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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.Callable; |
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import java.util.concurrent.CompletableFuture; |
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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.ThreadLocalRandom; |
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import java.util.concurrent.TimeUnit; |
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import java.util.concurrent.atomic.AtomicBoolean; |
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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.Consumer; |
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import java.util.function.Function; |
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|
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import junit.framework.Test; |
32 |
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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return List.of( |
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() -> lock.lock(), |
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() -> lock.lockInterruptibly(), |
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() -> lock.tryLock(), |
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() -> lock.tryLock(Long.MIN_VALUE, DAYS), |
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() -> lock.tryLock(0L, DAYS), |
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() -> lock.tryLock(Long.MAX_VALUE, DAYS)); |
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} |
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|
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List<Function<StampedLock, Long>> readLockers() { |
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return List.of( |
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sl -> sl.readLock(), |
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sl -> sl.tryReadLock(), |
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sl -> readLockInterruptiblyUninterrupted(sl), |
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sl -> tryReadLockUninterrupted(sl, Long.MIN_VALUE, DAYS), |
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sl -> tryReadLockUninterrupted(sl, 0L, DAYS), |
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sl -> sl.tryConvertToReadLock(sl.tryOptimisticRead())); |
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} |
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|
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List<BiConsumer<StampedLock, Long>> readUnlockers() { |
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return List.of( |
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(sl, stamp) -> sl.unlockRead(stamp), |
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(sl, stamp) -> assertTrue(sl.tryUnlockRead()), |
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(sl, stamp) -> sl.asReadLock().unlock(), |
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(sl, stamp) -> sl.unlock(stamp), |
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(sl, stamp) -> assertValid(sl, sl.tryConvertToOptimisticRead(stamp))); |
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} |
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|
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List<Function<StampedLock, Long>> writeLockers() { |
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return List.of( |
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sl -> sl.writeLock(), |
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sl -> sl.tryWriteLock(), |
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sl -> writeLockInterruptiblyUninterrupted(sl), |
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sl -> tryWriteLockUninterrupted(sl, Long.MIN_VALUE, DAYS), |
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sl -> tryWriteLockUninterrupted(sl, 0L, DAYS), |
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sl -> sl.tryConvertToWriteLock(sl.tryOptimisticRead())); |
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} |
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|
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List<BiConsumer<StampedLock, Long>> writeUnlockers() { |
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return List.of( |
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(sl, stamp) -> sl.unlockWrite(stamp), |
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(sl, stamp) -> assertTrue(sl.tryUnlockWrite()), |
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(sl, stamp) -> sl.asWriteLock().unlock(), |
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(sl, stamp) -> sl.unlock(stamp), |
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(sl, stamp) -> assertValid(sl, sl.tryConvertToOptimisticRead(stamp))); |
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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(); |
267 |
try { |
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action.run(); |
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shouldThrow(); |
270 |
} |
271 |
catch (InterruptedException success) {} |
272 |
catch (Throwable fail) { threadUnexpectedException(fail); } |
273 |
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 |
279 |
*/ |
280 |
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), |
296 |
}; |
297 |
shuffle(interruptibleLockActions); |
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|
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assertThrowInterruptedExceptionWhenPreInterrupted(interruptibleLockActions); |
300 |
{ |
301 |
long s = lock.writeLock(); |
302 |
assertThrowInterruptedExceptionWhenPreInterrupted(interruptibleLockActions); |
303 |
lock.unlockWrite(s); |
304 |
} |
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{ |
306 |
long s = lock.readLock(); |
307 |
assertThrowInterruptedExceptionWhenPreInterrupted(interruptibleLockActions); |
308 |
lock.unlockRead(s); |
309 |
} |
310 |
} |
311 |
|
312 |
void assertThrowInterruptedExceptionWhenInterrupted(Action[] actions) { |
313 |
int n = actions.length; |
