--- jsr166/src/test/tck/ReentrantReadWriteLockTest.java	2003/12/27 14:16:33	1.10
+++ jsr166/src/test/tck/ReentrantReadWriteLockTest.java	2019/09/26 20:48:53	1.84
@@ -1,50 +1,55 @@
 /*
- * Written by members of JCP JSR-166 Expert Group and released to the
- * public domain. Use, modify, and redistribute this code in any way
- * without acknowledgement. Other contributors include Andrew Wright,
- * Jeffrey Hayes, Pat Fischer, Mike Judd.
+ * Written by Doug Lea with assistance from members of JCP JSR-166
+ * Expert Group and released to the public domain, as explained at
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ * Other contributors include Andrew Wright, Jeffrey Hayes,
+ * Pat Fisher, Mike Judd.
  */
 
-import junit.framework.*;
-import java.util.concurrent.locks.*;
-import java.util.concurrent.*;
-import java.io.*;
-import java.util.*;
+import static java.util.concurrent.TimeUnit.MILLISECONDS;
 
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.concurrent.Callable;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.locks.Condition;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+
+import junit.framework.Test;
+import junit.framework.TestSuite;
+
+@SuppressWarnings("WaitNotInLoop") // we implement spurious-wakeup freedom
 public class ReentrantReadWriteLockTest extends JSR166TestCase {
     public static void main(String[] args) {
-	junit.textui.TestRunner.run (suite());	
+        main(suite(), args);
     }
     public static Test suite() {
-	return new TestSuite(ReentrantReadWriteLockTest.class);
+        return new TestSuite(ReentrantReadWriteLockTest.class);
     }
 
     /**
      * A runnable calling lockInterruptibly
      */
-    class InterruptibleLockRunnable implements Runnable {
+    class InterruptibleLockRunnable extends CheckedRunnable {
         final ReentrantReadWriteLock lock;
         InterruptibleLockRunnable(ReentrantReadWriteLock l) { lock = l; }
-        public void run() {
-            try {
-                lock.writeLock().lockInterruptibly();
-            } catch(InterruptedException success){}
+        public void realRun() throws InterruptedException {
+            lock.writeLock().lockInterruptibly();
         }
     }
 
-
     /**
      * A runnable calling lockInterruptibly that expects to be
      * interrupted
      */
-    class InterruptedLockRunnable implements Runnable {
+    class InterruptedLockRunnable extends CheckedInterruptedRunnable {
         final ReentrantReadWriteLock lock;
         InterruptedLockRunnable(ReentrantReadWriteLock l) { lock = l; }
-        public void run() {
-            try {
-                lock.writeLock().lockInterruptibly();
-                threadShouldThrow();
-            } catch(InterruptedException success){}
+        public void realRun() throws InterruptedException {
+            lock.writeLock().lockInterruptibly();
         }
     }
 
@@ -53,1032 +58,1687 @@ public class ReentrantReadWriteLockTest
      */
     static class PublicReentrantReadWriteLock extends ReentrantReadWriteLock {
         PublicReentrantReadWriteLock() { super(); }
-        public Collection<Thread> getQueuedThreads() { 
-            return super.getQueuedThreads(); 
+        PublicReentrantReadWriteLock(boolean fair) { super(fair); }
+        public Thread getOwner() {
+            return super.getOwner();
         }
-        public PublicCondition newCondition() { 
-            return new PublicCondition();
+        public Collection<Thread> getQueuedThreads() {
+            return super.getQueuedThreads();
         }
-
-        class PublicCondition extends ReentrantReadWriteLock.WriterConditionObject {
-            PublicCondition() { }
-            public Collection<Thread> getWaitingThreads() { 
-                return super.getWaitingThreads(); 
-            }
+        public Collection<Thread> getWaitingThreads(Condition c) {
+            return super.getWaitingThreads(c);
         }
-
     }
 
     /**
-     * Constructor sets given fairness, and is in unlocked state
+     * Releases write lock, checking that it had a hold count of 1.
      */
-    public void testConstructor() { 
-	ReentrantReadWriteLock rl = new ReentrantReadWriteLock();
-        assertFalse(rl.isFair());
-        assertFalse(rl.isWriteLocked());
-        assertEquals(0, rl.getReadLockCount());
-	ReentrantReadWriteLock r2 = new ReentrantReadWriteLock(true);
-        assertTrue(r2.isFair());
-        assertFalse(r2.isWriteLocked());
-        assertEquals(0, r2.getReadLockCount());
+    void releaseWriteLock(PublicReentrantReadWriteLock lock) {
+        ReentrantReadWriteLock.WriteLock writeLock = lock.writeLock();
+        assertWriteLockedByMoi(lock);
+        assertEquals(1, lock.getWriteHoldCount());
+        writeLock.unlock();
+        assertNotWriteLocked(lock);
     }
 
     /**
-     * write-locking and read-locking an unlocked lock succeed
+     * Spin-waits until lock.hasQueuedThread(t) becomes true.
      */
-    public void testLock() { 
-	ReentrantReadWriteLock rl = new ReentrantReadWriteLock();
-        rl.writeLock().lock();
-        assertTrue(rl.isWriteLocked());
-        assertTrue(rl.isWriteLockedByCurrentThread());
-        assertEquals(0, rl.getReadLockCount());
-        rl.writeLock().unlock();
-        assertFalse(rl.isWriteLocked());
-        assertFalse(rl.isWriteLockedByCurrentThread());
-        assertEquals(0, rl.getReadLockCount());
-        rl.readLock().lock();
-        assertFalse(rl.isWriteLocked());
-        assertFalse(rl.isWriteLockedByCurrentThread());
-        assertEquals(1, rl.getReadLockCount());
-        rl.readLock().unlock();
-        assertFalse(rl.isWriteLocked());
-        assertFalse(rl.isWriteLockedByCurrentThread());
-        assertEquals(0, rl.getReadLockCount());
+    void waitForQueuedThread(PublicReentrantReadWriteLock lock, Thread t) {
+        long startTime = System.nanoTime();
+        while (!lock.hasQueuedThread(t)) {
+            if (millisElapsedSince(startTime) > LONG_DELAY_MS)
+                throw new AssertionError("timed out");
+            Thread.yield();
+        }
+        assertTrue(t.isAlive());
+        assertNotSame(t, lock.getOwner());
     }
 
-
     /**
-     * locking an unlocked fair lock succeeds
-     */
-    public void testFairLock() { 
-	ReentrantReadWriteLock rl = new ReentrantReadWriteLock(true);
-        rl.writeLock().lock();
-        assertTrue(rl.isWriteLocked());
-        assertTrue(rl.isWriteLockedByCurrentThread());
-        assertEquals(0, rl.getReadLockCount());
-        rl.writeLock().unlock();
-        assertFalse(rl.isWriteLocked());
-        assertFalse(rl.isWriteLockedByCurrentThread());
-        assertEquals(0, rl.getReadLockCount());
-        rl.readLock().lock();
-        assertFalse(rl.isWriteLocked());
-        assertFalse(rl.isWriteLockedByCurrentThread());
-        assertEquals(1, rl.getReadLockCount());
-        rl.readLock().unlock();
-        assertFalse(rl.isWriteLocked());
-        assertFalse(rl.isWriteLockedByCurrentThread());
-        assertEquals(0, rl.getReadLockCount());
+     * Checks that lock is not write-locked.
+     */
+    void assertNotWriteLocked(PublicReentrantReadWriteLock lock) {
+        assertFalse(lock.isWriteLocked());
+        assertFalse(lock.isWriteLockedByCurrentThread());
+        assertFalse(lock.writeLock().isHeldByCurrentThread());
+        assertEquals(0, lock.getWriteHoldCount());
+        assertEquals(0, lock.writeLock().getHoldCount());
+        assertNull(lock.getOwner());
     }
 
     /**
-     * getWriteHoldCount returns number of recursive holds
+     * Checks that lock is write-locked by the given thread.
      */
-    public void testGetHoldCount() {
-	ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
-	for(int i = 1; i <= SIZE; i++) {
-	    lock.writeLock().lock();
-	    assertEquals(i,lock.getWriteHoldCount());
-	}
-	for(int i = SIZE; i > 0; i--) {
-	    lock.writeLock().unlock();
-	    assertEquals(i-1,lock.getWriteHoldCount());
-	}
+    void assertWriteLockedBy(PublicReentrantReadWriteLock lock, Thread t) {
+        assertTrue(lock.isWriteLocked());
+        assertSame(t, lock.getOwner());
+        assertEquals(t == Thread.currentThread(),
+                     lock.isWriteLockedByCurrentThread());
+        assertEquals(t == Thread.currentThread(),
+                     lock.writeLock().isHeldByCurrentThread());
+        assertEquals(t == Thread.currentThread(),
+                     lock.getWriteHoldCount() > 0);
+        assertEquals(t == Thread.currentThread(),
+                     lock.writeLock().getHoldCount() > 0);
+        assertEquals(0, lock.getReadLockCount());
     }
-    
 
     /**
-     * write-unlocking an unlocked lock throws IllegalMonitorStateException
+     * Checks that lock is write-locked by the current thread.
      */
-    public void testUnlock_IllegalMonitorStateException() { 
-	ReentrantReadWriteLock rl = new ReentrantReadWriteLock();
-	try {
-	    rl.writeLock().unlock();
-	    shouldThrow();
-	} catch(IllegalMonitorStateException success){}
+    void assertWriteLockedByMoi(PublicReentrantReadWriteLock lock) {
+        assertWriteLockedBy(lock, Thread.currentThread());
     }
 
-
     /**
-     * write-lockInterruptibly is interruptible
+     * Checks that condition c has no waiters.
      */
-    public void testWriteLockInterruptibly_Interrupted() { 
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
-	lock.writeLock().lock();
-	Thread t = new Thread(new Runnable() {
-                public void run() {
-                    try {
-			lock.writeLock().lockInterruptibly();
-			threadShouldThrow();
-		    } catch(InterruptedException success){}
-		}
-	    });
-        try {
-            t.start();
-            t.interrupt();
-            lock.writeLock().unlock();
-            t.join();
-        } catch(Exception e){
-            unexpectedException();
-        }
-    } 
+    void assertHasNoWaiters(PublicReentrantReadWriteLock lock, Condition c) {
+        assertHasWaiters(lock, c, new Thread[] {});
+    }
 
     /**
-     * timed write-trylock is interruptible
+     * Checks that condition c has exactly the given waiter threads.
      */
-    public void testWriteTryLock_Interrupted() { 
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
-	lock.writeLock().lock();
-	Thread t = new Thread(new Runnable() {
-                public void run() {
-                    try {
-			lock.writeLock().tryLock(1000,TimeUnit.MILLISECONDS);
-			threadShouldThrow();
-		    } catch(InterruptedException success){}
-		}
-	    });
-        try {
-            t.start();
-            t.interrupt();
-            lock.writeLock().unlock();
-            t.join();
-        } catch(Exception e){
-            unexpectedException();
-        }
+    void assertHasWaiters(PublicReentrantReadWriteLock lock, Condition c,
+                          Thread... threads) {
+        lock.writeLock().lock();
+        assertEquals(threads.length > 0, lock.hasWaiters(c));
+        assertEquals(threads.length, lock.getWaitQueueLength(c));
+        assertEquals(threads.length == 0, lock.getWaitingThreads(c).isEmpty());
+        assertEquals(threads.length, lock.getWaitingThreads(c).size());
+        assertEquals(new HashSet<Thread>(lock.getWaitingThreads(c)),
+                     new HashSet<Thread>(Arrays.asList(threads)));
+        lock.writeLock().unlock();
     }
 
