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/* |
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* Written by Doug Lea and Martin Buchholz |
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* with assistance from members of JCP JSR-166 Expert Group and |
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* released to the public domain, as explained at |
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* http://creativecommons.org/publicdomain/zero/1.0/ |
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*/ |
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|
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import static java.util.concurrent.TimeUnit.DAYS; |
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import static java.util.concurrent.TimeUnit.MILLISECONDS; |
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|
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import java.util.ArrayList; |
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import java.util.List; |
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import java.util.concurrent.CountDownLatch; |
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import java.util.concurrent.Future; |
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import java.util.concurrent.TimeUnit; |
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import java.util.concurrent.locks.Lock; |
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import java.util.concurrent.locks.StampedLock; |
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import java.util.function.BiConsumer; |
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import java.util.function.Function; |
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|
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import junit.framework.Test; |
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import junit.framework.TestSuite; |
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|
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public class StampedLockTest extends JSR166TestCase { |
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public static void main(String[] args) { |
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main(suite(), args); |
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} |
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public static Test suite() { |
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return new TestSuite(StampedLockTest.class); |
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} |
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|
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/** |
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* Releases write lock, checking isWriteLocked before and after |
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*/ |
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void releaseWriteLock(StampedLock lock, long stamp) { |
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assertTrue(lock.isWriteLocked()); |
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assertValid(lock, stamp); |
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lock.unlockWrite(stamp); |
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assertFalse(lock.isWriteLocked()); |
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assertFalse(lock.validate(stamp)); |
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} |
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|
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/** |
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* Releases read lock, checking isReadLocked before and after |
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*/ |
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void releaseReadLock(StampedLock lock, long stamp) { |
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assertTrue(lock.isReadLocked()); |
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assertValid(lock, stamp); |
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lock.unlockRead(stamp); |
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assertFalse(lock.isReadLocked()); |
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assertTrue(lock.validate(stamp)); |
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} |
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|
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long assertNonZero(long v) { |
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assertTrue(v != 0L); |
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return v; |
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} |
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|
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long assertValid(StampedLock lock, long stamp) { |
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assertTrue(stamp != 0L); |
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assertTrue(lock.validate(stamp)); |
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return stamp; |
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} |
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|
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void assertUnlocked(StampedLock lock) { |
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assertFalse(lock.isReadLocked()); |
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assertFalse(lock.isWriteLocked()); |
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assertEquals(0, lock.getReadLockCount()); |
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assertValid(lock, lock.tryOptimisticRead()); |
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} |
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|
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List<Action> lockLockers(Lock lock) { |
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List<Action> lockers = new ArrayList<>(); |
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lockers.add(() -> lock.lock()); |
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lockers.add(() -> lock.lockInterruptibly()); |
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lockers.add(() -> lock.tryLock()); |
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lockers.add(() -> lock.tryLock(Long.MIN_VALUE, DAYS)); |
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lockers.add(() -> lock.tryLock(0L, DAYS)); |
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lockers.add(() -> lock.tryLock(Long.MAX_VALUE, DAYS)); |
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return lockers; |
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} |
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|
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List<Function<StampedLock, Long>> readLockers() { |
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List<Function<StampedLock, Long>> readLockers = new ArrayList<>(); |
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readLockers.add(sl -> sl.readLock()); |
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readLockers.add(sl -> sl.tryReadLock()); |
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readLockers.add(sl -> readLockInterruptiblyUninterrupted(sl)); |
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readLockers.add(sl -> tryReadLockUninterrupted(sl, Long.MIN_VALUE, DAYS)); |
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readLockers.add(sl -> tryReadLockUninterrupted(sl, 0L, DAYS)); |
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readLockers.add(sl -> sl.tryConvertToReadLock(sl.tryOptimisticRead())); |
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return readLockers; |
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} |
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|
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List<BiConsumer<StampedLock, Long>> readUnlockers() { |
