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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 static java.util.concurrent.locks.StampedLock.isLockStamp; |
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import static java.util.concurrent.locks.StampedLock.isOptimisticReadStamp; |
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import static java.util.concurrent.locks.StampedLock.isReadLockStamp; |
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import static java.util.concurrent.locks.StampedLock.isWriteLockStamp; |
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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); |
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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() { |
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public void realRun() throws Throwable { |
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threadsStarted.countDown(); |
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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); } |
329 |
assertFalse(Thread.interrupted()); |
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done.countDown(); |
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}}); |
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} |
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|
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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); |
338 |
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 |
343 |
*/ |
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public void testInterruptibleOperationsThrowInterruptedExceptionWriteLockedInterrupted() { |
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final StampedLock lock = new StampedLock(); |
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long s = lock.writeLock(); |
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|
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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(), |
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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(Long.MAX_VALUE, DAYS), |
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}; |
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shuffle(interruptibleLockBlockingActions); |
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|
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assertThrowInterruptedExceptionWhenInterrupted(interruptibleLockBlockingActions); |
361 |
} |
362 |
|
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/** |
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* interruptible operations throw InterruptedException when read locked and interrupted |
365 |
*/ |
366 |
public void testInterruptibleOperationsThrowInterruptedExceptionReadLockedInterrupted() { |
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final StampedLock lock = new StampedLock(); |
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long s = lock.readLock(); |
369 |
|
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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.asWriteLock().lockInterruptibly(), |
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() -> lock.asWriteLock().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); |
379 |
} |
380 |
|
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/** |
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* Non-interruptible operations ignore and preserve interrupt status |
383 |
*/ |
384 |
public void testNonInterruptibleOperationsIgnoreInterrupts() { |
385 |
final StampedLock lock = new StampedLock(); |
386 |
Thread.currentThread().interrupt(); |
387 |
|
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for (BiConsumer<StampedLock, Long> readUnlocker : readUnlockers()) { |
389 |
long s = assertValid(lock, lock.readLock()); |
390 |
readUnlocker.accept(lock, s); |
391 |
s = assertValid(lock, lock.tryReadLock()); |
392 |
readUnlocker.accept(lock, s); |
393 |
} |
394 |
|
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lock.asReadLock().lock(); |
396 |
lock.asReadLock().unlock(); |
397 |
|
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for (BiConsumer<StampedLock, Long> writeUnlocker : writeUnlockers()) { |
399 |
long s = assertValid(lock, lock.writeLock()); |
400 |
writeUnlocker.accept(lock, s); |
401 |
s = assertValid(lock, lock.tryWriteLock()); |
402 |
writeUnlocker.accept(lock, s); |
403 |
} |
404 |
|
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lock.asWriteLock().lock(); |
406 |
lock.asWriteLock().unlock(); |
407 |
|
408 |
assertTrue(Thread.interrupted()); |
409 |
} |
410 |
|
411 |
/** |
412 |
* tryWriteLock on an unlocked lock succeeds |
413 |
*/ |
414 |
public void testTryWriteLock() { |
415 |
final StampedLock lock = new StampedLock(); |
416 |
long s = lock.tryWriteLock(); |
417 |
assertTrue(s != 0L); |
