Make NetplaySession not a singleton

Create a new NetplaySession each time we try to join a netplay game. Hold onto it in NetplayManager so its available to the different activities that need to access it. Close the session when backing out of the netplay UI. Some guardrails in case things go out of sync: creating a session closes the old one if it is still around for some reason, finalizer in NetplaySession to release native resources if not closed explicitly for some reason. Profiling done to ensure all kotlin and native objects are successfully cleared / garbage collected.
2026-09-14 22:36:01 -05:00 · 2026-05-12 11:20:01 -07:00
parent 183d6d778c
commit abd324e98d
14 changed files with 408 additions and 217 deletions
--- a/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/NativeLibrary.kt
+++ b/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/NativeLibrary.kt
@@ -346,7 +346,7 @@ object NativeLibrary {
     * Begins emulation for a netplay session, using the BootSessionData provided by the host.
     */
    @JvmStatic
-    external fun RunNetPlay(paths: Array<String>, riivolution: Boolean)
+    external fun RunNetPlay(paths: Array<String>, riivolution: Boolean, bootSessionDataPointer: Long)

    @JvmStatic
    external fun ChangeDisc(path: String)
--- a/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/netplay/NetplayManager.kt
+++ b/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/netplay/NetplayManager.kt
@@ -0,0 +1,38 @@
+// Copyright 2003 Dolphin Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+package org.dolphinemu.dolphinemu.features.netplay
+
+import kotlinx.coroutines.CompletableDeferred
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
+
+object NetplayManager {
+
+    private val mutex = Mutex()
+
+    @Volatile
+    private var closeComplete: CompletableDeferred<Unit>? = null
+
+    @Volatile
+    var activeSession: NetplaySession? = null
+        private set
+
+    suspend fun createSession(): NetplaySession = mutex.withLock {
+        closeComplete?.await()
+
+        // Sessions should be closed by UI navigation, but just in case.
+        activeSession?.closeBlocking()
+
+        closeComplete = CompletableDeferred()
+
+        NetplaySession(
+            onClosed = {
+                activeSession = null
+                closeComplete?.complete(Unit)
+            }
+        ).also {
+            activeSession = it
+        }
+    }
+}
--- a/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/netplay/NetplaySession.kt
+++ b/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/netplay/NetplaySession.kt
@@ -6,7 +6,6 @@ package org.dolphinemu.dolphinemu.features.netplay
 import androidx.annotation.Keep
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.SupervisorJob
 import kotlinx.coroutines.cancel
 import kotlinx.coroutines.channels.BufferOverflow
@@ -29,14 +28,21 @@ import org.dolphinemu.dolphinemu.features.netplay.model.NetplayMessage
 import org.dolphinemu.dolphinemu.features.netplay.model.Player
 import org.dolphinemu.dolphinemu.features.netplay.model.SaveTransferProgress

-object Netplay {
-    @Keep
+class NetplaySession(
+    private val onClosed: (NetplaySession) -> Unit,
+) {
+
+    private var netPlayUICallbacksPointer: Long = nativeCreateUICallbacks()
+
    private var netPlayClientPointer: Long = 0

-    @Keep
    private var bootSessionDataPointer: Long = 0

-    private var sessionScope: CoroutineScope? = null
+    private val sessionScope = CoroutineScope(SupervisorJob())
+
+    @Volatile
+    var isClosed = false
+        private set

    val isLaunching: Boolean
        get() = bootSessionDataPointer != 0L
@@ -93,85 +99,49 @@ object Netplay {
    val saveTransferProgress = _saveTransferProgress.asStateFlow()

    suspend fun join(): Boolean = withContext(Dispatchers.IO) {
-        val scope = createSessionScope()
+        if (isClosed) throw IllegalStateException("Cannot join a closed session")

-        // Gather all messages that should appear in the chat window.
        mergeMessages()
            .runningFold(emptyList<NetplayMessage>()) { acc, msg -> listOf(msg) + acc }
            .onEach { _messages.tryEmit(it) }
-            .launchIn(scope)
+            .launchIn(sessionScope)

-        netPlayClientPointer = Join()
-        val isConnected = netPlayClientPointer != 0L && isClientConnected()
+        netPlayClientPointer = nativeJoin()

-        if (!isActive) {
-            releaseNetplayClient()
+        if (netPlayClientPointer == 0L || !isActive) {
+            closeBlocking()
            return@withContext false
        }

-        if (isConnected) {
-            return@withContext true
-        }
-
-        releaseNetplayClient()
-        false
+        true
    }

-    suspend fun quit() = withContext(Dispatchers.IO) {
-        releaseNetplayClient()
-    }
+    fun sendMessage(message: String) = nativeSendMessage(message)

