368240: Improved handling of dispatch failure

jetty-io/src/main/java/org/eclipse/jetty/io/nio/SelectorManager.java

@@ -260,7 +260,7 @@ public abstract class SelectorManager extends AbstractLifeCycle implements Dumpa
         for (int i=0;i<getSelectSets();i++)
         {
             final int id=i;
-            dispatch(new Runnable()
+            boolean selecting=dispatch(new Runnable()
             {
                 public void run()
                 {
@@ -303,6 +303,9 @@ public abstract class SelectorManager extends AbstractLifeCycle implements Dumpa
                 }
 
             });
+            
+            if (!selecting)
+                throw new IllegalStateException("!Selecting");
         }
     }
 

jetty-server/src/main/java/org/eclipse/jetty/server/AbstractConnector.java

@@ -321,7 +321,8 @@ public abstract class AbstractConnector extends AggregateLifeCycle implements Ht
             _acceptorThread = new Thread[getAcceptors()];
 
             for (int i = 0; i < _acceptorThread.length; i++)
-                _threadPool.dispatch(new Acceptor(i));
+                if (!_threadPool.dispatch(new Acceptor(i)))
+                    throw new IllegalStateException("!accepting");
             if (_threadPool.isLowOnThreads())
                 LOG.warn("insufficient threads configured for {}",this);
         }

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

@@ -363,6 +363,7 @@ public class QueuedThreadPool extends AbstractLifeCycle implements SizedThreadPo
                 return true;
             }
         }
+        LOG.debug("Dispatched {} to stopped {}",job,this);
         return false;
     }