418 |
assertTrue(lock.isWriteLocked()); |
419 |
assertEquals(0L, lock.tryWriteLock()); |
420 |
releaseWriteLock(lock, s); |
421 |
} |
422 |
|
423 |
/** |
424 |
* tryWriteLock fails if locked |
425 |
*/ |
426 |
public void testTryWriteLockWhenLocked() { |
427 |
final StampedLock lock = new StampedLock(); |
428 |
long s = lock.writeLock(); |
429 |
Thread t = newStartedThread(new CheckedRunnable() { |
430 |
public void realRun() { |
431 |
assertEquals(0L, lock.tryWriteLock()); |
432 |
}}); |
433 |
|
434 |
assertEquals(0L, lock.tryWriteLock()); |
435 |
awaitTermination(t); |
436 |
releaseWriteLock(lock, s); |
437 |
} |
438 |
|
439 |
/** |
440 |
* tryReadLock fails if write-locked |
441 |
*/ |
442 |
public void testTryReadLockWhenLocked() { |
443 |
final StampedLock lock = new StampedLock(); |
444 |
long s = lock.writeLock(); |
445 |
Thread t = newStartedThread(new CheckedRunnable() { |
446 |
public void realRun() { |
447 |
assertEquals(0L, lock.tryReadLock()); |
448 |
}}); |
449 |
|
450 |
assertEquals(0L, lock.tryReadLock()); |
451 |
awaitTermination(t); |
452 |
releaseWriteLock(lock, s); |
453 |
} |
454 |
|
455 |
/** |
456 |
* Multiple threads can hold a read lock when not write-locked |
457 |
*/ |
458 |
public void testMultipleReadLocks() { |
459 |
final StampedLock lock = new StampedLock(); |
460 |
final long s = lock.readLock(); |
461 |
Thread t = newStartedThread(new CheckedRunnable() { |
462 |
public void realRun() throws InterruptedException { |
463 |
long s2 = lock.tryReadLock(); |
464 |
assertValid(lock, s2); |
465 |
lock.unlockRead(s2); |
466 |
long s3 = lock.tryReadLock(LONG_DELAY_MS, MILLISECONDS); |
467 |
assertValid(lock, s3); |
468 |
lock.unlockRead(s3); |
469 |
long s4 = lock.readLock(); |
470 |
assertValid(lock, s4); |
471 |
lock.unlockRead(s4); |
472 |
lock.asReadLock().lock(); |
473 |
lock.asReadLock().unlock(); |
474 |
lock.asReadLock().lockInterruptibly(); |
475 |
lock.asReadLock().unlock(); |
476 |
lock.asReadLock().tryLock(Long.MIN_VALUE, DAYS); |
477 |
lock.asReadLock().unlock(); |
478 |
}}); |
479 |
|
480 |
awaitTermination(t); |
481 |
lock.unlockRead(s); |
482 |
} |
483 |
|
484 |
/** |
485 |
* writeLock() succeeds only after a reading thread unlocks |
486 |
*/ |
487 |
public void testWriteAfterReadLock() throws InterruptedException { |
488 |
final CountDownLatch aboutToLock = new CountDownLatch(1); |
489 |
final StampedLock lock = new StampedLock(); |
490 |
long rs = lock.readLock(); |
491 |
Thread t = newStartedThread(new CheckedRunnable() { |
492 |
public void realRun() { |
493 |
aboutToLock.countDown(); |
494 |
long s = lock.writeLock(); |
495 |
assertTrue(lock.isWriteLocked()); |
496 |
assertFalse(lock.isReadLocked()); |
497 |
lock.unlockWrite(s); |
498 |
}}); |
499 |
|
500 |
await(aboutToLock); |
501 |
assertThreadBlocks(t, Thread.State.WAITING); |
502 |
assertFalse(lock.isWriteLocked()); |
503 |
assertTrue(lock.isReadLocked()); |
504 |
lock.unlockRead(rs); |
505 |
awaitTermination(t); |
506 |
assertUnlocked(lock); |
507 |
} |
508 |
|
509 |
/** |
510 |
* writeLock() succeeds only after reading threads unlock |
511 |
*/ |
512 |
public void testWriteAfterMultipleReadLocks() { |
513 |
final StampedLock lock = new StampedLock(); |
514 |
long s = lock.readLock(); |
515 |
Thread t1 = newStartedThread(new CheckedRunnable() { |
516 |
public void realRun() { |
517 |
long rs = lock.readLock(); |
518 |
lock.unlockRead(rs); |
519 |
}}); |
520 |
|
521 |
awaitTermination(t1); |
522 |
|
523 |
Thread t2 = newStartedThread(new CheckedRunnable() { |
524 |
public void realRun() { |
525 |
long ws = lock.writeLock(); |
526 |
lock.unlockWrite(ws); |
527 |
}}); |
528 |
|
529 |
assertTrue(lock.isReadLocked()); |
530 |
assertFalse(lock.isWriteLocked()); |
531 |
lock.unlockRead(s); |
532 |
awaitTermination(t2); |
533 |
assertUnlocked(lock); |
534 |
} |
535 |
|
536 |
/** |
537 |
* readLock() succeed only after a writing thread unlocks |
538 |
*/ |
539 |
public void testReadAfterWriteLock() { |
540 |
final StampedLock lock = new StampedLock(); |
541 |
final CountDownLatch threadsStarted = new CountDownLatch(2); |
542 |
final long s = lock.writeLock(); |
543 |
final Runnable acquireReleaseReadLock = new CheckedRunnable() { |
544 |
public void realRun() { |
545 |
threadsStarted.countDown(); |
546 |
long rs = lock.readLock(); |
547 |
assertTrue(lock.isReadLocked()); |
548 |
assertFalse(lock.isWriteLocked()); |
549 |
lock.unlockRead(rs); |
550 |
}}; |
551 |
Thread t1 = newStartedThread(acquireReleaseReadLock); |
552 |
Thread t2 = newStartedThread(acquireReleaseReadLock); |
553 |
|
554 |
await(threadsStarted); |
555 |
assertThreadBlocks(t1, Thread.State.WAITING); |
556 |
assertThreadBlocks(t2, Thread.State.WAITING); |
557 |
assertTrue(lock.isWriteLocked()); |
558 |
assertFalse(lock.isReadLocked()); |
559 |
releaseWriteLock(lock, s); |
560 |
awaitTermination(t1); |
561 |
awaitTermination(t2); |