-    @OptIn(ExperimentalCoroutinesApi::class)
-    private fun releaseNetplayClient() {
-        sessionScope?.cancel()
-        sessionScope = null
+    fun adjustPadBufferSize(buffer: Int) = nativeAdjustPadBufferSize(buffer)

-        if (bootSessionDataPointer != 0L) {
-            ReleaseBootSessionData()
+    fun consumeBootSessionData(): Long {
+        return bootSessionDataPointer.also {
            bootSessionDataPointer = 0
        }
-
-        if (netPlayClientPointer != 0L) {
-            ReleaseNetplayClient()
-            netPlayClientPointer = 0
-        }
-
-        _launchGame.flush()
-        _stopGame.flush()
-        _connectionErrors.flush()
-        _players.resetReplayCache()
-        _messages.resetReplayCache()
-        _chatMessages.resetReplayCache()
-        _game.resetReplayCache()
-        _hostInputAuthorityEnabled.resetReplayCache()
-        _padBuffer.resetReplayCache()
-        _saveTransferProgress.value = null
    }

-    private fun createSessionScope(): CoroutineScope {
-        sessionScope?.cancel()
-        return CoroutineScope(SupervisorJob() + Dispatchers.IO).also {
-            sessionScope = it
-        }
+    suspend fun close() = withContext(Dispatchers.IO) {
+        closeBlocking()
    }

-    @JvmStatic
-    private external fun Join(): Long
+    @Synchronized
+    fun closeBlocking() {
+        if (isClosed) return
+        isClosed = true
+        sessionScope.cancel()
+        releaseNativeResources()
+        onClosed(this)
+    }

-    @JvmStatic
-    external fun isClientConnected(): Boolean
-
-    @JvmStatic
-    external fun sendMessage(message: String)
-
-    @JvmStatic
-    external fun adjustPadBufferSize(buffer: Int)
-
-    @JvmStatic
-    private external fun ReleaseBootSessionData()
-
-    @JvmStatic
-    private external fun ReleaseNetplayClient()
+    protected fun finalize() {
+        releaseNativeResources()
+    }

    private fun mergeMessages(): Flow<NetplayMessage> = merge(
        chatMessages.map { NetplayMessage.Chat(it) },
@@ -180,10 +150,45 @@ object Netplay {
        padBuffer.map { NetplayMessage.BufferChanged(it) },
    )

+    private fun releaseNativeResources() {
+        val currentBootSessionDataPointer = bootSessionDataPointer
+        if (currentBootSessionDataPointer != 0L) {
+            bootSessionDataPointer = 0
+            nativeReleaseBootSessionData(currentBootSessionDataPointer)
+        }
+
+        val currentNetPlayClientPointer = netPlayClientPointer
+        if (currentNetPlayClientPointer != 0L) {
+            netPlayClientPointer = 0
+            nativeReleaseClient(currentNetPlayClientPointer)
+        }
+
+        val currentNetPlayUICallbacksPointer = netPlayUICallbacksPointer
+        if (currentNetPlayUICallbacksPointer != 0L) {
+            netPlayUICallbacksPointer = 0
+            nativeReleaseUICallbacks(currentNetPlayUICallbacksPointer)
+        }
+    }
+
+    // JNI methods
+
+    private external fun nativeCreateUICallbacks(): Long
+
+    private external fun nativeJoin(): Long
+
+    private external fun nativeSendMessage(message: String)
+
+    private external fun nativeAdjustPadBufferSize(buffer: Int)
+
+    private external fun nativeReleaseUICallbacks(pointer: Long)
+
+    private external fun nativeReleaseClient(pointer: Long)
+
+    private external fun nativeReleaseBootSessionData(pointer: Long)
+
    // NetPlayUI callbacks

    @Keep
-    @JvmStatic
    fun onBootGame(gameFilePath: String, bootSessionDataPointer: Long) {
        this.bootSessionDataPointer = bootSessionDataPointer
        _stopGame.flush()
@@ -191,57 +196,47 @@ object Netplay {
    }

    @Keep
-    @JvmStatic
    fun onStopGame() {
        _stopGame.trySend(Unit)
    }

    @Keep
-    @JvmStatic
    fun onConnectionLost() {
        _connectionLost.trySend(Unit)
    }

    @Keep
-    @JvmStatic
    fun onConnectionError(message: String) {
        _connectionErrors.trySend(message)
    }

    @Keep
-    @JvmStatic
    fun onUpdate(players: Array<Player>) {
        _players.tryEmit(players.toList())
    }