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List<BiConsumer<StampedLock, Long>> readUnlockers = new ArrayList<>(); |
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readUnlockers.add((sl, stamp) -> sl.unlockRead(stamp)); |
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readUnlockers.add((sl, stamp) -> assertTrue(sl.tryUnlockRead())); |
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readUnlockers.add((sl, stamp) -> sl.asReadLock().unlock()); |
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readUnlockers.add((sl, stamp) -> sl.unlock(stamp)); |
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readUnlockers.add((sl, stamp) -> assertValid(sl, sl.tryConvertToOptimisticRead(stamp))); |
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return readUnlockers; |
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} |
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|
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List<Function<StampedLock, Long>> writeLockers() { |
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List<Function<StampedLock, Long>> writeLockers = new ArrayList<>(); |
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writeLockers.add(sl -> sl.writeLock()); |
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writeLockers.add(sl -> sl.tryWriteLock()); |
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writeLockers.add(sl -> writeLockInterruptiblyUninterrupted(sl)); |
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writeLockers.add(sl -> tryWriteLockUninterrupted(sl, Long.MIN_VALUE, DAYS)); |
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writeLockers.add(sl -> tryWriteLockUninterrupted(sl, 0L, DAYS)); |
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writeLockers.add(sl -> sl.tryConvertToWriteLock(sl.tryOptimisticRead())); |
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return writeLockers; |
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} |
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|
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List<BiConsumer<StampedLock, Long>> writeUnlockers() { |
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List<BiConsumer<StampedLock, Long>> writeUnlockers = new ArrayList<>(); |
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writeUnlockers.add((sl, stamp) -> sl.unlockWrite(stamp)); |
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writeUnlockers.add((sl, stamp) -> assertTrue(sl.tryUnlockWrite())); |
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writeUnlockers.add((sl, stamp) -> sl.asWriteLock().unlock()); |
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writeUnlockers.add((sl, stamp) -> sl.unlock(stamp)); |
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writeUnlockers.add((sl, stamp) -> assertValid(sl, sl.tryConvertToOptimisticRead(stamp))); |
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return writeUnlockers; |
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} |
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|
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/** |
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* Constructed StampedLock is in unlocked state |
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*/ |
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public void testConstructor() { |
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assertUnlocked(new StampedLock()); |
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} |
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|
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/** |
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* write-locking, then unlocking, an unlocked lock succeed |
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*/ |
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public void testWriteLock_lockUnlock() { |
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StampedLock lock = new StampedLock(); |
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|
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for (Function<StampedLock, Long> writeLocker : writeLockers()) |
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for (BiConsumer<StampedLock, Long> writeUnlocker : writeUnlockers()) { |
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assertFalse(lock.isWriteLocked()); |
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assertFalse(lock.isReadLocked()); |
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assertEquals(0, lock.getReadLockCount()); |
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|
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long s = writeLocker.apply(lock); |
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assertValid(lock, s); |
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assertTrue(lock.isWriteLocked()); |
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assertFalse(lock.isReadLocked()); |
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assertEquals(0, lock.getReadLockCount()); |
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writeUnlocker.accept(lock, s); |
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assertUnlocked(lock); |
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} |
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} |
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|
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/** |
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* read-locking, then unlocking, an unlocked lock succeed |
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*/ |
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public void testReadLock_lockUnlock() { |
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StampedLock lock = new StampedLock(); |
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|
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for (Function<StampedLock, Long> readLocker : readLockers()) |
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for (BiConsumer<StampedLock, Long> readUnlocker : readUnlockers()) { |
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long s = 42; |
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for (int i = 0; i < 2; i++) { |
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s = assertValid(lock, readLocker.apply(lock)); |
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assertFalse(lock.isWriteLocked()); |
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assertTrue(lock.isReadLocked()); |
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assertEquals(i + 1, lock.getReadLockCount()); |
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} |
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for (int i = 0; i < 2; i++) { |
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assertFalse(lock.isWriteLocked()); |
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assertTrue(lock.isReadLocked()); |
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assertEquals(2 - i, lock.getReadLockCount()); |
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readUnlocker.accept(lock, s); |
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} |
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assertUnlocked(lock); |
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} |
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} |
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|
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/** |
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* tryUnlockWrite fails if not write locked |
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*/ |
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public void testTryUnlockWrite_failure() { |
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StampedLock lock = new StampedLock(); |
