Is Networking Async now?

[wicked mural]

When porting to 1.21 I noticed that my packets now experience race conditions (or just out of order, not sure yet):
Specifically the vanilla ClientboundContainerSetContentPacket arrives faster than my OpenGui packet, thus getting discarded.
My current hotfix is to just sleep 100ms but thats really not a permanent solution.

Old code, no longer works despite sending OpenGuiRequest first, then ClientboundContainerSetContentPacket through setSynchronizer.

    public void openInventory(ServerPlayer player) {
        ((ServerPlayerEntityMixin)player).ic$nextContainerCounter();
        AbstractContainerMenu screenHandler = createMenu(((ServerPlayerEntityMixin)player).getContainerCounter(), player.getInventory(), player);
        if (screenHandler != null) {
            NetworkHandler.sendToPlayer(new OpenGuiRequest(this, screenHandler.containerId), player);
            // A sleep here would "fix" the issue.
            player.containerMenu = screenHandler;
            ServerPlayerEntityMixin playerAccessor = (ServerPlayerEntityMixin) player;
            screenHandler.setSynchronizer(playerAccessor.getContainerSynchronizer());
        }
    }

[wicked mural]

The current fix is this and its horrible

    public void openInventory(ServerPlayer player) {
        ((ServerPlayerEntityMixin) player).ic$nextContainerCounter();
        AbstractContainerMenu screenHandler = createMenu(((ServerPlayerEntityMixin) player).getContainerCounter(), player.getInventory(), player);
        if (screenHandler != null) {
            NetworkHandler.sendToPlayer(new OpenGuiRequest(this, screenHandler.containerId), player);
            new Thread(() -> {
                try {
                    Thread.sleep(100);
                } catch (InterruptedException e) {
                    throw new RuntimeException(e);
                }
                MinecraftServer server = level().getServer();
                if (server != null) {
                    server.execute(() -> {
                        player.containerMenu = screenHandler;
                        ServerPlayerEntityMixin playerAccessor = (ServerPlayerEntityMixin) player;
                        screenHandler.setSynchronizer(playerAccessor.getContainerSynchronizer());
                    });
                }
            }).start();
        }
    }

[bold briar]

could you cache the necessary action and then mixin to the "ontick" method and execute the next tick?

That way they should be queued up nicely on the client aswell

[wicked mural]

Hmm, that would work, but its still odd that the network order is not granted anymore. NeoForge for example works as expected. I believe that I just misunderstood something

[warm trout]

packets in minecraft always arrive in the order you sent them, as guaranteed by the TCP protocol

[wicked mural]

You can have several parallel connections open tho, and the networking consists of more than just a plain socket. I could stumble across a problem with multiple channels handled one after another or whatelse.
What I see is this call order: OpenGui::new -> ClientboundContainerSetContentPacket::new -> ClientboundContainerSetContentPacket::handle -> OpenGui::handle

[warm trout]

um what

it doesn't matter if you can have multiple connections if minecraft only uses one

[wicked mural]

thats the question of this post

So packets should still be in order, and I need to look somewhere else

[warm trout]

yes

there's not enough information for me to provide any useful hints

[wicked mural]

https://github.com/Luke100000/ImmersiveAircraft/blob/1.20.1/common/src/main/java/immersive_aircraft/entity/InventoryVehicleEntity.java#L140

I call NetworkHandler.sendToPlayer(new OpenGuiRequest(this, screenHandler.containerId), player); (Which goes straight to ServerCommonPacketListenerImpl#send(...))
I then call screenHandler.setSynchronizer() which does ServerPlayer.this.connection.send(...);

But they come in the other way around.

[wicked mural]

Debugged more, the packets gets decoded in the correct order, but not handled.

[wicked mural]

Got it: For whatever reason I assumed the network handler to be on the netty thread and added an extra .execute(), which obviously delayed execution by up to one tick.

ServerPlayNetworking.registerGlobalReceiver(type, (payload, context) -> context.server().execute(() -> serverHandler.handle(payload, context.player())));

[formal root]

why aren't you using PlayerEntity#openHandledScreen to open your screen in the first place?

[wicked mural]

Good question. Legacy code or maybe registering menutypes was a bit more painful in 1.16.5, I don't remember