    @Keep
-    @JvmStatic
    fun onChatMessageReceived(message: String) {
        _chatMessages.tryEmit(message)
    }

    @Keep
-    @JvmStatic
    fun onHostInputAuthorityChanged(enabled: Boolean) {
        _hostInputAuthorityEnabled.tryEmit(enabled)
    }

    @Keep
-    @JvmStatic
    fun onGameChanged(game: String) {
        _game.tryEmit(game)
    }

    @Keep
-    @JvmStatic
    fun onPadBufferChanged(buffer: Int) {
-        // Only for remote pad buffer settings. Ignore local max buffer changes.
        if (_hostInputAuthorityEnabled.replayCache.firstOrNull() == true) return
        _padBuffer.tryEmit(buffer)
    }

    @Keep
-    @JvmStatic
    fun onShowChunkedProgressDialog(title: String, dataSize: Long, playerIds: IntArray) {
        val players = _players.replayCache.firstOrNull()
        _saveTransferProgress.value = SaveTransferProgress(
@@ -258,7 +253,6 @@ object Netplay {
    }

    @Keep
-    @JvmStatic
    fun onSetChunkedProgress(playerId: Int, progress: Long) {
        val current = _saveTransferProgress.value
        _saveTransferProgress.value = current?.copy(
@@ -273,11 +267,9 @@ object Netplay {
    }

    @Keep
-    @JvmStatic
    fun onHideChunkedProgressDialog() {
        _saveTransferProgress.value = null
    }
-
 }

 private fun <T> Channel<T>.flush() {
--- a/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/netplay/model/NetplaySetupViewModel.kt
+++ b/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/netplay/model/NetplaySetupViewModel.kt
@@ -3,22 +3,31 @@
 package org.dolphinemu.dolphinemu.features.netplay.model

 import androidx.lifecycle.ViewModel
+import androidx.lifecycle.ViewModelProvider
 import androidx.lifecycle.asFlow
 import androidx.lifecycle.viewModelScope
+import kotlinx.coroutines.Job
 import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.channels.Channel.Factory.CONFLATED
+import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.asSharedFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.flow.launchIn
+import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.flow.receiveAsFlow
 import kotlinx.coroutines.launch
-import org.dolphinemu.dolphinemu.features.netplay.Netplay
+import org.dolphinemu.dolphinemu.features.netplay.NetplayManager
 import org.dolphinemu.dolphinemu.features.settings.model.IntSetting
 import org.dolphinemu.dolphinemu.features.settings.model.NativeConfig
 import org.dolphinemu.dolphinemu.features.settings.model.StringSetting
 import org.dolphinemu.dolphinemu.services.GameFileCacheManager

-class NetplaySetupViewModel : ViewModel() {
+class NetplaySetupViewModel(
+    private val netplayManager: NetplayManager,
+) : ViewModel() {
+
    private val _connectionRole = MutableStateFlow<ConnectionRole>(ConnectionRole.Connect)
    val connectionRole = _connectionRole.asStateFlow()

@@ -45,7 +54,8 @@ class NetplaySetupViewModel : ViewModel() {
    private val _connecting = MutableStateFlow(false)
    val connecting = _connecting.asStateFlow()

-    val errors = Netplay.connectionErrors
+    private val _errors = MutableSharedFlow<String>(extraBufferCapacity = 8)
+    val errors = _errors.asSharedFlow()

    init {
        GameFileCacheManager.startLoad()
@@ -89,16 +99,42 @@ class NetplaySetupViewModel : ViewModel() {
    }

    fun connect() {
+        if (_connecting.value) return
+
        _connecting.value = true

        viewModelScope.launch {
-            GameFileCacheManager.isLoading().asFlow().first { it == false }
+            var errorForwarding: Job? = null

-            if (Netplay.join()) {
-                _showNetplayScreen.trySend(Unit)
+            try {
+                GameFileCacheManager.isLoading().asFlow().first { it == false }
+
+                val session = netplayManager.createSession()
+                errorForwarding = session.connectionErrors
+                    .onEach { _errors.emit(it) }
+                    .launchIn(this)
+
+                if (session.join()) {
+                    _showNetplayScreen.trySend(Unit)
+                }
+            } finally {
+                errorForwarding?.cancel()
+                _connecting.value = false
            }
+        }
+    }

