Examples with MultiLock uk.ac.ic.doc.slurp.multilock.MultiLock used on opensource projects

Example 1 with MultiLock

use of uk.ac.ic.doc.slurp.multilock.MultiLock in project exist by eXist-db.

the class LockManager method acquireDocumentWriteLock.

/**
 * Acquire a WRITE_LOCK on a Document
 *
 * @param documentPath The URI of the Document within the database
 *
 * @return the lock for the Document
 *
 * @throws LockException if the lock could not be acquired
 */
public ManagedDocumentLock acquireDocumentWriteLock(final XmldbURI documentPath) throws LockException {
    if (usePathLocksForDocuments) {
        final LockGroup lockGroup = acquirePathWriteLock(LockType.DOCUMENT, documentPath, false);
        return new ManagedDocumentLock(documentPath, Arrays.stream(lockGroup.locks).map(Tuple3::get_1).toArray(MultiLock[]::new), () -> unlockAll(lockGroup.locks, l -> lockTable.released(lockGroup.groupId, l._3, LockType.DOCUMENT, l._2)));
    } else {
        final long groupId = System.nanoTime();
        final String path = documentPath.toString();
        final MultiLock lock = getDocumentLock(path);
        lockTable.attempt(groupId, path, LockType.DOCUMENT, Lock.LockMode.WRITE_LOCK);
        if (lock(lock, Lock.LockMode.WRITE_LOCK)) {
            lockTable.acquired(groupId, path, LockType.DOCUMENT, Lock.LockMode.WRITE_LOCK);
        } else {
            lockTable.attemptFailed(groupId, path, LockType.DOCUMENT, Lock.LockMode.WRITE_LOCK);
            throw new LockException("Unable to acquire WRITE_LOCK for: " + path);
        }
        return new ManagedDocumentLock(documentPath, lock, () -> {
            lock.asWriteLock().unlock();
            lockTable.released(groupId, path, LockType.DOCUMENT, Lock.LockMode.WRITE_LOCK);
        });
    }
}

Example 2 with MultiLock

use of uk.ac.ic.doc.slurp.multilock.MultiLock in project exist by eXist-db.

the class LockManager method acquireDocumentReadLock.

/**
 * Acquire a READ_LOCK on a Document
 *
 * @param documentPath The URI of the Document within the database
 *
 * @return the lock for the Document
 *
 * @throws LockException if the lock could not be acquired
 */
public ManagedDocumentLock acquireDocumentReadLock(final XmldbURI documentPath) throws LockException {
    if (usePathLocksForDocuments) {
        final LockGroup lockGroup = acquirePathReadLock(LockType.DOCUMENT, documentPath);
        return new ManagedDocumentLock(documentPath, Arrays.stream(lockGroup.locks).map(Tuple3::get_1).toArray(MultiLock[]::new), () -> unlockAll(lockGroup.locks, l -> lockTable.released(lockGroup.groupId, l._3, LockType.DOCUMENT, l._2)));
    } else {
        final long groupId = System.nanoTime();
        final String path = documentPath.toString();
        final MultiLock lock = getDocumentLock(path);
        lockTable.attempt(groupId, path, LockType.DOCUMENT, Lock.LockMode.READ_LOCK);
        if (lock(lock, Lock.LockMode.READ_LOCK)) {
            lockTable.acquired(groupId, path, LockType.DOCUMENT, Lock.LockMode.READ_LOCK);
        } else {
            lockTable.attemptFailed(groupId, path, LockType.DOCUMENT, Lock.LockMode.READ_LOCK);
            throw new LockException("Unable to acquire READ_LOCK for: " + path);
        }
        return new ManagedDocumentLock(documentPath, lock, () -> {
            lock.asReadLock().unlock();
            lockTable.released(groupId, path, LockType.DOCUMENT, Lock.LockMode.READ_LOCK);
        });
    }
}

Example 3 with MultiLock

use of uk.ac.ic.doc.slurp.multilock.MultiLock in project exist by eXist-db.

the class LockManagerTest method getCollectionLock_isStripedByPath.

@Test
public void getCollectionLock_isStripedByPath() {
    final LockManager lockManager = new LockManager(CONCURRENCY_LEVEL);
    final MultiLock dbLock1 = lockManager.getPathLock("/db");
    assertNotNull(dbLock1);
    final MultiLock dbLock2 = lockManager.getPathLock("/db");
    assertNotNull(dbLock2);
    assertTrue(dbLock1 == dbLock2);
    final MultiLock abcLock = lockManager.getPathLock("/db/a/b/c");
    assertNotNull(abcLock);
    assertFalse(dbLock1 == abcLock);
    final MultiLock defLock = lockManager.getPathLock("/db/d/e/f");
    assertNotNull(defLock);
    assertFalse(dbLock1 == defLock);
    assertFalse(abcLock == defLock);
}

Example 4 with MultiLock

use of uk.ac.ic.doc.slurp.multilock.MultiLock in project exist by eXist-db.

the class LockManager method acquirePathWriteLock.