314 |
Future<?>[] futures = new Future<?>[n]; |
315 |
CountDownLatch threadsStarted = new CountDownLatch(n); |
316 |
CountDownLatch done = new CountDownLatch(n); |
317 |
|
318 |
for (int i = 0; i < n; i++) { |
319 |
Action action = actions[i]; |
320 |
futures[i] = cachedThreadPool.submit(new CheckedRunnable() { |
321 |
public void realRun() throws Throwable { |
322 |
threadsStarted.countDown(); |
323 |
try { |
324 |
action.run(); |
325 |
shouldThrow(); |
326 |
} |
327 |
catch (InterruptedException success) {} |
328 |
catch (Throwable fail) { threadUnexpectedException(fail); } |
329 |
assertFalse(Thread.interrupted()); |
330 |
done.countDown(); |
331 |
}}); |
332 |
} |
333 |
|
334 |
await(threadsStarted); |
335 |
assertEquals(n, done.getCount()); |
336 |
for (Future<?> future : futures) // Interrupt all the tasks |
337 |
future.cancel(true); |
338 |
await(done); |
339 |
} |
340 |
|
341 |
/** |
342 |
* interruptible operations throw InterruptedException when write locked and interrupted |
343 |
*/ |
344 |
public void testInterruptibleOperationsThrowInterruptedExceptionWriteLockedInterrupted() { |
345 |
final StampedLock lock = new StampedLock(); |
346 |
long stamp = lock.writeLock(); |
347 |
|
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Action[] interruptibleLockBlockingActions = { |
349 |
() -> lock.writeLockInterruptibly(), |
350 |
() -> lock.tryWriteLock(Long.MAX_VALUE, DAYS), |
351 |
() -> lock.readLockInterruptibly(), |
352 |
() -> lock.tryReadLock(Long.MAX_VALUE, DAYS), |
353 |
() -> lock.asWriteLock().lockInterruptibly(), |
354 |
() -> lock.asWriteLock().tryLock(Long.MAX_VALUE, DAYS), |
355 |
() -> lock.asReadLock().lockInterruptibly(), |
356 |
() -> lock.asReadLock().tryLock(Long.MAX_VALUE, DAYS), |
357 |
}; |
358 |
shuffle(interruptibleLockBlockingActions); |
359 |
|
360 |
assertThrowInterruptedExceptionWhenInterrupted(interruptibleLockBlockingActions); |
361 |
|
362 |
releaseWriteLock(lock, stamp); |
363 |
} |
364 |
|
365 |
/** |
366 |
* interruptible operations throw InterruptedException when read locked and interrupted |
367 |
*/ |
368 |
public void testInterruptibleOperationsThrowInterruptedExceptionReadLockedInterrupted() { |
369 |
final StampedLock lock = new StampedLock(); |
370 |
long stamp = lock.readLock(); |
371 |
|
372 |
Action[] interruptibleLockBlockingActions = { |
373 |
() -> lock.writeLockInterruptibly(), |
374 |
() -> lock.tryWriteLock(Long.MAX_VALUE, DAYS), |
375 |
() -> lock.asWriteLock().lockInterruptibly(), |
376 |
() -> lock.asWriteLock().tryLock(Long.MAX_VALUE, DAYS), |
377 |
}; |
378 |
shuffle(interruptibleLockBlockingActions); |
379 |
|
380 |
assertThrowInterruptedExceptionWhenInterrupted(interruptibleLockBlockingActions); |
381 |
|
382 |
releaseReadLock(lock, stamp); |
383 |
} |
384 |
|
385 |
/** |
386 |
* Non-interruptible operations ignore and preserve interrupt status |
387 |
*/ |
388 |
public void testNonInterruptibleOperationsIgnoreInterrupts() { |
389 |
final StampedLock lock = new StampedLock(); |
390 |
Thread.currentThread().interrupt(); |
391 |
|
392 |
for (BiConsumer<StampedLock, Long> readUnlocker : readUnlockers()) { |
393 |
long s = assertValid(lock, lock.readLock()); |
394 |
readUnlocker.accept(lock, s); |
395 |
s = assertValid(lock, lock.tryReadLock()); |
396 |
readUnlocker.accept(lock, s); |
397 |
} |
398 |
|
399 |
lock.asReadLock().lock(); |
400 |
lock.asReadLock().unlock(); |
401 |
|
402 |
for (BiConsumer<StampedLock, Long> writeUnlocker : writeUnlockers()) { |
403 |
long s = assertValid(lock, lock.writeLock()); |
404 |
writeUnlocker.accept(lock, s); |
405 |
s = assertValid(lock, lock.tryWriteLock()); |
406 |
writeUnlocker.accept(lock, s); |
407 |
} |
408 |
|
409 |
lock.asWriteLock().lock(); |
410 |
lock.asWriteLock().unlock(); |
411 |
|
412 |
assertTrue(Thread.interrupted()); |
413 |
} |
414 |
|
415 |
/** |
416 |
* tryWriteLock on an unlocked lock succeeds |
417 |
*/ |
418 |
public void testTryWriteLock() { |
419 |
final StampedLock lock = new StampedLock(); |
420 |
long s = lock.tryWriteLock(); |
421 |
assertTrue(s != 0L); |
422 |
assertTrue(lock.isWriteLocked()); |
423 |
assertEquals(0L, lock.tryWriteLock()); |
424 |
releaseWriteLock(lock, s); |
425 |
} |
426 |
|
427 |
/** |
428 |
* tryWriteLock fails if locked |
429 |
*/ |
430 |
public void testTryWriteLockWhenLocked() { |
431 |
final StampedLock lock = new StampedLock(); |
432 |
long s = lock.writeLock(); |
433 |
Thread t = newStartedThread(new CheckedRunnable() { |
434 |
public void realRun() { |
435 |
assertEquals(0L, lock.tryWriteLock()); |
436 |
}}); |
437 |
|
438 |
assertEquals(0L, lock.tryWriteLock()); |
439 |
awaitTermination(t); |
440 |
releaseWriteLock(lock, s); |
441 |
} |
442 |
|
443 |
/** |
444 |
* tryReadLock fails if write-locked |
445 |
*/ |
446 |
public void testTryReadLockWhenLocked() { |
447 |
final StampedLock lock = new StampedLock(); |
448 |
long s = lock.writeLock(); |
449 |
Thread t = newStartedThread(new CheckedRunnable() { |
450 |
public void realRun() { |
451 |
assertEquals(0L, lock.tryReadLock()); |
452 |
}}); |
453 |
|
454 |
assertEquals(0L, lock.tryReadLock()); |
455 |
awaitTermination(t); |
456 |
releaseWriteLock(lock, s); |
457 |
} |
458 |
|
459 |
/** |
460 |
* Multiple threads can hold a read lock when not write-locked |
461 |
*/ |
462 |
public void testMultipleReadLocks() { |
463 |
final StampedLock lock = new StampedLock(); |
464 |
final long s = lock.readLock(); |
465 |
Thread t = newStartedThread(new CheckedRunnable() { |
466 |
public void realRun() throws InterruptedException { |
467 |
long s2 = lock.tryReadLock(); |
468 |
assertValid(lock, s2); |
469 |
lock.unlockRead(s2); |
470 |
long s3 = lock.tryReadLock(LONG_DELAY_MS, MILLISECONDS); |
471 |
assertValid(lock, s3); |
472 |
lock.unlockRead(s3); |
473 |
long s4 = lock.readLock(); |
474 |
assertValid(lock, s4); |
475 |
lock.unlockRead(s4); |
476 |
lock.asReadLock().lock(); |
477 |
lock.asReadLock().unlock(); |
478 |
lock.asReadLock().lockInterruptibly(); |
479 |
lock.asReadLock().unlock(); |
480 |
lock.asReadLock().tryLock(Long.MIN_VALUE, DAYS); |
481 |
lock.asReadLock().unlock(); |
482 |
}}); |
483 |
|
484 |
awaitTermination(t); |
485 |