562 |
assertUnlocked(lock); |
563 |
} |
564 |
|
565 |
/** |
566 |
* tryReadLock succeeds if read locked but not write locked |
567 |
*/ |
568 |
public void testTryLockWhenReadLocked() { |
569 |
final StampedLock lock = new StampedLock(); |
570 |
long s = lock.readLock(); |
571 |
Thread t = newStartedThread(new CheckedRunnable() { |
572 |
public void realRun() { |
573 |
long rs = lock.tryReadLock(); |
574 |
assertValid(lock, rs); |
575 |
lock.unlockRead(rs); |
576 |
}}); |
577 |
|
578 |
awaitTermination(t); |
579 |
lock.unlockRead(s); |
580 |
} |
581 |
|
582 |
/** |
583 |
* tryWriteLock fails when read locked |
584 |
*/ |
585 |
public void testTryWriteLockWhenReadLocked() { |
586 |
final StampedLock lock = new StampedLock(); |
587 |
long s = lock.readLock(); |
588 |
Thread t = newStartedThread(new CheckedRunnable() { |
589 |
public void realRun() { |
590 |
threadAssertEquals(0L, lock.tryWriteLock()); |
591 |
}}); |
592 |
|
593 |
awaitTermination(t); |
594 |
lock.unlockRead(s); |
595 |
} |
596 |
|
597 |
/** |
598 |
* timed lock operations time out if lock not available |
599 |
*/ |
600 |
public void testTimedLock_Timeout() throws Exception { |
601 |
ArrayList<Future<?>> futures = new ArrayList<>(); |
602 |
|
603 |
// Write locked |
604 |
final StampedLock lock = new StampedLock(); |
605 |
long stamp = lock.writeLock(); |
606 |
assertEquals(0L, lock.tryReadLock(0L, DAYS)); |
607 |
assertEquals(0L, lock.tryReadLock(Long.MIN_VALUE, DAYS)); |
608 |
assertFalse(lock.asReadLock().tryLock(0L, DAYS)); |
609 |
assertFalse(lock.asReadLock().tryLock(Long.MIN_VALUE, DAYS)); |
610 |
assertEquals(0L, lock.tryWriteLock(0L, DAYS)); |
611 |
assertEquals(0L, lock.tryWriteLock(Long.MIN_VALUE, DAYS)); |
612 |
assertFalse(lock.asWriteLock().tryLock(0L, DAYS)); |
613 |
assertFalse(lock.asWriteLock().tryLock(Long.MIN_VALUE, DAYS)); |
614 |
|
615 |
futures.add(cachedThreadPool.submit(new CheckedRunnable() { |
616 |
public void realRun() throws InterruptedException { |
617 |
long startTime = System.nanoTime(); |
618 |
assertEquals(0L, lock.tryWriteLock(timeoutMillis(), MILLISECONDS)); |
619 |
assertTrue(millisElapsedSince(startTime) >= timeoutMillis()); |
620 |
}})); |
621 |
|
622 |
futures.add(cachedThreadPool.submit(new CheckedRunnable() { |
623 |
public void realRun() throws InterruptedException { |
624 |
long startTime = System.nanoTime(); |
625 |
assertEquals(0L, lock.tryReadLock(timeoutMillis(), MILLISECONDS)); |
626 |
assertTrue(millisElapsedSince(startTime) >= timeoutMillis()); |
627 |
}})); |
628 |
|
629 |
// Read locked |
630 |
final StampedLock lock2 = new StampedLock(); |
631 |
long stamp2 = lock2.readLock(); |
632 |
assertEquals(0L, lock2.tryWriteLock(0L, DAYS)); |
633 |
assertEquals(0L, lock2.tryWriteLock(Long.MIN_VALUE, DAYS)); |
634 |
assertFalse(lock2.asWriteLock().tryLock(0L, DAYS)); |
635 |
assertFalse(lock2.asWriteLock().tryLock(Long.MIN_VALUE, DAYS)); |
636 |
|
637 |
futures.add(cachedThreadPool.submit(new CheckedRunnable() { |
638 |
public void realRun() throws InterruptedException { |
639 |
long startTime = System.nanoTime(); |
640 |
assertEquals(0L, lock2.tryWriteLock(timeoutMillis(), MILLISECONDS)); |
641 |
assertTrue(millisElapsedSince(startTime) >= timeoutMillis()); |
642 |
}})); |
643 |
|
644 |
for (Future<?> future : futures) |
645 |
assertNull(future.get()); |
646 |
|
647 |
releaseWriteLock(lock, stamp); |
648 |
releaseReadLock(lock2, stamp2); |
649 |
} |
650 |
|
651 |
/** |
652 |
* writeLockInterruptibly succeeds if unlocked |
653 |
*/ |
654 |
public void testWriteLockInterruptibly() throws InterruptedException { |
655 |
final StampedLock lock = new StampedLock(); |
656 |
long s = lock.writeLockInterruptibly(); |
657 |
assertTrue(lock.isWriteLocked()); |
658 |
releaseWriteLock(lock, s); |
659 |
} |
660 |
|
661 |
/** |
662 |
* readLockInterruptibly succeeds if lock free |
663 |
*/ |
664 |
public void testReadLockInterruptibly() throws InterruptedException { |
665 |
final StampedLock lock = new StampedLock(); |
666 |
|
667 |
long s = assertValid(lock, lock.readLockInterruptibly()); |
668 |
assertTrue(lock.isReadLocked()); |
669 |
lock.unlockRead(s); |
670 |
|
671 |
lock.asReadLock().lockInterruptibly(); |
672 |
assertTrue(lock.isReadLocked()); |
673 |
lock.asReadLock().unlock(); |
674 |
} |
675 |
|
676 |
/** |
677 |
* A serialized lock deserializes as unlocked |
678 |
*/ |
679 |
public void testSerialization() { |
680 |
StampedLock lock = new StampedLock(); |
681 |
lock.writeLock(); |
682 |
StampedLock clone = serialClone(lock); |
683 |
assertTrue(lock.isWriteLocked()); |
684 |
assertFalse(clone.isWriteLocked()); |
685 |
long s = clone.writeLock(); |
686 |
assertTrue(clone.isWriteLocked()); |
687 |
clone.unlockWrite(s); |
688 |
assertFalse(clone.isWriteLocked()); |
689 |
} |
690 |
|
691 |
/** |
692 |
* toString indicates current lock state |
693 |
*/ |
694 |
public void testToString() { |