+    enum AwaitMethod { await, awaitTimed, awaitNanos, awaitUntil }
+
     /**
-     * read-lockInterruptibly is interruptible
+     * Awaits condition "indefinitely" using the specified AwaitMethod.
      */
-    public void testReadLockInterruptibly_Interrupted() { 
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
-	lock.writeLock().lock();
-	Thread t = new Thread(new Runnable() {
-                public void run() {
-                    try {
-			lock.readLock().lockInterruptibly();
-			threadShouldThrow();
-		    } catch(InterruptedException success){}
-		}
-	    });
-        try {
-            t.start();
-            t.interrupt();
-            lock.writeLock().unlock();
-            t.join();
-        } catch(Exception e){
-            unexpectedException();
+    void await(Condition c, AwaitMethod awaitMethod)
+            throws InterruptedException {
+        long timeoutMillis = 2 * LONG_DELAY_MS;
+        switch (awaitMethod) {
+        case await:
+            c.await();
+            break;
+        case awaitTimed:
+            assertTrue(c.await(timeoutMillis, MILLISECONDS));
+            break;
+        case awaitNanos:
+            long timeoutNanos = MILLISECONDS.toNanos(timeoutMillis);
+            long nanosRemaining = c.awaitNanos(timeoutNanos);
+            assertTrue(nanosRemaining > timeoutNanos / 2);
+            assertTrue(nanosRemaining <= timeoutNanos);
+            break;
+        case awaitUntil:
+            assertTrue(c.awaitUntil(delayedDate(timeoutMillis)));
+            break;
+        default:
+            throw new AssertionError();
         }
-    } 
+    }
 
     /**
-     * timed read-trylock is interruptible
+     * Constructor sets given fairness, and is in unlocked state
      */
-    public void testReadTryLock_Interrupted() { 
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
-	lock.writeLock().lock();
-	Thread t = new Thread(new Runnable() {
-                public void run() {
-                    try {
-			lock.readLock().tryLock(1000,TimeUnit.MILLISECONDS);
-			threadShouldThrow();
-		    } catch(InterruptedException success){}
-		}
-	    });
-        try {
-            t.start();
-            t.interrupt();
-            t.join();
-        } catch(Exception e){
-            unexpectedException();
-        }
+    public void testConstructor() {
+        PublicReentrantReadWriteLock lock;
+
+        lock = new PublicReentrantReadWriteLock();
+        assertFalse(lock.isFair());
+        assertNotWriteLocked(lock);
+        assertEquals(0, lock.getReadLockCount());
+
+        lock = new PublicReentrantReadWriteLock(true);
+        assertTrue(lock.isFair());
+        assertNotWriteLocked(lock);
+        assertEquals(0, lock.getReadLockCount());
+
+        lock = new PublicReentrantReadWriteLock(false);
+        assertFalse(lock.isFair());
+        assertNotWriteLocked(lock);
+        assertEquals(0, lock.getReadLockCount());
     }
 
-    
     /**
-     * write-trylock fails if locked
+     * write-locking and read-locking an unlocked lock succeed
      */
-    public void testWriteTryLockWhenLocked() { 
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
-	lock.writeLock().lock();
-	Thread t = new Thread(new Runnable() {
-                public void run() {
-                    threadAssertFalse(lock.writeLock().tryLock());
-		}
-	    });
-        try {
-            t.start();
-            t.join();
-            lock.writeLock().unlock();
-        } catch(Exception e){
-            unexpectedException();
-        }
-    } 
+    public void testLock()      { testLock(false); }
+    public void testLock_fair() { testLock(true); }
+    public void testLock(boolean fair) {
+        PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
+        assertNotWriteLocked(lock);
+        lock.writeLock().lock();
+        assertWriteLockedByMoi(lock);
+        lock.writeLock().unlock();
+        assertNotWriteLocked(lock);
+        assertEquals(0, lock.getReadLockCount());
+        lock.readLock().lock();
+        assertNotWriteLocked(lock);
+        assertEquals(1, lock.getReadLockCount());
+        lock.readLock().unlock();
+        assertNotWriteLocked(lock);
+        assertEquals(0, lock.getReadLockCount());
+    }
 
     /**
-     * read-trylock fails if locked
+     * getWriteHoldCount returns number of recursive holds
      */
-    public void testReadTryLockWhenLocked() { 
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
-	lock.writeLock().lock();
-	Thread t = new Thread(new Runnable() {
-                public void run() {
-                    threadAssertFalse(lock.readLock().tryLock());
-		}
-	    });
-        try {
-            t.start();
-            t.join();
+    public void testGetWriteHoldCount()      { testGetWriteHoldCount(false); }
+    public void testGetWriteHoldCount_fair() { testGetWriteHoldCount(true); }
+    public void testGetWriteHoldCount(boolean fair) {
+        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(fair);
+        for (int i = 1; i <= SIZE; i++) {
+            lock.writeLock().lock();
+            assertEquals(i,lock.getWriteHoldCount());
+        }
+        for (int i = SIZE; i > 0; i--) {
             lock.writeLock().unlock();
-        } catch(Exception e){
-            unexpectedException();
+            assertEquals(i - 1,lock.getWriteHoldCount());
         }
-    } 
+    }
 
     /**
-     * Multiple threads can hold a read lock when not write-locked
+     * writelock.getHoldCount returns number of recursive holds
      */
-    public void testMultipleReadLocks() { 
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
-	lock.readLock().lock();
-	Thread t = new Thread(new Runnable() {
-                public void run() {
-                    threadAssertTrue(lock.readLock().tryLock());
-                    lock.readLock().unlock();
-		}
-	    });
-        try {
-            t.start();
-            t.join();
-            lock.readLock().unlock();
-        } catch(Exception e){
-            unexpectedException();
+    public void testGetHoldCount()      { testGetHoldCount(false); }
+    public void testGetHoldCount_fair() { testGetHoldCount(true); }
+    public void testGetHoldCount(boolean fair) {
+        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(fair);
+        for (int i = 1; i <= SIZE; i++) {
+            lock.writeLock().lock();
+            assertEquals(i,lock.writeLock().getHoldCount());
         }
-    } 
+        for (int i = SIZE; i > 0; i--) {
+            lock.writeLock().unlock();
+            assertEquals(i - 1,lock.writeLock().getHoldCount());
+        }
+    }
 
     /**
-     * A writelock succeeds after reading threads unlock
+     * getReadHoldCount returns number of recursive holds
      */
-    public void testWriteAfterMultipleReadLocks() { 
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
-	lock.readLock().lock();
-	Thread t1 = new Thread(new Runnable() {
-                public void run() {
-                    lock.readLock().lock();
-                    lock.readLock().unlock();
-		}
-	    });
-	Thread t2 = new Thread(new Runnable() {
-                public void run() {
-                    lock.writeLock().lock();
-                    lock.writeLock().unlock();
-		}
-	    });
-
-        try {
-            t1.start();
-            t2.start();
-            Thread.sleep(SHORT_DELAY_MS);
+    public void testGetReadHoldCount()      { testGetReadHoldCount(false); }
+    public void testGetReadHoldCount_fair() { testGetReadHoldCount(true); }
+    public void testGetReadHoldCount(boolean fair) {
+        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(fair);
+        for (int i = 1; i <= SIZE; i++) {
+            lock.readLock().lock();
+            assertEquals(i,lock.getReadHoldCount());
+        }
+        for (int i = SIZE; i > 0; i--) {
             lock.readLock().unlock();
-            t1.join(MEDIUM_DELAY_MS);
-            t2.join(MEDIUM_DELAY_MS);
-            assertTrue(!t1.isAlive());
-            assertTrue(!t2.isAlive());
-           
-        } catch(Exception e){
-            unexpectedException();
+            assertEquals(i - 1,lock.getReadHoldCount());
         }
-    } 
+    }
 
     /**
-     * Readlocks succeed after a writing thread unlocks
+     * write-unlocking an unlocked lock throws IllegalMonitorStateException
      */
-    public void testReadAfterWriteLock() { 
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
-	lock.writeLock().lock();
-	Thread t1 = new Thread(new Runnable() {
-                public void run() {
-                    lock.readLock().lock();
-                    lock.readLock().unlock();
-		}
-	    });
-	Thread t2 = new Thread(new Runnable() {
-                public void run() {
-                    lock.readLock().lock();
-                    lock.readLock().unlock();
-		}
-	    });
-
+    public void testWriteUnlock_IMSE()      { testWriteUnlock_IMSE(false); }
+    public void testWriteUnlock_IMSE_fair() { testWriteUnlock_IMSE(true); }
+    public void testWriteUnlock_IMSE(boolean fair) {
+        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(fair);
         try {
-            t1.start();
-            t2.start();
-            Thread.sleep(SHORT_DELAY_MS);
             lock.writeLock().unlock();
-            t1.join(MEDIUM_DELAY_MS);
-            t2.join(MEDIUM_DELAY_MS);
-            assertTrue(!t1.isAlive());
-            assertTrue(!t2.isAlive());
-           
-        } catch(Exception e){
-            unexpectedException();
-        }
-    } 
-
+            shouldThrow();
+        } catch (IllegalMonitorStateException success) {}
+    }
 
     /**
-     * Read trylock succeeds if readlocked but not writelocked
+     * read-unlocking an unlocked lock throws IllegalMonitorStateException
      */
-    public void testTryLockWhenReadLocked() { 
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
-	lock.readLock().lock();
-	Thread t = new Thread(new Runnable() {
-                public void run() {
-                    threadAssertTrue(lock.readLock().tryLock());
-                    lock.readLock().unlock();
-		}
-	    });
+    public void testReadUnlock_IMSE()      { testReadUnlock_IMSE(false); }
+    public void testReadUnlock_IMSE_fair() { testReadUnlock_IMSE(true); }
+    public void testReadUnlock_IMSE(boolean fair) {
+        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(fair);
         try {
-            t.start();
-            t.join();
             lock.readLock().unlock();
-        } catch(Exception e){
-            unexpectedException();
-        }
-    } 
-
-    
+            shouldThrow();
+        } catch (IllegalMonitorStateException success) {}
+    }
 
     /**
-     * write trylock fails when readlocked
+     * write-lockInterruptibly is interruptible
      */
-    public void testWriteTryLockWhenReadLocked() { 
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
-	lock.readLock().lock();
-	Thread t = new Thread(new Runnable() {
-                public void run() {
-                    threadAssertFalse(lock.writeLock().tryLock());
-		}
-	    });
-        try {
-            t.start();
-            t.join();
-            lock.readLock().unlock();
-        } catch(Exception e){
-            unexpectedException();
-        }
-    } 
+    public void testWriteLockInterruptibly_Interruptible()      { testWriteLockInterruptibly_Interruptible(false); }
+    public void testWriteLockInterruptibly_Interruptible_fair() { testWriteLockInterruptibly_Interruptible(true); }
+    public void testWriteLockInterruptibly_Interruptible(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
+        lock.writeLock().lock();
+        Thread t = newStartedThread(new CheckedInterruptedRunnable() {
+            public void realRun() throws InterruptedException {
+                lock.writeLock().lockInterruptibly();
+            }});
 
-    
+        waitForQueuedThread(lock, t);
+        t.interrupt();
+        awaitTermination(t);
+        releaseWriteLock(lock);
+    }
 
