semaphoretest.java

来自「SRI international 发布的OAA框架软件」· Java 代码 · 共 927 行 · 第 1/3 页

    /**
     * hasQueuedThreads reports whether there are waiting threads
     */
    public void testHasQueuedThreads() {
//        final Semaphore lock = new Semaphore(1, false);
        final Semaphore lock = new Semaphore(1, true);
        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
        try {
            assertFalse(lock.hasQueuedThreads());
            lock.acquireUninterruptibly();
            t1.start();
            Thread.sleep(SHORT_DELAY_MS);
            assertTrue(lock.hasQueuedThreads());
            t2.start();
            Thread.sleep(SHORT_DELAY_MS);
            assertTrue(lock.hasQueuedThreads());
            t1.interrupt();
            Thread.sleep(SHORT_DELAY_MS);
            assertTrue(lock.hasQueuedThreads());
            lock.release();
            Thread.sleep(SHORT_DELAY_MS);
            assertFalse(lock.hasQueuedThreads());
            t1.join();
            t2.join();
        } catch(Exception e){
            e.printStackTrace();
            unexpectedException();
        }
    }

    /**
     * getQueueLength reports number of waiting threads
     */
    public void testGetQueueLength() {
//        final Semaphore lock = new Semaphore(1, false);
        final Semaphore lock = new Semaphore(1, true);
        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
        try {
            assertEquals(0, lock.getQueueLength());
            lock.acquireUninterruptibly();
            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.release();
            Thread.sleep(SHORT_DELAY_MS);
            assertEquals(0, lock.getQueueLength());
            t1.join();
            t2.join();
        } catch(Exception e){
            e.printStackTrace();
            unexpectedException();
        }
    }

    /**
     * getQueuedThreads includes waiting threads
     */
    public void testGetQueuedThreads() {
//	final PublicSemaphore lock = new PublicSemaphore(1, false);
        final PublicSemaphore lock = new PublicSemaphore(1, true);
        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
        try {
            assertTrue(lock.getQueuedThreads().isEmpty());
            lock.acquireUninterruptibly();
            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.release();
            Thread.sleep(SHORT_DELAY_MS);
            assertTrue(lock.getQueuedThreads().isEmpty());
            t1.join();
            t2.join();
        } catch(Exception e){
            e.printStackTrace();
            unexpectedException();
        }
    }

    /**
     * drainPermits reports and removes given number of permits
     */
    public void testDrainPermits() {
        Semaphore s = new Semaphore(0, false);
        assertEquals(0, s.availablePermits());
        assertEquals(0, s.drainPermits());
        s.release(10);
        assertEquals(10, s.availablePermits());
        assertEquals(10, s.drainPermits());
        assertEquals(0, s.availablePermits());
        assertEquals(0, s.drainPermits());
    }

    /**
     * reducePermits reduces number of permits
     */
    public void testReducePermits() {
        PublicSemaphore s = new PublicSemaphore(10, false);
        assertEquals(10, s.availablePermits());
        s.reducePermits(1);
        assertEquals(9, s.availablePermits());
        s.reducePermits(10);
        assertEquals(-1, s.availablePermits());
    }

    /**
     * a deserialized serialized semaphore has same number of permits
     */
    public void testSerialization() {
        Semaphore l = new Semaphore(3, false);
        try {
            l.acquire();
            l.release();
            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));
            Semaphore r = (Semaphore) in.readObject();
            assertEquals(3, r.availablePermits());
            assertFalse(r.isFair());
            r.acquire();
            r.release();
        } catch(Exception e){
            e.printStackTrace();
            unexpectedException();
        }
    }


    /**
     * Zero, negative, and positive initial values are allowed in constructor
     */
    public void testConstructor_fair() {
        Semaphore s0 = new Semaphore(0, true);
        assertEquals(0, s0.availablePermits());
        assertTrue(s0.isFair());
        Semaphore s1 = new Semaphore(-1, true);
        assertEquals(-1, s1.availablePermits());
        Semaphore s2 = new Semaphore(-1, true);
        assertEquals(-1, s2.availablePermits());
    }

