit) cancel()
+            if (exit) {
+                cancel()
+                dispatcher.close()
+            }
         }
     }
 }

mobile/src/main/java/be/mygod/vpnhotspot/RepeaterService.kt

@@ -149,7 +149,8 @@ class RepeaterService : Service(), CoroutineScope, WifiP2pManager.ChannelListene
     /**
      * Writes and critical reads to routingManager should be protected with this context.
      */
-    override val coroutineContext = newSingleThreadContext("RepeaterService") + Job()
+    private val dispatcher = newSingleThreadContext("RepeaterService")
+    override val coroutineContext = dispatcher + Job()
     private var routingManager: RoutingManager? = null
     private var persistNextGroup = false
 
@@ -419,6 +420,7 @@ class RepeaterService : Service(), CoroutineScope, WifiP2pManager.ChannelListene
         launch {    // force clean to prevent leakage
             cleanLocked()
             cancel()
+            dispatcher.close()
         }
         if (Build.VERSION.SDK_INT < 29) @Suppress("DEPRECATION") {
             app.pref.unregisterOnSharedPreferenceChangeListener(this)

mobile/src/main/java/be/mygod/vpnhotspot/TetheringService.kt

@@ -42,7 +42,8 @@ class TetheringService : IpNeighbourMonitoringService(), CoroutineScope {
     /**
      * Writes and critical reads to downstreams should be protected with this context.
      */
-    override val coroutineContext = newSingleThreadContext("TetheringService") + Job()
+    private val dispatcher = newSingleThreadContext("TetheringService")
+    override val coroutineContext = dispatcher + Job()
     private val binder = Binder()
     private val downstreams = ConcurrentHashMap<String, Downstream>()
     private var receiverRegistered = false
@@ -109,6 +110,7 @@ class TetheringService : IpNeighbourMonitoringService(), CoroutineScope {
             downstreams.values.forEach { it.destroy() } // force clean to prevent leakage
             unregisterReceiver()
             cancel()
+            dispatcher.close()
         }
         super.onDestroy()
     }