Ensure receiver unregistered synchronously in onDestroy

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

@@ -126,7 +126,6 @@ class RepeaterService : Service(), CoroutineScope, WifiP2pManager.ChannelListene
     private val handler = Handler()
     @RequiresApi(28)
     private var timeoutMonitor: TetherTimeoutMonitor? = null
-    private var receiverRegistered = false
     private val receiver = broadcastReceiver { _, intent ->
         when (intent.action) {
             WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION ->
@@ -257,10 +256,9 @@ class RepeaterService : Service(), CoroutineScope, WifiP2pManager.ChannelListene
         if (Build.VERSION.SDK_INT >= 26 && app.uiMode.currentModeType == Configuration.UI_MODE_TYPE_TELEVISION) {
             showNotification()
         }
+        registerReceiver(receiver, intentFilter(WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION,
+                WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION))
         launch {
-            registerReceiver(receiver, intentFilter(WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION,
-                    WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION))
-            receiverRegistered = true
             try {
                 p2pManager.requestGroupInfo(channel) {
                     when {
@@ -399,10 +397,7 @@ class RepeaterService : Service(), CoroutineScope, WifiP2pManager.ChannelListene
         })
     }
     private fun cleanLocked() {
-        if (receiverRegistered) {
+        ensureReceiverUnregistered(receiver)
-            unregisterReceiver(receiver)
-            receiverRegistered = false
-        }
         if (Build.VERSION.SDK_INT >= 28) {
             timeoutMonitor?.close()
             timeoutMonitor = null
@@ -417,6 +412,7 @@ class RepeaterService : Service(), CoroutineScope, WifiP2pManager.ChannelListene
     override fun onDestroy() {
         handler.removeCallbacksAndMessages(null)
         if (status != Status.IDLE) binder.shutdown()
+        ensureReceiverUnregistered(receiver)
         launch {    // force clean to prevent leakage
             cleanLocked()
             cancel()

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

@@ -10,6 +10,7 @@ import be.mygod.vpnhotspot.net.TetheringManager.tetheredIfaces
 import be.mygod.vpnhotspot.net.monitor.IpNeighbourMonitor
 import be.mygod.vpnhotspot.util.Event0
 import be.mygod.vpnhotspot.util.broadcastReceiver
+import be.mygod.vpnhotspot.util.ensureReceiverUnregistered
 import kotlinx.coroutines.*
 import java.util.concurrent.ConcurrentHashMap
 
@@ -46,7 +47,6 @@ class TetheringService : IpNeighbourMonitoringService(), CoroutineScope {
     override val coroutineContext = dispatcher + Job()
     private val binder = Binder()
     private val downstreams = ConcurrentHashMap<String, Downstream>()
-    private var receiverRegistered = false
     private val receiver = broadcastReceiver { _, intent ->
         launch {
             val toRemove = downstreams.toMutableMap()   // make a copy
@@ -69,11 +69,8 @@ class TetheringService : IpNeighbourMonitoringService(), CoroutineScope {
             ServiceNotification.stopForeground(this)
             stopSelf()
         } else {
-            if (!receiverRegistered) {
+            registerReceiver(receiver, IntentFilter(TetheringManager.ACTION_TETHER_STATE_CHANGED))
-                receiverRegistered = true
+            IpNeighbourMonitor.registerCallback(this)
-                registerReceiver(receiver, IntentFilter(TetheringManager.ACTION_TETHER_STATE_CHANGED))
-                IpNeighbourMonitor.registerCallback(this)
-            }
             updateNotification()
         }
         launch(Dispatchers.Main) { binder.routingsChanged() }
@@ -106,9 +103,9 @@ class TetheringService : IpNeighbourMonitoringService(), CoroutineScope {
     }
 
     override fun onDestroy() {
+        unregisterReceiver()
         launch {
             downstreams.values.forEach { it.destroy() } // force clean to prevent leakage
-            unregisterReceiver()
             cancel()
             dispatcher.close()
         }
@@ -116,10 +113,7 @@ class TetheringService : IpNeighbourMonitoringService(), CoroutineScope {
     }
 
     private fun unregisterReceiver() {
-        if (receiverRegistered) {
+        ensureReceiverUnregistered(receiver)
-            unregisterReceiver(receiver)
+        IpNeighbourMonitor.unregisterCallback(this)
-            IpNeighbourMonitor.unregisterCallback(this)
-            receiverRegistered = false
-        }
     }
 }

mobile/src/main/java/be/mygod/vpnhotspot/util/Utils.kt

@@ -19,6 +19,7 @@ import androidx.databinding.BindingAdapter
 import be.mygod.vpnhotspot.App.Companion.app
 import be.mygod.vpnhotspot.room.macToString
 import be.mygod.vpnhotspot.widget.SmartSnackbar
+import java.lang.IllegalArgumentException
 import java.net.InetAddress
 import java.net.NetworkInterface
 import java.net.SocketException
@@ -35,6 +36,12 @@ fun Long.toPluralInt(): Int {
     return (this % 1000000000).toInt() + 1000000000
 }
 
+fun Context.ensureReceiverUnregistered(receiver: BroadcastReceiver) {
+    try {
+        unregisterReceiver(receiver)
+    } catch (_: IllegalArgumentException) { }
+}
+
 @SuppressLint("Recycle")
 fun <T> useParcel(block: (Parcel) -> T) = Parcel.obtain().run {
     try {