695 |
StampedLock lock = new StampedLock(); |
696 |
assertTrue(lock.toString().contains("Unlocked")); |
697 |
long s = lock.writeLock(); |
698 |
assertTrue(lock.toString().contains("Write-locked")); |
699 |
lock.unlockWrite(s); |
700 |
s = lock.readLock(); |
701 |
assertTrue(lock.toString().contains("Read-locks")); |
702 |
} |
703 |
|
704 |
/** |
705 |
* tryOptimisticRead succeeds and validates if unlocked, fails if |
706 |
* exclusively locked |
707 |
*/ |
708 |
public void testValidateOptimistic() throws InterruptedException { |
709 |
StampedLock lock = new StampedLock(); |
710 |
|
711 |
assertValid(lock, lock.tryOptimisticRead()); |
712 |
|
713 |
for (Function<StampedLock, Long> writeLocker : writeLockers()) { |
714 |
long s = assertValid(lock, writeLocker.apply(lock)); |
715 |
assertEquals(0L, lock.tryOptimisticRead()); |
716 |
releaseWriteLock(lock, s); |
717 |
} |
718 |
|
719 |
for (Function<StampedLock, Long> readLocker : readLockers()) { |
720 |
long s = assertValid(lock, readLocker.apply(lock)); |
721 |
long p = assertValid(lock, lock.tryOptimisticRead()); |
722 |
releaseReadLock(lock, s); |
723 |
assertTrue(lock.validate(p)); |
724 |
} |
725 |
|
726 |
assertValid(lock, lock.tryOptimisticRead()); |
727 |
} |
728 |
|
729 |
/** |
730 |
* tryOptimisticRead stamp does not validate if a write lock intervenes |
731 |
*/ |
732 |
public void testValidateOptimisticWriteLocked() { |
733 |
final StampedLock lock = new StampedLock(); |
734 |
final long p = assertValid(lock, lock.tryOptimisticRead()); |
735 |
final long s = assertValid(lock, lock.writeLock()); |
736 |
assertFalse(lock.validate(p)); |
737 |
assertEquals(0L, lock.tryOptimisticRead()); |
738 |
assertTrue(lock.validate(s)); |
739 |
lock.unlockWrite(s); |
740 |
} |
741 |
|
742 |
/** |
743 |
* tryOptimisticRead stamp does not validate if a write lock |
744 |
* intervenes in another thread |
745 |
*/ |
746 |
public void testValidateOptimisticWriteLocked2() |
747 |
throws InterruptedException { |
748 |
final CountDownLatch locked = new CountDownLatch(1); |
749 |
final StampedLock lock = new StampedLock(); |
750 |
final long p = assertValid(lock, lock.tryOptimisticRead()); |
751 |
|
752 |
Thread t = newStartedThread(new CheckedInterruptedRunnable() { |
753 |
public void realRun() throws InterruptedException { |
754 |
lock.writeLockInterruptibly(); |
755 |
locked.countDown(); |
756 |
lock.writeLockInterruptibly(); |
757 |
}}); |
758 |
|
759 |
await(locked); |
760 |
assertFalse(lock.validate(p)); |
761 |
assertEquals(0L, lock.tryOptimisticRead()); |
762 |
assertThreadBlocks(t, Thread.State.WAITING); |
763 |
t.interrupt(); |
764 |
awaitTermination(t); |
765 |
assertTrue(lock.isWriteLocked()); |
766 |
} |
767 |
|
768 |
/** |
769 |
* tryConvertToOptimisticRead succeeds and validates if successfully locked |
770 |
*/ |
771 |
public void testTryConvertToOptimisticRead() throws InterruptedException { |
772 |
StampedLock lock = new StampedLock(); |
773 |
long s, p, q; |
774 |
assertEquals(0L, lock.tryConvertToOptimisticRead(0L)); |
775 |
|
776 |
s = assertValid(lock, lock.tryOptimisticRead()); |
777 |
assertEquals(s, lock.tryConvertToOptimisticRead(s)); |
778 |
assertTrue(lock.validate(s)); |
779 |
|
780 |
for (Function<StampedLock, Long> writeLocker : writeLockers()) { |
781 |
s = assertValid(lock, writeLocker.apply(lock)); |
782 |
p = assertValid(lock, lock.tryConvertToOptimisticRead(s)); |
783 |
assertFalse(lock.validate(s)); |
784 |
assertTrue(lock.validate(p)); |
785 |
assertUnlocked(lock); |
786 |
} |
787 |
|
788 |
for (Function<StampedLock, Long> readLocker : readLockers()) { |
789 |
s = assertValid(lock, readLocker.apply(lock)); |
790 |
q = assertValid(lock, lock.tryOptimisticRead()); |
791 |
assertEquals(q, lock.tryConvertToOptimisticRead(q)); |
792 |
assertTrue(lock.validate(q)); |
793 |
assertTrue(lock.isReadLocked()); |
794 |
p = assertValid(lock, lock.tryConvertToOptimisticRead(s)); |
795 |
assertTrue(lock.validate(p)); |
796 |
assertTrue(lock.validate(s)); |
797 |
assertUnlocked(lock); |
798 |
assertEquals(q, lock.tryConvertToOptimisticRead(q)); |
799 |
assertTrue(lock.validate(q)); |
800 |
} |
801 |
} |
802 |
|
803 |
/** |
804 |
* tryConvertToReadLock succeeds for valid stamps |
805 |
*/ |
806 |
public void testTryConvertToReadLock() throws InterruptedException { |
807 |
StampedLock lock = new StampedLock(); |
808 |
long s, p; |
809 |
|
810 |
assertEquals(0L, lock.tryConvertToReadLock(0L)); |
811 |
|
812 |
s = assertValid(lock, lock.tryOptimisticRead()); |
813 |
p = assertValid(lock, lock.tryConvertToReadLock(s)); |
814 |
assertTrue(lock.isReadLocked()); |
815 |
assertEquals(1, lock.getReadLockCount()); |
816 |
assertTrue(lock.validate(s)); |
817 |
lock.unlockRead(p); |
818 |
|
819 |
s = assertValid(lock, lock.tryOptimisticRead()); |
820 |
lock.readLock(); |
821 |
p = assertValid(lock, lock.tryConvertToReadLock(s)); |