lock.unlockRead(s); |
486 |
} |
487 |
|
488 |
/** |
489 |
* writeLock() succeeds only after a reading thread unlocks |
490 |
*/ |
491 |
public void testWriteAfterReadLock() throws InterruptedException { |
492 |
final CountDownLatch aboutToLock = new CountDownLatch(1); |
493 |
final StampedLock lock = new StampedLock(); |
494 |
long rs = lock.readLock(); |
495 |
Thread t = newStartedThread(new CheckedRunnable() { |
496 |
public void realRun() { |
497 |
aboutToLock.countDown(); |
498 |
long s = lock.writeLock(); |
499 |
assertTrue(lock.isWriteLocked()); |
500 |
assertFalse(lock.isReadLocked()); |
501 |
lock.unlockWrite(s); |
502 |
}}); |
503 |
|
504 |
await(aboutToLock); |
505 |
assertThreadBlocks(t, Thread.State.WAITING); |
506 |
assertFalse(lock.isWriteLocked()); |
507 |
assertTrue(lock.isReadLocked()); |
508 |
lock.unlockRead(rs); |
509 |
awaitTermination(t); |
510 |
assertUnlocked(lock); |
511 |
} |
512 |
|
513 |
/** |
514 |
* writeLock() succeeds only after reading threads unlock |
515 |
*/ |
516 |
public void testWriteAfterMultipleReadLocks() { |
517 |
final StampedLock lock = new StampedLock(); |
518 |
long s = lock.readLock(); |
519 |
Thread t1 = newStartedThread(new CheckedRunnable() { |
520 |
public void realRun() { |
521 |
long rs = lock.readLock(); |
522 |
lock.unlockRead(rs); |
523 |
}}); |
524 |
|
525 |
awaitTermination(t1); |
526 |
|
527 |
Thread t2 = newStartedThread(new CheckedRunnable() { |
528 |
public void realRun() { |
529 |
long ws = lock.writeLock(); |
530 |
lock.unlockWrite(ws); |
531 |
}}); |
532 |
|
533 |
assertTrue(lock.isReadLocked()); |
534 |
assertFalse(lock.isWriteLocked()); |
535 |
lock.unlockRead(s); |
536 |
awaitTermination(t2); |
537 |
assertUnlocked(lock); |
538 |
} |
539 |
|
540 |
/** |
541 |
* readLock() succeed only after a writing thread unlocks |
542 |
*/ |
543 |
public void testReadAfterWriteLock() { |
544 |
final StampedLock lock = new StampedLock(); |
545 |
final CountDownLatch threadsStarted = new CountDownLatch(2); |
546 |
final long s = lock.writeLock(); |
547 |
final Runnable acquireReleaseReadLock = new CheckedRunnable() { |
548 |
public void realRun() { |
549 |
threadsStarted.countDown(); |
550 |
long rs = lock.readLock(); |
551 |
assertTrue(lock.isReadLocked()); |
552 |
assertFalse(lock.isWriteLocked()); |
553 |
lock.unlockRead(rs); |
554 |
}}; |
555 |
Thread t1 = newStartedThread(acquireReleaseReadLock); |
556 |
Thread t2 = newStartedThread(acquireReleaseReadLock); |
557 |
|
558 |
await(threadsStarted); |
559 |
assertThreadBlocks(t1, Thread.State.WAITING); |
560 |
assertThreadBlocks(t2, Thread.State.WAITING); |
561 |
assertTrue(lock.isWriteLocked()); |
562 |
assertFalse(lock.isReadLocked()); |
563 |
releaseWriteLock(lock, s); |
564 |
awaitTermination(t1); |
565 |
awaitTermination(t2); |
566 |
assertUnlocked(lock); |
567 |
} |
568 |
|
569 |
/** |
570 |
* tryReadLock succeeds if read locked but not write locked |
571 |
*/ |
572 |
public void testTryLockWhenReadLocked() { |
573 |
final StampedLock lock = new StampedLock(); |
574 |
long s = lock.readLock(); |
575 |
Thread t = newStartedThread(new CheckedRunnable() { |
576 |
public void realRun() { |
577 |
long rs = lock.tryReadLock(); |
578 |
assertValid(lock, rs); |
579 |
lock.unlockRead(rs); |
580 |
}}); |
581 |
|
582 |
awaitTermination(t); |
583 |
lock.unlockRead(s); |
584 |
} |
585 |
|
586 |
/** |
587 |
* tryWriteLock fails when read locked |
588 |
*/ |
589 |
public void testTryWriteLockWhenReadLocked() { |
590 |
final StampedLock lock = new StampedLock(); |
591 |
long s = lock.readLock(); |
592 |
Thread t = newStartedThread(new CheckedRunnable() { |
593 |
public void realRun() { |
594 |
assertEquals(0L, lock.tryWriteLock()); |
595 |
}}); |
596 |
|
597 |
awaitTermination(t); |
598 |
lock.unlockRead(s); |
599 |
} |
600 |
|
601 |
/** |
602 |
* timed lock operations time out if lock not available |
603 |
*/ |
604 |
public void testTimedLock_Timeout() throws Exception { |
605 |
ArrayList<Future<?>> futures = new ArrayList<>(); |
606 |
|
607 |
// Write locked |
608 |
final StampedLock lock = new StampedLock(); |
609 |
long stamp = lock.writeLock(); |
610 |
assertEquals(0L, lock.tryReadLock(0L, DAYS)); |
611 |
assertEquals(0L, lock.tryReadLock(Long.MIN_VALUE, DAYS)); |
612 |
assertFalse(lock.asReadLock().tryLock(0L, DAYS)); |
613 |
assertFalse(lock.asReadLock().tryLock(Long.MIN_VALUE, DAYS)); |
614 |
assertEquals(0L, lock.tryWriteLock(0L, DAYS)); |
615 |
assertEquals(0L, lock.tryWriteLock(Long.MIN_VALUE, DAYS)); |
616 |
assertFalse(lock.asWriteLock().tryLock(0L, DAYS)); |
617 |
assertFalse(lock.asWriteLock().tryLock(Long.MIN_VALUE, DAYS)); |
618 |
|
619 |
futures.add(cachedThreadPool.submit(new CheckedRunnable() { |
620 |
public void realRun() throws InterruptedException { |
621 |
long startTime = System.nanoTime(); |
622 |
assertEquals(0L, lock.tryWriteLock(timeoutMillis(), MILLISECONDS)); |
623 |
assertTrue(millisElapsedSince(startTime) >= timeoutMillis()); |
624 |
}})); |
625 |
|
626 |
futures.add(cachedThreadPool.submit(new CheckedRunnable() { |
627 |
public void realRun() throws InterruptedException { |
628 |
long startTime = System.nanoTime(); |
629 |
assertEquals(0L, lock.tryReadLock(timeoutMillis(), MILLISECONDS)); |
630 |
assertTrue(millisElapsedSince(startTime) >= timeoutMillis()); |
631 |
}})); |
632 |
|
633 |
// Read locked |
634 |
final StampedLock lock2 = new StampedLock(); |
635 |
long stamp2 = lock2.readLock(); |
636 |
assertEquals(0L, lock2.tryWriteLock(0L, DAYS)); |
637 |
assertEquals(0L, lock2.tryWriteLock(Long.MIN_VALUE, DAYS)); |
638 |
assertFalse(lock2.asWriteLock().tryLock(0L, DAYS)); |
639 |
assertFalse(lock2.asWriteLock().tryLock(Long.MIN_VALUE, DAYS)); |
640 |
|
641 |
futures.add(cachedThreadPool.submit(new CheckedRunnable() { |
642 |
public void realRun() throws InterruptedException { |
643 |
long startTime = System.nanoTime(); |
644 |
assertEquals(0L, lock2.tryWriteLock(timeoutMillis(), MILLISECONDS)); |
645 |
assertTrue(millisElapsedSince(startTime) >= timeoutMillis()); |
646 |
}})); |
647 |
|
648 |
for (Future<?> future : futures) |
649 |
assertNull(future.get()); |
650 |
|
651 |
releaseWriteLock(lock, stamp); |
652 |
