Merge 1.19.2 into 1.20

Author: embeddedt

common/src/main/java/org/embeddedt/modernfix/common/mixin/core/MinecraftServerMixin.java

@@ -0,0 +1,24 @@
+package org.embeddedt.modernfix.common.mixin.core;
+
+import net.minecraft.Util;
+import net.minecraft.server.MinecraftServer;
+import org.embeddedt.modernfix.duck.ITimeTrackingServer;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+@Mixin(MinecraftServer.class)
+public class MinecraftServerMixin implements ITimeTrackingServer {
+    private long mfix$lastTickStartTime = -1L;
+
+    @Override
+    public long mfix$getLastTickStartTime() {
+        return mfix$lastTickStartTime;
+    }
+
+    @Inject(method = "runServer", at = @At(value = "INVOKE", target = "Lnet/minecraft/server/MinecraftServer;tickServer(Ljava/util/function/BooleanSupplier;)V"))
+    private void trackTickTime(CallbackInfo ci) {
+        mfix$lastTickStartTime = Util.getMillis();
+    }
+}

common/src/main/java/org/embeddedt/modernfix/duck/ITimeTrackingServer.java

@@ -0,0 +1,5 @@
+package org.embeddedt.modernfix.duck;
+
+public interface ITimeTrackingServer {
+    long mfix$getLastTickStartTime();
+}

common/src/main/java/org/embeddedt/modernfix/world/IntegratedWatchdog.java

@@ -4,9 +4,11 @@
 import net.minecraft.DefaultUncaughtExceptionHandlerWithName;
 import net.minecraft.Util;
 import net.minecraft.server.MinecraftServer;
+import org.embeddedt.modernfix.duck.ITimeTrackingServer;
 import org.slf4j.Logger;
 
 import java.lang.ref.WeakReference;
+import java.util.OptionalLong;
 
 public class IntegratedWatchdog extends Thread {
     private static final Logger LOGGER = LogUtils.getLogger();
@@ -22,23 +24,27 @@ public IntegratedWatchdog(MinecraftServer server) {
         this.setName("ModernFix integrated server watchdog");
     }
 
+    private OptionalLong getLastTickStart() {
+        MinecraftServer server = this.server.get();
+        if(server == null || !server.isRunning())
+            return OptionalLong.empty();
+        return OptionalLong.of(((ITimeTrackingServer)server).mfix$getLastTickStartTime());
+    }
+
     public void run() {
         while(true) {
-            MinecraftServer server = this.server.get();
-            if(server == null || !server.isRunning())
+            OptionalLong lastTickStart = getLastTickStart();
+            if(!lastTickStart.isPresent()) {
                 return;
-            long nextTick = server.getNextTickTime();
+            }
             long curTime = Util.getMillis();
-            long delta = curTime - nextTick;
+            long delta = curTime - lastTickStart.getAsLong();
             if(delta > MAX_TICK_DELTA) {
                 LOGGER.error("A single server tick has taken {}, more than {} milliseconds", delta, MAX_TICK_DELTA);
                 LOGGER.error(ThreadDumper.obtainThreadDump());
-                nextTick = 0;
-                curTime = 0;
             }
-            server = null; /* allow GC */
             try {
-                Thread.sleep(nextTick + MAX_TICK_DELTA - curTime);
+                Thread.sleep(MAX_TICK_DELTA - delta);
             } catch(InterruptedException ignored) {
             }
         }