822 |
assertTrue(lock.isReadLocked()); |
823 |
assertEquals(2, lock.getReadLockCount()); |
824 |
lock.unlockRead(p); |
825 |
lock.unlockRead(p); |
826 |
assertUnlocked(lock); |
827 |
|
828 |
for (BiConsumer<StampedLock, Long> readUnlocker : readUnlockers()) { |
829 |
for (Function<StampedLock, Long> writeLocker : writeLockers()) { |
830 |
s = assertValid(lock, writeLocker.apply(lock)); |
831 |
p = assertValid(lock, lock.tryConvertToReadLock(s)); |
832 |
assertFalse(lock.validate(s)); |
833 |
assertTrue(lock.isReadLocked()); |
834 |
assertEquals(1, lock.getReadLockCount()); |
835 |
readUnlocker.accept(lock, p); |
836 |
} |
837 |
|
838 |
for (Function<StampedLock, Long> readLocker : readLockers()) { |
839 |
s = assertValid(lock, readLocker.apply(lock)); |
840 |
assertEquals(s, lock.tryConvertToReadLock(s)); |
841 |
assertTrue(lock.validate(s)); |
842 |
assertTrue(lock.isReadLocked()); |
843 |
assertEquals(1, lock.getReadLockCount()); |
844 |
readUnlocker.accept(lock, s); |
845 |
} |
846 |
} |
847 |
} |
848 |
|
849 |
/** |
850 |
* tryConvertToWriteLock succeeds if lock available; fails if multiply read locked |
851 |
*/ |
852 |
public void testTryConvertToWriteLock() throws InterruptedException { |
853 |
StampedLock lock = new StampedLock(); |
854 |
long s, p; |
855 |
|
856 |
assertEquals(0L, lock.tryConvertToWriteLock(0L)); |
857 |
|
858 |
assertTrue((s = lock.tryOptimisticRead()) != 0L); |
859 |
assertTrue((p = lock.tryConvertToWriteLock(s)) != 0L); |
860 |
assertTrue(lock.isWriteLocked()); |
861 |
lock.unlockWrite(p); |
862 |
|
863 |
for (BiConsumer<StampedLock, Long> writeUnlocker : writeUnlockers()) { |
864 |
for (Function<StampedLock, Long> writeLocker : writeLockers()) { |
865 |
s = assertValid(lock, writeLocker.apply(lock)); |
866 |
assertEquals(s, lock.tryConvertToWriteLock(s)); |
867 |
assertTrue(lock.validate(s)); |
868 |
assertTrue(lock.isWriteLocked()); |
869 |
writeUnlocker.accept(lock, s); |
870 |
} |
871 |
|
872 |
for (Function<StampedLock, Long> readLocker : readLockers()) { |
873 |
s = assertValid(lock, readLocker.apply(lock)); |
874 |
p = assertValid(lock, lock.tryConvertToWriteLock(s)); |
875 |
assertFalse(lock.validate(s)); |
876 |
assertTrue(lock.validate(p)); |
877 |
assertTrue(lock.isWriteLocked()); |
878 |
writeUnlocker.accept(lock, p); |
879 |
} |
880 |
} |
881 |
|
882 |
// failure if multiply read locked |
883 |
for (Function<StampedLock, Long> readLocker : readLockers()) { |
884 |
s = assertValid(lock, readLocker.apply(lock)); |
885 |
p = assertValid(lock, readLocker.apply(lock)); |
886 |
assertEquals(0L, lock.tryConvertToWriteLock(s)); |
887 |
assertTrue(lock.validate(s)); |
888 |
assertTrue(lock.validate(p)); |
889 |
assertEquals(2, lock.getReadLockCount()); |
890 |
lock.unlock(p); |
891 |
lock.unlock(s); |
892 |
assertUnlocked(lock); |
893 |
} |
894 |
} |
895 |
|
896 |
/** |
897 |
* asWriteLock can be locked and unlocked |
898 |
*/ |
899 |
public void testAsWriteLock() throws Throwable { |
900 |
StampedLock sl = new StampedLock(); |
901 |
Lock lock = sl.asWriteLock(); |
902 |
for (Action locker : lockLockers(lock)) { |
903 |
locker.run(); |
904 |
assertTrue(sl.isWriteLocked()); |
905 |
assertFalse(sl.isReadLocked()); |
906 |
assertFalse(lock.tryLock()); |
907 |
lock.unlock(); |
908 |
assertUnlocked(sl); |
909 |
} |
910 |
} |
911 |
|
912 |
/** |
913 |
* asReadLock can be locked and unlocked |
914 |
*/ |
915 |
public void testAsReadLock() throws Throwable { |
916 |
StampedLock sl = new StampedLock(); |
917 |
Lock lock = sl.asReadLock(); |
918 |
for (Action locker : lockLockers(lock)) { |
919 |
locker.run(); |
920 |
assertTrue(sl.isReadLocked()); |
921 |
assertFalse(sl.isWriteLocked()); |
922 |
assertEquals(1, sl.getReadLockCount()); |
923 |
locker.run(); |
924 |
assertTrue(sl.isReadLocked()); |
925 |
assertEquals(2, sl.getReadLockCount()); |
926 |
lock.unlock(); |
927 |
lock.unlock(); |
928 |
assertUnlocked(sl); |
929 |
} |
930 |
} |
931 |
|
932 |
/** |
933 |
* asReadWriteLock.writeLock can be locked and unlocked |
934 |
*/ |
935 |
public void testAsReadWriteLockWriteLock() throws Throwable { |
936 |
StampedLock sl = new StampedLock(); |
937 |
Lock lock = sl.asReadWriteLock().writeLock(); |
938 |
for (Action locker : lockLockers(lock)) { |
939 |
locker.run(); |
940 |
assertTrue(sl.isWriteLocked()); |
941 |
assertFalse(sl.isReadLocked()); |
942 |
assertFalse(lock.tryLock()); |
943 |
lock.unlock(); |
944 |
assertUnlocked(sl); |
945 |
} |
946 |
} |
947 |
|
948 |
/** |
949 |
* asReadWriteLock.readLock can be locked and unlocked |
950 |
*/ |
951 |
public void testAsReadWriteLockReadLock() throws Throwable { |
952 |
StampedLock sl = new StampedLock(); |
953 |
Lock lock = sl.asReadWriteLock().readLock(); |
954 |
for (Action locker : lockLockers(lock)) { |
955 |
locker.run(); |
956 |
assertTrue(sl.isReadLocked()); |
957 |
assertFalse(sl.isWriteLocked()); |
958 |