releaseReadLock(lock2, stamp2); |
653 |
} |
654 |
|
655 |
/** |
656 |
* writeLockInterruptibly succeeds if unlocked |
657 |
*/ |
658 |
public void testWriteLockInterruptibly() throws InterruptedException { |
659 |
final StampedLock lock = new StampedLock(); |
660 |
long s = lock.writeLockInterruptibly(); |
661 |
assertTrue(lock.isWriteLocked()); |
662 |
releaseWriteLock(lock, s); |
663 |
} |
664 |
|
665 |
/** |
666 |
* readLockInterruptibly succeeds if lock free |
667 |
*/ |
668 |
public void testReadLockInterruptibly() throws InterruptedException { |
669 |
final StampedLock lock = new StampedLock(); |
670 |
|
671 |
long s = assertValid(lock, lock.readLockInterruptibly()); |
672 |
assertTrue(lock.isReadLocked()); |
673 |
lock.unlockRead(s); |
674 |
|
675 |
lock.asReadLock().lockInterruptibly(); |
676 |
assertTrue(lock.isReadLocked()); |
677 |
lock.asReadLock().unlock(); |
678 |
} |
679 |
|
680 |
/** |
681 |
* A serialized lock deserializes as unlocked |
682 |
*/ |
683 |
public void testSerialization() { |
684 |
StampedLock lock = new StampedLock(); |
685 |
lock.writeLock(); |
686 |
StampedLock clone = serialClone(lock); |
687 |
assertTrue(lock.isWriteLocked()); |
688 |
assertFalse(clone.isWriteLocked()); |
689 |
long s = clone.writeLock(); |
690 |
assertTrue(clone.isWriteLocked()); |
691 |
clone.unlockWrite(s); |
692 |
assertFalse(clone.isWriteLocked()); |
693 |
} |
694 |
|
695 |
/** |
696 |
* toString indicates current lock state |
697 |
*/ |
698 |
public void testToString() { |
699 |
StampedLock lock = new StampedLock(); |
700 |
assertTrue(lock.toString().contains("Unlocked")); |
701 |
long s = lock.writeLock(); |
702 |
assertTrue(lock.toString().contains("Write-locked")); |
703 |
lock.unlockWrite(s); |
704 |
s = lock.readLock(); |
705 |
assertTrue(lock.toString().contains("Read-locks")); |
706 |
releaseReadLock(lock, s); |
707 |
} |
708 |
|
709 |
/** |
710 |
* tryOptimisticRead succeeds and validates if unlocked, fails if |
711 |
* exclusively locked |
712 |
*/ |
713 |
public void testValidateOptimistic() throws InterruptedException { |
714 |
StampedLock lock = new StampedLock(); |
715 |
|
716 |
assertValid(lock, lock.tryOptimisticRead()); |
717 |
|
718 |
for (Function<StampedLock, Long> writeLocker : writeLockers()) { |
719 |
long s = assertValid(lock, writeLocker.apply(lock)); |
720 |
assertEquals(0L, lock.tryOptimisticRead()); |
721 |
releaseWriteLock(lock, s); |
722 |
} |
723 |
|
724 |
for (Function<StampedLock, Long> readLocker : readLockers()) { |
725 |
long s = assertValid(lock, readLocker.apply(lock)); |
726 |
long p = assertValid(lock, lock.tryOptimisticRead()); |
727 |
releaseReadLock(lock, s); |
728 |
assertTrue(lock.validate(p)); |
729 |
} |
730 |
|
731 |
assertValid(lock, lock.tryOptimisticRead()); |
732 |
} |
733 |
|
734 |
/** |
735 |
* tryOptimisticRead stamp does not validate if a write lock intervenes |
736 |
*/ |
737 |
public void testValidateOptimisticWriteLocked() { |
738 |
final StampedLock lock = new StampedLock(); |
739 |
final long p = assertValid(lock, lock.tryOptimisticRead()); |
740 |
final long s = assertValid(lock, lock.writeLock()); |
741 |
assertFalse(lock.validate(p)); |
742 |
assertEquals(0L, lock.tryOptimisticRead()); |
743 |
assertTrue(lock.validate(s)); |
744 |
lock.unlockWrite(s); |
745 |
} |
746 |
|
747 |
/** |
748 |
* tryOptimisticRead stamp does not validate if a write lock |
749 |
* intervenes in another thread |
750 |
*/ |
751 |
public void testValidateOptimisticWriteLocked2() |
752 |
throws InterruptedException { |
753 |
final CountDownLatch locked = new CountDownLatch(1); |
754 |
final StampedLock lock = new StampedLock(); |
755 |
final long p = assertValid(lock, lock.tryOptimisticRead()); |
756 |
|
757 |
Thread t = newStartedThread(new CheckedInterruptedRunnable() { |
758 |
public void realRun() throws InterruptedException { |
759 |
lock.writeLockInterruptibly(); |
760 |
locked.countDown(); |
761 |
lock.writeLockInterruptibly(); |
762 |
}}); |
763 |
|
764 |
await(locked); |
765 |
assertFalse(lock.validate(p)); |
766 |
assertEquals(0L, lock.tryOptimisticRead()); |
767 |
assertThreadBlocks(t, Thread.State.WAITING); |
768 |
t.interrupt(); |
769 |
awaitTermination(t); |
770 |
assertTrue(lock.isWriteLocked()); |
771 |
} |
772 |
|
773 |
/** |
774 |
* tryConvertToOptimisticRead succeeds and validates if successfully locked |
775 |
*/ |
776 |
public void testTryConvertToOptimisticRead() throws InterruptedException { |
777 |
StampedLock lock = new StampedLock(); |
778 |
long s, p, q; |
779 |
assertEquals(0L, lock.tryConvertToOptimisticRead(0L)); |
780 |
|
781 |
s = assertValid(lock, lock.tryOptimisticRead()); |
782 |
assertEquals(s, lock.tryConvertToOptimisticRead(s)); |
783 |
assertTrue(lock.validate(s)); |
784 |
|
785 |
for (Function<StampedLock, Long> writeLocker : writeLockers()) { |
786 |
s = assertValid(lock, writeLocker.apply(lock)); |
787 |
p = assertValid(lock, lock.tryConvertToOptimisticRead(s)); |
788 |
assertFalse(lock.validate(s)); |
789 |
assertTrue(lock.validate(p)); |
790 |
assertUnlocked(lock); |
791 |
} |
792 |
|
793 |
for (Function<StampedLock, Long> readLocker : readLockers()) { |
794 |
s = assertValid(lock, readLocker.apply(lock)); |
795 |
q = assertValid(lock, lock.tryOptimisticRead()); |
796 |
assertEquals(q, lock.tryConvertToOptimisticRead(q)); |
797 |
assertTrue(lock.validate(q)); |
798 |
assertTrue(lock.isReadLocked()); |
799 |
p = assertValid(lock, lock.tryConvertToOptimisticRead(s)); |
800 |
assertTrue(lock.validate(p)); |
801 |
assertTrue(lock.validate(s)); |
802 |
assertUnlocked(lock); |
803 |
assertEquals(q, lock.tryConvertToOptimisticRead(q)); |
804 |
assertTrue(lock.validate(q)); |
805 |
} |
806 |
} |
807 |
|
808 |
/** |
809 |
* tryConvertToReadLock succeeds for valid stamps |
810 |
*/ |
811 |
public void testTryConvertToReadLock() throws InterruptedException { |
812 |
StampedLock lock = new StampedLock(); |
813 |
long s, p; |
814 |
|
815 |
assertEquals(0L, lock.tryConvertToReadLock(0L)); |
816 |
|
817 |
s = assertValid(lock, lock.tryOptimisticRead()); |
818 |
p = assertValid(lock, lock.tryConvertToReadLock(s)); |
819 |
assertTrue(lock.isReadLocked()); |
820 |
assertEquals(1, lock.getReadLockCount()); |
