--- jsr166/src/test/tck/AbstractQueuedSynchronizerTest.java	2017/09/29 19:34:37	1.58
+++ jsr166/src/test/tck/AbstractQueuedSynchronizerTest.java	2018/01/07 23:05:44	1.62
@@ -9,9 +9,11 @@
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static java.util.concurrent.TimeUnit.NANOSECONDS;
 
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.HashSet;
+import java.util.concurrent.ThreadLocalRandom;
 import java.util.concurrent.locks.AbstractQueuedSynchronizer;
 import java.util.concurrent.locks.AbstractQueuedSynchronizer.ConditionObject;
 
@@ -1259,4 +1261,104 @@ public class AbstractQueuedSynchronizerT
         sync.release();
     }
 
+    /**
+     * JDK-8191483: AbstractQueuedSynchronizer cancel/cancel race
+     * ant -Djsr166.tckTestClass=AbstractQueuedSynchronizerTest -Djsr166.methodFilter=testCancelCancelRace -Djsr166.runsPerTest=100 tck
+     */
+    public void testCancelCancelRace() throws InterruptedException {
+        class Sync extends AbstractQueuedSynchronizer {
+            protected boolean tryAcquire(int acquires) {
+                return !hasQueuedPredecessors() && compareAndSetState(0, 1);
+            }
+            protected boolean tryRelease(int releases) {
+                return compareAndSetState(1, 0);
+            }
+        }
+
+        Sync s = new Sync();
+        s.acquire(1);           // acquire to force other threads to enqueue
+
+        // try to trigger double cancel race with two background threads
+        ArrayList<Thread> threads = new ArrayList<>();
+        Runnable failedAcquire = () -> {
+            try {
+                s.acquireInterruptibly(1);
+                shouldThrow();
+            } catch (InterruptedException expected) {}
+        };
+        for (int i = 0; i < 2; i++) {
+            Thread thread = new Thread(failedAcquire);
+            thread.start();
+            threads.add(thread);
+        }
+        Thread.sleep(100);
+        for (Thread thread : threads) thread.interrupt();
+        for (Thread thread : threads) awaitTermination(thread);
+
+        s.release(1);
+
+        // no one holds lock now, we should be able to acquire
+        if (!s.tryAcquire(1))
+            throw new RuntimeException(
+                String.format(
+                    "Broken: hasQueuedPredecessors=%s hasQueuedThreads=%s queueLength=%d firstQueuedThread=%s",
+                    s.hasQueuedPredecessors(),
+                    s.hasQueuedThreads(),
+                    s.getQueueLength(),
+                    s.getFirstQueuedThread()));
+    }
+
+    /**
+     * Tests scenario for
+     * JDK-8191937: Lost interrupt in AbstractQueuedSynchronizer when tryAcquire methods throw
+     */
+    public void testInterruptedFailingAcquire() throws InterruptedException {
+        final RuntimeException ex = new RuntimeException();
+
+        // A synchronizer only offering a choice of failure modes
+        class Sync extends AbstractQueuedSynchronizer {
+            boolean pleaseThrow;
+            @Override protected boolean tryAcquire(int ignored) {
+                if (pleaseThrow) throw ex;
+                return false;
+            }
+            @Override protected int tryAcquireShared(int ignored) {
+                if (pleaseThrow) throw ex;
+                return -1;
+            }
+            @Override protected boolean tryRelease(int ignored) {
+                return true;
+            }
+            @Override protected boolean tryReleaseShared(int ignored) {
+                return true;
+            }
+        }
+
+        final Sync s = new Sync();
+
+        final Thread thread = newStartedThread(new CheckedRunnable() {
+            public void realRun() {
+                try {
+                    if (ThreadLocalRandom.current().nextBoolean())
+                        s.acquire(1);
+                    else
+                        s.acquireShared(1);
+                    shouldThrow();
+                } catch (Throwable t) {
+                    assertSame(ex, t);
+                    assertTrue(Thread.interrupted());
+                }
+            }});
+        waitForThreadToEnterWaitState(thread);
+        assertSame(thread, s.getFirstQueuedThread());
+        assertTrue(s.hasQueuedPredecessors());
+        assertTrue(s.hasQueuedThreads());
+        assertEquals(1, s.getQueueLength());
+
+        s.pleaseThrow = true;
+        thread.interrupt();
+        s.release(1);
+        awaitTermination(thread);
+    }
+
 }