/**
 * Acquires a WRITE_LOCK on a path (and implicitly all descendant paths).
 *
 * @param path The path for which a lock is requested.
 * @param lockParent true if we should also explicitly write lock the parent path.
 *
 * @return A WRITE_LOCK on the path.
 */
LockGroup acquirePathWriteLock(final LockType lockType, final XmldbURI path, final boolean lockParent) throws LockException {
    final XmldbURI[] segments = path.getPathSegments();
    final long groupId = System.nanoTime();
    String pathStr = "";
    final Tuple3<MultiLock, Lock.LockMode, String>[] locked = new Tuple3[segments.length];
    for (int i = 0; i < segments.length; i++) {
        pathStr += '/' + segments[i].toString();
        final Lock.LockMode lockMode;
        if (lockParent && i + 2 == segments.length) {
            // parent
            lockMode = Lock.LockMode.WRITE_LOCK;
        } else if (i + 1 == segments.length) {
            // leaf
            lockMode = Lock.LockMode.WRITE_LOCK;
        } else {
            if (!pathsMultiWriter) {
                // single-writer/multi-reader
                lockMode = Lock.LockMode.WRITE_LOCK;
            } else {
                // multi-writer/multi-reader
                lockMode = Lock.LockMode.INTENTION_WRITE;
            }
        }
        final MultiLock lock = getPathLock(pathStr);
        if (upgradeCheck && lockMode == Lock.LockMode.WRITE_LOCK && (lock.getIntentionReadHoldCount() > 0 || lock.getReadHoldCount() > 0)) {
            throw new LockException("Lock upgrading would lead to a self-deadlock: " + pathStr);
        }
        if (warnWaitOnReadForWrite && lockMode == Lock.LockMode.WRITE_LOCK) {
            if (lock.getIntentionReadLockCount() > 0) {
                LOG.warn("About to acquire WRITE_LOCK for: {}, but INTENTION_READ_LOCK held by other thread(s): ", pathStr);
            } else if (lock.getReadLockCount() > 0) {
                LOG.warn("About to acquire WRITE_LOCK for: {}, but READ_LOCK held by other thread(s): ", pathStr);
            }
        }
        lockTable.attempt(groupId, pathStr, lockType, lockMode);
        if (lock(lock, lockMode)) {
            locked[i] = new Tuple3<>(lock, lockMode, pathStr);
            lockTable.acquired(groupId, pathStr, lockType, lockMode);
        } else {
            lockTable.attemptFailed(groupId, pathStr, lockType, lockMode);
            unlockAll(locked, l -> lockTable.released(groupId, l._3, lockType, l._2));
            throw new LockException("Unable to acquire " + lockType + " " + lockMode + " for: " + pathStr);
        }
    }
    return new LockGroup(groupId, locked);
}

Example 5 with MultiLock

use of uk.ac.ic.doc.slurp.multilock.MultiLock in project exist by eXist-db.

the class LockManager method acquirePathReadLock.

/**
 * Acquires a READ_LOCK on a database path (and implicitly all descendant paths).
 *
 * @param lockType The type of the lock
 * @param path The path for which a lock is requested.
 *
 * @return A READ_LOCK on the Collection.
 *
 * @throws LockException if a lock error occurs
 */
public LockGroup acquirePathReadLock(final LockType lockType, final XmldbURI path) throws LockException {
    final XmldbURI[] segments = path.getPathSegments();
    final long groupId = System.nanoTime();
    String pathStr = "";
    final Tuple3<MultiLock, Lock.LockMode, String>[] locked = new Tuple3[segments.length];
    for (int i = 0; i < segments.length; i++) {
        pathStr += '/' + segments[i].toString();
        final Lock.LockMode lockMode;
        if (i + 1 == segments.length) {
            // leaf
            lockMode = Lock.LockMode.READ_LOCK;
        } else {
            // ancestor
            lockMode = Lock.LockMode.INTENTION_READ;
        }
        final MultiLock lock = getPathLock(pathStr);
        lockTable.attempt(groupId, pathStr, lockType, lockMode);
        if (lock(lock, lockMode)) {
            locked[i] = new Tuple3<>(lock, lockMode, pathStr);
            lockTable.acquired(groupId, pathStr, lockType, lockMode);
        } else {
            lockTable.attemptFailed(groupId, pathStr, lockType, lockMode);
            unlockAll(locked, l -> lockTable.released(groupId, l._3, lockType, l._2));
            throw new LockException("Unable to acquire " + lockType + " " + lockMode + " for: " + pathStr);
        }
    }
    return new LockGroup(groupId, locked);
}