Simplify WifiDoubleLock invocations

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

@@ -8,7 +8,6 @@ import androidx.annotation.RequiresApi
 import be.mygod.vpnhotspot.App.Companion.app
 import be.mygod.vpnhotspot.net.TetheringManager
 import be.mygod.vpnhotspot.net.monitor.IpNeighbourMonitor
-import be.mygod.vpnhotspot.net.wifi.WifiDoubleLock
 import be.mygod.vpnhotspot.util.StickyEvent1
 import be.mygod.vpnhotspot.util.broadcastReceiver
 import be.mygod.vpnhotspot.widget.SmartSnackbar
@@ -39,7 +38,6 @@ class LocalOnlyHotspotService : IpNeighbourMonitoringService() {
     private val binder = Binder()
     private var reservation: WifiManager.LocalOnlyHotspotReservation? = null
     private var routingManager: RoutingManager? = null
-    private var locked = false
     private var receiverRegistered = false
     private val receiver = broadcastReceiver { _, intent ->
         val ifaces = TetheringManager.getLocalOnlyTetheredIfaces(intent.extras ?: return@broadcastReceiver)
@@ -76,9 +74,6 @@ class LocalOnlyHotspotService : IpNeighbourMonitoringService() {
                 override fun onStarted(reservation: WifiManager.LocalOnlyHotspotReservation?) {
                     if (reservation == null) onFailed(-2) else {
                         this@LocalOnlyHotspotService.reservation = reservation
-                        check(!locked)
-                        WifiDoubleLock.acquire()
-                        locked = true
                         if (!receiverRegistered) {
                             registerReceiver(receiver, IntentFilter(TetheringManager.ACTION_TETHER_STATE_CHANGED))
                             receiverRegistered = true
@@ -135,10 +130,6 @@ class LocalOnlyHotspotService : IpNeighbourMonitoringService() {
     private fun unregisterReceiver() {
         routingManager?.stop()
         routingManager = null
-        if (locked) {
-            WifiDoubleLock.release()
-            locked = false
-        }
         if (receiverRegistered) {
             unregisterReceiver(receiver)
             IpNeighbourMonitor.unregisterCallback(this)

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

@@ -15,7 +15,6 @@ import android.os.Looper
 import androidx.annotation.StringRes
 import androidx.core.content.getSystemService
 import be.mygod.vpnhotspot.App.Companion.app
-import be.mygod.vpnhotspot.net.wifi.WifiDoubleLock
 import be.mygod.vpnhotspot.net.wifi.WifiP2pManagerHelper
 import be.mygod.vpnhotspot.net.wifi.WifiP2pManagerHelper.deletePersistentGroup
 import be.mygod.vpnhotspot.net.wifi.WifiP2pManagerHelper.netId
@@ -133,7 +132,6 @@ class RepeaterService : Service(), WifiP2pManager.ChannelListener, SharedPrefere
         }
     }
     private var routingManager: RoutingManager? = null
-    private var locked = false
 
     var status = Status.IDLE
         private set(value) {
@@ -277,9 +275,6 @@ class RepeaterService : Service(), WifiP2pManager.ChannelListener, SharedPrefere
      * startService Step 3
      */
     private fun doStart(group: WifiP2pGroup) {
-        check(!locked)
-        WifiDoubleLock.acquire()
-        locked = true
         binder.group = group
         check(routingManager == null)
         routingManager = RoutingManager.LocalOnly(this, group.`interface`!!).apply { initRouting() }
@@ -316,10 +311,6 @@ class RepeaterService : Service(), WifiP2pManager.ChannelListener, SharedPrefere
         unregisterReceiver()
         routingManager?.stop()
         routingManager = null
-        if (locked) {
-            WifiDoubleLock.release()
-            locked = false
-        }
         status = Status.IDLE
         ServiceNotification.stopForeground(this)
         stopSelf()

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

@@ -2,10 +2,11 @@ package be.mygod.vpnhotspot
 
 import be.mygod.vpnhotspot.App.Companion.app
 import be.mygod.vpnhotspot.net.Routing
+import be.mygod.vpnhotspot.net.wifi.WifiDoubleLock
 import be.mygod.vpnhotspot.widget.SmartSnackbar
 import timber.log.Timber
 
-abstract class RoutingManager(private val caller: Any, val downstream: String) {
+abstract class RoutingManager(private val caller: Any, val downstream: String, private val isWifi: Boolean) {
     companion object {
         private const val KEY_MASQUERADE_MODE = "service.masqueradeMode"
         var masqueradeMode: Routing.MasqueradeMode
@@ -17,7 +18,10 @@ abstract class RoutingManager(private val caller: Any, val downstream: String) {
             set(value) = app.pref.edit().putString(KEY_MASQUERADE_MODE, value.name).apply()
     }
 
-    class LocalOnly(caller: Any, downstream: String) : RoutingManager(caller, downstream) {
+    /**
+     * Both repeater and local-only hotspot are Wi-Fi based.
+     */
+    class LocalOnly(caller: Any, downstream: String) : RoutingManager(caller, downstream, true) {
         override fun Routing.configure() {
             ipForward() // local only interfaces need to enable ip_forward
             forward()
@@ -31,6 +35,7 @@ abstract class RoutingManager(private val caller: Any, val downstream: String) {
     init {
         app.onPreCleanRoutings[this] = { routing?.stop() }
         app.onRoutingsCleaned[this] = { initRouting() }
+        if (isWifi) WifiDoubleLock.acquire(this)
     }
 
     fun initRouting() = try {
@@ -53,8 +58,9 @@ abstract class RoutingManager(private val caller: Any, val downstream: String) {
     protected abstract fun Routing.configure()
 
     fun stop() {
+        routing?.revert()
+        if (isWifi) WifiDoubleLock.release(this)
         app.onPreCleanRoutings -= this
         app.onRoutingsCleaned -= this
-        routing?.revert()
     }
 }

