make jboss remoting2 work with openjdk11

Mage.Common/src/main/java/mage/remote/CustomThreadPool.java

@@ -0,0 +1,32 @@
+package mage.remote;
+
+import java.lang.reflect.Field;
+import java.util.concurrent.ThreadPoolExecutor;
+
+import org.apache.log4j.Logger;
+import org.jboss.util.threadpool.BasicThreadPool;
+
+public class CustomThreadPool extends BasicThreadPool {
+    private static final Logger logger = Logger.getLogger(SessionImpl.class);
+
+    @Override
+    public void setMaximumPoolSize(int size) {
+        /*
+         * I really don't want to implement a whole new threadpool
+         * just to fix this and the executor is private
+         */
+        try {
+            Field executorField = BasicThreadPool.class.getField("executor");
+            executorField.setAccessible(true);
+            ThreadPoolExecutor executor = (ThreadPoolExecutor) executorField.get(this);
+            synchronized (executor) {
+                executor.setMaximumPoolSize(size);
+                executor.setCorePoolSize(size);
+            }
+        } catch (NoSuchFieldException | SecurityException e) {
+            logger.error("Failed to get field executor from BasicThreadPool", e);
+        } catch (IllegalArgumentException | IllegalAccessException e) {
+            logger.error("Failed to get executor object from BasicThreadPool", e);
+        }
+    }
+}