Only flush during player update

src/main/java/net/minestom/server/entity/Player.java

@@ -54,6 +54,7 @@ import net.minestom.server.utils.callback.OptionalCallback;
 import net.minestom.server.utils.chunk.ChunkCallback;
 import net.minestom.server.utils.chunk.ChunkUtils;
 import net.minestom.server.utils.instance.InstanceUtils;
+import net.minestom.server.utils.player.PlayerUtils;
 import net.minestom.server.utils.time.CooldownUtils;
 import net.minestom.server.utils.time.TimeUnit;
 import net.minestom.server.utils.time.UpdateOption;
@@ -295,6 +296,13 @@ public class Player extends LivingEntity implements CommandSender {
 
     @Override
     public void update(long time) {
+
+        // Flush all pending packets
+        if (PlayerUtils.isNettyClient(this)) {
+            ((NettyPlayerConnection) playerConnection).getChannel().flush();
+        }
+
+        // Network tick verification
         playerConnection.updateStats();
 
         // Process received packets

src/main/java/net/minestom/server/network/player/NettyPlayerConnection.java

@@ -82,10 +82,17 @@ public class NettyPlayerConnection extends PlayerConnection {
         channel.pipeline().addAfter("framer", "compressor", new PacketCompressor(threshold));
     }
 
+    /**
+     * Writes a packet to the connection channel.
+     * <p>
+     * All packets are flushed during {@link net.minestom.server.entity.Player#update(long)}.
+     *
+     * @param serverPacket the packet to write
+     */
     @Override
     public void sendPacket(@NotNull ServerPacket serverPacket) {
         if (shouldSendPacket(serverPacket)) {
-            channel.writeAndFlush(serverPacket);
+            channel.write(serverPacket);
         }
     }
 

src/test/java/demo/PlayerInit.java

@@ -30,6 +30,7 @@ import net.minestom.server.utils.time.TimeUnit;
 import net.minestom.server.world.DimensionType;
 
 import java.util.UUID;
+import java.util.concurrent.ThreadLocalRandom;
 
 public class PlayerInit {
 
@@ -43,7 +44,7 @@ public class PlayerInit {
         NoiseTestGenerator noiseTestGenerator = new NoiseTestGenerator();
         instanceContainer = MinecraftServer.getInstanceManager().createInstanceContainer(DimensionType.OVERWORLD);
         instanceContainer.enableAutoChunkLoad(true);
-        instanceContainer.setChunkGenerator(noiseTestGenerator);
+        instanceContainer.setChunkGenerator(chunkGeneratorDemo);
 
         // Load some chunks beforehand
         final int loopStart = -3;
@@ -162,6 +163,8 @@ public class PlayerInit {
             player.addEventCallback(PlayerLoginEvent.class, event -> {
 
                 event.setSpawningInstance(instanceContainer);
+                int x = ThreadLocalRandom.current().nextInt()%10000;
+                player.setRespawnPoint(new Position(x, 64f, 0));
 
                 /*player.getInventory().addInventoryCondition((p, slot, clickType, inventoryConditionResult) -> {
                     if (slot == -999)
@@ -174,9 +177,6 @@ public class PlayerInit {
 
             player.addEventCallback(PlayerSpawnEvent.class, event -> {
                 player.setGameMode(GameMode.SURVIVAL);
-                if (event.isFirstSpawn()) {
-                    player.teleport(new Position(0, 64f, 0));
-                }
 
                 ItemStack itemStack = new ItemStack(Material.DIAMOND_BLOCK, (byte) 64);
                 NbtDataImpl data = new NbtDataImpl();