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assertFalse(lock.tryUnlockWrite()); |
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|
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for (Function<StampedLock, Long> readLocker : readLockers()) |
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for (BiConsumer<StampedLock, Long> readUnlocker : readUnlockers()) { |
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long s = assertValid(lock, readLocker.apply(lock)); |
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assertFalse(lock.tryUnlockWrite()); |
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assertTrue(lock.isReadLocked()); |
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readUnlocker.accept(lock, s); |
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assertUnlocked(lock); |
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} |
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} |
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|
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/** |
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* tryUnlockRead fails if not read locked |
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*/ |
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public void testTryUnlockRead_failure() { |
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StampedLock lock = new StampedLock(); |
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assertFalse(lock.tryUnlockRead()); |
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|
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for (Function<StampedLock, Long> writeLocker : writeLockers()) |
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for (BiConsumer<StampedLock, Long> writeUnlocker : writeUnlockers()) { |
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long s = writeLocker.apply(lock); |
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assertFalse(lock.tryUnlockRead()); |
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assertTrue(lock.isWriteLocked()); |
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writeUnlocker.accept(lock, s); |
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assertUnlocked(lock); |
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} |
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} |
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|
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/** |
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* validate(0L) fails |
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*/ |
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public void testValidate0() { |
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StampedLock lock = new StampedLock(); |
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assertFalse(lock.validate(0L)); |
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} |
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|
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/** |
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* A stamp obtained from a successful lock operation validates while the lock is held |
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*/ |
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public void testValidate() throws InterruptedException { |
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StampedLock lock = new StampedLock(); |
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|
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for (Function<StampedLock, Long> readLocker : readLockers()) |
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for (BiConsumer<StampedLock, Long> readUnlocker : readUnlockers()) { |
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long s = assertNonZero(readLocker.apply(lock)); |
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assertTrue(lock.validate(s)); |
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readUnlocker.accept(lock, s); |
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} |
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|
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for (Function<StampedLock, Long> writeLocker : writeLockers()) |
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for (BiConsumer<StampedLock, Long> writeUnlocker : writeUnlockers()) { |
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long s = assertNonZero(writeLocker.apply(lock)); |
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assertTrue(lock.validate(s)); |
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writeUnlocker.accept(lock, s); |
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} |
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} |
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|
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/** |
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* A stamp obtained from an unsuccessful lock operation does not validate |
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*/ |
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public void testValidate2() throws InterruptedException { |
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StampedLock lock = new StampedLock(); |
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long s = assertNonZero(lock.writeLock()); |
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assertTrue(lock.validate(s)); |
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assertFalse(lock.validate(lock.tryWriteLock())); |
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assertFalse(lock.validate(lock.tryWriteLock(randomExpiredTimeout(), |
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randomTimeUnit()))); |
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assertFalse(lock.validate(lock.tryReadLock())); |
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assertFalse(lock.validate(lock.tryWriteLock(randomExpiredTimeout(), |
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randomTimeUnit()))); |
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assertFalse(lock.validate(lock.tryOptimisticRead())); |
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lock.unlockWrite(s); |
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} |
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|
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void assertThrowInterruptedExceptionWhenPreInterrupted(Action[] actions) { |
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for (Action action : actions) { |
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Thread.currentThread().interrupt(); |
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try { |
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action.run(); |
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shouldThrow(); |
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} |
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catch (InterruptedException success) {} |
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catch (Throwable fail) { threadUnexpectedException(fail); } |
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assertFalse(Thread.interrupted()); |
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} |
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} |
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|
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/** |
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* interruptible operations throw InterruptedException when pre-interrupted |
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*/ |
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public void testInterruptibleOperationsThrowInterruptedExceptionWhenPreInterrupted() { |
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final StampedLock lock = new StampedLock(); |