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

@@ -28,7 +28,7 @@ import java.net.SocketException
 class SettingsPreferenceFragment : PreferenceFragmentCompat() {
     override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
         preferenceManager.preferenceDataStore = SharedPreferenceDataStore(app.pref)
-        RoutingManager.masquerade = RoutingManager.masquerade   // flush default value
+        RoutingManager.masqueradeMode = RoutingManager.masqueradeMode   // flush default value
         addPreferencesFromResource(R.xml.pref_settings)
         val boot = findPreference("service.repeater.startOnBoot") as SwitchPreference
         if (RepeaterService.supported) {

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

@@ -7,7 +7,6 @@ import be.mygod.vpnhotspot.net.Routing
 import be.mygod.vpnhotspot.net.TetherType
 import be.mygod.vpnhotspot.net.TetheringManager
 import be.mygod.vpnhotspot.net.monitor.IpNeighbourMonitor
-import be.mygod.vpnhotspot.net.wifi.WifiDoubleLock
 import be.mygod.vpnhotspot.util.Event0
 import be.mygod.vpnhotspot.util.broadcastReceiver
 import kotlinx.coroutines.Dispatchers
@@ -26,7 +25,8 @@ class TetheringService : IpNeighbourMonitoringService() {
         fun isActive(iface: String): Boolean = synchronized(downstreams) { downstreams.containsKey(iface) }
     }
 
-    inner class Downstream(caller: Any, downstream: String) : RoutingManager(caller, downstream) {
+    inner class Downstream(caller: Any, downstream: String) :
+            RoutingManager(caller, downstream, TetherType.ofInterface(downstream).isWifi) {
         override fun Routing.configure() {
             forward()
             masquerade(RoutingManager.masqueradeMode)
@@ -37,7 +37,6 @@ class TetheringService : IpNeighbourMonitoringService() {
 
     private val binder = Binder()
     private val downstreams = mutableMapOf<String, Downstream>()
-    private var locked = false
     private var receiverRegistered = false
     private val receiver = broadcastReceiver { _, intent ->
         val extras = intent.extras ?: return@broadcastReceiver
@@ -50,10 +49,6 @@ class TetheringService : IpNeighbourMonitoringService() {
     override val activeIfaces get() = synchronized(downstreams) { downstreams.keys.toList() }
 
     private fun updateRoutingsLocked() {
-        if (locked && downstreams.keys.all { !TetherType.ofInterface(it).isWifi }) {
-            WifiDoubleLock.release()
-            locked = false
-        }
         if (downstreams.isEmpty()) {
             unregisterReceiver()
             ServiceNotification.stopForeground(this)
@@ -85,14 +80,10 @@ class TetheringService : IpNeighbourMonitoringService() {
             val ifaces = intent.getStringArrayExtra(EXTRA_ADD_INTERFACES) ?: emptyArray()
             synchronized(downstreams) {
                 for (iface in ifaces) {
-                    Downstream(this, iface).apply {
+                    Downstream(this, iface).run {
                         downstreams[iface] = this
                         initRouting()
                     }
-                    if (TetherType.ofInterface(iface).isWifi && !locked) {
-                        WifiDoubleLock.acquire()
-                        locked = true
-                    }
                 }
                 downstreams.remove(intent.getStringExtra(EXTRA_REMOVE_INTERFACE))?.stop()
                 updateRoutingsLocked()
@@ -110,8 +101,6 @@ class TetheringService : IpNeighbourMonitoringService() {
     private fun unregisterReceiver() {
         if (receiverRegistered) {
             unregisterReceiver(receiver)
-            app.onPreCleanRoutings -= this
-            app.onRoutingsCleaned -= this
             IpNeighbourMonitor.unregisterCallback(this)
             receiverRegistered = false
         }

mobile/src/main/java/be/mygod/vpnhotspot/net/wifi/WifiDoubleLock.kt

@@ -17,20 +17,20 @@ class WifiDoubleLock(lockType: Int) : AutoCloseable {
             WifiDoubleLock.Mode.valueOf(app.pref.getString(KEY, WifiDoubleLock.Mode.Full.toString()) ?: "").lockType
         private val service by lazy { app.getSystemService<PowerManager>()!! }
 
-        private var referenceCount = 0
+        private var holders = mutableSetOf<Any>()
         private var lock: WifiDoubleLock? = null
 
-        fun acquire() = synchronized(this) {
+        fun acquire(holder: Any) = synchronized(this) {
-            if (referenceCount == 0) {
+            if (holders.isEmpty()) {
                 app.pref.registerOnSharedPreferenceChangeListener(this)
                 val lockType = lockType
                 if (lockType != null) lock = WifiDoubleLock(lockType)
             }
-            referenceCount += 1
+            check(holders.add(holder))
         }
-        fun release() = synchronized(this) {
+        fun release(holder: Any) = synchronized(this) {
-            referenceCount -= 1
+            check(holders.remove(holder))
-            if (referenceCount == 0) {
+            if (holders.isEmpty()) {
                 lock?.close()
                 lock = null
                 app.pref.unregisterOnSharedPreferenceChangeListener(this)