[1.21.11] [Update checker] loading resources are delayed

[mahdoosh1]

loading resources are delayed and i get stuck on loading screen, after it loads the first thing i see is:

[20:07:19] [ModMenu/Update Checker/Fabric Loader/ERROR]: Failed Fabric Loader update check!
java.net.ConnectException
	at java.net.http/jdk.internal.net.http.HttpClientImpl.send(HttpClientImpl.java:923)
	at java.net.http/jdk.internal.net.http.HttpClientFacade.send(HttpClientFacade.java:133)
	at knot//com.terraformersmc.modmenu.util.HttpUtil.request(HttpUtil.java:24)
	at knot//com.terraformersmc.modmenu.util.mod.fabric.FabricLoaderUpdateChecker.checkForUpdates0(FabricLoaderUpdateChecker.java:47)
	at knot//com.terraformersmc.modmenu.util.mod.fabric.FabricLoaderUpdateChecker.checkForUpdates(FabricLoaderUpdateChecker.java:33)
	at knot//com.terraformersmc.modmenu.util.UpdateCheckerUtil.lambda$checkForUpdates0$0(UpdateCheckerUtil.java:69)
	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:545)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:328)
	at java.base/java.util.concurrent.ThreadPerTaskExecutor$ThreadBoundFuture.run(ThreadPerTaskExecutor.java:323)
	at java.base/java.lang.VirtualThread.run(VirtualThread.java:456)
Caused by: java.net.ConnectException
	at java.net.http/jdk.internal.net.http.common.Utils.toConnectException(Utils.java:1070)
	at java.net.http/jdk.internal.net.http.PlainHttpConnection.connectAsync(PlainHttpConnection.java:223)
	at java.net.http/jdk.internal.net.http.PlainHttpConnection.checkRetryConnect(PlainHttpConnection.java:277)
	at java.net.http/jdk.internal.net.http.PlainHttpConnection.lambda$connectAsync$0(PlainHttpConnection.java:235)
	at java.base/java.util.concurrent.CompletableFuture.uniHandle(CompletableFuture.java:955)
	at java.base/java.util.concurrent.CompletableFuture$UniHandle.tryFire(CompletableFuture.java:932)
	at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:531)
	at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1794)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1090)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:614)
	at java.base/java.lang.Thread.run(Thread.java:1474)
Caused by: java.nio.channels.ClosedChannelException
	at java.base/sun.nio.ch.SocketChannelImpl.ensureOpen(SocketChannelImpl.java:204)
	at java.base/sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:942)
	at java.net.http/jdk.internal.net.http.PlainHttpConnection.connectAsync(PlainHttpConnection.java:211)
	... 9 more

[mahdoosh1]

there is a possibility that i'm wrong and resources loading is delayed because of something else, i'll check that.

[mahdoosh1]

validated. this is the correct cause.

[gniftygnome]

It's not a fix per se but you can always turn off the update checking.

I don't think update checking is supposed to block other activities, but it could be a while before anybody has time to investigate.

[litetex]

So I had a look at this, maybe sold my soul to the devil and found out that roughly half of the German userbase can basically not launch the game if they have continuity (or similar mods?) and modmenu installed.

Why?

1. The domain meta.fabricmc.net is used to check for newer Fabric Loader versions.
2. This domain is hosted on Cloudflare (likely using their free tier). Cloudflare is currently having trouble completing requests to meta.fabricmc.net here in Germany because they are having a peering dispute with one of the big German ISPs and are rerouting all traffic of Free tier users to external data centers (likely located at the other end of the milky way).
3. Therefore the requests to meta.fabricmc.net hang forever
4. There are no timeouts when executing update requests (fixed with Add timeouts for HTTP requests #970)
5. The code is executed on Util#MAIN_WORKER_EXECUTOR
6. This blocks at least one thread of this executor because it waits for all Update Checks to finish due to close being called at the end of the try statement in

   ModMenu/src/main/java/com/terraformersmc/modmenu/util/UpdateCheckerUtil.java

   Line 51 in 0ee953c

   try (var executor = Executors.newThreadPerTaskExecutor(new UpdateCheckerThreadFactory())) {

7. I'm not 100% sure what Continuity code is doing in detail however it looks like they are modifying how resources are loaded and seem to somehow "depend" on this one blocked thread.
8. Therefore prepareExecutor in SimpleResourceReload#startAsync starts hanging
9. This causes ReloadableResourceManager#reload - that is executed during the initial game reload - to hang
10. The game hangs:

Workaround:

You basically have to disable all other mods except modmenu, then launch the game, enter the modmenu settings, disable update checks and then re-enable all mods again.

[gniftygnome]

4. There are no timeouts when executing update requests (fixed with [Add timeouts for HTTP requests #970](https://github.com/TerraformersMC/ModMenu/pull/970))

I'll push it back to some of the 1.21 versions when I have time.

5. The code is executed on `Util#MAIN_WORKER_EXECUTOR`

We are using Util.getDownloadWorkerExecutor() (mojmap Util.nonCriticalIoPool()) but maybe there is some better choice.

You basically have to disable all other mods except modmenu, then launch the game, enter the modmenu settings, disable update checks and then re-enable all mods again.

It's in config/modmenu.json for the users savvy enough to edit the config file directly.

[litetex]

@gniftygnome I create a new PR #972 that effectively fixes points 5 and 6. Feel free to have a look :)

[gniftygnome]

I've merged #972 into ModMenu for 26.1 where we're still at the alpha stage. We'll see how it shakes out there.