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|
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Action[] interruptibleLockActions = { |
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() -> lock.writeLockInterruptibly(), |
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() -> lock.tryWriteLock(Long.MIN_VALUE, DAYS), |
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() -> lock.tryWriteLock(Long.MAX_VALUE, DAYS), |
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() -> lock.readLockInterruptibly(), |
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() -> lock.tryReadLock(Long.MIN_VALUE, DAYS), |
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() -> lock.tryReadLock(Long.MAX_VALUE, DAYS), |
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() -> lock.asWriteLock().lockInterruptibly(), |
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() -> lock.asWriteLock().tryLock(0L, DAYS), |
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() -> lock.asWriteLock().tryLock(Long.MAX_VALUE, DAYS), |
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() -> lock.asReadLock().lockInterruptibly(), |
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() -> lock.asReadLock().tryLock(0L, DAYS), |
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() -> lock.asReadLock().tryLock(Long.MAX_VALUE, DAYS), |
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}; |
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shuffle(interruptibleLockActions); |
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|
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assertThrowInterruptedExceptionWhenPreInterrupted(interruptibleLockActions); |
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{ |
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long s = lock.writeLock(); |
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assertThrowInterruptedExceptionWhenPreInterrupted(interruptibleLockActions); |
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lock.unlockWrite(s); |
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} |
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{ |
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long s = lock.readLock(); |
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assertThrowInterruptedExceptionWhenPreInterrupted(interruptibleLockActions); |
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lock.unlockRead(s); |
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} |
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} |
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|
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void assertThrowInterruptedExceptionWhenInterrupted(Action[] actions) { |
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int n = actions.length; |
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Future<?>[] futures = new Future<?>[n]; |
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CountDownLatch threadsStarted = new CountDownLatch(n); |
311 |
CountDownLatch done = new CountDownLatch(n); |
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|
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for (int i = 0; i < n; i++) { |
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Action action = actions[i]; |
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futures[i] = cachedThreadPool.submit(new CheckedRunnable() { |
316 |
public void realRun() throws Throwable { |
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threadsStarted.countDown(); |
318 |
try { |
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action.run(); |
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shouldThrow(); |
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} |
322 |
catch (InterruptedException success) {} |
323 |
catch (Throwable fail) { threadUnexpectedException(fail); } |
324 |
assertFalse(Thread.interrupted()); |
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done.countDown(); |
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}}); |
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} |
328 |
|
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await(threadsStarted); |
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assertEquals(n, done.getCount()); |
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for (Future<?> future : futures) // Interrupt all the tasks |
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future.cancel(true); |
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await(done); |
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} |
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|
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/** |
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* interruptible operations throw InterruptedException when write locked and interrupted |
338 |
*/ |
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public void testInterruptibleOperationsThrowInterruptedExceptionWriteLockedInterrupted() { |
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final StampedLock lock = new StampedLock(); |
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long s = lock.writeLock(); |
342 |
|
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Action[] interruptibleLockBlockingActions = { |
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() -> lock.writeLockInterruptibly(), |
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() -> lock.tryWriteLock(Long.MAX_VALUE, DAYS), |
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() -> lock.readLockInterruptibly(), |
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() -> lock.tryReadLock(Long.MAX_VALUE, DAYS), |
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() -> lock.asWriteLock().lockInterruptibly(), |
349 |
() -> lock.asWriteLock().tryLock(Long.MAX_VALUE, DAYS), |
350 |
() -> lock.asReadLock().lockInterruptibly(), |
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() -> lock.asReadLock().tryLock(Long.MAX_VALUE, DAYS), |
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}; |
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shuffle(interruptibleLockBlockingActions); |
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|
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assertThrowInterruptedExceptionWhenInterrupted(interruptibleLockBlockingActions); |
356 |
} |
357 |
|
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/** |
359 |
* interruptible operations throw InterruptedException when read locked and interrupted |
360 |
*/ |
361 |
public void testInterruptibleOperationsThrowInterruptedExceptionReadLockedInterrupted() { |
362 |
final StampedLock lock = new StampedLock(); |
363 |
long s = lock.readLock(); |
364 |
|
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Action[] interruptibleLockBlockingActions = { |
366 |
() -> lock.writeLockInterruptibly(), |
367 |
() -> lock.tryWriteLock(Long.MAX_VALUE, DAYS), |
368 |
() -> lock.asWriteLock().lockInterruptibly(), |
369 |
() -> lock.asWriteLock().tryLock(Long.MAX_VALUE, DAYS), |
370 |
}; |
371 |
shuffle(interruptibleLockBlockingActions); |
372 |
|
373 |
assertThrowInterruptedExceptionWhenInterrupted(interruptibleLockBlockingActions); |
374 |
} |
375 |
|
376 |
/** |
377 |
* Non-interruptible operations ignore and preserve interrupt status |
378 |
*/ |
379 |
public void testNonInterruptibleOperationsIgnoreInterrupts() { |
380 |
final StampedLock lock = new StampedLock(); |
381 |
Thread.currentThread().interrupt(); |
382 |
|
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for (BiConsumer<StampedLock, Long> readUnlocker : readUnlockers()) { |
384 |
long s = assertValid(lock, lock.readLock()); |
385 |
readUnlocker.accept(lock, s); |
386 |
s = assertValid(lock, lock.tryReadLock()); |
387 |
readUnlocker.accept(lock, s); |
388 |
} |
389 |
|
390 |
lock.asReadLock().lock(); |
391 |
