Ensure that exceptions in player event loop are handled

Any stray exception means that the entire event loop comes crashing down.

connector/src/main/java/org/geysermc/connector/network/UpstreamPacketHandler.java

@@ -161,7 +161,7 @@ public class UpstreamPacketHandler extends LoggingPacketHandler {
 
     @Override
     public boolean handle(ModalFormResponsePacket packet) {
-        session.getEventLoop().execute(() -> session.getFormCache().handleResponse(packet));
+        session.executeInEventLoop(() -> session.getFormCache().handleResponse(packet));
         return true;
     }
 

connector/src/main/java/org/geysermc/connector/network/session/GeyserSession.java

@@ -115,6 +115,7 @@ public class GeyserSession implements CommandSender {
     private final UpstreamSession upstream;
     /**
      * The loop where all packets and ticking is processed to prevent concurrency issues.
+     * If this is manually called, ensure that any exceptions are properly handled.
      */
     private final EventLoop eventLoop;
     private TcpClientSession downstream;
@@ -804,9 +805,8 @@ public class GeyserSession implements CommandSender {
 
             @Override
             public void packetReceived(PacketReceivedEvent event) {
-                if (!closed) {
+                Packet packet = event.getPacket();
-                    PacketTranslatorRegistry.JAVA_TRANSLATOR.translate(event.getPacket().getClass(), event.getPacket(), GeyserSession.this);
+                PacketTranslatorRegistry.JAVA_TRANSLATOR.translate(packet.getClass(), packet, GeyserSession.this);
-                }
             }
 
             @Override
@@ -874,6 +874,32 @@ public class GeyserSession implements CommandSender {
         disconnect(LanguageUtils.getPlayerLocaleString("geyser.network.close", getClientData().getLanguageCode()));
     }
 
+    /**
+     * Executes a task and prints a stack trace if an error occurs.
+     */
+    public void executeInEventLoop(Runnable runnable) {
+        eventLoop.execute(() -> {
+            try {
+                runnable.run();
+            } catch (Throwable e) {
+                e.printStackTrace();
+            }
+        });
+    }
+
+    /**
+     * Schedules a task and prints a stack trace if an error occurs.
+     */
+    public ScheduledFuture<?> scheduleInEventLoop(Runnable runnable, long duration, TimeUnit timeUnit) {
+        return eventLoop.schedule(() -> {
+            try {
+                runnable.run();
+            } catch (Throwable e) {
+                e.printStackTrace();
+            }
+        }, duration, timeUnit);
+    }
+
     /**
      * Called every 50 milliseconds - one Minecraft tick.
      */

connector/src/main/java/org/geysermc/connector/network/translators/PacketTranslatorRegistry.java

@@ -87,27 +87,31 @@ public class PacketTranslatorRegistry<T> {
     @SuppressWarnings("unchecked")
     public <P extends T> boolean translate(Class<? extends P> clazz, P packet, GeyserSession session) {
         if (!session.getUpstream().isClosed() && !session.isClosed()) {
-            try {
+            PacketTranslator<P> translator = (PacketTranslator<P>) translators.get(clazz);
-                PacketTranslator<P> translator = (PacketTranslator<P>) translators.get(clazz);
+            if (translator != null) {
-                if (translator != null) {
+                EventLoop eventLoop = session.getEventLoop();
-                    EventLoop eventLoop = session.getEventLoop();
+                if (eventLoop.inEventLoop()) {
-                    if (eventLoop.inEventLoop()) {
+                    translate0(session, translator, packet);
-                        translator.translate(packet, session);
-                    } else {
-                        eventLoop.execute(() -> translator.translate(packet, session));
-                    }
-                    return true;
                 } else {
-                    if ((GeyserConnector.getInstance().getPlatformType() != PlatformType.STANDALONE || !(packet instanceof BedrockPacket)) && !IGNORED_PACKETS.contains(clazz)) {
+                    eventLoop.execute(() -> translate0(session, translator, packet));
-                        // Other debug logs already take care of Bedrock packets for us if on standalone
+                }
-                        GeyserConnector.getInstance().getLogger().debug("Could not find packet for " + (packet.toString().length() > 25 ? packet.getClass().getSimpleName() : packet));
+                return true;
-                    }
+            } else {
+                if ((GeyserConnector.getInstance().getPlatformType() != PlatformType.STANDALONE || !(packet instanceof BedrockPacket)) && !IGNORED_PACKETS.contains(clazz)) {
+                    // Other debug logs already take care of Bedrock packets for us if on standalone
+                    GeyserConnector.getInstance().getLogger().debug("Could not find packet for " + (packet.toString().length() > 25 ? packet.getClass().getSimpleName() : packet));
                 }
-            } catch (Throwable ex) {
-                GeyserConnector.getInstance().getLogger().error(LanguageUtils.getLocaleStringLog("geyser.network.translator.packet.failed", packet.getClass().getSimpleName()), ex);
-                ex.printStackTrace();
             }
         }
         return false;
     }
+
+    private <P extends T> void translate0(GeyserSession session, PacketTranslator<P> translator, P packet) {
+        try {
+            translator.translate(packet, session);
+        } catch (Throwable ex) {
+            GeyserConnector.getInstance().getLogger().error(LanguageUtils.getLocaleStringLog("geyser.network.translator.packet.failed", packet.getClass().getSimpleName()), ex);
+            ex.printStackTrace();
+        }
+    }
 }

connector/src/main/java/org/geysermc/connector/network/translators/bedrock/BedrockAnimateTranslator.java