     /**
-     * write timed trylock times out if locked
-     */
-    public void testWriteTryLock_Timeout() { 
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
-	lock.writeLock().lock();
-	Thread t = new Thread(new Runnable() {
-                public void run() {
-		    try {
-                        threadAssertFalse(lock.writeLock().tryLock(1, TimeUnit.MILLISECONDS));
-                    } catch (Exception ex) {
-                        threadUnexpectedException();
-                    }
-		}
-	    });
-        try {
-            t.start();
-            t.join();
-            lock.writeLock().unlock();
-        } catch(Exception e){
-            unexpectedException();
-        }
-    } 
+     * timed write-tryLock is interruptible
+     */
+    public void testWriteTryLock_Interruptible()      { testWriteTryLock_Interruptible(false); }
+    public void testWriteTryLock_Interruptible_fair() { testWriteTryLock_Interruptible(true); }
+    public void testWriteTryLock_Interruptible(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
+        lock.writeLock().lock();
+        Thread t = newStartedThread(new CheckedInterruptedRunnable() {
+            public void realRun() throws InterruptedException {
+                lock.writeLock().tryLock(2 * LONG_DELAY_MS, MILLISECONDS);
+            }});
+
+        waitForQueuedThread(lock, t);
+        t.interrupt();
+        awaitTermination(t);
+        releaseWriteLock(lock);
+    }
 
     /**
-     * read timed trylock times out if write-locked
+     * read-lockInterruptibly is interruptible
      */
-    public void testReadTryLock_Timeout() { 
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
-	lock.writeLock().lock();
-	Thread t = new Thread(new Runnable() {
-                public void run() {
-		    try {
-                        threadAssertFalse(lock.readLock().tryLock(1, TimeUnit.MILLISECONDS));
-                    } catch (Exception ex) {
-                        threadUnexpectedException();
-                    }
-		}
-	    });
-        try {
-            t.start();
-            t.join();
-            lock.writeLock().unlock();
-        } catch(Exception e){
-            unexpectedException();
-        }
-    } 
+    public void testReadLockInterruptibly_Interruptible()      { testReadLockInterruptibly_Interruptible(false); }
+    public void testReadLockInterruptibly_Interruptible_fair() { testReadLockInterruptibly_Interruptible(true); }
+    public void testReadLockInterruptibly_Interruptible(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
+        lock.writeLock().lock();
+        Thread t = newStartedThread(new CheckedInterruptedRunnable() {
+            public void realRun() throws InterruptedException {
+                lock.readLock().lockInterruptibly();
+            }});
+
+        waitForQueuedThread(lock, t);
+        t.interrupt();
+        awaitTermination(t);
+        releaseWriteLock(lock);
+    }
+
+    /**
+     * timed read-tryLock is interruptible
+     */
+    public void testReadTryLock_Interruptible()      { testReadTryLock_Interruptible(false); }
+    public void testReadTryLock_Interruptible_fair() { testReadTryLock_Interruptible(true); }
+    public void testReadTryLock_Interruptible(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
+        lock.writeLock().lock();
+        Thread t = newStartedThread(new CheckedInterruptedRunnable() {
+            public void realRun() throws InterruptedException {
+                lock.readLock().tryLock(2 * LONG_DELAY_MS, MILLISECONDS);
+            }});
+
+        waitForQueuedThread(lock, t);
+        t.interrupt();
+        awaitTermination(t);
+        releaseWriteLock(lock);
+    }
+
+    /**
+     * write-tryLock on an unlocked lock succeeds
+     */
+    public void testWriteTryLock()      { testWriteTryLock(false); }
+    public void testWriteTryLock_fair() { testWriteTryLock(true); }
+    public void testWriteTryLock(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
+        assertTrue(lock.writeLock().tryLock());
+        assertWriteLockedByMoi(lock);
+        assertTrue(lock.writeLock().tryLock());
+        assertWriteLockedByMoi(lock);
+        lock.writeLock().unlock();
+        releaseWriteLock(lock);
+    }
+
+    /**
+     * write-tryLock fails if locked
+     */
+    public void testWriteTryLockWhenLocked()      { testWriteTryLockWhenLocked(false); }
+    public void testWriteTryLockWhenLocked_fair() { testWriteTryLockWhenLocked(true); }
+    public void testWriteTryLockWhenLocked(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
+        lock.writeLock().lock();
+        Thread t = newStartedThread(new CheckedRunnable() {
+            public void realRun() {
+                assertFalse(lock.writeLock().tryLock());
+            }});
+
+        awaitTermination(t);
+        releaseWriteLock(lock);
+    }
+
+    /**
+     * read-tryLock fails if locked
+     */
+    public void testReadTryLockWhenLocked()      { testReadTryLockWhenLocked(false); }
+    public void testReadTryLockWhenLocked_fair() { testReadTryLockWhenLocked(true); }
+    public void testReadTryLockWhenLocked(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
+        lock.writeLock().lock();
+        Thread t = newStartedThread(new CheckedRunnable() {
+            public void realRun() {
+                assertFalse(lock.readLock().tryLock());
+            }});
 