lock.asReadLock().unlock(); |
392 |
|
393 |
for (BiConsumer<StampedLock, Long> writeUnlocker : writeUnlockers()) { |
394 |
long s = assertValid(lock, lock.writeLock()); |
395 |
writeUnlocker.accept(lock, s); |
396 |
s = assertValid(lock, lock.tryWriteLock()); |
397 |
writeUnlocker.accept(lock, s); |
398 |
} |
399 |
|
400 |
lock.asWriteLock().lock(); |
401 |
lock.asWriteLock().unlock(); |
402 |
|
403 |
assertTrue(Thread.interrupted()); |
404 |
} |
405 |
|
406 |
/** |
407 |
* tryWriteLock on an unlocked lock succeeds |
408 |
*/ |
409 |
public void testTryWriteLock() { |
410 |
final StampedLock lock = new StampedLock(); |
411 |
long s = lock.tryWriteLock(); |
412 |
assertTrue(s != 0L); |
413 |
assertTrue(lock.isWriteLocked()); |
414 |
assertEquals(0L, lock.tryWriteLock()); |
415 |
releaseWriteLock(lock, s); |
416 |
} |
417 |
|
418 |
/** |
419 |
* tryWriteLock fails if locked |
420 |
*/ |
421 |
public void testTryWriteLockWhenLocked() { |
422 |
final StampedLock lock = new StampedLock(); |
423 |
long s = lock.writeLock(); |
424 |
Thread t = newStartedThread(new CheckedRunnable() { |
425 |
public void realRun() { |
426 |
assertEquals(0L, lock.tryWriteLock()); |
427 |
}}); |
428 |
|
429 |
assertEquals(0L, lock.tryWriteLock()); |
430 |
awaitTermination(t); |
431 |
releaseWriteLock(lock, s); |
432 |
} |
433 |
|
434 |
/** |
435 |
* tryReadLock fails if write-locked |
436 |
*/ |
437 |
public void testTryReadLockWhenLocked() { |
438 |
final StampedLock lock = new StampedLock(); |
439 |
long s = lock.writeLock(); |
440 |
Thread t = newStartedThread(new CheckedRunnable() { |
441 |
public void realRun() { |
442 |
assertEquals(0L, lock.tryReadLock()); |
443 |
}}); |
444 |
|
445 |
assertEquals(0L, lock.tryReadLock()); |
446 |
awaitTermination(t); |
447 |
releaseWriteLock(lock, s); |
448 |
} |
449 |
|
450 |
/** |
451 |
* Multiple threads can hold a read lock when not write-locked |
452 |
*/ |
453 |
public void testMultipleReadLocks() { |
454 |
final StampedLock lock = new StampedLock(); |
455 |
final long s = lock.readLock(); |
456 |
Thread t = newStartedThread(new CheckedRunnable() { |
457 |
public void realRun() throws InterruptedException { |
458 |
long s2 = lock.tryReadLock(); |
459 |
assertValid(lock, s2); |
460 |
lock.unlockRead(s2); |
461 |
long s3 = lock.tryReadLock(LONG_DELAY_MS, MILLISECONDS); |
462 |
assertValid(lock, s3); |
463 |
lock.unlockRead(s3); |
464 |
long s4 = lock.readLock(); |
465 |
assertValid(lock, s4); |
466 |
lock.unlockRead(s4); |
467 |
lock.asReadLock().lock(); |
468 |
lock.asReadLock().unlock(); |
469 |
lock.asReadLock().lockInterruptibly(); |
470 |
lock.asReadLock().unlock(); |
471 |
lock.asReadLock().tryLock(Long.MIN_VALUE, DAYS); |
472 |
lock.asReadLock().unlock(); |
473 |
}}); |
474 |
|
475 |
awaitTermination(t); |
476 |
lock.unlockRead(s); |
477 |
} |
478 |
|
479 |
/** |
480 |
* writeLock() succeeds only after a reading thread unlocks |
481 |
*/ |
482 |
public void testWriteAfterReadLock() throws InterruptedException { |
483 |
final CountDownLatch aboutToLock = new CountDownLatch(1); |
484 |
final StampedLock lock = new StampedLock(); |
485 |
long rs = lock.readLock(); |
486 |
Thread t = newStartedThread(new CheckedRunnable() { |
487 |
public void realRun() { |
488 |
aboutToLock.countDown(); |
489 |
long s = lock.writeLock(); |
490 |
assertTrue(lock.isWriteLocked()); |
491 |
assertFalse(lock.isReadLocked()); |
492 |
lock.unlockWrite(s); |
493 |
}}); |
494 |
|
495 |
await(aboutToLock); |
496 |
assertThreadBlocks(t, Thread.State.WAITING); |
497 |
assertFalse(lock.isWriteLocked()); |
498 |
assertTrue(lock.isReadLocked()); |
499 |
lock.unlockRead(rs); |
500 |
awaitTermination(t); |
501 |
assertUnlocked(lock); |
502 |
} |
503 |
|
504 |
/** |
505 |
* writeLock() succeeds only after reading threads unlock |
506 |
*/ |
507 |
public void testWriteAfterMultipleReadLocks() { |
508 |
final StampedLock lock = new StampedLock(); |
509 |
long s = lock.readLock(); |
510 |
Thread t1 = newStartedThread(new CheckedRunnable() { |
511 |
public void realRun() { |
512 |
long rs = lock.readLock(); |
513 |
lock.unlockRead(rs); |
514 |
}}); |
515 |
|
516 |
awaitTermination(t1); |
517 |
|
518 |
Thread t2 = newStartedThread(new CheckedRunnable() { |
519 |
public void realRun() { |
520 |
long ws = lock.writeLock(); |
521 |
lock.unlockWrite(ws); |
522 |
}}); |
523 |
|
524 |
assertTrue(lock.isReadLocked()); |
525 |
assertFalse(lock.isWriteLocked()); |
526 |
lock.unlockRead(s); |
527 |
awaitTermination(t2); |
528 |
assertUnlocked(lock); |
529 |
} |
530 |
|
531 |
/** |
532 |
* readLock() succeed only after a writing thread unlocks |
533 |
*/ |
534 |
public void testReadAfterWriteLock() { |
535 |
final StampedLock lock = new StampedLock(); |
536 |
final CountDownLatch threadsStarted = new CountDownLatch(2); |
537 |
final long s = lock.writeLock(); |
538 |
final Runnable acquireReleaseReadLock = new CheckedRunnable() { |
539 |
public void realRun() { |
540 |
threadsStarted.countDown(); |
541 |
long rs = lock.readLock(); |
542 |
assertTrue(lock.isReadLocked()); |
543 |
assertFalse(lock.isWriteLocked()); |
544 |
lock.unlockRead(rs); |
545 |
}}; |
546 |
Thread t1 = newStartedThread(acquireReleaseReadLock); |
547 |
Thread t2 = newStartedThread(acquireReleaseReadLock); |
548 |
|
549 |
await(threadsStarted); |
550 |
assertThreadBlocks(t1, Thread.State.WAITING); |
551 |
assertThreadBlocks(t2, Thread.State.WAITING); |
552 |
assertTrue(lock.isWriteLocked()); |
553 |
assertFalse(lock.isReadLocked()); |
554 |
releaseWriteLock(lock, s); |
555 |
awaitTermination(t1); |
556 |
awaitTermination(t2); |
557 |
assertUnlocked(lock); |
558 |
} |
559 |
|
560 |
/** |
561 |
* tryReadLock succeeds if read locked but not write locked |
562 |
*/ |
563 |
public void testTryLockWhenReadLocked() { |
564 |
final StampedLock lock = new StampedLock(); |
565 |
long s = lock.readLock(); |
566 |
Thread t = newStartedThread(new CheckedRunnable() { |
567 |
public void realRun() { |
568 |
long rs = lock.tryReadLock(); |
569 |
assertValid(lock, rs); |
570 |
lock.unlockRead(rs); |
571 |
}}); |
572 |
|
573 |
awaitTermination(t); |
574 |
lock.unlockRead(s); |
575 |
} |
576 |
|
577 |
/** |
578 |
* tryWriteLock fails when read locked |
579 |
*/ |
580 |
public void testTryWriteLockWhenReadLocked() { |
581 |
final StampedLock lock = new StampedLock(); |
582 |
long s = lock.readLock(); |
583 |
Thread t = newStartedThread(new CheckedRunnable() { |
584 |
public void realRun() { |
585 |
threadAssertEquals(0L, lock.tryWriteLock()); |
586 |
}}); |
587 |
|
588 |
awaitTermination(t); |
589 |
lock.unlockRead(s); |
590 |
} |
591 |
|
592 |
/** |
593 |
* timed lock operations time out if lock not available |
594 |
*/ |
595 |
public void testTimedLock_Timeout() throws Exception { |
596 |
ArrayList<Future<?>> futures = new ArrayList<>(); |
597 |
|
598 |
// Write locked |
599 |
final StampedLock lock = new StampedLock(); |
600 |
long stamp = lock.writeLock(); |
601 |
assertEquals(0L, lock.tryReadLock(0L, DAYS)); |
602 |
assertEquals(0L, lock.tryReadLock(Long.MIN_VALUE, DAYS)); |
603 |
assertFalse(lock.asReadLock().tryLock(0L, DAYS)); |
604 |
assertFalse(lock.asReadLock().tryLock(Long.MIN_VALUE, DAYS)); |
605 |
assertEquals(0L, lock.tryWriteLock(0L, DAYS)); |
606 |
assertEquals(0L, lock.tryWriteLock(Long.MIN_VALUE, DAYS)); |
607 |
assertFalse(lock.asWriteLock().tryLock(0L, DAYS)); |
608 |
assertFalse(lock.asWriteLock().tryLock(Long.MIN_VALUE, DAYS)); |
609 |
|
610 |
futures.add(cachedThreadPool.submit(new CheckedRunnable() { |
611 |
public void realRun() throws InterruptedException { |
612 |
long startTime = System.nanoTime(); |
613 |
assertEquals(0L, lock.tryWriteLock(timeoutMillis(), MILLISECONDS)); |
614 |
assertTrue(millisElapsedSince(startTime) >= timeoutMillis()); |
615 |
}})); |
616 |
|
617 |
futures.add(cachedThreadPool.submit(new CheckedRunnable() { |
618 |
public void realRun() throws InterruptedException { |
