Limit size of Authenticator Cache Thread Pool (#8360)

patches/server/Cache-user-authenticator-threads.patch

@@ -12,18 +12,8 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
  
      }
  
-+    // Paper start - Cache authenticator threads
-+    private static final AtomicInteger threadId = new AtomicInteger(0);
-+    private static final java.util.concurrent.ExecutorService authenticatorPool = java.util.concurrent.Executors.newCachedThreadPool(
-+            r -> {
-+                Thread ret = new Thread(r, "User Authenticator #" + threadId.incrementAndGet());
++    private static final java.util.concurrent.ExecutorService authenticatorPool = new java.util.concurrent.ThreadPoolExecutor(0, 16, 60L, java.util.concurrent.TimeUnit.SECONDS, new java.util.concurrent.SynchronousQueue<>(),  new com.google.common.util.concurrent.ThreadFactoryBuilder().setNameFormat("User Authenticator #%d").setUncaughtExceptionHandler(new DefaultUncaughtExceptionHandler(LOGGER)).build()); // Paper - Cache authenticator threads
 +
-+                ret.setUncaughtExceptionHandler(new DefaultUncaughtExceptionHandler(LOGGER));
-+
-+                return ret;
-+            }
-+    );
-+    // Paper end
      // Spigot start
      public void initUUID()
      {