+        awaitTermination(t);
+        releaseWriteLock(lock);
+    }
 
     /**
-     * write lockInterruptibly succeeds if lock free else is interruptible
+     * Multiple threads can hold a read lock when not write-locked
      */
-    public void testWriteLockInterruptibly() {
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
-	try {
-            lock.writeLock().lockInterruptibly();
-        } catch(Exception e) {
-            unexpectedException();
-        }
-	Thread t = new Thread(new Runnable() { 
-		public void run() {
-		    try {
-			lock.writeLock().lockInterruptibly();
-			threadShouldThrow();
-		    }
-		    catch(InterruptedException success) {
-                    }
-		}
-	    });
+    public void testMultipleReadLocks()      { testMultipleReadLocks(false); }
+    public void testMultipleReadLocks_fair() { testMultipleReadLocks(true); }
+    public void testMultipleReadLocks(boolean fair) {
+        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(fair);
+        lock.readLock().lock();
+        Thread t = newStartedThread(new CheckedRunnable() {
+            public void realRun() throws InterruptedException {
+                assertTrue(lock.readLock().tryLock());
+                lock.readLock().unlock();
+                assertTrue(lock.readLock().tryLock(LONG_DELAY_MS, MILLISECONDS));
+                lock.readLock().unlock();
+                lock.readLock().lock();
+                lock.readLock().unlock();
+            }});
+
+        awaitTermination(t);
+        lock.readLock().unlock();
+    }
+
+    /**
+     * A writelock succeeds only after a reading thread unlocks
+     */
+    public void testWriteAfterReadLock()      { testWriteAfterReadLock(false); }
+    public void testWriteAfterReadLock_fair() { testWriteAfterReadLock(true); }
+    public void testWriteAfterReadLock(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
+        lock.readLock().lock();
+        Thread t = newStartedThread(new CheckedRunnable() {
+            public void realRun() {
+                assertEquals(1, lock.getReadLockCount());
+                lock.writeLock().lock();
+                assertEquals(0, lock.getReadLockCount());
+                lock.writeLock().unlock();
+            }});
+        waitForQueuedThread(lock, t);
+        assertNotWriteLocked(lock);
+        assertEquals(1, lock.getReadLockCount());
+        lock.readLock().unlock();
+        assertEquals(0, lock.getReadLockCount());
+        awaitTermination(t);
+        assertNotWriteLocked(lock);
+    }
+
+    /**
+     * A writelock succeeds only after reading threads unlock
+     */
+    public void testWriteAfterMultipleReadLocks()      { testWriteAfterMultipleReadLocks(false); }
+    public void testWriteAfterMultipleReadLocks_fair() { testWriteAfterMultipleReadLocks(true); }
+    public void testWriteAfterMultipleReadLocks(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
+        lock.readLock().lock();
+        lock.readLock().lock();
+        Thread t1 = newStartedThread(new CheckedRunnable() {
+            public void realRun() {
+                lock.readLock().lock();
+                assertEquals(3, lock.getReadLockCount());
+                lock.readLock().unlock();
+            }});
+        awaitTermination(t1);
+
+        Thread t2 = newStartedThread(new CheckedRunnable() {
+            public void realRun() {
+                assertEquals(2, lock.getReadLockCount());
+                lock.writeLock().lock();
+                assertEquals(0, lock.getReadLockCount());
+                lock.writeLock().unlock();
+            }});
+        waitForQueuedThread(lock, t2);
+        assertNotWriteLocked(lock);
+        assertEquals(2, lock.getReadLockCount());
+        lock.readLock().unlock();
+        lock.readLock().unlock();
+        assertEquals(0, lock.getReadLockCount());
+        awaitTermination(t2);
+        assertNotWriteLocked(lock);
+    }
+
+    /**
+     * A thread that tries to acquire a fair read lock (non-reentrantly)
+     * will block if there is a waiting writer thread
+     */
+    public void testReaderWriterReaderFairFifo() {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(true);
+        final AtomicBoolean t1GotLock = new AtomicBoolean(false);
+
+        lock.readLock().lock();
+        Thread t1 = newStartedThread(new CheckedRunnable() {
+            public void realRun() {
+                assertEquals(1, lock.getReadLockCount());
+                lock.writeLock().lock();
+                assertEquals(0, lock.getReadLockCount());
+                t1GotLock.set(true);
+                lock.writeLock().unlock();
+            }});
+        waitForQueuedThread(lock, t1);
+
+        Thread t2 = newStartedThread(new CheckedRunnable() {
+            public void realRun() {
+                assertEquals(1, lock.getReadLockCount());
+                lock.readLock().lock();
+                assertEquals(1, lock.getReadLockCount());
+                assertTrue(t1GotLock.get());
+                lock.readLock().unlock();
+            }});
+        waitForQueuedThread(lock, t2);
+        assertTrue(t1.isAlive());
+        assertNotWriteLocked(lock);
+        assertEquals(1, lock.getReadLockCount());
+        lock.readLock().unlock();
+        awaitTermination(t1);
+        awaitTermination(t2);
+        assertNotWriteLocked(lock);
+    }
+
+    /**
+     * Readlocks succeed only after a writing thread unlocks
+     */
+    public void testReadAfterWriteLock()      { testReadAfterWriteLock(false); }
+    public void testReadAfterWriteLock_fair() { testReadAfterWriteLock(true); }
+    public void testReadAfterWriteLock(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
+        lock.writeLock().lock();
+        Thread t1 = newStartedThread(new CheckedRunnable() {
+            public void realRun() {
+                lock.readLock().lock();
+                lock.readLock().unlock();
+            }});
+        Thread t2 = newStartedThread(new CheckedRunnable() {
+            public void realRun() {
+                lock.readLock().lock();
+                lock.readLock().unlock();
+            }});
+
+        waitForQueuedThread(lock, t1);
+        waitForQueuedThread(lock, t2);
+        releaseWriteLock(lock);
+        awaitTermination(t1);
+        awaitTermination(t2);
+    }
+
+    /**
+     * Read trylock succeeds if write locked by current thread
+     */
+    public void testReadHoldingWriteLock()      { testReadHoldingWriteLock(false); }
+    public void testReadHoldingWriteLock_fair() { testReadHoldingWriteLock(true); }
+    public void testReadHoldingWriteLock(boolean fair) {
+        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(fair);
+        lock.writeLock().lock();
+        assertTrue(lock.readLock().tryLock());
+        lock.readLock().unlock();
+        lock.writeLock().unlock();
+    }
+
+    /**
+     * Read trylock succeeds (barging) even in the presence of waiting
+     * readers and/or writers
+     */
+    public void testReadTryLockBarging()      { testReadTryLockBarging(false); }
+    public void testReadTryLockBarging_fair() { testReadTryLockBarging(true); }
+    public void testReadTryLockBarging(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
+        lock.readLock().lock();
+
+        Thread t1 = newStartedThread(new CheckedRunnable() {
+            public void realRun() {
+                lock.writeLock().lock();
+                lock.writeLock().unlock();
+            }});
+
+        waitForQueuedThread(lock, t1);
+
+        Thread t2 = newStartedThread(new CheckedRunnable() {
+            public void realRun() {
+                lock.readLock().lock();
+                lock.readLock().unlock();
+            }});
+
+        if (fair)
+            waitForQueuedThread(lock, t2);
+
+        Thread t3 = newStartedThread(new CheckedRunnable() {
+            public void realRun() {
+                lock.readLock().tryLock();
+                lock.readLock().unlock();
+            }});
+
+        assertTrue(lock.getReadLockCount() > 0);
+        awaitTermination(t3);
+        assertTrue(t1.isAlive());
+        if (fair) assertTrue(t2.isAlive());
+        lock.readLock().unlock();
+        awaitTermination(t1);
+        awaitTermination(t2);
+    }
+
+    /**
+     * Read lock succeeds if write locked by current thread even if
+     * other threads are waiting for readlock
+     */
+    public void testReadHoldingWriteLock2()      { testReadHoldingWriteLock2(false); }
+    public void testReadHoldingWriteLock2_fair() { testReadHoldingWriteLock2(true); }
+    public void testReadHoldingWriteLock2(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
+        lock.writeLock().lock();
+        lock.readLock().lock();
+        lock.readLock().unlock();
+
+        Thread t1 = newStartedThread(new CheckedRunnable() {
+            public void realRun() {
+                lock.readLock().lock();
+                lock.readLock().unlock();
+            }});
+        Thread t2 = newStartedThread(new CheckedRunnable() {
+            public void realRun() {
+                lock.readLock().lock();
+                lock.readLock().unlock();
+            }});
+
+        waitForQueuedThread(lock, t1);
+        waitForQueuedThread(lock, t2);
+        assertWriteLockedByMoi(lock);
+        lock.readLock().lock();
+        lock.readLock().unlock();
+        releaseWriteLock(lock);
+        awaitTermination(t1);
+        awaitTermination(t2);
+    }
+
+    /**
+     * Read lock succeeds if write locked by current thread even if
+     * other threads are waiting for writelock
+     */
+    public void testReadHoldingWriteLock3()      { testReadHoldingWriteLock3(false); }
+    public void testReadHoldingWriteLock3_fair() { testReadHoldingWriteLock3(true); }
+    public void testReadHoldingWriteLock3(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
+        lock.writeLock().lock();
+        lock.readLock().lock();
+        lock.readLock().unlock();
+
+        Thread t1 = newStartedThread(new CheckedRunnable() {
+            public void realRun() {
+                lock.writeLock().lock();
+                lock.writeLock().unlock();
+            }});
+        Thread t2 = newStartedThread(new CheckedRunnable() {
+            public void realRun() {
+                lock.writeLock().lock();
+                lock.writeLock().unlock();
+            }});
+
+        waitForQueuedThread(lock, t1);
+        waitForQueuedThread(lock, t2);
+        assertWriteLockedByMoi(lock);
+        lock.readLock().lock();
+        lock.readLock().unlock();
+        assertWriteLockedByMoi(lock);
+        lock.writeLock().unlock();
+        awaitTermination(t1);
+        awaitTermination(t2);
+    }
+
+    /**
+     * Write lock succeeds if write locked by current thread even if
+     * other threads are waiting for writelock
+     */
+    public void testWriteHoldingWriteLock4()      { testWriteHoldingWriteLock4(false); }
+    public void testWriteHoldingWriteLock4_fair() { testWriteHoldingWriteLock4(true); }
+    public void testWriteHoldingWriteLock4(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
+        lock.writeLock().lock();
+        lock.writeLock().lock();
+        lock.writeLock().unlock();
+
+        Thread t1 = newStartedThread(new CheckedRunnable() {
+            public void realRun() {
+                lock.writeLock().lock();
+                lock.writeLock().unlock();
+            }});
+        Thread t2 = newStartedThread(new CheckedRunnable() {
+            public void realRun() {
+                lock.writeLock().lock();
+                lock.writeLock().unlock();
+            }});
+
+        waitForQueuedThread(lock, t1);
+        waitForQueuedThread(lock, t2);
+        assertWriteLockedByMoi(lock);
+        assertEquals(1, lock.getWriteHoldCount());
+        lock.writeLock().lock();
+        assertWriteLockedByMoi(lock);
+        assertEquals(2, lock.getWriteHoldCount());
+        lock.writeLock().unlock();
+        assertWriteLockedByMoi(lock);
+        assertEquals(1, lock.getWriteHoldCount());
+        lock.writeLock().unlock();
+        awaitTermination(t1);
+        awaitTermination(t2);
+    }
+
+    /**
+     * Read tryLock succeeds if readlocked but not writelocked
+     */
+    public void testTryLockWhenReadLocked()      { testTryLockWhenReadLocked(false); }
+    public void testTryLockWhenReadLocked_fair() { testTryLockWhenReadLocked(true); }
+    public void testTryLockWhenReadLocked(boolean fair) {
+        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(fair);
+        lock.readLock().lock();
+        Thread t = newStartedThread(new CheckedRunnable() {
+            public void realRun() {
+                assertTrue(lock.readLock().tryLock());
+                lock.readLock().unlock();
+            }});
+
+        awaitTermination(t);
+        lock.readLock().unlock();
+    }
+
+    /**
+     * write tryLock fails when readlocked
+     */
+    public void testWriteTryLockWhenReadLocked()      { testWriteTryLockWhenReadLocked(false); }
+    public void testWriteTryLockWhenReadLocked_fair() { testWriteTryLockWhenReadLocked(true); }
+    public void testWriteTryLockWhenReadLocked(boolean fair) {
+        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(fair);
+        lock.readLock().lock();
+        Thread t = newStartedThread(new CheckedRunnable() {
+            public void realRun() {
+                assertFalse(lock.writeLock().tryLock());
+            }});
+
+        awaitTermination(t);
+        lock.readLock().unlock();
+    }
+
+    /**
+     * write timed tryLock times out if locked
+     */
+    public void testWriteTryLock_Timeout()      { testWriteTryLock_Timeout(false); }
+    public void testWriteTryLock_Timeout_fair() { testWriteTryLock_Timeout(true); }
+    public void testWriteTryLock_Timeout(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
+        final long timeoutMillis = timeoutMillis();
+        lock.writeLock().lock();
+        Thread t = newStartedThread(new CheckedRunnable() {
+            public void realRun() throws InterruptedException {
+                long startTime = System.nanoTime();
+                assertFalse(lock.writeLock().tryLock(timeoutMillis, MILLISECONDS));
+                assertTrue(millisElapsedSince(startTime) >= timeoutMillis);
+            }});
+
+        awaitTermination(t);
+        releaseWriteLock(lock);
+    }
+
+    /**
+     * read timed tryLock times out if write-locked
+     */
+    public void testReadTryLock_Timeout()      { testReadTryLock_Timeout(false); }
+    public void testReadTryLock_Timeout_fair() { testReadTryLock_Timeout(true); }
+    public void testReadTryLock_Timeout(boolean fair) {
+        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(fair);
+        lock.writeLock().lock();
+        Thread t = newStartedThread(new CheckedRunnable() {
+            public void realRun() throws InterruptedException {
+                long startTime = System.nanoTime();
+                long timeoutMillis = timeoutMillis();
+                assertFalse(lock.readLock().tryLock(timeoutMillis, MILLISECONDS));
+                assertTrue(millisElapsedSince(startTime) >= timeoutMillis);
+            }});
+
+        awaitTermination(t);
+        assertTrue(lock.writeLock().isHeldByCurrentThread());
+        lock.writeLock().unlock();
+    }
+
+    /**
+     * write lockInterruptibly succeeds if unlocked, else is interruptible
+     */
+    public void testWriteLockInterruptibly()      { testWriteLockInterruptibly(false); }
+    public void testWriteLockInterruptibly_fair() { testWriteLockInterruptibly(true); }
+    public void testWriteLockInterruptibly(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
         try {
-            t.start();
-            t.interrupt();
-            t.join();
-            lock.writeLock().unlock();
-        } catch(Exception e){
-            unexpectedException();
-        }
+            lock.writeLock().lockInterruptibly();
+        } catch (InterruptedException fail) { threadUnexpectedException(fail); }
+        Thread t = newStartedThread(new CheckedInterruptedRunnable() {
+            public void realRun() throws InterruptedException {
+                lock.writeLock().lockInterruptibly();
+            }});
+
+        waitForQueuedThread(lock, t);
+        t.interrupt();
+        assertTrue(lock.writeLock().isHeldByCurrentThread());
+        awaitTermination(t);
+        releaseWriteLock(lock);
     }
 
     /**
-     *  read lockInterruptibly succeeds if lock free else is interruptible
+     * read lockInterruptibly succeeds if lock free else is interruptible
      */
-    public void testReadLockInterruptibly() {
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
-	try {
-            lock.writeLock().lockInterruptibly();
-        } catch(Exception e) {
-            unexpectedException();
-        }
-	Thread t = new Thread(new Runnable() { 
-		public void run() {
-		    try {
-			lock.readLock().lockInterruptibly();
-			threadShouldThrow();
-		    }
-		    catch(InterruptedException success) {
-                    }
-		}
-	    });
+    public void testReadLockInterruptibly()      { testReadLockInterruptibly(false); }
+    public void testReadLockInterruptibly_fair() { testReadLockInterruptibly(true); }
+    public void testReadLockInterruptibly(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
         try {
-            t.start();
-            t.interrupt();
-            t.join();
-            lock.writeLock().unlock();
-        } catch(Exception e){
-            unexpectedException();
-        }
+            lock.readLock().lockInterruptibly();
+            lock.readLock().unlock();
+            lock.writeLock().lockInterruptibly();
+        } catch (InterruptedException fail) { threadUnexpectedException(fail); }
+        Thread t = newStartedThread(new CheckedInterruptedRunnable() {
+            public void realRun() throws InterruptedException {
+                lock.readLock().lockInterruptibly();
+            }});
+
+        waitForQueuedThread(lock, t);
+        t.interrupt();
+        awaitTermination(t);
+        releaseWriteLock(lock);
     }
 
     /**
      * Calling await without holding lock throws IllegalMonitorStateException
      */
-    public void testAwait_IllegalMonitor() {
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();	
+    public void testAwait_IMSE()      { testAwait_IMSE(false); }
+    public void testAwait_IMSE_fair() { testAwait_IMSE(true); }
+    public void testAwait_IMSE(boolean fair) {
+        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(fair);
         final Condition c = lock.writeLock().newCondition();
-        try {
-            c.await();
-            shouldThrow();
-        }
-        catch (IllegalMonitorStateException success) {
-        }
-        catch (Exception ex) {
-            shouldThrow();
+        for (AwaitMethod awaitMethod : AwaitMethod.values()) {
+            long startTime = System.nanoTime();
+            try {
+                await(c, awaitMethod);
+                shouldThrow();
+            } catch (IllegalMonitorStateException success) {
+            } catch (InterruptedException fail) {
+                threadUnexpectedException(fail);
+            }
+            assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
         }
     }
 
     /**
      * Calling signal without holding lock throws IllegalMonitorStateException
      */
-    public void testSignal_IllegalMonitor() {
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();	
+    public void testSignal_IMSE()      { testSignal_IMSE(false); }
+    public void testSignal_IMSE_fair() { testSignal_IMSE(true); }
+    public void testSignal_IMSE(boolean fair) {
+        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(fair);
         final Condition c = lock.writeLock().newCondition();
         try {
             c.signal();
             shouldThrow();
-        }
-        catch (IllegalMonitorStateException success) {
-        }
-        catch (Exception ex) {
-            unexpectedException();
-        }
+        } catch (IllegalMonitorStateException success) {}
     }
 
