Add config value for render-thread-priority

Author: TBlueF

common/src/main/java/de/bluecolored/bluemap/common/api/RenderManagerImpl.java

@@ -84,16 +84,16 @@ public boolean isRunning() {
 
     @Override
     public void start() {
-        if (!isRunning()){
-            renderManager.start(plugin.getBlueMap().getConfig().getCoreConfig().resolveRenderThreadCount());
-        }
-        plugin.getPluginState().setRenderThreadsEnabled(true);
+        start(plugin.getBlueMap().getConfig().getCoreConfig().resolveRenderThreadCount());
     }
 
     @Override
     public void start(int threadCount) {
         if (!isRunning()){
-            renderManager.start(threadCount);
+            renderManager.start(
+                    threadCount,
+                    plugin.getBlueMap().getConfig().getCoreConfig().getRenderThreadPriority()
+            );
         }
         plugin.getPluginState().setRenderThreadsEnabled(true);
     }

common/src/main/java/de/bluecolored/bluemap/common/config/CoreConfig.java

@@ -38,6 +38,8 @@ public class CoreConfig {
 
     private int renderThreadCount = 1;
 
+    private int renderThreadPriority = Thread.NORM_PRIORITY;
+
     private boolean metrics = true;
 
     private Path data = Path.of("bluemap");

common/src/main/java/de/bluecolored/bluemap/common/plugin/Plugin.java

@@ -67,7 +67,6 @@
 import java.net.UnknownHostException;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.time.Duration;
 import java.time.Instant;
 import java.time.ZoneId;
 import java.time.ZonedDateTime;
@@ -422,7 +421,7 @@ public void unload(boolean keepWebserver) {
                 if (renderManager != null){
                     if (renderManager.getCurrentRenderTask() != null) {
                         renderManager.removeAllRenderTasks();
-                        if (!renderManager.isRunning()) renderManager.start(1);
+                        if (!renderManager.isRunning()) renderManager.start(1, Thread.NORM_PRIORITY);
                         try {
                             renderManager.awaitIdle(true);
                         } catch (InterruptedException ex) {
@@ -633,7 +632,7 @@ public boolean checkPausedByPlayerCount() {
             return true;
         } else {
             if (!renderManager.isRunning() && getPluginState().isRenderThreadsEnabled())
-                renderManager.start(coreConfig.resolveRenderThreadCount());
+                renderManager.start(coreConfig.resolveRenderThreadCount(), coreConfig.getRenderThreadPriority());
             return false;
         }
     }

common/src/main/java/de/bluecolored/bluemap/common/rendermanager/RenderManager.java

@@ -71,7 +71,7 @@ protected boolean removeEldestEntry(Map.Entry<RenderTask, Long> eldest) {
         };
     }
 
-    public void start(int threadCount) throws IllegalStateException {
+    public void start(int threadCount, int threadPriority) throws IllegalStateException {
         if (threadCount <= 0) throw new IllegalArgumentException("threadCount has to be 1 or more!");
 
         synchronized (this.workerThreads) {
@@ -86,7 +86,7 @@ public void start(int threadCount) throws IllegalStateException {
             this.running = true;
 
             for (int i = 0; i < threadCount; i++) {
-                WorkerThread worker = new WorkerThread();
+                WorkerThread worker = new WorkerThread(threadPriority);
                 this.workerThreads.add(worker);
                 worker.start();
             }
@@ -352,9 +352,10 @@ public class WorkerThread extends Thread {
 
         private final int id;
 
-        private WorkerThread() {
+        private WorkerThread(int threadPriority) {
             this.id = RenderManager.this.nextWorkerThreadIndex.getAndIncrement();
             this.setName("BlueMap-RenderThread-" + RenderManager.this.id + "-" + this.id);
+            this.setPriority(Math.clamp(threadPriority, Thread.MIN_PRIORITY, Thread.MAX_PRIORITY));
         }
 
         @Override

common/src/main/resources/de/bluecolored/bluemap/config/core.conf

@@ -24,6 +24,12 @@ data: "${data}"
 # Default is 1
 render-thread-count: ${render-thread-count}
 
+# This changes the priority that BlueMap's render-threads will get.
+# How the thread-priority affects actual performance depends on your JVM.
+# The priority must be a value between 1 and 10.
+# Default is Javas default priority (5)
+#render-thread-priority: 1
+
 # Controls whether BlueMap should try to find and load mod resources and datapacks from the server/world directories.
 # Default is true
 scan-for-mod-resources: true

implementations/cli/src/main/java/de/bluecolored/bluemap/cli/BlueMapCLI.java

@@ -132,7 +132,10 @@ public void renderMaps(BlueMapService blueMap, boolean watch, TileUpdateStrategy
         Logger.global.logInfo("Start updating " + maps.size() + " maps ...");
 
         // start rendering
-        renderManager.start(blueMap.getConfig().getCoreConfig().resolveRenderThreadCount());
+        renderManager.start(
+                blueMap.getConfig().getCoreConfig().resolveRenderThreadCount(),
+                blueMap.getConfig().getCoreConfig().getRenderThreadPriority()
+        );
 
         Timer timer = new Timer("BlueMap-CLI-Timer", true);
         TimerTask updateInfoTask = new TimerTask() {