619 |
long startTime = System.nanoTime(); |
620 |
assertEquals(0L, lock.tryReadLock(timeoutMillis(), MILLISECONDS)); |
621 |
assertTrue(millisElapsedSince(startTime) >= timeoutMillis()); |
622 |
}})); |
623 |
|
624 |
// Read locked |
625 |
final StampedLock lock2 = new StampedLock(); |
626 |
long stamp2 = lock2.readLock(); |
627 |
assertEquals(0L, lock2.tryWriteLock(0L, DAYS)); |
628 |
assertEquals(0L, lock2.tryWriteLock(Long.MIN_VALUE, DAYS)); |
629 |
assertFalse(lock2.asWriteLock().tryLock(0L, DAYS)); |
630 |
assertFalse(lock2.asWriteLock().tryLock(Long.MIN_VALUE, DAYS)); |
631 |
|
632 |
futures.add(cachedThreadPool.submit(new CheckedRunnable() { |
633 |
public void realRun() throws InterruptedException { |
634 |
long startTime = System.nanoTime(); |
635 |
assertEquals(0L, lock2.tryWriteLock(timeoutMillis(), MILLISECONDS)); |
636 |
assertTrue(millisElapsedSince(startTime) >= timeoutMillis()); |
637 |
}})); |
638 |
|
639 |
for (Future<?> future : futures) |
640 |
assertNull(future.get()); |
641 |
|
642 |
releaseWriteLock(lock, stamp); |
643 |
releaseReadLock(lock2, stamp2); |
644 |
} |
645 |
|
646 |
/** |
647 |
* writeLockInterruptibly succeeds if unlocked |
648 |
*/ |
649 |
public void testWriteLockInterruptibly() throws InterruptedException { |
650 |
final StampedLock lock = new StampedLock(); |
651 |
long s = lock.writeLockInterruptibly(); |
652 |
assertTrue(lock.isWriteLocked()); |
653 |
releaseWriteLock(lock, s); |
654 |
} |
655 |
|
656 |
/** |
657 |
* readLockInterruptibly succeeds if lock free |
658 |
*/ |
659 |
public void testReadLockInterruptibly() throws InterruptedException { |
660 |
final StampedLock lock = new StampedLock(); |
661 |
|
662 |
long s = assertValid(lock, lock.readLockInterruptibly()); |
663 |
assertTrue(lock.isReadLocked()); |
664 |
lock.unlockRead(s); |
665 |
|
666 |
lock.asReadLock().lockInterruptibly(); |
667 |
assertTrue(lock.isReadLocked()); |
668 |
lock.asReadLock().unlock(); |
669 |
} |
670 |
|
671 |
/** |
672 |
* A serialized lock deserializes as unlocked |
673 |
*/ |
674 |
public void testSerialization() { |
675 |
StampedLock lock = new StampedLock(); |
676 |
lock.writeLock(); |
677 |
StampedLock clone = serialClone(lock); |
678 |
assertTrue(lock.isWriteLocked()); |
679 |
assertFalse(clone.isWriteLocked()); |
680 |
long s = clone.writeLock(); |
681 |
assertTrue(clone.isWriteLocked()); |
682 |
clone.unlockWrite(s); |
683 |
assertFalse(clone.isWriteLocked()); |
684 |
} |
685 |
|
686 |
/** |
687 |
* toString indicates current lock state |
688 |
*/ |
689 |
public void testToString() { |
690 |
StampedLock lock = new StampedLock(); |
691 |
assertTrue(lock.toString().contains("Unlocked")); |
692 |
long s = lock.writeLock(); |
693 |
assertTrue(lock.toString().contains("Write-locked")); |
694 |
lock.unlockWrite(s); |
695 |
s = lock.readLock(); |
696 |
assertTrue(lock.toString().contains("Read-locks")); |
697 |
} |
698 |
|
699 |
/** |
700 |
* tryOptimisticRead succeeds and validates if unlocked, fails if |
701 |
* exclusively locked |
702 |
*/ |
703 |
public void testValidateOptimistic() throws InterruptedException { |
704 |
StampedLock lock = new StampedLock(); |
705 |
|
706 |
assertValid(lock, lock.tryOptimisticRead()); |
707 |
|
708 |
for (Function<StampedLock, Long> writeLocker : writeLockers()) { |
709 |
long s = assertValid(lock, writeLocker.apply(lock)); |
710 |
assertEquals(0L, lock.tryOptimisticRead()); |
711 |
releaseWriteLock(lock, s); |
712 |
} |
713 |
|
714 |
for (Function<StampedLock, Long> readLocker : readLockers()) { |
715 |
long s = assertValid(lock, readLocker.apply(lock)); |
716 |
long p = assertValid(lock, lock.tryOptimisticRead()); |
717 |
releaseReadLock(lock, s); |
718 |
assertTrue(lock.validate(p)); |
719 |
} |
720 |
|
721 |
assertValid(lock, lock.tryOptimisticRead()); |
722 |
} |
723 |
|
724 |
/** |
725 |
* tryOptimisticRead stamp does not validate if a write lock intervenes |
726 |
*/ |
727 |
public void testValidateOptimisticWriteLocked() { |
728 |
final StampedLock lock = new StampedLock(); |
729 |
final long p = assertValid(lock, lock.tryOptimisticRead()); |
730 |
final long s = assertValid(lock, lock.writeLock()); |
731 |
assertFalse(lock.validate(p)); |
732 |
assertEquals(0L, lock.tryOptimisticRead()); |
733 |
assertTrue(lock.validate(s)); |
734 |
lock.unlockWrite(s); |
735 |
} |
736 |
|
737 |
/** |
738 |
* tryOptimisticRead stamp does not validate if a write lock |
739 |
* intervenes in another thread |
740 |
*/ |
741 |
public void testValidateOptimisticWriteLocked2() |
742 |
throws InterruptedException { |
743 |
final CountDownLatch locked = new CountDownLatch(1); |
744 |
final StampedLock lock = new StampedLock(); |
745 |
final long p = assertValid(lock, lock.tryOptimisticRead()); |
746 |
|
747 |
Thread t = newStartedThread(new CheckedInterruptedRunnable() { |
748 |
public void realRun() throws InterruptedException { |
749 |
lock.writeLockInterruptibly(); |
750 |
locked.countDown(); |
751 |
lock.writeLockInterruptibly(); |
752 |
}}); |
753 |
|
754 |
await(locked); |
755 |
assertFalse(lock.validate(p)); |
756 |
assertEquals(0L, lock.tryOptimisticRead()); |
757 |
assertThreadBlocks(t, Thread.State.WAITING); |
758 |
t.interrupt(); |
759 |
awaitTermination(t); |
760 |
assertTrue(lock.isWriteLocked()); |
761 |
} |
762 |
|
763 |
/** |
764 |
* tryConvertToOptimisticRead succeeds and validates if successfully locked |
765 |
*/ |
766 |
public void testTryConvertToOptimisticRead() throws InterruptedException { |
767 |
StampedLock lock = new StampedLock(); |
768 |
long s, p, q; |
769 |
assertEquals(0L, lock.tryConvertToOptimisticRead(0L)); |
770 |
|
771 |
s = assertValid(lock, lock.tryOptimisticRead()); |
772 |
assertEquals(s, lock.tryConvertToOptimisticRead(s)); |
773 |
assertTrue(lock.validate(s)); |
774 |
|
775 |
for (Function<StampedLock, Long> writeLocker : writeLockers()) { |
776 |
s = assertValid(lock, writeLocker.apply(lock)); |
777 |
p = assertValid(lock, lock.tryConvertToOptimisticRead(s)); |
778 |
assertFalse(lock.validate(s)); |
779 |
assertTrue(lock.validate(p)); |
780 |
assertUnlocked(lock); |
781 |
} |
782 |
|
783 |
for (Function<StampedLock, Long> readLocker : readLockers()) { |
784 |
s = assertValid(lock, readLocker.apply(lock)); |
785 |
q = assertValid(lock, lock.tryOptimisticRead()); |
786 |
assertEquals(q, lock.tryConvertToOptimisticRead(q)); |
787 |
assertTrue(lock.validate(q)); |
788 |
assertTrue(lock.isReadLocked()); |
789 |
p = assertValid(lock, lock.tryConvertToOptimisticRead(s)); |
790 |
assertTrue(lock.validate(p)); |
791 |
assertTrue(lock.validate(s)); |
792 |
assertUnlocked(lock); |
793 |
assertEquals(q, lock.tryConvertToOptimisticRead(q)); |
794 |
assertTrue(lock.validate(q)); |
795 |
} |
796 |
} |
797 |
|
798 |
/** |
799 |
* tryConvertToReadLock succeeds for valid stamps |
800 |
*/ |
801 |
public void testTryConvertToReadLock() throws InterruptedException { |
802 |
StampedLock lock = new StampedLock(); |
803 |
long s, p; |
804 |
|
805 |
assertEquals(0L, lock.tryConvertToReadLock(0L)); |
806 |
|
807 |
s = assertValid(lock, lock.tryOptimisticRead()); |
808 |
p = assertValid(lock, lock.tryConvertToReadLock(s)); |
809 |
assertTrue(lock.isReadLocked()); |
810 |
assertEquals(1, lock.getReadLockCount()); |
811 |
assertTrue(lock.validate(s)); |
812 |
lock.unlockRead(p); |
813 |
|
814 |
s = assertValid(lock, lock.tryOptimisticRead()); |
815 |
lock.readLock(); |
816 |
p = assertValid(lock, lock.tryConvertToReadLock(s)); |
817 |
assertTrue(lock.isReadLocked()); |
818 |
assertEquals(2, lock.getReadLockCount()); |
819 |
lock.unlockRead(p); |
820 |
lock.unlockRead(p); |
821 |
assertUnlocked(lock); |
822 |
|
823 |
for (BiConsumer<StampedLock, Long> readUnlocker : readUnlockers()) { |
824 |
for (Function<StampedLock, Long> writeLocker : writeLockers()) { |
825 |
s = assertValid(lock, writeLocker.apply(lock)); |
826 |
p = assertValid(lock, lock.tryConvertToReadLock(s)); |