-            _connecting.value = false
+    override fun onCleared() {
+        super.onCleared()
+        // There should not be an active session at this point but in case one was created
+        // but launching the Netplay screen failed, close it.
+        netplayManager.activeSession?.closeBlocking()
+    }
+
+    class Factory(private val netplayManager: NetplayManager) : ViewModelProvider.Factory {
+        @Suppress("UNCHECKED_CAST")
+        override fun <T : ViewModel> create(modelClass: Class<T>): T {
+            return NetplaySetupViewModel(netplayManager) as T
        }
    }
 }
--- a/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/netplay/model/NetplayViewModel.kt
+++ b/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/netplay/model/NetplayViewModel.kt
@@ -3,51 +3,43 @@
 package org.dolphinemu.dolphinemu.features.netplay.model

 import androidx.lifecycle.ViewModel
+import androidx.lifecycle.ViewModelProvider
 import androidx.lifecycle.viewModelScope
 import kotlinx.coroutines.DelicateCoroutinesApi
 import kotlinx.coroutines.GlobalScope
-import kotlinx.coroutines.channels.Channel
-import kotlinx.coroutines.channels.Channel.Factory.CONFLATED
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.asStateFlow
-import kotlinx.coroutines.flow.receiveAsFlow
 import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.launch
-import org.dolphinemu.dolphinemu.features.netplay.Netplay
+import org.dolphinemu.dolphinemu.features.netplay.NetplaySession
 import org.dolphinemu.dolphinemu.features.settings.model.IntSetting
 import org.dolphinemu.dolphinemu.features.settings.model.NativeConfig

-class NetplayViewModel : ViewModel() {
-    val launchGame = Netplay.launchGame
+class NetplayViewModel(
+    private val netplaySession: NetplaySession,
+) : ViewModel() {

-    private val _goBack = Channel<Unit>(CONFLATED)
-    val goBack = _goBack.receiveAsFlow()
+    val launchGame = netplaySession.launchGame

-    val connectionLost = Netplay.connectionLost
+    val connectionLost = netplaySession.connectionLost

-    val players = Netplay.players
+    val players = netplaySession.players
        .stateIn(viewModelScope, SharingStarted.WhileSubscribed(), emptyList())

-    val messages = Netplay.messages
+    val messages = netplaySession.messages
        .stateIn(viewModelScope, SharingStarted.WhileSubscribed(), emptyList())

-    val game = Netplay.game
+    val game = netplaySession.game
        .stateIn(viewModelScope, SharingStarted.WhileSubscribed(), "")

-    val hostInputAuthority = Netplay.hostInputAuthorityEnabled
+    val hostInputAuthority = netplaySession.hostInputAuthorityEnabled
        .stateIn(viewModelScope, SharingStarted.WhileSubscribed(), false)

    private val _maxBuffer = MutableStateFlow(IntSetting.NETPLAY_CLIENT_BUFFER_SIZE.int)
    val maxBuffer = _maxBuffer.asStateFlow()

-    val saveTransferProgress = Netplay.saveTransferProgress
-
-    init {
-        if (!Netplay.isClientConnected()) {
-            _goBack.trySend(Unit)
-        }
-    }
+    val saveTransferProgress = netplaySession.saveTransferProgress

    fun sendMessage(message: String) {
        val trimmedMessage = message.trim()
@@ -55,20 +47,29 @@ class NetplayViewModel : ViewModel() {
            return
        }

-        Netplay.sendMessage(trimmedMessage)
+        netplaySession.sendMessage(trimmedMessage)
    }

    fun setMaxBuffer(buffer: Int) {
        _maxBuffer.value = buffer
        IntSetting.NETPLAY_CLIENT_BUFFER_SIZE.setInt(NativeConfig.LAYER_BASE, buffer)
-        Netplay.adjustPadBufferSize(buffer)
+        netplaySession.adjustPadBufferSize(buffer)
    }

    @OptIn(DelicateCoroutinesApi::class)
    override fun onCleared() {
        super.onCleared()
+        // Closing the netplay session is a bit slow for the main thread so launch in
+        // GlobalScope and allow the activity and view model to finish immediately.
        GlobalScope.launch {
-            Netplay.quit()
+            netplaySession.close()
+        }
+    }
+
+    class Factory(private val session: NetplaySession) : ViewModelProvider.Factory {
+        @Suppress("UNCHECKED_CAST")
+        override fun <T : ViewModel> create(modelClass: Class<T>): T {
+            return NetplayViewModel(session) as T
        }
    }
 }
--- a/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/netplay/ui/NetplayActivity.kt
+++ b/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/netplay/ui/NetplayActivity.kt
@@ -16,6 +16,7 @@ import androidx.lifecycle.lifecycleScope
 import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.onEach
 import org.dolphinemu.dolphinemu.activities.EmulationActivity
+import org.dolphinemu.dolphinemu.features.netplay.NetplayManager
 import org.dolphinemu.dolphinemu.features.netplay.model.NetplayViewModel
 import org.dolphinemu.dolphinemu.ui.main.ThemeProvider
 import org.dolphinemu.dolphinemu.ui.theme.DolphinTheme
@@ -29,11 +30,13 @@ class NetplayActivity : AppCompatActivity(), ThemeProvider {
        enableEdgeToEdge()
        super.onCreate(savedInstanceState)