     /**
-     * awaitNanos without a signal times out
+     * Calling signalAll without holding lock throws IllegalMonitorStateException
      */
-    public void testAwaitNanos_Timeout() {
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();	
+    public void testSignalAll_IMSE()      { testSignalAll_IMSE(false); }
+    public void testSignalAll_IMSE_fair() { testSignalAll_IMSE(true); }
+    public void testSignalAll_IMSE(boolean fair) {
+        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(fair);
         final Condition c = lock.writeLock().newCondition();
         try {
-            lock.writeLock().lock();
-            long t = c.awaitNanos(100);
-            assertTrue(t <= 0);
-            lock.writeLock().unlock();
-        }
-        catch (Exception ex) {
-            unexpectedException();
-        }
+            c.signalAll();
+            shouldThrow();
+        } catch (IllegalMonitorStateException success) {}
     }
 
-
     /**
-     *  timed await without a signal times out
+     * awaitNanos without a signal times out
      */
-    public void testAwait_Timeout() {
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();	
+    public void testAwaitNanos_Timeout()      { testAwaitNanos_Timeout(false); }
+    public void testAwaitNanos_Timeout_fair() { testAwaitNanos_Timeout(true); }
+    public void testAwaitNanos_Timeout(boolean fair) {
+        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(fair);
         final Condition c = lock.writeLock().newCondition();
+        final long timeoutMillis = timeoutMillis();
+        lock.writeLock().lock();
+        final long startTime = System.nanoTime();
+        final long timeoutNanos = MILLISECONDS.toNanos(timeoutMillis);
         try {
-            lock.writeLock().lock();
-            assertFalse(c.await(10, TimeUnit.MILLISECONDS));
-            lock.writeLock().unlock();
-        }
-        catch (Exception ex) {
-            unexpectedException();
-        }
+            long nanosRemaining = c.awaitNanos(timeoutNanos);
+            assertTrue(nanosRemaining <= 0);
+        } catch (InterruptedException fail) { threadUnexpectedException(fail); }
+        assertTrue(millisElapsedSince(startTime) >= timeoutMillis);
+        lock.writeLock().unlock();
+    }
+
+    /**
+     * timed await without a signal times out
+     */
+    public void testAwait_Timeout()      { testAwait_Timeout(false); }
+    public void testAwait_Timeout_fair() { testAwait_Timeout(true); }
+    public void testAwait_Timeout(boolean fair) {
+        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(fair);
+        final Condition c = lock.writeLock().newCondition();
+        final long timeoutMillis = timeoutMillis();
+        lock.writeLock().lock();
+        final long startTime = System.nanoTime();
+        try {
+            assertFalse(c.await(timeoutMillis, MILLISECONDS));
+        } catch (InterruptedException fail) { threadUnexpectedException(fail); }
+        assertTrue(millisElapsedSince(startTime) >= timeoutMillis);
+        lock.writeLock().unlock();
     }
 
     /**
      * awaitUntil without a signal times out
      */
-    public void testAwaitUntil_Timeout() {
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();	
+    public void testAwaitUntil_Timeout()      { testAwaitUntil_Timeout(false); }
+    public void testAwaitUntil_Timeout_fair() { testAwaitUntil_Timeout(true); }
+    public void testAwaitUntil_Timeout(boolean fair) {
+        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(fair);
         final Condition c = lock.writeLock().newCondition();
-        try {
-            lock.writeLock().lock();
-            java.util.Date d = new java.util.Date();
-            assertFalse(c.awaitUntil(new java.util.Date(d.getTime() + 10)));
-            lock.writeLock().unlock();
-        }
-        catch (Exception ex) {
-            unexpectedException();
-        }
+        lock.writeLock().lock();
+        // We shouldn't assume that nanoTime and currentTimeMillis
+        // use the same time source, so don't use nanoTime here.
+        final java.util.Date delayedDate = delayedDate(timeoutMillis());
+        try {
+            assertFalse(c.awaitUntil(delayedDate));
+        } catch (InterruptedException fail) { threadUnexpectedException(fail); }
+        assertTrue(new java.util.Date().getTime() >= delayedDate.getTime());
+        lock.writeLock().unlock();
     }
 
     /**
      * await returns when signalled
      */
-    public void testAwait() {
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();	
+    public void testAwait()      { testAwait(false); }
+    public void testAwait_fair() { testAwait(true); }
+    public void testAwait(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
+        final Condition c = lock.writeLock().newCondition();
+        final CountDownLatch locked = new CountDownLatch(1);
+        Thread t = newStartedThread(new CheckedRunnable() {
+            public void realRun() throws InterruptedException {
+                lock.writeLock().lock();
+                locked.countDown();
+                c.await();
+                lock.writeLock().unlock();
+            }});
+
+        await(locked);
+        lock.writeLock().lock();
+        assertHasWaiters(lock, c, t);
+        c.signal();
+        assertHasNoWaiters(lock, c);
+        assertTrue(t.isAlive());
+        lock.writeLock().unlock();
+        awaitTermination(t);
+    }
+
+    /**
+     * awaitUninterruptibly is uninterruptible
+     */
+    public void testAwaitUninterruptibly()      { testAwaitUninterruptibly(false); }
+    public void testAwaitUninterruptibly_fair() { testAwaitUninterruptibly(true); }
+    public void testAwaitUninterruptibly(boolean fair) {
+        final Lock lock = new ReentrantReadWriteLock(fair).writeLock();
+        final Condition condition = lock.newCondition();
+        final CountDownLatch pleaseInterrupt = new CountDownLatch(2);
+
+        Thread t1 = newStartedThread(new CheckedRunnable() {
+            public void realRun() {
+                // Interrupt before awaitUninterruptibly
+                lock.lock();
+                pleaseInterrupt.countDown();
+                Thread.currentThread().interrupt();
+                condition.awaitUninterruptibly();
+                assertTrue(Thread.interrupted());
+                lock.unlock();
+            }});
+
+        Thread t2 = newStartedThread(new CheckedRunnable() {
+            public void realRun() {
+                // Interrupt during awaitUninterruptibly
+                lock.lock();
+                pleaseInterrupt.countDown();
+                condition.awaitUninterruptibly();
+                assertTrue(Thread.interrupted());
+                lock.unlock();
+            }});
+
+        await(pleaseInterrupt);
+        t2.interrupt();
+        lock.lock();
+        lock.unlock();
+        assertThreadBlocks(t1, Thread.State.WAITING);
+        assertThreadBlocks(t2, Thread.State.WAITING);
+
+        lock.lock();
+        condition.signalAll();
+        lock.unlock();
+
+        awaitTermination(t1);
+        awaitTermination(t2);
+    }
+
+    /**
+     * await/awaitNanos/awaitUntil is interruptible
+     */
+    public void testInterruptible_await()           { testInterruptible(false, AwaitMethod.await); }
+    public void testInterruptible_await_fair()      { testInterruptible(true,  AwaitMethod.await); }
+    public void testInterruptible_awaitTimed()      { testInterruptible(false, AwaitMethod.awaitTimed); }
+    public void testInterruptible_awaitTimed_fair() { testInterruptible(true,  AwaitMethod.awaitTimed); }
+    public void testInterruptible_awaitNanos()      { testInterruptible(false, AwaitMethod.awaitNanos); }
+    public void testInterruptible_awaitNanos_fair() { testInterruptible(true,  AwaitMethod.awaitNanos); }
+    public void testInterruptible_awaitUntil()      { testInterruptible(false, AwaitMethod.awaitUntil); }
+    public void testInterruptible_awaitUntil_fair() { testInterruptible(true,  AwaitMethod.awaitUntil); }
+    public void testInterruptible(boolean fair, final AwaitMethod awaitMethod) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
         final Condition c = lock.writeLock().newCondition();
-	Thread t = new Thread(new Runnable() { 
-		public void run() {
-		    try {
-			lock.writeLock().lock();
-                        c.await();
-                        lock.writeLock().unlock();
-		    }
-		    catch(InterruptedException e) {
-                        threadUnexpectedException();
-                    }
-		}
-	    });
+        final CountDownLatch locked = new CountDownLatch(1);
+        Thread t = newStartedThread(new CheckedInterruptedRunnable() {
+            public void realRun() throws InterruptedException {
+                lock.writeLock().lock();
+                assertWriteLockedByMoi(lock);
+                assertHasNoWaiters(lock, c);
+                locked.countDown();
+                try {
+                    await(c, awaitMethod);
+                } finally {
+                    assertWriteLockedByMoi(lock);
+                    assertHasNoWaiters(lock, c);
+                    lock.writeLock().unlock();
+                    assertFalse(Thread.interrupted());
+                }
+            }});
+
+        await(locked);
+        assertHasWaiters(lock, c, t);
+        t.interrupt();
+        awaitTermination(t);
+        assertNotWriteLocked(lock);
+    }
 
-        try {
-            t.start();
-            Thread.sleep(SHORT_DELAY_MS);
-            lock.writeLock().lock();
-            c.signal();
-            lock.writeLock().unlock();
-            t.join(SHORT_DELAY_MS);
-            assertFalse(t.isAlive());
-        }
-        catch (Exception ex) {
-            unexpectedException();
+    /**
+     * signalAll wakes up all threads
+     */
+    public void testSignalAll_await()           { testSignalAll(false, AwaitMethod.await); }
+    public void testSignalAll_await_fair()      { testSignalAll(true,  AwaitMethod.await); }
+    public void testSignalAll_awaitTimed()      { testSignalAll(false, AwaitMethod.awaitTimed); }
+    public void testSignalAll_awaitTimed_fair() { testSignalAll(true,  AwaitMethod.awaitTimed); }
+    public void testSignalAll_awaitNanos()      { testSignalAll(false, AwaitMethod.awaitNanos); }
+    public void testSignalAll_awaitNanos_fair() { testSignalAll(true,  AwaitMethod.awaitNanos); }
+    public void testSignalAll_awaitUntil()      { testSignalAll(false, AwaitMethod.awaitUntil); }
+    public void testSignalAll_awaitUntil_fair() { testSignalAll(true,  AwaitMethod.awaitUntil); }
+    public void testSignalAll(boolean fair, final AwaitMethod awaitMethod) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
+        final Condition c = lock.writeLock().newCondition();
+        final CountDownLatch locked = new CountDownLatch(2);
+        final Lock writeLock = lock.writeLock();
+        class Awaiter extends CheckedRunnable {
+            public void realRun() throws InterruptedException {
+                writeLock.lock();
+                locked.countDown();
+                await(c, awaitMethod);
+                writeLock.unlock();
+            }
         }
+
+        Thread t1 = newStartedThread(new Awaiter());
+        Thread t2 = newStartedThread(new Awaiter());
+
+        await(locked);
+        writeLock.lock();
+        assertHasWaiters(lock, c, t1, t2);
+        c.signalAll();
+        assertHasNoWaiters(lock, c);
+        writeLock.unlock();
+        awaitTermination(t1);
+        awaitTermination(t2);
     }
 
