server: fixed server app freeze on another instance already running, improved threads usage (related to #11285);

Mage/src/main/java/mage/util/XMageThreadFactory.java

@@ -0,0 +1,42 @@
+package mage.util;
+
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * Helper class to give debug friendly names for a threads
+ *
+ * @author JayDi85
+ */
+public class XMageThreadFactory implements ThreadFactory {
+
+    private final String prefix;
+    private final AtomicInteger counter = new AtomicInteger();
+    private final boolean isDaemon;
+
+    public XMageThreadFactory(String prefix) {
+        this(prefix, true);
+    }
+
+    /**
+     * @param prefix   thread's starting name (can be changed by thread itself later)
+     * @param isDaemon mark thread as daemon on non-writeable tasks (e.g. can be terminated at any time without data loss)
+     */
+    public XMageThreadFactory(String prefix, boolean isDaemon) {
+        this.prefix = prefix;
+        this.isDaemon = isDaemon;
+    }
+
+    @Override
+    public Thread newThread(Runnable r) {
+        int instanceNumber = this.counter.incrementAndGet();
+
+        Thread thread = new Thread(r);
+        thread.setDaemon(this.isDaemon);
+
+        // gives default name, but threads can change it by Thread.currentThread().setName (example: on game or tourney start)
+        thread.setName(String.format("%s - %d", this.prefix, instanceNumber));
+
+        return thread;
+    }
+}