assertEquals(1, sl.getReadLockCount()); |
959 |
locker.run(); |
960 |
assertTrue(sl.isReadLocked()); |
961 |
assertEquals(2, sl.getReadLockCount()); |
962 |
lock.unlock(); |
963 |
lock.unlock(); |
964 |
assertUnlocked(sl); |
965 |
} |
966 |
} |
967 |
|
968 |
/** |
969 |
* Lock.newCondition throws UnsupportedOperationException |
970 |
*/ |
971 |
public void testLockViewsDoNotSupportConditions() { |
972 |
StampedLock sl = new StampedLock(); |
973 |
assertThrows(UnsupportedOperationException.class, |
974 |
() -> sl.asWriteLock().newCondition(), |
975 |
() -> sl.asReadLock().newCondition(), |
976 |
() -> sl.asReadWriteLock().writeLock().newCondition(), |
977 |
() -> sl.asReadWriteLock().readLock().newCondition()); |
978 |
} |
979 |
|
980 |
/** |
981 |
* Passing optimistic read stamps to unlock operations result in |
982 |
* IllegalMonitorStateException |
983 |
*/ |
984 |
public void testCannotUnlockOptimisticReadStamps() { |
985 |
Runnable[] actions = { |
986 |
() -> { |
987 |
StampedLock sl = new StampedLock(); |
988 |
long stamp = assertValid(sl, sl.tryOptimisticRead()); |
989 |
sl.unlockRead(stamp); |
990 |
}, |
991 |
() -> { |
992 |
StampedLock sl = new StampedLock(); |
993 |
long stamp = sl.tryOptimisticRead(); |
994 |
sl.unlock(stamp); |
995 |
}, |
996 |
|
997 |
() -> { |
998 |
StampedLock sl = new StampedLock(); |
999 |
long stamp = sl.tryOptimisticRead(); |
1000 |
sl.writeLock(); |
1001 |
sl.unlock(stamp); |
1002 |
}, |
1003 |
() -> { |
1004 |
StampedLock sl = new StampedLock(); |
1005 |
sl.readLock(); |
1006 |
long stamp = assertValid(sl, sl.tryOptimisticRead()); |
1007 |
sl.unlockRead(stamp); |
1008 |
}, |
1009 |
() -> { |
1010 |
StampedLock sl = new StampedLock(); |
1011 |
sl.readLock(); |
1012 |
long stamp = assertValid(sl, sl.tryOptimisticRead()); |
1013 |
sl.unlock(stamp); |
1014 |
}, |
1015 |
|
1016 |
() -> { |
1017 |
StampedLock sl = new StampedLock(); |
1018 |
long stamp = sl.tryConvertToOptimisticRead(sl.writeLock()); |
1019 |
assertValid(sl, stamp); |
1020 |
sl.writeLock(); |
1021 |
sl.unlockWrite(stamp); |
1022 |
}, |
1023 |
() -> { |
1024 |
StampedLock sl = new StampedLock(); |
1025 |
long stamp = sl.tryConvertToOptimisticRead(sl.writeLock()); |
1026 |
sl.writeLock(); |
1027 |
sl.unlock(stamp); |
1028 |
}, |
1029 |
() -> { |
1030 |
StampedLock sl = new StampedLock(); |
1031 |
long stamp = sl.tryConvertToOptimisticRead(sl.writeLock()); |
1032 |
sl.readLock(); |
1033 |
sl.unlockRead(stamp); |
1034 |
}, |
1035 |
() -> { |
1036 |
StampedLock sl = new StampedLock(); |
1037 |
long stamp = sl.tryConvertToOptimisticRead(sl.writeLock()); |
1038 |
sl.readLock(); |
1039 |
sl.unlock(stamp); |
1040 |
}, |
1041 |
|
1042 |
() -> { |
1043 |
StampedLock sl = new StampedLock(); |
1044 |
long stamp = sl.tryConvertToOptimisticRead(sl.readLock()); |
1045 |
assertValid(sl, stamp); |
1046 |
sl.writeLock(); |
1047 |
sl.unlockWrite(stamp); |
1048 |
}, |
1049 |
() -> { |
1050 |
StampedLock sl = new StampedLock(); |
1051 |
long stamp = sl.tryConvertToOptimisticRead(sl.readLock()); |
1052 |
sl.writeLock(); |
1053 |
sl.unlock(stamp); |
1054 |
}, |
1055 |
() -> { |
1056 |
StampedLock sl = new StampedLock(); |
1057 |
long stamp = sl.tryConvertToOptimisticRead(sl.readLock()); |
1058 |
sl.readLock(); |
1059 |
sl.unlockRead(stamp); |
1060 |
}, |
1061 |
() -> { |
1062 |
StampedLock sl = new StampedLock(); |
1063 |
sl.readLock(); |
1064 |
long stamp = sl.tryConvertToOptimisticRead(sl.readLock()); |
1065 |
assertValid(sl, stamp); |
1066 |
sl.readLock(); |
1067 |
sl.unlockRead(stamp); |
1068 |
}, |
1069 |
() -> { |
1070 |
StampedLock sl = new StampedLock(); |
1071 |
long stamp = sl.tryConvertToOptimisticRead(sl.readLock()); |
1072 |
sl.readLock(); |
1073 |
sl.unlock(stamp); |
1074 |
}, |
1075 |
() -> { |
1076 |
StampedLock sl = new StampedLock(); |
1077 |
sl.readLock(); |
1078 |
long stamp = sl.tryConvertToOptimisticRead(sl.readLock()); |
1079 |
sl.readLock(); |
1080 |
sl.unlock(stamp); |
1081 |
}, |
1082 |
}; |
1083 |
|
1084 |
assertThrows(IllegalMonitorStateException.class, actions); |
1085 |
} |
1086 |
|
1087 |
static long writeLockInterruptiblyUninterrupted(StampedLock sl) { |
1088 |
try { return sl.writeLockInterruptibly(); } |
1089 |
catch (InterruptedException ex) { throw new AssertionError(ex); } |
1090 |
} |
1091 |
|
1092 |
static long tryWriteLockUninterrupted(StampedLock sl, long time, TimeUnit unit) { |
1093 |
try { return sl.tryWriteLock(time, unit); } |
1094 |
catch (InterruptedException ex) { throw new AssertionError(ex); } |
1095 |
} |
1096 |
|
1097 |
static long readLockInterruptiblyUninterrupted(StampedLock sl) { |
1098 |
try { return sl.readLockInterruptibly(); } |
1099 |
catch (InterruptedException ex) { throw new AssertionError(ex); } |
1100 |
} |
1101 |
|
1102 |
static long tryReadLockUninterrupted(StampedLock sl, long time, TimeUnit unit) { |
1103 |
try { return sl.tryReadLock(time, unit); } |