-        val viewModel = ViewModelProvider(this)[NetplayViewModel::class.java]
+        val session = NetplayManager.activeSession
+        if (session == null) {
+            finish()
+            return
+        }

-        viewModel.goBack
-            .onEach { finish() }
-            .launchIn(lifecycleScope)
+        val viewModel = ViewModelProvider(this, NetplayViewModel.Factory(session))[NetplayViewModel::class.java]

        viewModel.launchGame
            .flowWithLifecycle(lifecycle, Lifecycle.State.STARTED)
--- a/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/netplay/ui/NetplaySetupActivity.kt
+++ b/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/netplay/ui/NetplaySetupActivity.kt
@@ -15,6 +15,7 @@ import androidx.lifecycle.flowWithLifecycle
 import androidx.lifecycle.lifecycleScope
 import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.onEach
+import org.dolphinemu.dolphinemu.features.netplay.NetplayManager
 import org.dolphinemu.dolphinemu.features.netplay.model.NetplaySetupViewModel
 import org.dolphinemu.dolphinemu.ui.main.ThemeProvider
 import org.dolphinemu.dolphinemu.ui.theme.DolphinTheme
@@ -28,7 +29,10 @@ class NetplaySetupActivity : AppCompatActivity(), ThemeProvider {
        enableEdgeToEdge()
        super.onCreate(savedInstanceState)

-        val viewModel = ViewModelProvider(this)[NetplaySetupViewModel::class.java]
+        val viewModel = ViewModelProvider(
+            this,
+            NetplaySetupViewModel.Factory(NetplayManager)
+        )[NetplaySetupViewModel::class.java]

        viewModel.showNetplayScreen
            .flowWithLifecycle(lifecycle, Lifecycle.State.STARTED)
--- a/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/fragments/EmulationFragment.kt
+++ b/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/fragments/EmulationFragment.kt
@@ -16,7 +16,7 @@ import kotlinx.coroutines.launch
 import org.dolphinemu.dolphinemu.NativeLibrary
 import org.dolphinemu.dolphinemu.activities.EmulationActivity
 import org.dolphinemu.dolphinemu.databinding.FragmentEmulationBinding
-import org.dolphinemu.dolphinemu.features.netplay.Netplay
+import org.dolphinemu.dolphinemu.features.netplay.NetplayManager
 import org.dolphinemu.dolphinemu.features.settings.model.BooleanSetting
 import org.dolphinemu.dolphinemu.features.settings.model.Settings
 import org.dolphinemu.dolphinemu.overlay.InputOverlay
@@ -211,7 +211,8 @@ class EmulationFragment : Fragment(), SurfaceHolder.Callback {
                // Don't load temporary saves when launching Netplay, this path can trigger
                // when a game starts due to orientation changes caused by a mismatch in menu
                // vs emulation activity orientations.
-                if (loadPreviousTemporaryState && !Netplay.isLaunching) {
+                val netplaySession = NetplayManager.activeSession
+                if (loadPreviousTemporaryState && netplaySession?.isLaunching != true) {
                    Log.debug("[EmulationFragment] Starting emulation thread from previous state.")
                    val paths = requireNotNull(gamePaths) {
                        "Cannot start emulation without any game paths"
@@ -221,16 +222,20 @@ class EmulationFragment : Fragment(), SurfaceHolder.Callback {
                if (launchSystemMenu) {
                    Log.debug("[EmulationFragment] Starting emulation thread for the Wii Menu.")
                    NativeLibrary.RunSystemMenu()
-                } else if (Netplay.isLaunching) {
+                } else if (netplaySession?.isLaunching == true) {
                    Log.debug("[EmulationFragment] Starting emulation thread for Netplay.")
                    val paths = requireNotNull(gamePaths) {
                        "Cannot start emulation without any game paths"
                    }
                    lifecycleScope.launch {
-                        Netplay.stopGame.first()
+                        netplaySession.stopGame.first()
                        stopEmulation()
                    }
-                    NativeLibrary.RunNetPlay(paths, riivolution)
+                    NativeLibrary.RunNetPlay(
+                        paths,
+                        riivolution,
+                        netplaySession.consumeBootSessionData()
+                    )
                } else {
                    Log.debug("[EmulationFragment] Starting emulation thread.")
                    val paths = requireNotNull(gamePaths) {