821 |
assertTrue(lock.validate(s)); |
822 |
lock.unlockRead(p); |
823 |
|
824 |
s = assertValid(lock, lock.tryOptimisticRead()); |
825 |
lock.readLock(); |
826 |
p = assertValid(lock, lock.tryConvertToReadLock(s)); |
827 |
assertTrue(lock.isReadLocked()); |
828 |
assertEquals(2, lock.getReadLockCount()); |
829 |
lock.unlockRead(p); |
830 |
lock.unlockRead(p); |
831 |
assertUnlocked(lock); |
832 |
|
833 |
for (BiConsumer<StampedLock, Long> readUnlocker : readUnlockers()) { |
834 |
for (Function<StampedLock, Long> writeLocker : writeLockers()) { |
835 |
s = assertValid(lock, writeLocker.apply(lock)); |
836 |
p = assertValid(lock, lock.tryConvertToReadLock(s)); |
837 |
assertFalse(lock.validate(s)); |
838 |
assertTrue(lock.isReadLocked()); |
839 |
assertEquals(1, lock.getReadLockCount()); |
840 |
readUnlocker.accept(lock, p); |
841 |
} |
842 |
|
843 |
for (Function<StampedLock, Long> readLocker : readLockers()) { |
844 |
s = assertValid(lock, readLocker.apply(lock)); |
845 |
assertEquals(s, lock.tryConvertToReadLock(s)); |
846 |
assertTrue(lock.validate(s)); |
847 |
assertTrue(lock.isReadLocked()); |
848 |
assertEquals(1, lock.getReadLockCount()); |
849 |
readUnlocker.accept(lock, s); |
850 |
} |
851 |
} |
852 |
} |
853 |
|
854 |
/** |
855 |
* tryConvertToWriteLock succeeds if lock available; fails if multiply read locked |
856 |
*/ |
857 |
public void testTryConvertToWriteLock() throws InterruptedException { |
858 |
StampedLock lock = new StampedLock(); |
859 |
long s, p; |
860 |
|
861 |
assertEquals(0L, lock.tryConvertToWriteLock(0L)); |
862 |
|
863 |
assertTrue((s = lock.tryOptimisticRead()) != 0L); |
864 |
assertTrue((p = lock.tryConvertToWriteLock(s)) != 0L); |
865 |
assertTrue(lock.isWriteLocked()); |
866 |
lock.unlockWrite(p); |
867 |
|
868 |
for (BiConsumer<StampedLock, Long> writeUnlocker : writeUnlockers()) { |
869 |
for (Function<StampedLock, Long> writeLocker : writeLockers()) { |
870 |
s = assertValid(lock, writeLocker.apply(lock)); |
871 |
assertEquals(s, lock.tryConvertToWriteLock(s)); |
872 |
assertTrue(lock.validate(s)); |
873 |
assertTrue(lock.isWriteLocked()); |
874 |
writeUnlocker.accept(lock, s); |
875 |
} |
876 |
|
877 |
for (Function<StampedLock, Long> readLocker : readLockers()) { |
878 |
s = assertValid(lock, readLocker.apply(lock)); |
879 |
p = assertValid(lock, lock.tryConvertToWriteLock(s)); |
880 |
assertFalse(lock.validate(s)); |
881 |
assertTrue(lock.validate(p)); |
882 |
assertTrue(lock.isWriteLocked()); |
883 |
writeUnlocker.accept(lock, p); |
884 |
} |
885 |
} |
886 |
|
887 |
// failure if multiply read locked |
888 |
for (Function<StampedLock, Long> readLocker : readLockers()) { |
889 |
s = assertValid(lock, readLocker.apply(lock)); |
890 |
p = assertValid(lock, readLocker.apply(lock)); |
891 |
assertEquals(0L, lock.tryConvertToWriteLock(s)); |
892 |
assertTrue(lock.validate(s)); |
893 |
assertTrue(lock.validate(p)); |
894 |
assertEquals(2, lock.getReadLockCount()); |
895 |
lock.unlock(p); |
896 |
lock.unlock(s); |
897 |
assertUnlocked(lock); |
898 |
} |
899 |
} |
900 |
|
901 |
/** |
902 |
* asWriteLock can be locked and unlocked |
903 |
*/ |
904 |
public void testAsWriteLock() throws Throwable { |
905 |
StampedLock sl = new StampedLock(); |
906 |
Lock lock = sl.asWriteLock(); |
907 |
for (Action locker : lockLockers(lock)) { |
908 |
locker.run(); |
909 |
assertTrue(sl.isWriteLocked()); |
910 |
assertFalse(sl.isReadLocked()); |
911 |
assertFalse(lock.tryLock()); |
912 |
lock.unlock(); |
913 |
assertUnlocked(sl); |
914 |
} |
915 |
} |
916 |
|
917 |
/** |
918 |
* asReadLock can be locked and unlocked |
919 |
*/ |
920 |
public void testAsReadLock() throws Throwable { |
921 |
StampedLock sl = new StampedLock(); |
922 |
Lock lock = sl.asReadLock(); |
923 |
for (Action locker : lockLockers(lock)) { |
924 |
locker.run(); |
925 |
assertTrue(sl.isReadLocked()); |
926 |
assertFalse(sl.isWriteLocked()); |
927 |
assertEquals(1, sl.getReadLockCount()); |
928 |
locker.run(); |
929 |
assertTrue(sl.isReadLocked()); |
930 |
assertEquals(2, sl.getReadLockCount()); |
931 |
lock.unlock(); |
932 |
lock.unlock(); |
933 |
assertUnlocked(sl); |
934 |
} |
935 |
} |
936 |
|
937 |
/** |
938 |
* asReadWriteLock.writeLock can be locked and unlocked |
939 |
*/ |
940 |
public void testAsReadWriteLockWriteLock() throws Throwable { |
941 |
StampedLock sl = new StampedLock(); |
942 |
Lock lock = sl.asReadWriteLock().writeLock(); |
943 |
for (Action locker : lockLockers(lock)) { |
944 |
locker.run(); |
945 |
assertTrue(sl.isWriteLocked()); |
946 |
assertFalse(sl.isReadLocked()); |
947 |
assertFalse(lock.tryLock()); |
948 |
lock.unlock(); |
949 |
assertUnlocked(sl); |
950 |
} |
951 |
} |
952 |
|
953 |
/** |
954 |
* asReadWriteLock.readLock can be locked and unlocked |
955 |
*/ |
956 |
public void testAsReadWriteLockReadLock() throws Throwable { |
957 |
StampedLock sl = new StampedLock(); |
958 |
Lock lock = sl.asReadWriteLock().readLock(); |
959 |
for (Action locker : lockLockers(lock)) { |
960 |
locker.run(); |
961 |
assertTrue(sl.isReadLocked()); |
962 |
assertFalse(sl.isWriteLocked()); |
963 |
assertEquals(1, sl.getReadLockCount()); |
964 |
locker.run(); |
965 |
assertTrue(sl.isReadLocked()); |
966 |
assertEquals(2, sl.getReadLockCount()); |
967 |
lock.unlock(); |
968 |
lock.unlock(); |
969 |
assertUnlocked(sl); |
970 |
} |
971 |
} |
972 |
|
973 |
/** |
974 |
* Lock.newCondition throws UnsupportedOperationException |
975 |
*/ |
976 |
public void testLockViewsDoNotSupportConditions() { |
977 |
StampedLock sl = new StampedLock(); |
978 |
assertThrows(UnsupportedOperationException.class, |
979 |
() -> sl.asWriteLock().newCondition(), |
980 |
() -> sl.asReadLock().newCondition(), |
981 |
() -> sl.asReadWriteLock().writeLock().newCondition(), |
982 |
() -> sl.asReadWriteLock().readLock().newCondition()); |
983 |
} |
984 |
|
985 |
/** |
986 |
* Passing optimistic read stamps to unlock operations result in |
987 |
* IllegalMonitorStateException |
988 |
*/ |
989 |
public void testCannotUnlockOptimisticReadStamps() { |
990 |
{ |
991 |
StampedLock sl = new StampedLock(); |
992 |
long stamp = assertValid(sl, sl.tryOptimisticRead()); |