     /**
-     * awaitUninterruptibly doesn't abort on interrupt
-     */
-    public void testAwaitUninterruptibly() {
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();	
+     * signal wakes up waiting threads in FIFO order
+     */
+    public void testSignalWakesFifo()      { testSignalWakesFifo(false); }
+    public void testSignalWakesFifo_fair() { testSignalWakesFifo(true); }
+    public void testSignalWakesFifo(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
         final Condition c = lock.writeLock().newCondition();
-	Thread t = new Thread(new Runnable() { 
-		public void run() {
-                    lock.writeLock().lock();
-                    c.awaitUninterruptibly();
-                    lock.writeLock().unlock();
-		}
-	    });
+        final CountDownLatch locked1 = new CountDownLatch(1);
+        final CountDownLatch locked2 = new CountDownLatch(1);
+        final Lock writeLock = lock.writeLock();
+        Thread t1 = newStartedThread(new CheckedRunnable() {
+            public void realRun() throws InterruptedException {
+                writeLock.lock();
+                locked1.countDown();
+                c.await();
+                writeLock.unlock();
+            }});
+
+        await(locked1);
+
+        Thread t2 = newStartedThread(new CheckedRunnable() {
+            public void realRun() throws InterruptedException {
+                writeLock.lock();
+                locked2.countDown();
+                c.await();
+                writeLock.unlock();
+            }});
+
+        await(locked2);
+
+        writeLock.lock();
+        assertHasWaiters(lock, c, t1, t2);
+        assertFalse(lock.hasQueuedThreads());
+        c.signal();
+        assertHasWaiters(lock, c, t2);
+        assertTrue(lock.hasQueuedThread(t1));
+        assertFalse(lock.hasQueuedThread(t2));
+        c.signal();
+        assertHasNoWaiters(lock, c);
+        assertTrue(lock.hasQueuedThread(t1));
+        assertTrue(lock.hasQueuedThread(t2));
+        writeLock.unlock();
+        awaitTermination(t1);
+        awaitTermination(t2);
+    }
 
-        try {
-            t.start();
-            Thread.sleep(SHORT_DELAY_MS);
-            t.interrupt();
-            lock.writeLock().lock();
-            c.signal();
-            lock.writeLock().unlock();
-            assert(t.isInterrupted());
-            t.join(SHORT_DELAY_MS);
-            assertFalse(t.isAlive());
-        }
-        catch (Exception ex) {
-            unexpectedException();
-        }
+    /**
+     * await after multiple reentrant locking preserves lock count
+     */
+    public void testAwaitLockCount()      { testAwaitLockCount(false); }
+    public void testAwaitLockCount_fair() { testAwaitLockCount(true); }
+    public void testAwaitLockCount(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
+        final Condition c = lock.writeLock().newCondition();
+        final CountDownLatch locked = new CountDownLatch(2);
+        Thread t1 = newStartedThread(new CheckedRunnable() {
+            public void realRun() throws InterruptedException {
+                lock.writeLock().lock();
+                assertWriteLockedByMoi(lock);
+                assertEquals(1, lock.writeLock().getHoldCount());
+                locked.countDown();
+                c.await();
+                assertWriteLockedByMoi(lock);
+                assertEquals(1, lock.writeLock().getHoldCount());
+                lock.writeLock().unlock();
+            }});
+
+        Thread t2 = newStartedThread(new CheckedRunnable() {
+            public void realRun() throws InterruptedException {
+                lock.writeLock().lock();
+                lock.writeLock().lock();
+                assertWriteLockedByMoi(lock);
+                assertEquals(2, lock.writeLock().getHoldCount());
+                locked.countDown();
+                c.await();
+                assertWriteLockedByMoi(lock);
+                assertEquals(2, lock.writeLock().getHoldCount());
+                lock.writeLock().unlock();
+                lock.writeLock().unlock();
+            }});
+
+        await(locked);
+        lock.writeLock().lock();
+        assertHasWaiters(lock, c, t1, t2);
+        c.signalAll();
+        assertHasNoWaiters(lock, c);
+        lock.writeLock().unlock();
+        awaitTermination(t1);
+        awaitTermination(t2);
     }
 
     /**
-     * await is interruptible
+     * A serialized lock deserializes as unlocked
      */
-    public void testAwait_Interrupt() {
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();	
-        final Condition c = lock.writeLock().newCondition();
-	Thread t = new Thread(new Runnable() { 
-		public void run() {
-		    try {
-			lock.writeLock().lock();
-                        c.await();
-                        lock.writeLock().unlock();
-                        threadShouldThrow();
-		    }
-		    catch(InterruptedException success) {
-                    }
-		}
-	    });
+    public void testSerialization()      { testSerialization(false); }
+    public void testSerialization_fair() { testSerialization(true); }
+    public void testSerialization(boolean fair) {
+        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(fair);
+        lock.writeLock().lock();
+        lock.readLock().lock();
+
+        ReentrantReadWriteLock clone = serialClone(lock);
+        assertEquals(lock.isFair(), clone.isFair());
+        assertTrue(lock.isWriteLocked());
+        assertFalse(clone.isWriteLocked());
+        assertEquals(1, lock.getReadLockCount());
+        assertEquals(0, clone.getReadLockCount());
+        clone.writeLock().lock();
+        clone.readLock().lock();
+        assertTrue(clone.isWriteLocked());
+        assertEquals(1, clone.getReadLockCount());
+        clone.readLock().unlock();
+        clone.writeLock().unlock();
+        assertFalse(clone.isWriteLocked());
+        assertEquals(1, lock.getReadLockCount());
+        assertEquals(0, clone.getReadLockCount());
+    }
 
+    /**
+     * hasQueuedThreads reports whether there are waiting threads
+     */
+    public void testHasQueuedThreads()      { testHasQueuedThreads(false); }
+    public void testHasQueuedThreads_fair() { testHasQueuedThreads(true); }
+    public void testHasQueuedThreads(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
+        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
+        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
+        assertFalse(lock.hasQueuedThreads());
+        lock.writeLock().lock();
+        assertFalse(lock.hasQueuedThreads());
+        t1.start();
+        waitForQueuedThread(lock, t1);
+        assertTrue(lock.hasQueuedThreads());
+        t2.start();
+        waitForQueuedThread(lock, t2);
+        assertTrue(lock.hasQueuedThreads());
+        t1.interrupt();
+        awaitTermination(t1);
+        assertTrue(lock.hasQueuedThreads());
+        lock.writeLock().unlock();
+        awaitTermination(t2);
+        assertFalse(lock.hasQueuedThreads());
+    }
+
+    /**
+     * hasQueuedThread(null) throws NPE
+     */
+    public void testHasQueuedThreadNPE()      { testHasQueuedThreadNPE(false); }
+    public void testHasQueuedThreadNPE_fair() { testHasQueuedThreadNPE(true); }
+    public void testHasQueuedThreadNPE(boolean fair) {
+        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(fair);
         try {
-            t.start();
-            Thread.sleep(SHORT_DELAY_MS);
-            t.interrupt();
-            t.join(SHORT_DELAY_MS);
-            assertFalse(t.isAlive());
-        }
-        catch (Exception ex) {
-            unexpectedException();
-        }
+            lock.hasQueuedThread(null);
+            shouldThrow();
+        } catch (NullPointerException success) {}
     }
 
     /**
-     * awaitNanos is interruptible
+     * hasQueuedThread reports whether a thread is queued
      */
-    public void testAwaitNanos_Interrupt() {
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();	
-        final Condition c = lock.writeLock().newCondition();
-	Thread t = new Thread(new Runnable() { 
-		public void run() {
-		    try {
-			lock.writeLock().lock();
-                        c.awaitNanos(SHORT_DELAY_MS * 2 * 1000000);
-                        lock.writeLock().unlock();
-                        threadShouldThrow();
-		    }
-		    catch(InterruptedException success) {
-                    }
-		}
-	    });
+    public void testHasQueuedThread()      { testHasQueuedThread(false); }
+    public void testHasQueuedThread_fair() { testHasQueuedThread(true); }
+    public void testHasQueuedThread(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
+        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
+        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
+        assertFalse(lock.hasQueuedThread(t1));
+        assertFalse(lock.hasQueuedThread(t2));
+        lock.writeLock().lock();
+        t1.start();
+        waitForQueuedThread(lock, t1);
+        assertTrue(lock.hasQueuedThread(t1));
+        assertFalse(lock.hasQueuedThread(t2));
+        t2.start();
+        waitForQueuedThread(lock, t2);
+        assertTrue(lock.hasQueuedThread(t1));
+        assertTrue(lock.hasQueuedThread(t2));
+        t1.interrupt();
+        awaitTermination(t1);
+        assertFalse(lock.hasQueuedThread(t1));
+        assertTrue(lock.hasQueuedThread(t2));
+        lock.writeLock().unlock();
+        awaitTermination(t2);
+        assertFalse(lock.hasQueuedThread(t1));
+        assertFalse(lock.hasQueuedThread(t2));
+    }
+
+    /**
+     * getQueueLength reports number of waiting threads
+     */
+    public void testGetQueueLength()      { testGetQueueLength(false); }
+    public void testGetQueueLength_fair() { testGetQueueLength(true); }
+    public void testGetQueueLength(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
+        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
+        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
+        assertEquals(0, lock.getQueueLength());
+        lock.writeLock().lock();
+        t1.start();
+        waitForQueuedThread(lock, t1);
+        assertEquals(1, lock.getQueueLength());
+        t2.start();
+        waitForQueuedThread(lock, t2);
+        assertEquals(2, lock.getQueueLength());
+        t1.interrupt();
+        awaitTermination(t1);
+        assertEquals(1, lock.getQueueLength());
+        lock.writeLock().unlock();
+        awaitTermination(t2);
+        assertEquals(0, lock.getQueueLength());
+    }
 
+    /**
+     * getQueuedThreads includes waiting threads
+     */
+    public void testGetQueuedThreads()      { testGetQueuedThreads(false); }
+    public void testGetQueuedThreads_fair() { testGetQueuedThreads(true); }
+    public void testGetQueuedThreads(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
+        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
+        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
+        assertTrue(lock.getQueuedThreads().isEmpty());
+        lock.writeLock().lock();
+        assertTrue(lock.getQueuedThreads().isEmpty());
+        t1.start();
+        waitForQueuedThread(lock, t1);
+        assertEquals(1, lock.getQueuedThreads().size());
+        assertTrue(lock.getQueuedThreads().contains(t1));
+        t2.start();
+        waitForQueuedThread(lock, t2);
+        assertEquals(2, lock.getQueuedThreads().size());
+        assertTrue(lock.getQueuedThreads().contains(t1));
+        assertTrue(lock.getQueuedThreads().contains(t2));
+        t1.interrupt();
+        awaitTermination(t1);
+        assertFalse(lock.getQueuedThreads().contains(t1));
+        assertTrue(lock.getQueuedThreads().contains(t2));
+        assertEquals(1, lock.getQueuedThreads().size());
+        lock.writeLock().unlock();
+        awaitTermination(t2);
+        assertTrue(lock.getQueuedThreads().isEmpty());
+    }
+
+    /**
+     * hasWaiters throws NPE if null
+     */
+    public void testHasWaitersNPE()      { testHasWaitersNPE(false); }
+    public void testHasWaitersNPE_fair() { testHasWaitersNPE(true); }
+    public void testHasWaitersNPE(boolean fair) {
+        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(fair);
         try {
-            t.start();
-            Thread.sleep(SHORT_DELAY_MS);
-            t.interrupt();
-            t.join(SHORT_DELAY_MS);
-            assertFalse(t.isAlive());
-        }
-        catch (Exception ex) {
-            unexpectedException();
-        }
+            lock.hasWaiters(null);
+            shouldThrow();
+        } catch (NullPointerException success) {}
     }
 