@@ -48,7 +48,7 @@ public class BedrockAnimateTranslator extends PacketTranslator<AnimatePacket> {
         switch (packet.getAction()) {
             case SWING_ARM:
                 // Delay so entity damage can be processed first
-                session.getEventLoop().schedule(() ->
+                session.scheduleInEventLoop(() ->
                         session.sendDownstreamPacket(new ClientPlayerSwingArmPacket(Hand.MAIN_HAND)),
                         25,
                         TimeUnit.MILLISECONDS

connector/src/main/java/org/geysermc/connector/network/translators/bedrock/BedrockInventoryTransactionTranslator.java

@@ -220,7 +220,7 @@ public class BedrockInventoryTransactionTranslator extends PacketTranslator<Inve
                                     if (session.isSneaking() || blockState != BlockRegistries.JAVA_IDENTIFIERS.get("minecraft:crafting_table")) {
                                         // Delay the interaction in case the client doesn't intend to actually use the bucket
                                         // See BedrockActionTranslator.java
-                                        session.setBucketScheduledFuture(session.getEventLoop().schedule(() -> {
+                                        session.setBucketScheduledFuture(session.scheduleInEventLoop(() -> {
                                             ClientPlayerUseItemPacket itemPacket = new ClientPlayerUseItemPacket(Hand.MAIN_HAND);
                                             session.sendDownstreamPacket(itemPacket);
                                         }, 5, TimeUnit.MILLISECONDS));

connector/src/main/java/org/geysermc/connector/network/translators/bedrock/entity/BedrockEntityEventTranslator.java

@@ -53,7 +53,7 @@ public class BedrockEntityEventTranslator extends PacketTranslator<EntityEventPa
                 ClientSelectTradePacket selectTradePacket = new ClientSelectTradePacket(packet.getData());
                 session.sendDownstreamPacket(selectTradePacket);
 
-                session.getEventLoop().schedule(() -> {
+                session.scheduleInEventLoop(() -> {
                     Entity villager = session.getPlayerEntity();
                     Inventory openInventory = session.getOpenInventory();
                     if (openInventory instanceof MerchantContainer) {

connector/src/main/java/org/geysermc/connector/network/translators/java/window/JavaSetSlotTranslator.java

@@ -78,7 +78,7 @@ public class JavaSetSlotTranslator extends PacketTranslator<ServerSetSlotPacket>
             if (session.getCraftingGridFuture() != null) {
                 session.getCraftingGridFuture().cancel(false);
             }
-            session.setCraftingGridFuture(session.getEventLoop().schedule(() -> updateCraftingGrid(session, packet, inventory, translator), 150, TimeUnit.MILLISECONDS));
+            session.setCraftingGridFuture(session.scheduleInEventLoop(() -> updateCraftingGrid(session, packet, inventory, translator), 150, TimeUnit.MILLISECONDS));
 
             GeyserItemStack newItem = GeyserItemStack.from(packet.getItem());
             if (packet.getWindowId() == 0 && !(translator instanceof PlayerInventoryTranslator)) {

connector/src/main/java/org/geysermc/connector/network/translators/world/block/entity/SkullBlockEntityTranslator.java

@@ -147,7 +147,7 @@ public class SkullBlockEntityTranslator extends BlockEntityTranslator implements
             if (session.getUpstream().isInitialized()) {
                 player.spawnEntity(session);
 
-                SkullSkinManager.requestAndHandleSkin(player, session, (skin -> session.getEventLoop().schedule(() -> {
+                SkullSkinManager.requestAndHandleSkin(player, session, (skin -> session.scheduleInEventLoop(() -> {
                     // Delay to minimize split-second "player" pop-in
                     player.getMetadata().getFlags().setFlag(EntityFlag.INVISIBLE, false);
                     player.updateBedrockMetadata(session);

connector/src/main/java/org/geysermc/connector/utils/InventoryUtils.java

@@ -79,7 +79,7 @@ public class InventoryUtils {
         if (translator != null) {
             translator.prepareInventory(session, inventory);
             if (translator instanceof DoubleChestInventoryTranslator && !((Container) inventory).isUsingRealBlock()) {
-                session.getEventLoop().schedule(() -> {
+                session.scheduleInEventLoop(() -> {
                     Inventory openInv = session.getOpenInventory();
                     if (openInv != null && openInv.getId() == inventory.getId()) {
                         translator.openInventory(session, inventory);