Allow getting a threadump

src/main/java/dev/ithundxr/railwaystweaks/mixin/DedicatedServerMixin.java

@@ -0,0 +1,71 @@
+package dev.ithundxr.railwaystweaks.mixin;
+
+import com.google.common.collect.Streams;
+import com.mojang.datafixers.DataFixer;
+import com.mojang.logging.LogUtils;
+import net.minecraft.CrashReport;
+import net.minecraft.CrashReportCategory;
+import net.minecraft.Util;
+import net.minecraft.server.Bootstrap;
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.server.Services;
+import net.minecraft.server.WorldStem;
+import net.minecraft.server.dedicated.DedicatedServer;
+import net.minecraft.server.level.progress.ChunkProgressListenerFactory;
+import net.minecraft.server.packs.repository.PackRepository;
+import net.minecraft.world.level.GameRules;
+import net.minecraft.world.level.storage.LevelStorageSource;
+import org.slf4j.Logger;
+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;
+
+import java.io.File;
+import java.lang.management.ManagementFactory;
+import java.lang.management.ThreadInfo;
+import java.lang.management.ThreadMXBean;
+import java.net.Proxy;
+import java.util.stream.Collectors;
+
+@Mixin(DedicatedServer.class)
+public abstract class DedicatedServerMixin extends MinecraftServer {
+    @Unique private static final Logger railwaysTweaks$LOGGER = LogUtils.getLogger();
+
+    public DedicatedServerMixin(Thread serverThread, LevelStorageSource.LevelStorageAccess storageSource, PackRepository packRepository, WorldStem worldStem, Proxy proxy, DataFixer fixerUpper, Services services, ChunkProgressListenerFactory progressListenerFactory) {
+        super(serverThread, storageSource, packRepository, worldStem, proxy, fixerUpper, services, progressListenerFactory);
+    }
+
+    @Inject(method = "onServerExit", at = @At("TAIL"))
+    private void railwaysTweaks$threadDumpOnShutdown(CallbackInfo ci) {
+        ThreadMXBean threadmxbean = ManagementFactory.getThreadMXBean();
+        ThreadInfo[] athreadinfo = threadmxbean.dumpAllThreads(true, true);
+        StringBuilder stringbuilder = new StringBuilder();
+        Error error = new Error("Shutdown Thread Dump");
+
+        for(ThreadInfo threadinfo : athreadinfo) {
+            if (threadinfo.getThreadId() == this.getRunningThread().getId()) {
+                error.setStackTrace(threadinfo.getStackTrace());
+            }
+
+            stringbuilder.append(threadinfo);
+            stringbuilder.append("\n");
+        }
+
+        CrashReport crashreport = new CrashReport("Server shutdown thread dump", error);
+        this.fillSystemReport(crashreport.getSystemReport());
+        CrashReportCategory crashreportcategory = crashreport.addCategory("Thread Dump");
+        crashreportcategory.setDetail("Threads", stringbuilder);
+        CrashReportCategory crashreportcategory1 = crashreport.addCategory("Performance stats");
+        crashreportcategory1.setDetail("Random tick rate", () -> this.getWorldData().getGameRules().getRule(GameRules.RULE_RANDOMTICKING).toString());
+        crashreportcategory1.setDetail("Level stats", () -> Streams.stream(this.getAllLevels()).map((level) -> level.dimension() + ": " + level.getWatchdogStats()).collect(Collectors.joining(",\n")));
+        Bootstrap.realStdoutPrintln("Crash report:\n" + crashreport.getFriendlyReport());
+        File file1 = new File(new File(this.getServerDirectory(), "shutdown-thread-dumps"), "thread-dump-" + Util.getFilenameFormattedDateTime() + "-server.txt");
+        if (crashreport.saveToFile(file1)) {
+            railwaysTweaks$LOGGER.error("This crash report has been saved to: {}", file1.getAbsolutePath());
+        } else {
+            railwaysTweaks$LOGGER.error("We were unable to save this crash report to disk.");
+        }
+    }
+}

src/main/resources/railwaystweaks.mixins.json

@@ -4,6 +4,7 @@
   "package": "dev.ithundxr.railwaystweaks.mixin",
   "compatibilityLevel": "JAVA_17",
   "mixins": [
+    "DedicatedServerMixin",
     "LivingEntityMixin",
     "ServerPlayerMixin",
     "ServerStatusPacketListenerImplMixin",