     /**
-     * awaitUntil is interruptible
+     * getWaitQueueLength throws NPE if null
      */
-    public void testAwaitUntil_Interrupt() {
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();	
-        final Condition c = lock.writeLock().newCondition();
-	Thread t = new Thread(new Runnable() { 
-		public void run() {
-		    try {
-			lock.writeLock().lock();
-                        java.util.Date d = new java.util.Date();
-                        c.awaitUntil(new java.util.Date(d.getTime() + 10000));
-                        lock.writeLock().unlock();
-                        threadShouldThrow();
-		    }
-		    catch(InterruptedException success) {
-                    }
-		}
-	    });
+    public void testGetWaitQueueLengthNPE()      { testGetWaitQueueLengthNPE(false); }
+    public void testGetWaitQueueLengthNPE_fair() { testGetWaitQueueLengthNPE(true); }
+    public void testGetWaitQueueLengthNPE(boolean fair) {
+        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(fair);
+        try {
+            lock.getWaitQueueLength(null);
+            shouldThrow();
+        } catch (NullPointerException success) {}
+    }
 
+    /**
+     * getWaitingThreads throws NPE if null
+     */
+    public void testGetWaitingThreadsNPE()      { testGetWaitingThreadsNPE(false); }
+    public void testGetWaitingThreadsNPE_fair() { testGetWaitingThreadsNPE(true); }
+    public void testGetWaitingThreadsNPE(boolean fair) {
+        final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock(fair);
         try {
-            t.start();
-            Thread.sleep(SHORT_DELAY_MS);
-            t.interrupt();
-            t.join(SHORT_DELAY_MS);
-            assertFalse(t.isAlive());
-        }
-        catch (Exception ex) {
-            unexpectedException();
-        }
+            lock.getWaitingThreads(null);
+            shouldThrow();
+        } catch (NullPointerException success) {}
     }
 
     /**
-     * signalAll wakes up all threads
+     * hasWaiters throws IllegalArgumentException if not owned
      */
-    public void testSignalAll() {
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();	
+    public void testHasWaitersIAE()      { testHasWaitersIAE(false); }
+    public void testHasWaitersIAE_fair() { testHasWaitersIAE(true); }
+    public void testHasWaitersIAE(boolean fair) {
+        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(fair);
         final Condition c = lock.writeLock().newCondition();
-	Thread t1 = new Thread(new Runnable() { 
-		public void run() {
-		    try {
-			lock.writeLock().lock();
-                        c.await();
-                        lock.writeLock().unlock();
-		    }
-		    catch(InterruptedException e) {
-                        threadUnexpectedException();
-                    }
-		}
-	    });
-
-	Thread t2 = new Thread(new Runnable() { 
-		public void run() {
-		    try {
-			lock.writeLock().lock();
-                        c.await();
-                        lock.writeLock().unlock();
-		    }
-		    catch(InterruptedException e) {
-                        threadUnexpectedException();
-                    }
-		}
-	    });
+        final ReentrantReadWriteLock lock2 = new ReentrantReadWriteLock(fair);
+        try {
+            lock2.hasWaiters(c);
+            shouldThrow();
+        } catch (IllegalArgumentException success) {}
+    }
 
+    /**
+     * hasWaiters throws IllegalMonitorStateException if not locked
+     */
+    public void testHasWaitersIMSE()      { testHasWaitersIMSE(false); }
+    public void testHasWaitersIMSE_fair() { testHasWaitersIMSE(true); }
+    public void testHasWaitersIMSE(boolean fair) {
+        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(fair);
+        final Condition c = lock.writeLock().newCondition();
         try {
-            t1.start();
-            t2.start();
-            Thread.sleep(SHORT_DELAY_MS);
-            lock.writeLock().lock();
-            c.signalAll();
-            lock.writeLock().unlock();
-            t1.join(SHORT_DELAY_MS);
-            t2.join(SHORT_DELAY_MS);
-            assertFalse(t1.isAlive());
-            assertFalse(t2.isAlive());
-        }
-        catch (Exception ex) {
-            unexpectedException();
-        }
+            lock.hasWaiters(c);
+            shouldThrow();
+        } catch (IllegalMonitorStateException success) {}
     }
 
     /**
-     * A serialized lock deserializes as unlocked
+     * getWaitQueueLength throws IllegalArgumentException if not owned
      */
-    public void testSerialization() {
-        ReentrantReadWriteLock l = new ReentrantReadWriteLock();
-        l.readLock().lock();
-        l.readLock().unlock();
+    public void testGetWaitQueueLengthIAE()      { testGetWaitQueueLengthIAE(false); }
+    public void testGetWaitQueueLengthIAE_fair() { testGetWaitQueueLengthIAE(true); }
+    public void testGetWaitQueueLengthIAE(boolean fair) {
+        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(fair);
+        final Condition c = lock.writeLock().newCondition();
+        final ReentrantReadWriteLock lock2 = new ReentrantReadWriteLock(fair);
+        try {
+            lock2.getWaitQueueLength(c);
+            shouldThrow();
+        } catch (IllegalArgumentException success) {}
+    }
 
+    /**
+     * getWaitQueueLength throws IllegalMonitorStateException if not locked
+     */
+    public void testGetWaitQueueLengthIMSE()      { testGetWaitQueueLengthIMSE(false); }
+    public void testGetWaitQueueLengthIMSE_fair() { testGetWaitQueueLengthIMSE(true); }
+    public void testGetWaitQueueLengthIMSE(boolean fair) {
+        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(fair);
+        final Condition c = lock.writeLock().newCondition();
         try {
-            ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
-            ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
-            out.writeObject(l);
-            out.close();
-
-            ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
-            ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
-            ReentrantReadWriteLock r = (ReentrantReadWriteLock) in.readObject();
-            r.readLock().lock();
-            r.readLock().unlock();
-        } catch(Exception e){
-            e.printStackTrace();
-            unexpectedException();
-        }
+            lock.getWaitQueueLength(c);
+            shouldThrow();
+        } catch (IllegalMonitorStateException success) {}
     }
 
     /**
-     * getQueueLength reports number of waiting threads
+     * getWaitingThreads throws IllegalArgumentException if not owned
      */
-    public void testGetQueueLength() { 
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
-        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
-        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
+    public void testGetWaitingThreadsIAE()      { testGetWaitingThreadsIAE(false); }
+    public void testGetWaitingThreadsIAE_fair() { testGetWaitingThreadsIAE(true); }
+    public void testGetWaitingThreadsIAE(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
+        final Condition c = lock.writeLock().newCondition();
+        final PublicReentrantReadWriteLock lock2 =
+            new PublicReentrantReadWriteLock(fair);
         try {
-            assertEquals(0, lock.getQueueLength());
-            lock.writeLock().lock();
-            t1.start();
-            Thread.sleep(SHORT_DELAY_MS);
-            assertEquals(1, lock.getQueueLength());
-            t2.start();
-            Thread.sleep(SHORT_DELAY_MS);
-            assertEquals(2, lock.getQueueLength());
-            t1.interrupt();
-            Thread.sleep(SHORT_DELAY_MS);
-            assertEquals(1, lock.getQueueLength());
-            lock.writeLock().unlock();
-            Thread.sleep(SHORT_DELAY_MS);
-            assertEquals(0, lock.getQueueLength());
-            t1.join();
-            t2.join();
-        } catch(Exception e){
-            unexpectedException();
-        }
-    } 
+            lock2.getWaitingThreads(c);
+            shouldThrow();
+        } catch (IllegalArgumentException success) {}
+    }
 
     /**
-     * getQueuedThreads includes waiting threads
+     * getWaitingThreads throws IllegalMonitorStateException if not locked
      */
-    public void testGetQueuedThreads() { 
-	final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock();
-        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
-        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
+    public void testGetWaitingThreadsIMSE()      { testGetWaitingThreadsIMSE(false); }
+    public void testGetWaitingThreadsIMSE_fair() { testGetWaitingThreadsIMSE(true); }
+    public void testGetWaitingThreadsIMSE(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
+        final Condition c = lock.writeLock().newCondition();
         try {
-            assertTrue(lock.getQueuedThreads().isEmpty());
-            lock.writeLock().lock();
-            assertTrue(lock.getQueuedThreads().isEmpty());
-            t1.start();
-            Thread.sleep(SHORT_DELAY_MS);
-            assertTrue(lock.getQueuedThreads().contains(t1));
-            t2.start();
-            Thread.sleep(SHORT_DELAY_MS);
-            assertTrue(lock.getQueuedThreads().contains(t1));
-            assertTrue(lock.getQueuedThreads().contains(t2));
-            t1.interrupt();
-            Thread.sleep(SHORT_DELAY_MS);
-            assertFalse(lock.getQueuedThreads().contains(t1));
-            assertTrue(lock.getQueuedThreads().contains(t2));
-            lock.writeLock().unlock();
-            Thread.sleep(SHORT_DELAY_MS);
-            assertTrue(lock.getQueuedThreads().isEmpty());
-            t1.join();
-            t2.join();
-        } catch(Exception e){
-            unexpectedException();
-        }
-    } 
+            lock.getWaitingThreads(c);
+            shouldThrow();
+        } catch (IllegalMonitorStateException success) {}
+    }
 
     /**
      * hasWaiters returns true when a thread is waiting, else false
      */
-    public void testHasWaiters() {
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();	
-        final ReentrantReadWriteLock.WriterConditionObject c = (ReentrantReadWriteLock.WriterConditionObject)(lock.writeLock().newCondition());
-	Thread t = new Thread(new Runnable() { 
-		public void run() {
-		    try {
-			lock.writeLock().lock();
-                        threadAssertFalse(c.hasWaiters());
-                        threadAssertEquals(0, c.getWaitQueueLength());
-                        c.await();
-                        lock.writeLock().unlock();
-		    }
-		    catch(InterruptedException e) {
-                        threadUnexpectedException();
-                    }
-		}
-	    });
-
-        try {
-            t.start();
-            Thread.sleep(SHORT_DELAY_MS);
-            lock.writeLock().lock();
-            assertTrue(c.hasWaiters());
-            assertEquals(1, c.getWaitQueueLength());
-            c.signal();
-            lock.writeLock().unlock();
-            Thread.sleep(SHORT_DELAY_MS);
-            lock.writeLock().lock();
-            assertFalse(c.hasWaiters());
-            assertEquals(0, c.getWaitQueueLength());
-            lock.writeLock().unlock();
-            t.join(SHORT_DELAY_MS);
-            assertFalse(t.isAlive());
-        }
-        catch (Exception ex) {
-            unexpectedException();
-        }
+    public void testHasWaiters()      { testHasWaiters(false); }
+    public void testHasWaiters_fair() { testHasWaiters(true); }
+    public void testHasWaiters(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
+        final Condition c = lock.writeLock().newCondition();
+        final CountDownLatch locked = new CountDownLatch(1);
+        Thread t = newStartedThread(new CheckedRunnable() {
+            public void realRun() throws InterruptedException {
+                lock.writeLock().lock();
+                assertHasNoWaiters(lock, c);
+                assertFalse(lock.hasWaiters(c));
+                locked.countDown();
+                c.await();
+                assertHasNoWaiters(lock, c);
+                assertFalse(lock.hasWaiters(c));
+                lock.writeLock().unlock();
+            }});
+
+        await(locked);
+        lock.writeLock().lock();
+        assertHasWaiters(lock, c, t);
+        assertTrue(lock.hasWaiters(c));
+        c.signal();
+        assertHasNoWaiters(lock, c);
+        assertFalse(lock.hasWaiters(c));
+        lock.writeLock().unlock();
+        awaitTermination(t);
+        assertHasNoWaiters(lock, c);
     }
 