993 |
assertThrows(IllegalMonitorStateException.class, |
994 |
() -> sl.unlockRead(stamp)); |
995 |
} |
996 |
{ |
997 |
StampedLock sl = new StampedLock(); |
998 |
long stamp = sl.tryOptimisticRead(); |
999 |
assertThrows(IllegalMonitorStateException.class, |
1000 |
() -> sl.unlock(stamp)); |
1001 |
} |
1002 |
|
1003 |
{ |
1004 |
StampedLock sl = new StampedLock(); |
1005 |
long stamp = sl.tryOptimisticRead(); |
1006 |
sl.writeLock(); |
1007 |
assertThrows(IllegalMonitorStateException.class, |
1008 |
() -> sl.unlock(stamp)); |
1009 |
} |
1010 |
{ |
1011 |
StampedLock sl = new StampedLock(); |
1012 |
sl.readLock(); |
1013 |
long stamp = assertValid(sl, sl.tryOptimisticRead()); |
1014 |
assertThrows(IllegalMonitorStateException.class, |
1015 |
() -> sl.unlockRead(stamp)); |
1016 |
} |
1017 |
{ |
1018 |
StampedLock sl = new StampedLock(); |
1019 |
sl.readLock(); |
1020 |
long stamp = assertValid(sl, sl.tryOptimisticRead()); |
1021 |
assertThrows(IllegalMonitorStateException.class, |
1022 |
() -> sl.unlock(stamp)); |
1023 |
} |
1024 |
|
1025 |
{ |
1026 |
StampedLock sl = new StampedLock(); |
1027 |
long stamp = sl.tryConvertToOptimisticRead(sl.writeLock()); |
1028 |
assertValid(sl, stamp); |
1029 |
sl.writeLock(); |
1030 |
assertThrows(IllegalMonitorStateException.class, |
1031 |
() -> sl.unlockWrite(stamp)); |
1032 |
} |
1033 |
{ |
1034 |
StampedLock sl = new StampedLock(); |
1035 |
long stamp = sl.tryConvertToOptimisticRead(sl.writeLock()); |
1036 |
sl.writeLock(); |
1037 |
assertThrows(IllegalMonitorStateException.class, |
1038 |
() -> sl.unlock(stamp)); |
1039 |
} |
1040 |
{ |
1041 |
StampedLock sl = new StampedLock(); |
1042 |
long stamp = sl.tryConvertToOptimisticRead(sl.writeLock()); |
1043 |
sl.readLock(); |
1044 |
assertThrows(IllegalMonitorStateException.class, |
1045 |
() -> sl.unlockRead(stamp)); |
1046 |
} |
1047 |
{ |
1048 |
StampedLock sl = new StampedLock(); |
1049 |
long stamp = sl.tryConvertToOptimisticRead(sl.writeLock()); |
1050 |
sl.readLock(); |
1051 |
assertThrows(IllegalMonitorStateException.class, |
1052 |
() -> sl.unlock(stamp)); |
1053 |
} |
1054 |
|
1055 |
{ |
1056 |
StampedLock sl = new StampedLock(); |
1057 |
long stamp = sl.tryConvertToOptimisticRead(sl.readLock()); |
1058 |
assertValid(sl, stamp); |
1059 |
sl.writeLock(); |
1060 |
assertThrows(IllegalMonitorStateException.class, |
1061 |
() -> sl.unlockWrite(stamp)); |
1062 |
} |
1063 |
{ |
1064 |
StampedLock sl = new StampedLock(); |
1065 |
long stamp = sl.tryConvertToOptimisticRead(sl.readLock()); |
1066 |
sl.writeLock(); |
1067 |
assertThrows(IllegalMonitorStateException.class, |
1068 |
() -> sl.unlock(stamp)); |
1069 |
} |
1070 |
{ |
1071 |
StampedLock sl = new StampedLock(); |
1072 |
long stamp = sl.tryConvertToOptimisticRead(sl.readLock()); |
1073 |
sl.readLock(); |
1074 |
assertThrows(IllegalMonitorStateException.class, |
1075 |
() -> sl.unlockRead(stamp)); |
1076 |
} |
1077 |
{ |
1078 |
StampedLock sl = new StampedLock(); |
1079 |
sl.readLock(); |
1080 |
long stamp = sl.tryConvertToOptimisticRead(sl.readLock()); |
1081 |
assertValid(sl, stamp); |
1082 |
sl.readLock(); |
1083 |
assertThrows(IllegalMonitorStateException.class, |
1084 |
() -> sl.unlockRead(stamp)); |
1085 |
} |
1086 |
{ |
1087 |
StampedLock sl = new StampedLock(); |
1088 |
long stamp = sl.tryConvertToOptimisticRead(sl.readLock()); |
1089 |
sl.readLock(); |
1090 |
assertThrows(IllegalMonitorStateException.class, |
1091 |
() -> sl.unlock(stamp)); |
1092 |
} |
1093 |
{ |
1094 |
StampedLock sl = new StampedLock(); |
1095 |
sl.readLock(); |
1096 |
long stamp = sl.tryConvertToOptimisticRead(sl.readLock()); |
1097 |
sl.readLock(); |
1098 |
assertThrows(IllegalMonitorStateException.class, |
1099 |
() -> sl.unlock(stamp)); |
1100 |
} |
1101 |
} |
1102 |
|
1103 |
static long writeLockInterruptiblyUninterrupted(StampedLock sl) { |
1104 |
try { return sl.writeLockInterruptibly(); } |
1105 |
catch (InterruptedException ex) { throw new AssertionError(ex); } |
1106 |
} |
1107 |
|
1108 |
static long tryWriteLockUninterrupted(StampedLock sl, long time, TimeUnit unit) { |
1109 |
try { return sl.tryWriteLock(time, unit); } |
1110 |
catch (InterruptedException ex) { throw new AssertionError(ex); } |
1111 |
} |
1112 |
|
1113 |
static long readLockInterruptiblyUninterrupted(StampedLock sl) { |
1114 |
try { return sl.readLockInterruptibly(); } |
1115 |
catch (InterruptedException ex) { throw new AssertionError(ex); } |
1116 |
} |
1117 |
|
1118 |
static long tryReadLockUninterrupted(StampedLock sl, long time, TimeUnit unit) { |
1119 |
try { return sl.tryReadLock(time, unit); } |
1120 |
catch (InterruptedException ex) { throw new AssertionError(ex); } |
1121 |
} |
1122 |
|
1123 |
/** |
1124 |
* Invalid stamps result in IllegalMonitorStateException |
1125 |
*/ |
1126 |
public void testInvalidStampsThrowIllegalMonitorStateException() { |
1127 |
final StampedLock sl = new StampedLock(); |
1128 |
|
1129 |
assertThrows(IllegalMonitorStateException.class, |
1130 |
() -> sl.unlockWrite(0L), |
1131 |
() -> sl.unlockRead(0L), |
1132 |
() -> sl.unlock(0L)); |
1133 |
|
1134 |
final long optimisticStamp = sl.tryOptimisticRead(); |
1135 |
final long readStamp = sl.readLock(); |
1136 |
sl.unlockRead(readStamp); |
1137 |
final long writeStamp = sl.writeLock(); |
1138 |
sl.unlockWrite(writeStamp); |
1139 |
assertTrue(optimisticStamp != 0L && readStamp != 0L && writeStamp != 0L); |
1140 |
final long[] noLongerValidStamps = { optimisticStamp, readStamp, writeStamp }; |
1141 |
final Runnable assertNoLongerValidStampsThrow = () -> { |
1142 |
for (long noLongerValidStamp : noLongerValidStamps) |
1143 |
assertThrows(IllegalMonitorStateException.class, |
1144 |
() -> sl.unlockWrite(noLongerValidStamp), |
1145 |
() -> sl.unlockRead(noLongerValidStamp), |
1146 |
() -> sl.unlock(noLongerValidStamp)); |
1147 |
}; |
1148 |
assertNoLongerValidStampsThrow.run(); |
1149 |
|
1150 |
for (Function<StampedLock, Long> readLocker : readLockers()) |
1151 |
for (BiConsumer<StampedLock, Long> readUnlocker : readUnlockers()) { |
1152 |
final long stamp = readLocker.apply(sl); |
1153 |
assertValid(sl, stamp); |
1154 |
assertNoLongerValidStampsThrow.run(); |
1155 |
