--- jsr166/src/test/tck/JSR166TestCase.java	2015/10/04 18:40:57	1.164
+++ jsr166/src/test/tck/JSR166TestCase.java	2015/10/08 22:39:57	1.170
@@ -188,7 +188,9 @@ public class JSR166TestCase extends Test
         return (regex == null) ? null : Pattern.compile(regex);
     }
 
+    // Instrumentation to debug very rare, but very annoying hung test runs.
     static volatile TestCase currentTestCase;
+    static volatile int currentRun = 0;
     static {
         Runnable checkForWedgedTest = new Runnable() { public void run() {
             // avoid spurious reports with enormous runsPerTest
@@ -197,10 +199,17 @@ public class JSR166TestCase extends Test
                 try { MINUTES.sleep(timeoutMinutes); }
                 catch (InterruptedException unexpected) { break; }
                 if (lastTestCase == currentTestCase) {
+                    System.err.printf(
+                        "Looks like we're stuck running test: %s (%d/%d)%n",
+                        lastTestCase, currentRun, runsPerTest);
                     System.err.println
                         ("Looks like we're stuck running test: "
-                         + lastTestCase);
+                         + lastTestCase + " (" + currentRun + "/" + runsPerTest + ")");
+                    System.err.println("availableProcessors=" +
+                        Runtime.getRuntime().availableProcessors());
                     dumpTestThreads();
+                    // one stack dump is probably enough; more would be spam
+                    break;
                 }
                 lastTestCase = currentTestCase;
             }}};
@@ -218,6 +227,7 @@ public class JSR166TestCase extends Test
 
     protected void runTest() throws Throwable {
         for (int i = 0; i < runsPerTest; i++) {
+            currentRun = i;
             if (profileTests)
                 runTestProfiled();
             else
@@ -774,10 +784,43 @@ public class JSR166TestCase extends Test
         public void close() { joinPool(pool); }
     }
 
+    /**
+     * An extension of PoolCleaner that has an action to release the pool.
+     */
+    class PoolCleanerWithReleaser extends PoolCleaner {
+        private final Runnable releaser;
+        public PoolCleanerWithReleaser(ExecutorService pool, Runnable releaser) {
+            super(pool);
+            this.releaser = releaser;
+        }
+        public void close() {
+            try {
+                releaser.run();
+            } finally {
+                super.close();
+            }
+        }
+    }
+
     PoolCleaner cleaner(ExecutorService pool) {
         return new PoolCleaner(pool);
     }
 
+    PoolCleaner cleaner(ExecutorService pool, Runnable releaser) {
+        return new PoolCleanerWithReleaser(pool, releaser);
+    }
+
+    PoolCleaner cleaner(ExecutorService pool, CountDownLatch latch) {
+        return new PoolCleanerWithReleaser(pool, releaser(latch));
+    }
+
+    Runnable releaser(final CountDownLatch latch) {
+        return new Runnable() { public void run() {
+            do { latch.countDown(); }
+            while (latch.getCount() > 0);
+        }};
+    }
+
     /**
      * Waits out termination of a thread pool or fails doing so.
      */
@@ -791,7 +834,7 @@ public class JSR166TestCase extends Test
                 } finally {
                     // last resort, for the benefit of subsequent tests
                     pool.shutdownNow();
-                    pool.awaitTermination(SMALL_DELAY_MS, MILLISECONDS);
+                    pool.awaitTermination(MEDIUM_DELAY_MS, MILLISECONDS);
                 }
             }
         } catch (SecurityException ok) {
@@ -1168,7 +1211,7 @@ public class JSR166TestCase extends Test
         } finally {
             if (t.getState() != Thread.State.TERMINATED) {
                 t.interrupt();
-                fail("Test timed out");
+                threadFail("Test timed out");
             }
         }
     }