    /**
     * tryAcquire succeeds when sufficient permits, else fails
     */
    public void testTryAcquireInSameThread_fair() {
        Semaphore s = new Semaphore(2, true);
        assertEquals(2, s.availablePermits());
        assertTrue(s.tryAcquire());
        assertTrue(s.tryAcquire());
        assertEquals(0, s.availablePermits());
        assertFalse(s.tryAcquire());
    }

//    /**
//     * tryAcquire(n) succeeds when sufficient permits, else fails
//     */
//    public void testTryAcquireNInSameThread_fair() {
//        Semaphore s = new Semaphore(2, true);
//        assertEquals(2, s.availablePermits());
//        assertTrue(s.tryAcquire(2));
//        assertEquals(0, s.availablePermits());
//        assertFalse(s.tryAcquire());
//    }
//
    /**
     * Acquire and release of semaphore succeed if initially available
     */
    public void testAcquireReleaseInSameThread_fair() {
        Semaphore s = new Semaphore(1, true);
        try {
            s.acquire();
            s.release();
            s.acquire();
            s.release();
            s.acquire();
            s.release();
            s.acquire();
            s.release();
            s.acquire();
            s.release();
            assertEquals(1, s.availablePermits());
        } catch( InterruptedException e){
            unexpectedException();
        }
    }

//    /**
//     * Acquire(n) and release(n) of semaphore succeed if initially available
//     */
//    public void testAcquireReleaseNInSameThread_fair() {
//        Semaphore s = new Semaphore(1, true);
//        try {
//            s.release(1);
//            s.acquire(1);
//            s.release(2);
//            s.acquire(2);
//            s.release(3);
//            s.acquire(3);
//            s.release(4);
//            s.acquire(4);
//            s.release(5);
//            s.acquire(5);
//            assertEquals(1, s.availablePermits());
//	} catch( InterruptedException e){
//            unexpectedException();
//        }
//    }

//    /**
//     * Acquire(n) and release(n) of semaphore succeed if initially available
//     */
//    public void testAcquireUninterruptiblyReleaseNInSameThread_fair() {
//        Semaphore s = new Semaphore(1, true);
//        try {
//            s.release(1);
//            s.acquireUninterruptibly(1);
//            s.release(2);
//            s.acquireUninterruptibly(2);
//            s.release(3);
//            s.acquireUninterruptibly(3);
//            s.release(4);
//            s.acquireUninterruptibly(4);
//            s.release(5);
//            s.acquireUninterruptibly(5);
//            assertEquals(1, s.availablePermits());
//	} finally {
//        }
//    }

//    /**
//     * release(n) in one thread enables timed acquire(n) in another thread
//     */
//    public void testTimedAcquireReleaseNInSameThread_fair() {
//        Semaphore s = new Semaphore(1, true);
//        try {
//            s.release(1);
//            assertTrue(s.tryAcquire(1, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
//            s.release(2);
//            assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
//            s.release(3);
//            assertTrue(s.tryAcquire(3, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
//            s.release(4);
//            assertTrue(s.tryAcquire(4, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
//            s.release(5);
//            assertTrue(s.tryAcquire(5, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
//            assertEquals(1, s.availablePermits());
//	} catch( InterruptedException e){
//            unexpectedException();
//        }
//    }

    /**
     * release in one thread enables timed acquire in another thread
     */
    public void testTimedAcquireReleaseInSameThread_fair() {
        Semaphore s = new Semaphore(1, true);
        try {
            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
            s.release();
            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
            s.release();
            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
            s.release();
            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
            s.release();
            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
            s.release();
            assertEquals(1, s.availablePermits());
        } catch( InterruptedException e){
            unexpectedException();
        }
    }

    /**
     * A release in one thread enables an acquire in another thread
     */
    public void testAcquireReleaseInDifferentThreads_fair() {
        final Semaphore s = new Semaphore(0, true);
        Thread t = new Thread(new Runnable() {
                public void run() {
                    try {
                        s.acquire();
                        s.acquire();
                        s.acquire();
                        s.acquire();
                    } catch(InterruptedException ie){
                        threadUnexpectedException();