assertThrows(IllegalMonitorStateException.class, |
1156 |
() -> sl.unlockWrite(stamp), |
1157 |
() -> sl.unlockRead(sl.tryOptimisticRead()), |
1158 |
() -> sl.unlockRead(0L)); |
1159 |
readUnlocker.accept(sl, stamp); |
1160 |
assertUnlocked(sl); |
1161 |
assertNoLongerValidStampsThrow.run(); |
1162 |
} |
1163 |
|
1164 |
for (Function<StampedLock, Long> writeLocker : writeLockers()) |
1165 |
for (BiConsumer<StampedLock, Long> writeUnlocker : writeUnlockers()) { |
1166 |
final long stamp = writeLocker.apply(sl); |
1167 |
assertValid(sl, stamp); |
1168 |
assertNoLongerValidStampsThrow.run(); |
1169 |
assertThrows(IllegalMonitorStateException.class, |
1170 |
() -> sl.unlockRead(stamp), |
1171 |
() -> sl.unlockWrite(0L)); |
1172 |
writeUnlocker.accept(sl, stamp); |
1173 |
assertUnlocked(sl); |
1174 |
assertNoLongerValidStampsThrow.run(); |
1175 |
} |
1176 |
} |
1177 |
|
1178 |
/** |
1179 |
* Read locks can be very deeply nested |
1180 |
*/ |
1181 |
public void testDeeplyNestedReadLocks() { |
1182 |
final StampedLock lock = new StampedLock(); |
1183 |
final int depth = 300; |
1184 |
final long[] stamps = new long[depth]; |
1185 |
final List<Function<StampedLock, Long>> readLockers = readLockers(); |
1186 |
final List<BiConsumer<StampedLock, Long>> readUnlockers = readUnlockers(); |
1187 |
for (int i = 0; i < depth; i++) { |
1188 |
Function<StampedLock, Long> readLocker |
1189 |
= readLockers.get(i % readLockers.size()); |
1190 |
long stamp = readLocker.apply(lock); |
1191 |
assertEquals(i + 1, lock.getReadLockCount()); |
1192 |
assertTrue(lock.isReadLocked()); |
1193 |
stamps[i] = stamp; |
1194 |
} |
1195 |
for (int i = 0; i < depth; i++) { |
1196 |
BiConsumer<StampedLock, Long> readUnlocker |
1197 |
= readUnlockers.get(i % readUnlockers.size()); |
1198 |
assertEquals(depth - i, lock.getReadLockCount()); |
1199 |
assertTrue(lock.isReadLocked()); |
1200 |
readUnlocker.accept(lock, stamps[depth - 1 - i]); |
1201 |
} |
1202 |
assertUnlocked(lock); |
1203 |
} |
1204 |
|
1205 |
/** |
1206 |
* Stamped locks are not reentrant. |
1207 |
*/ |
1208 |
public void testNonReentrant() throws InterruptedException { |
1209 |
final StampedLock lock = new StampedLock(); |
1210 |
long stamp; |
1211 |
|
1212 |
stamp = lock.writeLock(); |
1213 |
assertValid(lock, stamp); |
1214 |
assertEquals(0L, lock.tryWriteLock(0L, DAYS)); |
1215 |
assertEquals(0L, lock.tryReadLock(0L, DAYS)); |
1216 |
assertValid(lock, stamp); |
1217 |
lock.unlockWrite(stamp); |
1218 |
|
1219 |
stamp = lock.tryWriteLock(1L, DAYS); |
1220 |
assertEquals(0L, lock.tryWriteLock(0L, DAYS)); |
1221 |
assertValid(lock, stamp); |
1222 |
lock.unlockWrite(stamp); |
1223 |
|
1224 |
stamp = lock.readLock(); |
1225 |
assertEquals(0L, lock.tryWriteLock(0L, DAYS)); |
1226 |
assertValid(lock, stamp); |
1227 |
lock.unlockRead(stamp); |
1228 |
} |
1229 |
|
1230 |
/** |
1231 |
* """StampedLocks have no notion of ownership. Locks acquired in |
1232 |
* one thread can be released or converted in another.""" |
1233 |
*/ |
1234 |
public void testNoOwnership() throws Throwable { |
1235 |
ArrayList<Future<?>> futures = new ArrayList<>(); |
1236 |
for (Function<StampedLock, Long> writeLocker : writeLockers()) |
1237 |
for (BiConsumer<StampedLock, Long> writeUnlocker : writeUnlockers()) { |
1238 |
StampedLock lock = new StampedLock(); |
1239 |
long stamp = writeLocker.apply(lock); |
1240 |
futures.add(cachedThreadPool.submit(new CheckedRunnable() { |
1241 |
public void realRun() { |
1242 |
writeUnlocker.accept(lock, stamp); |
1243 |
assertUnlocked(lock); |
1244 |
assertFalse(lock.validate(stamp)); |
1245 |
}})); |
1246 |
} |
1247 |
for (Future<?> future : futures) |
1248 |
assertNull(future.get()); |
1249 |
} |
1250 |
|
1251 |
/** Tries out sample usage code from StampedLock javadoc. */ |
1252 |
public void testSampleUsage() throws Throwable { |
1253 |
class Point { |
1254 |
private double x, y; |
1255 |
private final StampedLock sl = new StampedLock(); |
1256 |
|
1257 |
void move(double deltaX, double deltaY) { // an exclusively locked method |
1258 |
long stamp = sl.writeLock(); |
1259 |
try { |
1260 |
x += deltaX; |
1261 |
y += deltaY; |
1262 |
} finally { |
1263 |
sl.unlockWrite(stamp); |
1264 |
} |
1265 |
} |
1266 |
|
1267 |
double distanceFromOrigin() { // A read-only method |
1268 |
double currentX, currentY; |
1269 |
long stamp = sl.tryOptimisticRead(); |
1270 |
do { |
1271 |
if (stamp == 0L) |
1272 |
stamp = sl.readLock(); |
1273 |
try { |
1274 |
// possibly racy reads |
1275 |
currentX = x; |
1276 |
currentY = y; |
1277 |
} finally { |
1278 |
stamp = sl.tryConvertToOptimisticRead(stamp); |
1279 |
} |
1280 |
} while (stamp == 0); |
1281 |
return Math.hypot(currentX, currentY); |
1282 |
} |
1283 |
|
1284 |
double distanceFromOrigin2() { |
1285 |
long stamp = sl.tryOptimisticRead(); |
1286 |
try { |
1287 |
retryHoldingLock: |
1288 |
for (;; stamp = sl.readLock()) { |
1289 |
if (stamp == 0L) |
1290 |
continue retryHoldingLock; |
1291 |
// possibly racy reads |
1292 |
double currentX = x; |
1293 |
double currentY = y; |
1294 |
if (!sl.validate(stamp)) |
1295 |
continue retryHoldingLock; |
1296 |
return Math.hypot(currentX, currentY); |
1297 |
} |
1298 |
} finally { |
1299 |
if (StampedLock.isReadLockStamp(stamp)) |
1300 |
sl.unlockRead(stamp); |
1301 |
} |
1302 |
} |
1303 |
|
1304 |
void moveIfAtOrigin(double newX, double newY) { |
1305 |
long stamp = sl.readLock(); |
1306 |
try { |
1307 |
while (x == 0.0 && y == 0.0) { |
1308 |
long ws = sl.tryConvertToWriteLock(stamp); |
1309 |
if (ws != 0L) { |
1310 |
stamp = ws; |
1311 |
x = newX; |
1312 |
y = newY; |
1313 |
return; |
1314 |
} |
1315 |
else { |
1316 |
sl.unlockRead(stamp); |
1317 |
stamp = sl.writeLock(); |
1318 |
} |
1319 |
} |
1320 |
} finally { |
1321 |
sl.unlock(stamp); |
1322 |
} |
1323 |
} |
1324 |
} |
1325 |
|
1326 |
Point p = new Point(); |
1327 |
p.move(3.0, 4.0); |
1328 |
assertEquals(5.0, p.distanceFromOrigin()); |
1329 |
p.moveIfAtOrigin(5.0, 12.0); |
1330 |
assertEquals(5.0, p.distanceFromOrigin2()); |
1331 |
} |
1332 |
|
1333 |
/** |
1334 |
* Stamp inspection methods work as expected, and do not inspect |
1335 |
* the state of the lock itself. |
1336 |
