qtp constructor min-max validation

When min and max threads are passed together, verify
max >= min to detect bad configuration.

Signed-off-by: David Ha <davidha@1493.net>

jetty-util/src/main/java/org/eclipse/jetty/util/thread/QueuedThreadPool.java

@@ -75,7 +75,7 @@ public class QueuedThreadPool extends ContainerLifeCycle implements SizedThreadP
 
     public QueuedThreadPool(@Name("maxThreads") int maxThreads)
     {
-        this(maxThreads, 8);
+        this(maxThreads, Math.min(8, maxThreads));
     }
 
     public QueuedThreadPool(@Name("maxThreads") int maxThreads,  @Name("minThreads") int minThreads)
@@ -100,6 +100,11 @@ public class QueuedThreadPool extends ContainerLifeCycle implements SizedThreadP
     
     public QueuedThreadPool(@Name("maxThreads") int maxThreads, @Name("minThreads") int minThreads, @Name("idleTimeout") int idleTimeout, @Name("reservedThreads") int reservedThreads, @Name("queue") BlockingQueue<Runnable> queue, @Name("threadGroup") ThreadGroup threadGroup)
     {
+        if (maxThreads < minThreads) {
+            throw new IllegalArgumentException("max threads ("+maxThreads+") less than min threads ("
+                    +minThreads+")");
+        }
+
         setMinThreads(minThreads);
         setMaxThreads(maxThreads);
         setIdleTimeout(idleTimeout);

jetty-util/src/test/java/org/eclipse/jetty/util/thread/QueuedThreadPoolTest.java

@@ -302,4 +302,10 @@ public class QueuedThreadPoolTest
 
         assertTrue(latch.await(5, TimeUnit.SECONDS));
     }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testConstructorMinMaxThreadsValidation()
+    {
+        new QueuedThreadPool(4, 8);
+    }
 }