public void untimed() { boolean captured = lock.tryLock(); try { System.out.println("tryLock(): " + captured); } finally { if (captured) lock.unlock(); } }
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); }
public void timed() { boolean captured = false; try { captured = lock.tryLock(2, TimeUnit.SECONDS); } catch (InterruptedException e) { throw new RuntimeException(e); } try { System.out.println("tryLock(2, TimeUnit.SECONDS): " + captured); } finally { if (captured) lock.unlock(); } }
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); }
/** * Cache preloader should call this method within partition lock. * * @param key Key. * @param ver Version. * @return {@code True} if preloading is permitted. */ public boolean preloadingPermitted(KeyCacheObject key, GridCacheVersion ver) { assert key != null; assert ver != null; assert lock.isHeldByCurrentThread(); // Only one thread can enter this method at a time. if (state() != MOVING) return false; Map<KeyCacheObject, GridCacheVersion> evictHist0 = evictHist; if (evictHist0 != null) { GridCacheVersion ver0 = evictHist0.get(key); // Permit preloading if version in history // is missing or less than passed in. return ver0 == null || ver0.isLess(ver); } return false; }
/** * @param key Key. * @param ver Version. */ public void onEntryEvicted(KeyCacheObject key, GridCacheVersion ver) { assert key != null; assert ver != null; assert lock.isHeldByCurrentThread(); // Only one thread can enter this method at a time. if (state() != MOVING) return; Map<KeyCacheObject, GridCacheVersion> evictHist0 = evictHist; if (evictHist0 != null) { GridCacheVersion ver0 = evictHist0.get(key); if (ver0 == null || ver0.isLess(ver)) { GridCacheVersion ver1 = evictHist0.put(key, ver); assert ver1 == ver0; } } }
/** Unlocks partition. */ public void unlock() { lock.unlock(); }
/** Locks partition. */ @SuppressWarnings({"LockAcquiredButNotSafelyReleased"}) public void lock() { lock.lock(); }