Examples with FileLock java.nio.channels.FileLock used on opensource projects

Example 1 with FileLock

use of java.nio.channels.FileLock in project kafka by apache.

the class StateDirectory method lock.

/**
     * Get the lock for the {@link TaskId}s directory if it is available
     * @param taskId
     * @param retry
     * @return true if successful
     * @throws IOException
     */
boolean lock(final TaskId taskId, int retry) throws IOException {
    // we already have the lock so bail out here
    if (locks.containsKey(taskId)) {
        return true;
    }
    final File lockFile = new File(directoryForTask(taskId), LOCK_FILE_NAME);
    final FileChannel channel;
    try {
        channel = getOrCreateFileChannel(taskId, lockFile.toPath());
    } catch (NoSuchFileException e) {
        // file, in this case we will return immediately indicating locking failed.
        return false;
    }
    final FileLock lock = tryLock(retry, channel);
    if (lock != null) {
        locks.put(taskId, lock);
    }
    return lock != null;
}

Example 2 with FileLock

use of java.nio.channels.FileLock in project kafka by apache.

the class StateDirectory method tryLock.

private FileLock tryLock(int retry, final FileChannel channel) throws IOException {
    FileLock lock = tryAcquireLock(channel);
    while (lock == null && retry > 0) {
        try {
            Thread.sleep(200);
        } catch (Exception ex) {
        // do nothing
        }
        retry--;
        lock = tryAcquireLock(channel);
    }
    return lock;
}

Example 3 with FileLock

use of java.nio.channels.FileLock in project android_frameworks_base by ParanoidAndroid.

the class MiniThumbFile method saveMiniThumbToFile.

public synchronized void saveMiniThumbToFile(byte[] data, long id, long magic) throws IOException {
    RandomAccessFile r = miniThumbDataFile();
    if (r == null)
        return;
    long pos = id * BYTES_PER_MINTHUMB;
    FileLock lock = null;
    try {
        if (data != null) {
            if (data.length > BYTES_PER_MINTHUMB - HEADER_SIZE) {
                // not enough space to store it.
                return;
            }
            mBuffer.clear();
            mBuffer.put((byte) 1);
            mBuffer.putLong(magic);
            mBuffer.putInt(data.length);
            mBuffer.put(data);
            mBuffer.flip();
            lock = mChannel.lock(pos, BYTES_PER_MINTHUMB, false);
            mChannel.write(mBuffer, pos);
        }
    } catch (IOException ex) {
        Log.e(TAG, "couldn't save mini thumbnail data for " + id + "; ", ex);
        throw ex;
    } catch (RuntimeException ex) {
        // Other NIO related exception like disk full, read only channel..etc
        Log.e(TAG, "couldn't save mini thumbnail data for " + id + "; disk full or mount read-only? " + ex.getClass());
    } finally {
        try {
            if (lock != null)
                lock.release();
        } catch (IOException ex) {
        // ignore it.
        }
    }
}

Example 4 with FileLock

use of java.nio.channels.FileLock in project XobotOS by xamarin.

the class FileChannelImpl method addLock.

/**
     * Add a new pending lock to the manager. Throws an exception if the lock
     * would overlap an existing lock. Once the lock is acquired it remains in
     * this set as an acquired lock.
     */
private synchronized void addLock(FileLock lock) throws OverlappingFileLockException {
    long lockEnd = lock.position() + lock.size();
    for (FileLock existingLock : locks) {
        if (existingLock.position() > lockEnd) {
            // cannot overlap).
            break;
        }
        if (existingLock.overlaps(lock.position(), lock.size())) {
            throw new OverlappingFileLockException();
        }
    }
    locks.add(lock);
}

Example 5 with FileLock

use of java.nio.channels.FileLock in project XobotOS by xamarin.

the class FileChannelImpl method basicLock.

private FileLock basicLock(long position, long size, boolean shared, boolean wait) throws IOException {
    int accessMode = (mode & O_ACCMODE);
    if (accessMode == O_RDONLY) {
        if (!shared) {
            throw new NonWritableChannelException();
        }
    } else if (accessMode == O_WRONLY) {
        if (shared) {
            throw new NonReadableChannelException();
        }
    }
    if (position < 0 || size < 0) {
        throw new IllegalArgumentException("position=" + position + " size=" + size);
    }
    FileLock pendingLock = new FileLockImpl(this, position, size, shared);
    addLock(pendingLock);
    StructFlock flock = new StructFlock();
    flock.l_type = (short) (shared ? F_RDLCK : F_WRLCK);
    flock.l_whence = (short) SEEK_SET;
    flock.l_start = position;
    flock.l_len = translateLockLength(size);
    boolean success = false;
    try {
        success = (Libcore.os.fcntlFlock(fd, wait ? F_SETLKW64 : F_SETLK64, flock) != -1);
    } catch (ErrnoException errnoException) {
        throw errnoException.rethrowAsIOException();
    } finally {
        if (!success) {
            removeLock(pendingLock);
        }
    }
    return success ? pendingLock : null;
}