fix: shut down co-processes on dedicated servers even if the server failed to start

libjf-base/src/main/java/io/gitlab/jfronny/libjf/coprocess/CoProcessManager.java

@@ -2,31 +2,34 @@ package io.gitlab.jfronny.libjf.coprocess;
 
 import io.gitlab.jfronny.libjf.LibJf;
 import net.fabricmc.api.EnvType;
-import net.fabricmc.api.ModInitializer;
 import net.fabricmc.fabric.api.event.lifecycle.v1.ServerLifecycleEvents;
 import net.fabricmc.loader.api.FabricLoader;
 
 import java.io.Closeable;
 import java.io.IOException;
 import java.util.*;
+import java.util.concurrent.atomic.AtomicBoolean;
 
-public class CoProcessManager implements ModInitializer {
+public class CoProcessManager {
-    private final List<CoProcess> coProcesses = new ArrayList<>();
+    private static final List<CoProcess> coProcesses = new ArrayList<>();
-    @Override
+
-    public void onInitialize() {
+    static {
         coProcesses.addAll(FabricLoader.getInstance().getEntrypoints(LibJf.MOD_ID + ":coprocess", CoProcess.class));
-        Runtime.getRuntime().addShutdownHook(new Thread(this::stop));
+        if (FabricLoader.getInstance().getEnvironmentType() == EnvType.SERVER) ServerLifecycleEvents.SERVER_STOPPED.register(server -> CoProcessManager.stop());
-        if (FabricLoader.getInstance().getEnvironmentType() == EnvType.SERVER) ServerLifecycleEvents.SERVER_STOPPED.register(server -> this.stop());
+        Runtime.getRuntime().addShutdownHook(new Thread(CoProcessManager::stop));
-        start();
     }
 
-    private void start() {
+    private static final AtomicBoolean started = new AtomicBoolean(false);
+
+    public static void start() {
+        if (started.getAndSet(true)) return;
         for (CoProcess coProcess : coProcesses) {
             coProcess.start();
         }
     }
 
-    private void stop() {
+    public static void stop() {
+        if (!started.getAndSet(false)) return;
         for (Iterator<CoProcess> iter = coProcesses.iterator(); iter.hasNext(); ) {
             CoProcess coProcess = iter.next();
             coProcess.stop();

libjf-base/src/main/java/io/gitlab/jfronny/libjf/coprocess/ThreadCoProcess.java

@@ -1,13 +1,24 @@
 package io.gitlab.jfronny.libjf.coprocess;
 
 public abstract class ThreadCoProcess implements CoProcess, Runnable {
+    private final boolean isDaemon;
     private Thread th = null;
     private boolean closed = true;
+
+    protected ThreadCoProcess() {
+        this(false);
+    }
+
+    protected ThreadCoProcess(boolean isDaemon) {
+        this.isDaemon = isDaemon;
+    }
+
     @Override
     public void start() {
         if (th != null) stop();
         closed = false;
         th = new Thread(this, getClass().getSimpleName());
+        th.setDaemon(isDaemon);
         th.start();
     }
 

libjf-base/src/main/java/io/gitlab/jfronny/libjf/mixin/MainMixin.java

@@ -0,0 +1,27 @@
+package io.gitlab.jfronny.libjf.mixin;
+
+import io.gitlab.jfronny.libjf.coprocess.CoProcessManager;
+import net.fabricmc.api.DedicatedServerModInitializer;
+import net.minecraft.server.Main;
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.server.dedicated.MinecraftDedicatedServer;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+@Mixin(Main.class)
+public class MainMixin {
+    @Unique private static boolean libjf$started = false;
+
+    @Inject(method = "main", at = @At(value = "INVOKE_ASSIGN", target = "Lnet/minecraft/server/MinecraftServer;startServer(Ljava/util/function/Function;)Lnet/minecraft/server/MinecraftServer;"))
+    private static void onStartServer(String[] args, CallbackInfo ci) {
+        libjf$started = true;
+    }
+
+    @Inject(method = "main", at = @At("RETURN"))
+    private static void onMain(String[] args, CallbackInfo ci) {
+        if (!libjf$started) CoProcessManager.stop();
+    }
+}

libjf-base/src/main/resources/fabric.mod.json

@@ -18,9 +18,10 @@
     "fabric-lifecycle-events-v1": "*"
   },
   "entrypoints": {
-    "main": ["io.gitlab.jfronny.libjf.coprocess.CoProcessManager"],
+    "main": ["io.gitlab.jfronny.libjf.coprocess.CoProcessManager::start"],
     "preLaunch": ["io.gitlab.jfronny.libjf.LibJf"]
   },
+  "mixins": ["libjf-base.mixins.json"],
   "custom": {
     "modmenu": {
       "parent": "libjf",

libjf-base/src/main/resources/libjf-base.mixins.json

@@ -0,0 +1,14 @@
+{
+  "required": true,
+  "minVersion": "0.8",
+  "package": "io.gitlab.jfronny.libjf.mixin",
+  "compatibilityLevel": "JAVA_16",
+  "mixins": [
+  ],
+  "server": [
+    "MainMixin"
+  ],
+  "injectors": {
+    "defaultRequire": 1
+  }
+}