*/ |
1337 |
public void testStampStateInspectionMethods() { |
1338 |
StampedLock lock = new StampedLock(); |
1339 |
|
1340 |
assertFalse(isWriteLockStamp(0L)); |
1341 |
assertFalse(isReadLockStamp(0L)); |
1342 |
assertFalse(isLockStamp(0L)); |
1343 |
assertFalse(isOptimisticReadStamp(0L)); |
1344 |
|
1345 |
{ |
1346 |
long stamp = lock.writeLock(); |
1347 |
for (int i = 0; i < 2; i++) { |
1348 |
assertTrue(isWriteLockStamp(stamp)); |
1349 |
assertFalse(isReadLockStamp(stamp)); |
1350 |
assertTrue(isLockStamp(stamp)); |
1351 |
assertFalse(isOptimisticReadStamp(stamp)); |
1352 |
if (i == 0) |
1353 |
lock.unlockWrite(stamp); |
1354 |
} |
1355 |
} |
1356 |
|
1357 |
{ |
1358 |
long stamp = lock.readLock(); |
1359 |
for (int i = 0; i < 2; i++) { |
1360 |
assertFalse(isWriteLockStamp(stamp)); |
1361 |
assertTrue(isReadLockStamp(stamp)); |
1362 |
assertTrue(isLockStamp(stamp)); |
1363 |
assertFalse(isOptimisticReadStamp(stamp)); |
1364 |
if (i == 0) |
1365 |
lock.unlockRead(stamp); |
1366 |
} |
1367 |
} |
1368 |
|
1369 |
{ |
1370 |
long optimisticStamp = lock.tryOptimisticRead(); |
1371 |
long readStamp = lock.tryConvertToReadLock(optimisticStamp); |
1372 |
long writeStamp = lock.tryConvertToWriteLock(readStamp); |
1373 |
for (int i = 0; i < 2; i++) { |
1374 |
assertFalse(isWriteLockStamp(optimisticStamp)); |
1375 |
assertFalse(isReadLockStamp(optimisticStamp)); |
1376 |
assertFalse(isLockStamp(optimisticStamp)); |
1377 |
assertTrue(isOptimisticReadStamp(optimisticStamp)); |
1378 |
|
1379 |
assertFalse(isWriteLockStamp(readStamp)); |
1380 |
assertTrue(isReadLockStamp(readStamp)); |
1381 |
assertTrue(isLockStamp(readStamp)); |
1382 |
assertFalse(isOptimisticReadStamp(readStamp)); |
1383 |
|
1384 |
assertTrue(isWriteLockStamp(writeStamp)); |
1385 |
assertFalse(isReadLockStamp(writeStamp)); |
1386 |
assertTrue(isLockStamp(writeStamp)); |
1387 |
assertFalse(isOptimisticReadStamp(writeStamp)); |
1388 |
if (i == 0) |
1389 |
lock.unlockWrite(writeStamp); |
1390 |
} |
1391 |
} |
1392 |
} |
1393 |
|
1394 |
/** |
1395 |
* Multiple threads repeatedly contend for the same lock. |
1396 |
*/ |
1397 |
public void testConcurrentAccess() throws Exception { |
1398 |
final StampedLock sl = new StampedLock(); |
1399 |
final Lock wl = sl.asWriteLock(); |
1400 |
final Lock rl = sl.asReadLock(); |
1401 |
final long testDurationMillis = expensiveTests ? 1000 : 2; |
1402 |
final int nTasks = ThreadLocalRandom.current().nextInt(1, 10); |
1403 |
final AtomicBoolean done = new AtomicBoolean(false); |
1404 |
final List<CompletableFuture> futures = new ArrayList<>(); |
1405 |
final List<Callable<Long>> stampedWriteLockers = List.of( |
1406 |
() -> sl.writeLock(), |
1407 |
() -> writeLockInterruptiblyUninterrupted(sl), |
1408 |
() -> tryWriteLockUninterrupted(sl, LONG_DELAY_MS, MILLISECONDS), |
1409 |
() -> { |
1410 |
long stamp; |
1411 |
do { stamp = sl.tryConvertToWriteLock(sl.tryOptimisticRead()); } |
1412 |
while (stamp == 0L); |
1413 |
return stamp; |
1414 |
}, |
1415 |
() -> { |
1416 |
long stamp; |
1417 |
do { stamp = sl.tryWriteLock(); } while (stamp == 0L); |
1418 |
return stamp; |
1419 |
}, |
1420 |
() -> { |
1421 |
long stamp; |
1422 |
do { stamp = sl.tryWriteLock(0L, DAYS); } while (stamp == 0L); |
1423 |
return stamp; |
1424 |
}); |
1425 |
final List<Callable<Long>> stampedReadLockers = List.of( |
1426 |
() -> sl.readLock(), |
1427 |
() -> readLockInterruptiblyUninterrupted(sl), |
1428 |
() -> tryReadLockUninterrupted(sl, LONG_DELAY_MS, MILLISECONDS), |
1429 |
() -> { |
1430 |
long stamp; |
1431 |
do { stamp = sl.tryConvertToReadLock(sl.tryOptimisticRead()); } |
1432 |
while (stamp == 0L); |
1433 |
return stamp; |
1434 |
}, |
1435 |
() -> { |
1436 |
long stamp; |
1437 |
do { stamp = sl.tryReadLock(); } while (stamp == 0L); |
1438 |
return stamp; |
1439 |
}, |
1440 |
() -> { |
1441 |
long stamp; |
1442 |
do { stamp = sl.tryReadLock(0L, DAYS); } while (stamp == 0L); |
1443 |
return stamp; |
1444 |
}); |
1445 |
final List<Consumer<Long>> stampedWriteUnlockers = List.of( |
1446 |
stamp -> sl.unlockWrite(stamp), |
1447 |
stamp -> sl.unlock(stamp), |
1448 |
stamp -> assertTrue(sl.tryUnlockWrite()), |
1449 |
stamp -> wl.unlock(), |
1450 |
stamp -> sl.tryConvertToOptimisticRead(stamp)); |
1451 |
final List<Consumer<Long>> stampedReadUnlockers = List.of( |
1452 |
stamp -> sl.unlockRead(stamp), |
1453 |
stamp -> sl.unlock(stamp), |
1454 |
stamp -> assertTrue(sl.tryUnlockRead()), |
1455 |
stamp -> rl.unlock(), |
1456 |
stamp -> sl.tryConvertToOptimisticRead(stamp)); |
1457 |
final Action writer = () -> { |
1458 |
// repeatedly acquires write lock |
1459 |
var locker = chooseRandomly(stampedWriteLockers); |
1460 |
var unlocker = chooseRandomly(stampedWriteUnlockers); |
1461 |
while (!done.getAcquire()) { |
1462 |
long stamp = locker.call(); |
1463 |
try { |
1464 |
assertTrue(isWriteLockStamp(stamp)); |
1465 |
assertTrue(sl.isWriteLocked()); |
1466 |
assertFalse(isReadLockStamp(stamp)); |
1467 |
assertFalse(sl.isReadLocked()); |
1468 |
assertEquals(0, sl.getReadLockCount()); |
1469 |
assertTrue(sl.validate(stamp)); |
1470 |
} finally { |
1471 |
unlocker.accept(stamp); |
1472 |
} |
1473 |
} |
1474 |
}; |
1475 |
final Action reader = () -> { |
1476 |
// repeatedly acquires read lock |
1477 |
var locker = chooseRandomly(stampedReadLockers); |
1478 |
var unlocker = chooseRandomly(stampedReadUnlockers); |
1479 |
while (!done.getAcquire()) { |
1480 |
long stamp = locker.call(); |
1481 |
try { |
1482 |
assertFalse(isWriteLockStamp(stamp)); |
1483 |
assertFalse(sl.isWriteLocked()); |
1484 |
assertTrue(isReadLockStamp(stamp)); |
1485 |
assertTrue(sl.isReadLocked()); |
1486 |
assertTrue(sl.getReadLockCount() > 0); |
1487 |
assertTrue(sl.validate(stamp)); |
1488 |
} finally { |
1489 |
unlocker.accept(stamp); |
1490 |
} |
1491 |
} |
1492 |
}; |
1493 |
for (int i = nTasks; i--> 0; ) { |
1494 |
Action task = chooseRandomly(writer, reader); |
1495 |
futures.add(CompletableFuture.runAsync(checkedRunnable(task))); |
1496 |
} |
1497 |
Thread.sleep(testDurationMillis); |
1498 |
done.setRelease(true); |
1499 |
for (var future : futures) |
1500 |
checkTimedGet(future, null); |
1501 |
} |
1502 |
|
1503 |
} |