827 |
assertFalse(lock.validate(s)); |
828 |
assertTrue(lock.isReadLocked()); |
829 |
assertEquals(1, lock.getReadLockCount()); |
830 |
readUnlocker.accept(lock, p); |
831 |
} |
832 |
|
833 |
for (Function<StampedLock, Long> readLocker : readLockers()) { |
834 |
s = assertValid(lock, readLocker.apply(lock)); |
835 |
assertEquals(s, lock.tryConvertToReadLock(s)); |
836 |
assertTrue(lock.validate(s)); |
837 |
assertTrue(lock.isReadLocked()); |
838 |
assertEquals(1, lock.getReadLockCount()); |
839 |
readUnlocker.accept(lock, s); |
840 |
} |
841 |
} |
842 |
} |
843 |
|
844 |
/** |
845 |
* tryConvertToWriteLock succeeds if lock available; fails if multiply read locked |
846 |
*/ |
847 |
public void testTryConvertToWriteLock() throws InterruptedException { |
848 |
StampedLock lock = new StampedLock(); |
849 |
long s, p; |
850 |
|
851 |
assertEquals(0L, lock.tryConvertToWriteLock(0L)); |
852 |
|
853 |
assertTrue((s = lock.tryOptimisticRead()) != 0L); |
854 |
assertTrue((p = lock.tryConvertToWriteLock(s)) != 0L); |
855 |
assertTrue(lock.isWriteLocked()); |
856 |
lock.unlockWrite(p); |
857 |
|
858 |
for (BiConsumer<StampedLock, Long> writeUnlocker : writeUnlockers()) { |
859 |
for (Function<StampedLock, Long> writeLocker : writeLockers()) { |
860 |
s = assertValid(lock, writeLocker.apply(lock)); |
861 |
assertEquals(s, lock.tryConvertToWriteLock(s)); |
862 |
assertTrue(lock.validate(s)); |
863 |
assertTrue(lock.isWriteLocked()); |
864 |
writeUnlocker.accept(lock, s); |
865 |
} |
866 |
|
867 |
for (Function<StampedLock, Long> readLocker : readLockers()) { |
868 |
s = assertValid(lock, readLocker.apply(lock)); |
869 |
p = assertValid(lock, lock.tryConvertToWriteLock(s)); |
870 |
assertFalse(lock.validate(s)); |
871 |
assertTrue(lock.validate(p)); |
872 |
assertTrue(lock.isWriteLocked()); |
873 |
writeUnlocker.accept(lock, p); |
874 |
} |
875 |
} |
876 |
|
877 |
// failure if multiply read locked |
878 |
for (Function<StampedLock, Long> readLocker : readLockers()) { |
879 |
s = assertValid(lock, readLocker.apply(lock)); |
880 |
p = assertValid(lock, readLocker.apply(lock)); |
881 |
assertEquals(0L, lock.tryConvertToWriteLock(s)); |
882 |
assertTrue(lock.validate(s)); |
883 |
assertTrue(lock.validate(p)); |
884 |
assertEquals(2, lock.getReadLockCount()); |
885 |
lock.unlock(p); |
886 |
lock.unlock(s); |
887 |
assertUnlocked(lock); |
888 |
} |
889 |
} |
890 |
|
891 |
/** |
892 |
* asWriteLock can be locked and unlocked |
893 |
*/ |
894 |
public void testAsWriteLock() throws Throwable { |
895 |
StampedLock sl = new StampedLock(); |
896 |
Lock lock = sl.asWriteLock(); |
897 |
for (Action locker : lockLockers(lock)) { |
898 |
locker.run(); |
899 |
assertTrue(sl.isWriteLocked()); |
900 |
assertFalse(sl.isReadLocked()); |
901 |
assertFalse(lock.tryLock()); |
902 |
lock.unlock(); |
903 |
assertUnlocked(sl); |
904 |
} |
905 |
} |
906 |
|
907 |
/** |
908 |
* asReadLock can be locked and unlocked |
909 |
*/ |
910 |
public void testAsReadLock() throws Throwable { |
911 |
StampedLock sl = new StampedLock(); |
912 |
Lock lock = sl.asReadLock(); |
913 |
for (Action locker : lockLockers(lock)) { |
914 |
locker.run(); |
915 |
assertTrue(sl.isReadLocked()); |
916 |
assertFalse(sl.isWriteLocked()); |
917 |
assertEquals(1, sl.getReadLockCount()); |
918 |
locker.run(); |
919 |
assertTrue(sl.isReadLocked()); |
920 |
assertEquals(2, sl.getReadLockCount()); |
921 |
lock.unlock(); |
922 |
lock.unlock(); |
923 |
assertUnlocked(sl); |
924 |
} |
925 |
} |
926 |
|
927 |
/** |
928 |
* asReadWriteLock.writeLock can be locked and unlocked |
929 |
*/ |
930 |
public void testAsReadWriteLockWriteLock() throws Throwable { |
931 |
StampedLock sl = new StampedLock(); |
932 |
Lock lock = sl.asReadWriteLock().writeLock(); |
933 |
for (Action locker : lockLockers(lock)) { |
934 |
locker.run(); |
935 |
assertTrue(sl.isWriteLocked()); |
936 |
assertFalse(sl.isReadLocked()); |
937 |
assertFalse(lock.tryLock()); |
938 |
lock.unlock(); |
939 |
assertUnlocked(sl); |
940 |
} |
941 |
} |
942 |
|
943 |
/** |
944 |
* asReadWriteLock.readLock can be locked and unlocked |
945 |
*/ |
946 |
public void testAsReadWriteLockReadLock() throws Throwable { |
947 |
StampedLock sl = new StampedLock(); |
948 |
Lock lock = sl.asReadWriteLock().readLock(); |
949 |
for (Action locker : lockLockers(lock)) { |
950 |
locker.run(); |
951 |
assertTrue(sl.isReadLocked()); |
952 |
assertFalse(sl.isWriteLocked()); |
953 |
assertEquals(1, sl.getReadLockCount()); |
954 |
locker.run(); |
955 |
assertTrue(sl.isReadLocked()); |
956 |
assertEquals(2, sl.getReadLockCount()); |
957 |
lock.unlock(); |
958 |
lock.unlock(); |
959 |
assertUnlocked(sl); |
960 |
} |
961 |
} |
962 |
|
963 |
/** |
964 |
* Lock.newCondition throws UnsupportedOperationException |
965 |
*/ |
966 |
public void testLockViewsDoNotSupportConditions() { |
967 |
StampedLock sl = new StampedLock(); |
968 |
assertThrows(UnsupportedOperationException.class, |
969 |
() -> sl.asWriteLock().newCondition(), |
970 |
() -> sl.asReadLock().newCondition(), |
971 |
() -> sl.asReadWriteLock().writeLock().newCondition(), |
972 |
() -> sl.asReadWriteLock().readLock().newCondition()); |
973 |
} |
974 |
|
975 |
/** |
976 |
* Passing optimistic read stamps to unlock operations result in |
977 |
* IllegalMonitorStateException |
978 |
*/ |
979 |
public void testCannotUnlockOptimisticReadStamps() { |
980 |
Runnable[] actions = { |
981 |
() -> { |
982 |
StampedLock sl = new StampedLock(); |
983 |
long stamp = assertValid(sl, sl.tryOptimisticRead()); |
984 |
sl.unlockRead(stamp); |
985 |
}, |
986 |
() -> { |
987 |
StampedLock sl = new StampedLock(); |
988 |
long stamp = sl.tryOptimisticRead(); |
989 |
sl.unlock(stamp); |
990 |
}, |
991 |
|
992 |
() -> { |
993 |
StampedLock sl = new StampedLock(); |
994 |
long stamp = sl.tryOptimisticRead(); |
995 |
sl.writeLock(); |
996 |
sl.unlock(stamp); |
997 |
}, |
998 |
() -> { |
999 |
StampedLock sl = new StampedLock(); |
1000 |
sl.readLock(); |
1001 |
long stamp = assertValid(sl, sl.tryOptimisticRead()); |
1002 |
sl.unlockRead(stamp); |
1003 |
}, |
1004 |
() -> { |
1005 |
StampedLock sl = new StampedLock(); |
1006 |
sl.readLock(); |
1007 |
long stamp = assertValid(sl, sl.tryOptimisticRead()); |
1008 |
sl.unlock(stamp); |
1009 |
}, |
1010 |
|
1011 |
() -> { |
1012 |
StampedLock sl = new StampedLock(); |
1013 |
long stamp = sl.tryConvertToOptimisticRead(sl.writeLock()); |
1014 |
assertValid(sl, stamp); |
1015 |
sl.writeLock(); |
1016 |
sl.unlockWrite(stamp); |
1017 |
}, |
1018 |
() -> { |
1019 |
StampedLock sl = new StampedLock(); |
1020 |
long stamp = sl.tryConvertToOptimisticRead(sl.writeLock()); |
1021 |
sl.writeLock(); |
1022 |
sl.unlock(stamp); |
1023 |
}, |
1024 |
() -> { |
1025 |
StampedLock sl = new StampedLock(); |
1026 |
long stamp = sl.tryConvertToOptimisticRead(sl.writeLock()); |
1027 |
sl.readLock(); |
1028 |
sl.unlockRead(stamp); |
1029 |
}, |
1030 |
() -> { |
1031 |
StampedLock sl = new StampedLock(); |
1032 |
long stamp = sl.tryConvertToOptimisticRead(sl.writeLock()); |
1033 |
sl.readLock(); |
1034 |
sl.unlock(stamp); |
1035 |
}, |
1036 |
|
1037 |
() -> { |
1038 |
StampedLock sl = new StampedLock(); |
1039 |
long stamp = sl.tryConvertToOptimisticRead(sl.readLock()); |
1040 |
assertValid(sl, stamp); |
1041 |
sl.writeLock(); |
1042 |
sl.unlockWrite(stamp); |
1043 |
}, |
1044 |
() -> { |
1045 |
StampedLock sl = new StampedLock(); |
1046 |
long stamp = sl.tryConvertToOptimisticRead(sl.readLock()); |
1047 |
sl.writeLock(); |
1048 |
sl.unlock(stamp); |
1049 |
}, |
1050 |
() -> { |
1051 |
StampedLock sl = new StampedLock(); |
1052 |
long stamp = sl.tryConvertToOptimisticRead(sl.readLock()); |
1053 |
sl.readLock(); |
1054 |
sl.unlockRead(stamp); |
1055 |
}, |
1056 |
() -> { |
1057 |
StampedLock sl = new StampedLock(); |
1058 |
sl.readLock(); |
1059 |
long stamp = sl.tryConvertToOptimisticRead(sl.readLock()); |
1060 |