1104 |
catch (InterruptedException ex) { throw new AssertionError(ex); } |
1105 |
} |
1106 |
|
1107 |
/** |
1108 |
* Invalid stamps result in IllegalMonitorStateException |
1109 |
*/ |
1110 |
public void testInvalidStampsThrowIllegalMonitorStateException() { |
1111 |
final StampedLock sl = new StampedLock(); |
1112 |
|
1113 |
assertThrows(IllegalMonitorStateException.class, |
1114 |
() -> sl.unlockWrite(0L), |
1115 |
() -> sl.unlockRead(0L), |
1116 |
() -> sl.unlock(0L)); |
1117 |
|
1118 |
final long optimisticStamp = sl.tryOptimisticRead(); |
1119 |
final long readStamp = sl.readLock(); |
1120 |
sl.unlockRead(readStamp); |
1121 |
final long writeStamp = sl.writeLock(); |
1122 |
sl.unlockWrite(writeStamp); |
1123 |
assertTrue(optimisticStamp != 0L && readStamp != 0L && writeStamp != 0L); |
1124 |
final long[] noLongerValidStamps = { optimisticStamp, readStamp, writeStamp }; |
1125 |
final Runnable assertNoLongerValidStampsThrow = () -> { |
1126 |
for (long noLongerValidStamp : noLongerValidStamps) |
1127 |
assertThrows(IllegalMonitorStateException.class, |
1128 |
() -> sl.unlockWrite(noLongerValidStamp), |
1129 |
() -> sl.unlockRead(noLongerValidStamp), |
1130 |
() -> sl.unlock(noLongerValidStamp)); |
1131 |
}; |
1132 |
assertNoLongerValidStampsThrow.run(); |
1133 |
|
1134 |
for (Function<StampedLock, Long> readLocker : readLockers()) |
1135 |
for (BiConsumer<StampedLock, Long> readUnlocker : readUnlockers()) { |
1136 |
final long stamp = readLocker.apply(sl); |
1137 |
assertValid(sl, stamp); |
1138 |
assertNoLongerValidStampsThrow.run(); |
1139 |
assertThrows(IllegalMonitorStateException.class, |
1140 |
() -> sl.unlockWrite(stamp), |
1141 |
() -> sl.unlockRead(sl.tryOptimisticRead()), |
1142 |
() -> sl.unlockRead(0L)); |
1143 |
readUnlocker.accept(sl, stamp); |
1144 |
assertUnlocked(sl); |
1145 |
assertNoLongerValidStampsThrow.run(); |
1146 |
} |
1147 |
|
1148 |
for (Function<StampedLock, Long> writeLocker : writeLockers()) |
1149 |
for (BiConsumer<StampedLock, Long> writeUnlocker : writeUnlockers()) { |
1150 |
final long stamp = writeLocker.apply(sl); |
1151 |
assertValid(sl, stamp); |
1152 |
assertNoLongerValidStampsThrow.run(); |
1153 |
assertThrows(IllegalMonitorStateException.class, |
1154 |
() -> sl.unlockRead(stamp), |
1155 |
() -> sl.unlockWrite(0L)); |
1156 |
writeUnlocker.accept(sl, stamp); |
1157 |
assertUnlocked(sl); |
1158 |
assertNoLongerValidStampsThrow.run(); |
1159 |
} |
1160 |
} |
1161 |
|
1162 |
/** |
1163 |
* Read locks can be very deeply nested |
1164 |
*/ |
1165 |
public void testDeeplyNestedReadLocks() { |
1166 |
final StampedLock lock = new StampedLock(); |
1167 |
final int depth = 300; |
1168 |
final long[] stamps = new long[depth]; |
1169 |
final List<Function<StampedLock, Long>> readLockers = readLockers(); |
1170 |
final List<BiConsumer<StampedLock, Long>> readUnlockers = readUnlockers(); |
1171 |
for (int i = 0; i < depth; i++) { |
1172 |
Function<StampedLock, Long> readLocker |
1173 |
= readLockers.get(i % readLockers.size()); |
1174 |
long stamp = readLocker.apply(lock); |
1175 |
assertEquals(i + 1, lock.getReadLockCount()); |
1176 |
assertTrue(lock.isReadLocked()); |
1177 |
stamps[i] = stamp; |
1178 |
} |
1179 |
for (int i = 0; i < depth; i++) { |
1180 |
BiConsumer<StampedLock, Long> readUnlocker |
1181 |
= readUnlockers.get(i % readUnlockers.size()); |
1182 |
assertEquals(depth - i, lock.getReadLockCount()); |
1183 |
assertTrue(lock.isReadLocked()); |
1184 |
readUnlocker.accept(lock, stamps[depth - 1 - i]); |
1185 |
} |
1186 |
assertUnlocked(lock); |
1187 |
} |
1188 |
|
1189 |
/** |
1190 |
* Stamped locks are not reentrant. |
1191 |
*/ |
1192 |
public void testNonReentrant() throws InterruptedException { |
1193 |
final StampedLock lock = new StampedLock(); |
1194 |
long stamp; |
1195 |
|
1196 |
stamp = lock.writeLock(); |
1197 |
assertValid(lock, stamp); |
1198 |
assertEquals(0L, lock.tryWriteLock(0L, DAYS)); |
1199 |
assertEquals(0L, lock.tryReadLock(0L, DAYS)); |
1200 |
assertValid(lock, stamp); |
1201 |
lock.unlockWrite(stamp); |
1202 |
|
1203 |
stamp = lock.tryWriteLock(1L, DAYS); |
1204 |
assertEquals(0L, lock.tryWriteLock(0L, DAYS)); |
1205 |
assertValid(lock, stamp); |
1206 |
lock.unlockWrite(stamp); |
1207 |
|
1208 |
stamp = lock.readLock(); |
1209 |
assertEquals(0L, lock.tryWriteLock(0L, DAYS)); |
1210 |
assertValid(lock, stamp); |
1211 |
lock.unlockRead(stamp); |
1212 |
} |
1213 |
|
1214 |
/** |
1215 |
* """StampedLocks have no notion of ownership. Locks acquired in |
1216 |
* one thread can be released or converted in another.""" |
1217 |
*/ |
1218 |
public void testNoOwnership() throws Throwable { |
1219 |
ArrayList<Future<?>> futures = new ArrayList<>(); |
1220 |
for (Function<StampedLock, Long> writeLocker : writeLockers()) |
1221 |
for (BiConsumer<StampedLock, Long> writeUnlocker : writeUnlockers()) { |
1222 |
StampedLock lock = new StampedLock(); |
