public static void main(String[] args) throws Throwable { final ReentrantLock lock = new ReentrantLock(); lock.lock(); final ReentrantReadWriteLock rwlock = new ReentrantReadWriteLock(); final ReentrantReadWriteLock.ReadLock readLock = rwlock.readLock(); final ReentrantReadWriteLock.WriteLock writeLock = rwlock.writeLock(); rwlock.writeLock().lock(); final BlockingQueue<Object> q = new LinkedBlockingQueue<Object>(); final Semaphore fairSem = new Semaphore(0, true); final Semaphore unfairSem = new Semaphore(0, false); // final int threads = // rnd.nextInt(Runtime.getRuntime().availableProcessors() + 1) + 1; final int threads = 3; // On Linux, this test runs very slowly for some reason, // so use a smaller number of iterations. // Solaris can handle 1 << 18. // On the other hand, jmap is much slower on Solaris... final int iterations = 1 << 8; final CyclicBarrier cb = new CyclicBarrier(threads + 1); for (int i = 0; i < threads; i++) new Thread() { public void run() { try { final Random rnd = new Random(); for (int j = 0; j < iterations; j++) { if (j == iterations / 10 || j == iterations - 1) { cb.await(); // Quiesce cb.await(); // Resume } // int t = rnd.nextInt(2000); int t = rnd.nextInt(900); check(!lock.tryLock(t, NANOSECONDS)); check(!readLock.tryLock(t, NANOSECONDS)); check(!writeLock.tryLock(t, NANOSECONDS)); equal(null, q.poll(t, NANOSECONDS)); check(!fairSem.tryAcquire(t, NANOSECONDS)); check(!unfairSem.tryAcquire(t, NANOSECONDS)); } } catch (Throwable t) { unexpected(t); } } }.start(); cb.await(); // Quiesce rendezvousChild(); // Measure cb.await(); // Resume cb.await(); // Quiesce rendezvousChild(); // Measure cb.await(); // Resume System.exit(failed); }
final void test() throws Exception { Future[] futures = new Future[nthreads]; for (int i = 0; i < nthreads; ++i) futures[i] = pool.submit(this); barrier.await(); Thread.sleep(TIMEOUT); boolean tooLate = false; for (int i = 1; i < nthreads; ++i) { if (!futures[i].cancel(true)) tooLate = true; // Unbunch some of the cancels if ((i & 3) == 0) Thread.sleep(1 + rng.next() % 10); } Object f0 = futures[0].get(); if (!tooLate) { for (int i = 1; i < nthreads; ++i) { if (!futures[i].isDone() || !futures[i].isCancelled()) throw new Error("Only one thread should complete"); } } else System.out.print("(cancelled too late) "); long endTime = System.nanoTime(); long time = endTime - timer.startTime; if (print) { double secs = (double) (time) / 1000000000.0; System.out.println("\t " + secs + "s run time"); } }
public final Object call() throws Exception { barrier.await(); int sum = v; int x = 0; int n = ITERS; while (n-- > 0) { lock.lockInterruptibly(); try { v = x = LoopHelpers.compute1(v); } finally { lock.unlock(); } sum += LoopHelpers.compute2(LoopHelpers.compute2(x)); } return new Integer(sum); }