     /**
      * getWaitQueueLength returns number of waiting threads
      */
-    public void testGetWaitQueueLength() {
-	final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();	
-        final ReentrantReadWriteLock.WriterConditionObject c = (ReentrantReadWriteLock.WriterConditionObject)(lock.writeLock().newCondition());
-	Thread t1 = new Thread(new Runnable() { 
-		public void run() {
-		    try {
-			lock.writeLock().lock();
-                        threadAssertFalse(c.hasWaiters());
-                        threadAssertEquals(0, c.getWaitQueueLength());
-                        c.await();
-                        lock.writeLock().unlock();
-		    }
-		    catch(InterruptedException e) {
-                        threadUnexpectedException();
-                    }
-		}
-	    });
-
-	Thread t2 = new Thread(new Runnable() { 
-		public void run() {
-		    try {
-			lock.writeLock().lock();
-                        threadAssertTrue(c.hasWaiters());
-                        threadAssertEquals(1, c.getWaitQueueLength());
-                        c.await();
-                        lock.writeLock().unlock();
-		    }
-		    catch(InterruptedException e) {
-                        threadUnexpectedException();
-                    }
-		}
-	    });
-
-        try {
-            t1.start();
-            Thread.sleep(SHORT_DELAY_MS);
-            t2.start();
-            Thread.sleep(SHORT_DELAY_MS);
-            lock.writeLock().lock();
-            assertTrue(c.hasWaiters());
-            assertEquals(2, c.getWaitQueueLength());
-            c.signalAll();
-            lock.writeLock().unlock();
-            Thread.sleep(SHORT_DELAY_MS);
-            lock.writeLock().lock();
-            assertFalse(c.hasWaiters());
-            assertEquals(0, c.getWaitQueueLength());
-            lock.writeLock().unlock();
-            t1.join(SHORT_DELAY_MS);
-            t2.join(SHORT_DELAY_MS);
-            assertFalse(t1.isAlive());
-            assertFalse(t2.isAlive());
-        }
-        catch (Exception ex) {
-            unexpectedException();
-        }
+    public void testGetWaitQueueLength()      { testGetWaitQueueLength(false); }
+    public void testGetWaitQueueLength_fair() { testGetWaitQueueLength(true); }
+    public void testGetWaitQueueLength(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
+        final Condition c = lock.writeLock().newCondition();
+        final CountDownLatch locked = new CountDownLatch(1);
+        Thread t = newStartedThread(new CheckedRunnable() {
+            public void realRun() throws InterruptedException {
+                lock.writeLock().lock();
+                assertEquals(0, lock.getWaitQueueLength(c));
+                locked.countDown();
+                c.await();
+                lock.writeLock().unlock();
+            }});
+
+        await(locked);
+        lock.writeLock().lock();
+        assertHasWaiters(lock, c, t);
+        assertEquals(1, lock.getWaitQueueLength(c));
+        c.signal();
+        assertHasNoWaiters(lock, c);
+        assertEquals(0, lock.getWaitQueueLength(c));
+        lock.writeLock().unlock();
+        awaitTermination(t);
     }
 
     /**
      * getWaitingThreads returns only and all waiting threads
      */
-    public void testGetWaitingThreads() {
-	final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock();	
-        final PublicReentrantReadWriteLock.PublicCondition c = (PublicReentrantReadWriteLock.PublicCondition)lock.newCondition();
-	Thread t1 = new Thread(new Runnable() { 
-		public void run() {
-		    try {
-			lock.writeLock().lock();
-                        threadAssertTrue(c.getWaitingThreads().isEmpty());
-                        c.await();
-                        lock.writeLock().unlock();
-		    }
-		    catch(InterruptedException e) {
-                        threadUnexpectedException();
-                    }
-		}
-	    });
-
-	Thread t2 = new Thread(new Runnable() { 
-		public void run() {
-		    try {
-			lock.writeLock().lock();
-                        threadAssertFalse(c.getWaitingThreads().isEmpty());
-                        c.await();
-                        lock.writeLock().unlock();
-		    }
-		    catch(InterruptedException e) {
-                        threadUnexpectedException();
-                    }
-		}
-	    });
-
+    public void testGetWaitingThreads()      { testGetWaitingThreads(false); }
+    public void testGetWaitingThreads_fair() { testGetWaitingThreads(true); }
+    public void testGetWaitingThreads(boolean fair) {
+        final PublicReentrantReadWriteLock lock =
+            new PublicReentrantReadWriteLock(fair);
+        final Condition c = lock.writeLock().newCondition();
+        final CountDownLatch locked1 = new CountDownLatch(1);
+        final CountDownLatch locked2 = new CountDownLatch(1);
+        Thread t1 = new Thread(new CheckedRunnable() {
+            public void realRun() throws InterruptedException {
+                lock.writeLock().lock();
+                assertTrue(lock.getWaitingThreads(c).isEmpty());
+                locked1.countDown();
+                c.await();
+                lock.writeLock().unlock();
+            }});
+
+        Thread t2 = new Thread(new CheckedRunnable() {
+            public void realRun() throws InterruptedException {
+                lock.writeLock().lock();
+                assertFalse(lock.getWaitingThreads(c).isEmpty());
+                locked2.countDown();
+                c.await();
+                lock.writeLock().unlock();
+            }});
+
+        lock.writeLock().lock();
+        assertTrue(lock.getWaitingThreads(c).isEmpty());
+        lock.writeLock().unlock();
+
+        t1.start();
+        await(locked1);
+        t2.start();
+        await(locked2);
+
+        lock.writeLock().lock();
+        assertTrue(lock.hasWaiters(c));
+        assertTrue(lock.getWaitingThreads(c).contains(t1));
+        assertTrue(lock.getWaitingThreads(c).contains(t2));
+        assertEquals(2, lock.getWaitingThreads(c).size());
+        c.signalAll();
+        assertHasNoWaiters(lock, c);
+        lock.writeLock().unlock();
+
+        awaitTermination(t1);
+        awaitTermination(t2);
+
+        assertHasNoWaiters(lock, c);
+    }
+
+    /**
+     * toString indicates current lock state
+     */
+    public void testToString()      { testToString(false); }
+    public void testToString_fair() { testToString(true); }
+    public void testToString(boolean fair) {
+        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(fair);
+        assertTrue(lock.toString().contains("Write locks = 0"));
+        assertTrue(lock.toString().contains("Read locks = 0"));
+        lock.writeLock().lock();
+        assertTrue(lock.toString().contains("Write locks = 1"));
+        assertTrue(lock.toString().contains("Read locks = 0"));
+        lock.writeLock().lock();
+        assertTrue(lock.toString().contains("Write locks = 2"));
+        assertTrue(lock.toString().contains("Read locks = 0"));
+        lock.writeLock().unlock();
+        lock.writeLock().unlock();
+        lock.readLock().lock();
+        assertTrue(lock.toString().contains("Write locks = 0"));
+        assertTrue(lock.toString().contains("Read locks = 1"));
+        lock.readLock().lock();
+        assertTrue(lock.toString().contains("Write locks = 0"));
+        assertTrue(lock.toString().contains("Read locks = 2"));
+    }
+
+    /**
+     * readLock.toString indicates current lock state
+     */
+    public void testReadLockToString()      { testReadLockToString(false); }
+    public void testReadLockToString_fair() { testReadLockToString(true); }
+    public void testReadLockToString(boolean fair) {
+        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(fair);
+        assertTrue(lock.readLock().toString().contains("Read locks = 0"));
+        lock.readLock().lock();
+        assertTrue(lock.readLock().toString().contains("Read locks = 1"));
+        lock.readLock().lock();
+        assertTrue(lock.readLock().toString().contains("Read locks = 2"));
+        lock.readLock().unlock();
+        assertTrue(lock.readLock().toString().contains("Read locks = 1"));
+        lock.readLock().unlock();
+        assertTrue(lock.readLock().toString().contains("Read locks = 0"));
+    }
+
+    /**
+     * writeLock.toString indicates current lock state
+     */
+    public void testWriteLockToString()      { testWriteLockToString(false); }
+    public void testWriteLockToString_fair() { testWriteLockToString(true); }
+    public void testWriteLockToString(boolean fair) {
+        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(fair);
+        assertTrue(lock.writeLock().toString().contains("Unlocked"));
+        lock.writeLock().lock();
+        assertTrue(lock.writeLock().toString().contains("Locked by"));
+        lock.writeLock().unlock();
+        assertTrue(lock.writeLock().toString().contains("Unlocked"));
+    }
+
+    /**
+     * ThreadMXBean reports the blockers that we expect.
+     */
+    public void testBlockers() {
+        if (!testImplementationDetails) return;
+        final boolean fair = randomBoolean();
+        final boolean timedAcquire = randomBoolean();
+        final boolean timedAwait = randomBoolean();
+        final String syncClassName = fair
+            ? "ReentrantReadWriteLock$FairSync"
+            : "ReentrantReadWriteLock$NonfairSync";
+        final String conditionClassName
+            = "AbstractQueuedSynchronizer$ConditionObject";
+        final Thread.State expectedAcquireState = timedAcquire
+            ? Thread.State.TIMED_WAITING
+            : Thread.State.WAITING;
+        final Thread.State expectedAwaitState = timedAwait
+            ? Thread.State.TIMED_WAITING
+            : Thread.State.WAITING;
+        final Lock lock = new ReentrantReadWriteLock(fair).writeLock();
+        final Condition condition = lock.newCondition();
+        final AtomicBoolean conditionSatisfied = new AtomicBoolean(false);
+        lock.lock();
+        final Thread thread = newStartedThread((Action) () -> {
+            if (timedAcquire)
+                lock.tryLock(LONGER_DELAY_MS, MILLISECONDS);
+            else
+                lock.lock();
+            while (!conditionSatisfied.get())
+                if (timedAwait)
+                    condition.await(LONGER_DELAY_MS, MILLISECONDS);
+                else
+                    condition.await();
+        });
+        Callable<Boolean> waitingForLock = () -> {
+            String className;
+            return thread.getState() == expectedAcquireState
+            && (className = blockerClassName(thread)) != null
+            && className.endsWith(syncClassName);
+        };
+        waitForThreadToEnterWaitState(thread, waitingForLock);
+
+        lock.unlock();
+        Callable<Boolean> waitingForCondition = () -> {
+            String className;
+            return thread.getState() == expectedAwaitState
+            && (className = blockerClassName(thread)) != null
+            && className.endsWith(conditionClassName);
+        };
+        waitForThreadToEnterWaitState(thread, waitingForCondition);
+
+        // politely release the waiter
+        conditionSatisfied.set(true);
+        lock.lock();
         try {
-            lock.writeLock().lock();
-            assertTrue(c.getWaitingThreads().isEmpty());
-            lock.writeLock().unlock();
-            t1.start();
-            Thread.sleep(SHORT_DELAY_MS);
-            t2.start();
-            Thread.sleep(SHORT_DELAY_MS);
-            lock.writeLock().lock();
-            assertTrue(c.hasWaiters());
-            assertTrue(c.getWaitingThreads().contains(t1));
-            assertTrue(c.getWaitingThreads().contains(t2));
-            c.signalAll();
-            lock.writeLock().unlock();
-            Thread.sleep(SHORT_DELAY_MS);
-            lock.writeLock().lock();
-            assertFalse(c.hasWaiters());
-            assertTrue(c.getWaitingThreads().isEmpty());
-            lock.writeLock().unlock();
-            t1.join(SHORT_DELAY_MS);
-            t2.join(SHORT_DELAY_MS);
-            assertFalse(t1.isAlive());
-            assertFalse(t2.isAlive());
-        }
-        catch (Exception ex) {
-            unexpectedException();
-        }
-    }
+            condition.signal();
+        } finally { lock.unlock(); }
 
+        awaitTermination(thread);
+    }
 }