From 4d0ed2a6dc2b1a083b1e8b2cbbe2b710e57f64ec Mon Sep 17 00:00:00 2001
From: James Seibel <jeseibel@gondtc.com>
Date: Mon, 27 Apr 2026 07:48:06 -0500
Subject: [PATCH] fix null pointer on dedicated server shutdown

---
 .../core/render/RenderThreadTaskHandler.java  | 45 ++++++++++++++++---
 1 file changed, 40 insertions(+), 5 deletions(-)

diff --git a/core/src/main/java/com/seibel/distanthorizons/core/render/RenderThreadTaskHandler.java b/core/src/main/java/com/seibel/distanthorizons/core/render/RenderThreadTaskHandler.java
index 7d0bd380c..f1f404d9f 100644
--- a/core/src/main/java/com/seibel/distanthorizons/core/render/RenderThreadTaskHandler.java
+++ b/core/src/main/java/com/seibel/distanthorizons/core/render/RenderThreadTaskHandler.java
@@ -10,6 +10,7 @@ import com.seibel.distanthorizons.core.util.TimerUtil;
 import com.seibel.distanthorizons.core.util.objects.RollingAverage;
 import com.seibel.distanthorizons.core.wrapperInterfaces.minecraft.IMinecraftClientWrapper;
 import com.seibel.distanthorizons.core.wrapperInterfaces.minecraft.IMinecraftRenderWrapper;
+import com.seibel.distanthorizons.core.wrapperInterfaces.minecraft.IMinecraftSharedWrapper;
 import com.seibel.distanthorizons.coreapi.ModInfo;
 import org.jetbrains.annotations.Nullable;
 
@@ -49,6 +50,7 @@ public class RenderThreadTaskHandler
 	
 	
 	private long nanoSinceTasksRun = System.nanoTime();
+	private final boolean running; 
 	
 	
 	
@@ -57,7 +59,22 @@ public class RenderThreadTaskHandler
 	//=============//
 	//region
 	
-	private RenderThreadTaskHandler() { TIMER.scheduleAtFixedRate(TimerUtil.createTimerTask(this::manualCleanupTick), MS_BETWEEN_CLEANUP_TICKS, MS_BETWEEN_CLEANUP_TICKS); }
+	private RenderThreadTaskHandler() 
+	{
+		// we only want to run this when the client is available
+		IMinecraftSharedWrapper mcShared = SingletonInjector.INSTANCE.get(IMinecraftSharedWrapper.class);
+		if (!mcShared.isDedicatedServer())
+		{
+			LOGGER.debug("Starting ["+RenderThreadTaskHandler.class.getSimpleName()+"]...");
+			this.running = true;
+			TIMER.scheduleAtFixedRate(TimerUtil.createTimerTask(this::manualCleanupTick), MS_BETWEEN_CLEANUP_TICKS, MS_BETWEEN_CLEANUP_TICKS);
+		}
+		else
+		{
+			this.running = false;
+			LOGGER.debug("Skipping ["+RenderThreadTaskHandler.class.getSimpleName()+"] startup due to running on a dedicated server.");
+		}
+	}
 	
 	//endregion
 	
@@ -70,6 +87,13 @@ public class RenderThreadTaskHandler
 	
 	public void queueRunningOnRenderThread(String name, Runnable renderCall)
 	{
+		// don't queuing tasks if they'll never be run
+		if (!this.running)
+		{
+			return;
+		}
+		
+		
 		// don't get the stacktrace on release to reduce GC pressure
 		StackTraceElement[] stackTrace = null;
 		if (ModInfo.IS_DEV_BUILD)
@@ -179,8 +203,19 @@ public class RenderThreadTaskHandler
 		// this means we could have GL jobs building up.
 		// Run the queued tasks on MC's executor (hopefully this should always run,
 		// even if DH's render code isn't being hit).
-		IMinecraftClientWrapper MC = SingletonInjector.INSTANCE.get(IMinecraftClientWrapper.class);
-		MC.executeOnRenderThread(() -> this.runRenderThreadTasks(500 * 1_000_000L));
+		IMinecraftClientWrapper mcClient = SingletonInjector.INSTANCE.get(IMinecraftClientWrapper.class);
+		if (mcClient != null)
+		{
+			mcClient.executeOnRenderThread(() -> this.runRenderThreadTasks(500 * 1_000_000L));
+		}
+		else
+		{
+			// shouldn't happen, but just in case
+			
+			// somehow the timer started when there wasn't a client wrapper
+			// this probably means the timer was started on a dedicated server
+			RATE_LIMITED_LOGGER.warn("["+RenderThreadTaskHandler.class.getSimpleName()+"] timer started when ["+IMinecraftClientWrapper.class.getSimpleName()+"] is null. This shouldn't happen but can likely be ignored.");
+		}
 	}
 	
 	//endregion
@@ -190,7 +225,7 @@ public class RenderThreadTaskHandler
 	//===========//
 	// debugging //
 	//===========//
-	///region
+	//region
 	
 	/** 
 	 * if tasks are currently queued the debug
@@ -246,7 +281,7 @@ public class RenderThreadTaskHandler
 		});
 	}
 	
-	///endregion
+	//endregion