assertValid(sl, stamp); |
1061 |
sl.readLock(); |
1062 |
sl.unlockRead(stamp); |
1063 |
}, |
1064 |
() -> { |
1065 |
StampedLock sl = new StampedLock(); |
1066 |
long stamp = sl.tryConvertToOptimisticRead(sl.readLock()); |
1067 |
sl.readLock(); |
1068 |
sl.unlock(stamp); |
1069 |
}, |
1070 |
() -> { |
1071 |
StampedLock sl = new StampedLock(); |
1072 |
sl.readLock(); |
1073 |
long stamp = sl.tryConvertToOptimisticRead(sl.readLock()); |
1074 |
sl.readLock(); |
1075 |
sl.unlock(stamp); |
1076 |
}, |
1077 |
}; |
1078 |
|
1079 |
assertThrows(IllegalMonitorStateException.class, actions); |
1080 |
} |
1081 |
|
1082 |
static long writeLockInterruptiblyUninterrupted(StampedLock sl) { |
1083 |
try { return sl.writeLockInterruptibly(); } |
1084 |
catch (InterruptedException ex) { throw new AssertionError(ex); } |
1085 |
} |
1086 |
|
1087 |
static long tryWriteLockUninterrupted(StampedLock sl, long time, TimeUnit unit) { |
1088 |
try { return sl.tryWriteLock(time, unit); } |
1089 |
catch (InterruptedException ex) { throw new AssertionError(ex); } |
1090 |
} |
1091 |
|
1092 |
static long readLockInterruptiblyUninterrupted(StampedLock sl) { |
1093 |
try { return sl.readLockInterruptibly(); } |
1094 |
catch (InterruptedException ex) { throw new AssertionError(ex); } |
1095 |
} |
1096 |
|
1097 |
static long tryReadLockUninterrupted(StampedLock sl, long time, TimeUnit unit) { |
1098 |
try { return sl.tryReadLock(time, unit); } |
1099 |
catch (InterruptedException ex) { throw new AssertionError(ex); } |
1100 |
} |
1101 |
|
1102 |
/** |
1103 |
* Invalid stamps result in IllegalMonitorStateException |
1104 |
*/ |
1105 |
public void testInvalidStampsThrowIllegalMonitorStateException() { |
1106 |
final StampedLock sl = new StampedLock(); |
1107 |
|
1108 |
assertThrows(IllegalMonitorStateException.class, |
1109 |
() -> sl.unlockWrite(0L), |
1110 |
() -> sl.unlockRead(0L), |
1111 |
() -> sl.unlock(0L)); |
1112 |
|
1113 |
final long optimisticStamp = sl.tryOptimisticRead(); |
1114 |
final long readStamp = sl.readLock(); |
1115 |
sl.unlockRead(readStamp); |
1116 |
final long writeStamp = sl.writeLock(); |
1117 |
sl.unlockWrite(writeStamp); |
1118 |
assertTrue(optimisticStamp != 0L && readStamp != 0L && writeStamp != 0L); |
1119 |
final long[] noLongerValidStamps = { optimisticStamp, readStamp, writeStamp }; |
1120 |
final Runnable assertNoLongerValidStampsThrow = () -> { |
1121 |
for (long noLongerValidStamp : noLongerValidStamps) |
1122 |
assertThrows(IllegalMonitorStateException.class, |
1123 |
() -> sl.unlockWrite(noLongerValidStamp), |
1124 |
() -> sl.unlockRead(noLongerValidStamp), |
1125 |
() -> sl.unlock(noLongerValidStamp)); |
1126 |
}; |
1127 |
assertNoLongerValidStampsThrow.run(); |
1128 |
|
1129 |
for (Function<StampedLock, Long> readLocker : readLockers()) |
1130 |
for (BiConsumer<StampedLock, Long> readUnlocker : readUnlockers()) { |
1131 |
final long stamp = readLocker.apply(sl); |
1132 |
assertValid(sl, stamp); |
1133 |
assertNoLongerValidStampsThrow.run(); |
1134 |
assertThrows(IllegalMonitorStateException.class, |
1135 |
() -> sl.unlockWrite(stamp), |
1136 |
() -> sl.unlockRead(sl.tryOptimisticRead()), |
1137 |
() -> sl.unlockRead(0L)); |
1138 |
readUnlocker.accept(sl, stamp); |
1139 |
assertUnlocked(sl); |
1140 |
assertNoLongerValidStampsThrow.run(); |
1141 |
} |
1142 |
|
1143 |
for (Function<StampedLock, Long> writeLocker : writeLockers()) |
1144 |
for (BiConsumer<StampedLock, Long> writeUnlocker : writeUnlockers()) { |
1145 |
final long stamp = writeLocker.apply(sl); |
1146 |
assertValid(sl, stamp); |
1147 |
assertNoLongerValidStampsThrow.run(); |
1148 |
assertThrows(IllegalMonitorStateException.class, |
1149 |
() -> sl.unlockRead(stamp), |
1150 |
() -> sl.unlockWrite(0L)); |
1151 |
writeUnlocker.accept(sl, stamp); |
1152 |
assertUnlocked(sl); |
1153 |
assertNoLongerValidStampsThrow.run(); |
1154 |
} |
1155 |
} |
1156 |
|
1157 |
/** |
1158 |
* Read locks can be very deeply nested |
1159 |
*/ |
1160 |
public void testDeeplyNestedReadLocks() { |
1161 |
final StampedLock lock = new StampedLock(); |
1162 |
final int depth = 300; |
1163 |
final long[] stamps = new long[depth]; |
1164 |
final List<Function<StampedLock, Long>> readLockers = readLockers(); |
1165 |
final List<BiConsumer<StampedLock, Long>> readUnlockers = readUnlockers(); |
1166 |
for (int i = 0; i < depth; i++) { |
1167 |
Function<StampedLock, Long> readLocker |
1168 |
= readLockers.get(i % readLockers.size()); |
1169 |
long stamp = readLocker.apply(lock); |
1170 |
assertEquals(i + 1, lock.getReadLockCount()); |
1171 |
assertTrue(lock.isReadLocked()); |
1172 |
stamps[i] = stamp; |
1173 |
} |
1174 |
for (int i = 0; i < depth; i++) { |
1175 |
BiConsumer<StampedLock, Long> readUnlocker |
1176 |
= readUnlockers.get(i % readUnlockers.size()); |
1177 |
assertEquals(depth - i, lock.getReadLockCount()); |
1178 |
assertTrue(lock.isReadLocked()); |
1179 |
readUnlocker.accept(lock, stamps[depth - 1 - i]); |
1180 |
} |
1181 |
assertUnlocked(lock); |
1182 |
} |
1183 |
|
1184 |
/** |
1185 |
* Stamped locks are not reentrant. |
1186 |
*/ |
1187 |
public void testNonReentrant() throws InterruptedException { |
1188 |
final StampedLock lock = new StampedLock(); |
1189 |
long stamp; |
1190 |
|
1191 |
stamp = lock.writeLock(); |
1192 |
assertValid(lock, stamp); |
1193 |
assertEquals(0L, lock.tryWriteLock(0L, DAYS)); |
1194 |
assertEquals(0L, lock.tryReadLock(0L, DAYS)); |
1195 |
assertValid(lock, stamp); |
1196 |
lock.unlockWrite(stamp); |
1197 |
|
1198 |
stamp = lock.tryWriteLock(1L, DAYS); |
1199 |
assertEquals(0L, lock.tryWriteLock(0L, DAYS)); |
1200 |
assertValid(lock, stamp); |
1201 |
lock.unlockWrite(stamp); |
1202 |
|
1203 |
stamp = lock.readLock(); |
1204 |
assertEquals(0L, lock.tryWriteLock(0L, DAYS)); |
1205 |
assertValid(lock, stamp); |
1206 |
lock.unlockRead(stamp); |
1207 |
} |
1208 |
|
1209 |
/** |
1210 |
* """StampedLocks have no notion of ownership. Locks acquired in |
1211 |
* one thread can be released or converted in another.""" |
1212 |
*/ |
1213 |
public void testNoOwnership() throws Throwable { |
1214 |
ArrayList<Future<?>> futures = new ArrayList<>(); |
1215 |
for (Function<StampedLock, Long> writeLocker : writeLockers()) |
1216 |
for (BiConsumer<StampedLock, Long> writeUnlocker : writeUnlockers()) { |
1217 |
StampedLock lock = new StampedLock(); |
1218 |
long stamp = writeLocker.apply(lock); |
1219 |
futures.add(cachedThreadPool.submit(new CheckedRunnable() { |
1220 |
public void realRun() { |
1221 |
writeUnlocker.accept(lock, stamp); |
1222 |
assertUnlocked(lock); |
1223 |
assertFalse(lock.validate(stamp)); |
1224 |
}})); |
1225 |
} |
1226 |
for (Future<?> future : futures) |
1227 |
assertNull(future.get()); |
1228 |
} |
1229 |
|
1230 |
/** Tries out sample usage code from StampedLock javadoc. */ |
1231 |
public void testSampleUsage() throws Throwable { |
1232 |
class Point { |
1233 |
private double x, y; |
1234 |
private final StampedLock sl = new StampedLock(); |
1235 |
|
1236 |
void move(double deltaX, double deltaY) { // an exclusively locked method |
1237 |
long stamp = sl.writeLock(); |
1238 |
try { |
1239 |
x += deltaX; |
1240 |
y += deltaY; |
1241 |
} finally { |
1242 |
sl.unlockWrite(stamp); |
1243 |
} |
1244 |
} |
1245 |
|
1246 |
double distanceFromOrigin() { // A read-only method |
1247 |
double currentX, currentY; |
1248 |
long stamp = sl.tryOptimisticRead(); |
1249 |
do { |
1250 |
if (stamp == 0L) |
1251 |
stamp = sl.readLock(); |
1252 |
try { |
1253 |
// possibly racy reads |
1254 |
currentX = x; |
1255 |
currentY = y; |
1256 |
} finally { |
1257 |
stamp = sl.tryConvertToOptimisticRead(stamp); |
1258 |
} |
1259 |
} while (stamp == 0); |
1260 |
return Math.hypot(currentX, currentY); |
1261 |
} |
1262 |
} |
1263 |
|
1264 |
Point p = new Point(); |
1265 |
p.move(3.0, 4.0); |
1266 |
assertEquals(5.0, p.distanceFromOrigin()); |
1267 |
} |
1268 |
|
1269 |
} |