Create NetPlayServer and start game

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/netplay/NetplaySession.kt

@@ -37,6 +37,8 @@ class NetplaySession(
 
     private var netPlayClientPointer: Long = 0
 
+    private var netPlayServerPointer: Long = 0
+
     private var bootSessionDataPointer: Long = 0
 
     private val sessionScope = CoroutineScope(SupervisorJob())
@@ -44,6 +46,9 @@ class NetplaySession(
     @Volatile
     var isClosed = false
         private set
+        
+    val isHosting: Boolean
+        get() = netPlayServerPointer != 0L
 
     val isLaunching: Boolean
         get() = bootSessionDataPointer != 0L
@@ -126,10 +131,24 @@ class NetplaySession(
         true
     }
 
+    suspend fun host(): Boolean = withContext(Dispatchers.IO) {
+        if (isClosed) throw IllegalStateException("Cannot host a closed session")
+
+        netPlayServerPointer = nativeHost()
+        if (netPlayServerPointer == 0L || !isActive) {
+            closeBlocking()
+            return@withContext false
+        }
+
+        join()
+    }
+
     fun sendMessage(message: String) = nativeSendMessage(message)
 
     fun adjustPadBufferSize(buffer: Int) = nativeAdjustPadBufferSize(buffer)
 
+    fun startGame() = nativeStartGame()
+
     fun consumeBootSessionData(): Long {
         return bootSessionDataPointer.also {
             bootSessionDataPointer = 0
@@ -174,6 +193,12 @@ class NetplaySession(
             nativeReleaseClient(currentNetPlayClientPointer)
         }
 
+        val currentNetPlayServerPointer = netPlayServerPointer
+        if (currentNetPlayServerPointer != 0L) {
+            netPlayServerPointer = 0
+            nativeReleaseServer(currentNetPlayServerPointer)
+        }
+
         val currentNetPlayUICallbacksPointer = netPlayUICallbacksPointer
         if (currentNetPlayUICallbacksPointer != 0L) {
             netPlayUICallbacksPointer = 0
@@ -187,6 +212,8 @@ class NetplaySession(
 
     private external fun nativeJoin(): Long
 
+    private external fun nativeHost(): Long
+
     private external fun nativeSendMessage(message: String)
 
     private external fun nativeAdjustPadBufferSize(buffer: Int)
@@ -195,8 +222,12 @@ class NetplaySession(
 
     private external fun nativeReleaseClient(pointer: Long)
 
+    private external fun nativeReleaseServer(pointer: Long)
+
     private external fun nativeReleaseBootSessionData(pointer: Long)
 
+    private external fun nativeStartGame()
+
     // NetPlayUI callbacks
 
     @Keep

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/netplay/model/NetplaySetupViewModel.kt

@@ -119,11 +119,9 @@ class NetplaySetupViewModel(
         BooleanSetting.NETPLAY_USE_UPNP.setBoolean(NativeConfig.LAYER_BASE, useUpnp)
     }
 
-    fun host() {
+    fun host() = connect(host = true)
 
-    }
-
-    fun connect() {
+    fun connect(host: Boolean = false) {
         if (_connecting.value) return
 
         _connecting.value = true
@@ -139,7 +137,12 @@ class NetplaySetupViewModel(
                     .onEach { _errors.emit(it) }
                     .launchIn(this)
 
-                if (session.join()) {
+                val success = if (host) {
+                    session.host()
+                } else {
+                    session.join()
+                }
+                if (success) {
                     _showNetplayScreen.trySend(Unit)
                 }
             } finally {

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/netplay/model/NetplayViewModel.kt

@@ -22,6 +22,8 @@ class NetplayViewModel(
 
     val launchGame = netplaySession.launchGame
 
+    val isHosting = netplaySession.isHosting
+
     val connectionLost = netplaySession.connectionLost
 
     val players = netplaySession.players
@@ -43,6 +45,10 @@ class NetplayViewModel(
 
     val gameDigestProgress = netplaySession.gameDigestProgress
 
+    fun startGame() {
+        netplaySession.startGame()
+    }
+
     fun sendMessage(message: String) {
         val trimmedMessage = message.trim()
         if (trimmedMessage.isEmpty()) {

Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/netplay/ui/NetplayActivity.kt

@@ -51,8 +51,8 @@ class NetplayActivity : AppCompatActivity(), ThemeProvider {
                     messages = viewModel.messages.collectAsState().value,
                     onSendMessage = viewModel::sendMessage,
                     game = viewModel.game.collectAsState().value,
-                    isHosting = false,
-                    onStartGame = {},
+                    isHosting = viewModel.isHosting,
+                    onStartGame = viewModel::startGame,
                     players = viewModel.players.collectAsState().value,
                     hostInputAuthorityEnabled = viewModel.hostInputAuthority.collectAsState().value,
                     maxBuffer = viewModel.maxBuffer.collectAsState().value,