1223 |
long stamp = writeLocker.apply(lock); |
1224 |
futures.add(cachedThreadPool.submit(new CheckedRunnable() { |
1225 |
public void realRun() { |
1226 |
writeUnlocker.accept(lock, stamp); |
1227 |
assertUnlocked(lock); |
1228 |
assertFalse(lock.validate(stamp)); |
1229 |
}})); |
1230 |
} |
1231 |
for (Future<?> future : futures) |
1232 |
assertNull(future.get()); |
1233 |
} |
1234 |
|
1235 |
/** Tries out sample usage code from StampedLock javadoc. */ |
1236 |
public void testSampleUsage() throws Throwable { |
1237 |
class Point { |
1238 |
private double x, y; |
1239 |
private final StampedLock sl = new StampedLock(); |
1240 |
|
1241 |
void move(double deltaX, double deltaY) { // an exclusively locked method |
1242 |
long stamp = sl.writeLock(); |
1243 |
try { |
1244 |
x += deltaX; |
1245 |
y += deltaY; |
1246 |
} finally { |
1247 |
sl.unlockWrite(stamp); |
1248 |
} |
1249 |
} |
1250 |
|
1251 |
double distanceFromOrigin() { // A read-only method |
1252 |
double currentX, currentY; |
1253 |
long stamp = sl.tryOptimisticRead(); |
1254 |
do { |
1255 |
if (stamp == 0L) |
1256 |
stamp = sl.readLock(); |
1257 |
try { |
1258 |
// possibly racy reads |
1259 |
currentX = x; |
1260 |
currentY = y; |
1261 |
} finally { |
1262 |
stamp = sl.tryConvertToOptimisticRead(stamp); |
1263 |
} |
1264 |
} while (stamp == 0); |
1265 |
return Math.hypot(currentX, currentY); |
1266 |
} |
1267 |
|
1268 |
double distanceFromOrigin2() { |
1269 |
long stamp = sl.tryOptimisticRead(); |
1270 |
try { |
1271 |
retryHoldingLock: |
1272 |
for (;; stamp = sl.readLock()) { |
1273 |
if (stamp == 0L) |
1274 |
continue retryHoldingLock; |
1275 |
// possibly racy reads |
1276 |
double currentX = x; |
1277 |
double currentY = y; |
1278 |
if (!sl.validate(stamp)) |
1279 |
continue retryHoldingLock; |
1280 |
return Math.hypot(currentX, currentY); |
1281 |
} |
1282 |
} finally { |
1283 |
if (StampedLock.isReadLockStamp(stamp)) |
1284 |
sl.unlockRead(stamp); |
1285 |
} |
1286 |
} |
1287 |
|
1288 |
void moveIfAtOrigin(double newX, double newY) { |
1289 |
long stamp = sl.readLock(); |
1290 |
try { |
1291 |
while (x == 0.0 && y == 0.0) { |
1292 |
long ws = sl.tryConvertToWriteLock(stamp); |
1293 |
if (ws != 0L) { |
1294 |
stamp = ws; |
1295 |
x = newX; |
1296 |
y = newY; |
1297 |
return; |
1298 |
} |
1299 |
else { |
1300 |
sl.unlockRead(stamp); |
1301 |
stamp = sl.writeLock(); |
1302 |
} |
1303 |
} |
1304 |
} finally { |
1305 |
sl.unlock(stamp); |
1306 |
} |
1307 |
} |
1308 |
} |
1309 |
|
1310 |
Point p = new Point(); |
1311 |
p.move(3.0, 4.0); |
1312 |
assertEquals(5.0, p.distanceFromOrigin()); |
1313 |
p.moveIfAtOrigin(5.0, 12.0); |
1314 |
assertEquals(5.0, p.distanceFromOrigin2()); |
1315 |
} |
1316 |
|
1317 |
/** |
1318 |
* Stamp inspection methods work as expected, and do not inspect |
1319 |
* the state of the lock itself. |
1320 |
*/ |
1321 |
public void testStampStateInspectionMethods() { |
1322 |
StampedLock lock = new StampedLock(); |
1323 |
|
1324 |
assertFalse(isWriteLockStamp(0L)); |
1325 |
assertFalse(isReadLockStamp(0L)); |
1326 |
assertFalse(isLockStamp(0L)); |
1327 |
assertFalse(isOptimisticReadStamp(0L)); |
1328 |
|
1329 |
{ |
1330 |
long stamp = lock.writeLock(); |
1331 |
for (int i = 0; i < 2; i++) { |
1332 |
assertTrue(isWriteLockStamp(stamp)); |
1333 |
assertFalse(isReadLockStamp(stamp)); |
1334 |
assertTrue(isLockStamp(stamp)); |
1335 |
assertFalse(isOptimisticReadStamp(stamp)); |
1336 |
if (i == 0) |
1337 |
lock.unlockWrite(stamp); |
1338 |
} |
1339 |
} |
1340 |
|
1341 |
{ |
1342 |
long stamp = lock.readLock(); |
1343 |
for (int i = 0; i < 2; i++) { |
1344 |
assertFalse(isWriteLockStamp(stamp)); |
1345 |
assertTrue(isReadLockStamp(stamp)); |
1346 |
assertTrue(isLockStamp(stamp)); |
1347 |
assertFalse(isOptimisticReadStamp(stamp)); |
1348 |
if (i == 0) |
1349 |
lock.unlockRead(stamp); |
1350 |
} |
1351 |
} |
1352 |
|
1353 |
{ |
1354 |
long optimisticStamp = lock.tryOptimisticRead(); |
1355 |
long readStamp = lock.tryConvertToReadLock(optimisticStamp); |
1356 |
long writeStamp = lock.tryConvertToWriteLock(readStamp); |
1357 |
for (int i = 0; i < 2; i++) { |
1358 |
assertFalse(isWriteLockStamp(optimisticStamp)); |
1359 |
assertFalse(isReadLockStamp(optimisticStamp)); |
1360 |
assertFalse(isLockStamp(optimisticStamp)); |
1361 |
assertTrue(isOptimisticReadStamp(optimisticStamp)); |
1362 |
|
1363 |
assertFalse(isWriteLockStamp(readStamp)); |
1364 |
assertTrue(isReadLockStamp(readStamp)); |
1365 |
assertTrue(isLockStamp(readStamp)); |
1366 |
assertFalse(isOptimisticReadStamp(readStamp)); |
1367 |
|
1368 |
assertTrue(isWriteLockStamp(writeStamp)); |
1369 |
assertFalse(isReadLockStamp(writeStamp)); |
1370 |
assertTrue(isLockStamp(writeStamp)); |
1371 |
assertFalse(isOptimisticReadStamp(writeStamp)); |
1372 |
if (i == 0) |
1373 |
lock.unlockWrite(writeStamp); |
1374 |
} |
1375 |
} |
1376 |
} |
1377 |
|
1378 |
} |