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

Example 61 with FileLock

use of java.nio.channels.FileLock in project spf4j by zolyfarkas.

the class TimeSeriesDatabase method reReadTableInfos.

public void reReadTableInfos() throws IOException {
    synchronized (path) {
        FileLock lock = ch.lock(0, Long.MAX_VALUE, true);
        try {
            // reread toc
            toc = new TableOfContents(file, toc.getLocation());
            readTableInfos();
        } catch (IOException | RuntimeException e) {
            try {
                lock.release();
                throw e;
            } catch (IOException ex) {
                ex.addSuppressed(e);
                throw ex;
            }
        }
        lock.release();
    }
}

Example 62 with FileLock

use of java.nio.channels.FileLock in project spf4j by zolyfarkas.

the class TimeSeriesDatabase method addTSTable.

public void addTSTable(final String tableName, final byte[] tableMetaData, final int sampleTime, final String[] columnNames, final byte[][] columnMetaData) throws IOException {
    synchronized (path) {
        if (hasTSTable(tableName)) {
            throw new IllegalArgumentException("group already exists " + tableName);
        }
        flush();
        FileLock lock = ch.lock();
        TSTable colInfo;
        try {
            readLastTableInfo();
            // write column information at the end of the file.
            file.seek(file.length());
            colInfo = new TSTable(tableName, tableMetaData, columnNames, columnMetaData, sampleTime, file.getFilePointer());
            colInfo.writeTo(file);
            // update refferences to this new TableInfo.
            if (lastTableInfo != null) {
                lastTableInfo.setNextColumnInfo(colInfo.getLocation(), file);
            } else {
                toc.setFirstTableInfo(colInfo.getLocation(), file);
            }
            toc.setLastTableInfo(colInfo.getLocation(), file);
        } catch (IOException | RuntimeException e) {
            try {
                lock.release();
                throw e;
            } catch (IOException ex) {
                ex.addSuppressed(e);
                throw ex;
            }
        }
        lock.release();
        lastTableInfo = colInfo;
        tables.put(tableName, colInfo);
    }
}

Example 63 with FileLock

use of java.nio.channels.FileLock in project twister2 by DSC-SPIDAL.

the class KubernetesWorker method updateCompletions.

/**
 * update the count in the shared file with a lock
 * to let other workers in this pod to know that a worker has finished
 * @return
 */
public static int updateCompletions() {
    String completionsFile = POD_SHARED_VOLUME + "/" + COMPLETIONS_FILE_NAME;
    try {
        Path path = Paths.get(completionsFile);
        FileChannel fileChannel = FileChannel.open(path, StandardOpenOption.WRITE, StandardOpenOption.READ);
        LOG.info("Opened File channel. Acquiring lock ...");
        // exclusive lock
        FileLock lock = fileChannel.lock();
        LOG.info("Acquired the file lock. Validity of the lock: " + lock.isValid());
        // read the counter from the file
        ByteBuffer buffer = ByteBuffer.allocate(20);
        int noOfBytesRead = fileChannel.read(buffer);
        byte[] readByteArray = buffer.array();
        String inStr = new String(readByteArray, 0, noOfBytesRead, StandardCharsets.UTF_8);
        int count = Integer.parseInt(inStr);
        // update the counter and write back to the file
        count++;
        String outStr = Integer.toString(count);
        byte[] outByteArray = outStr.getBytes(StandardCharsets.UTF_8);
        ByteBuffer outBuffer = ByteBuffer.wrap(outByteArray);
        fileChannel.write(outBuffer, 0);
        LOG.info("Counter in file [" + completionsFile + "] updated to: " + count);
        // close the file channel and release the lock
        // also releases the lock
        fileChannel.close();
        return count;
    } catch (IOException e) {
        LOG.log(Level.SEVERE, "Exception when updating the counter in file: " + completionsFile, e);
        return -1;
    }
}

Example 64 with FileLock

use of java.nio.channels.FileLock in project apache-kafka-on-k8s by banzaicloud.

the class StateDirectory method lockGlobalState.

synchronized boolean lockGlobalState() throws IOException {
    if (globalStateLock != null) {
        log.trace("{} Found cached state dir lock for the global task", logPrefix());
        return true;
    }
    final File lockFile = new File(globalStateDir(), LOCK_FILE_NAME);
    final FileChannel channel;
    try {
        channel = FileChannel.open(lockFile.toPath(), StandardOpenOption.CREATE, StandardOpenOption.WRITE);
    } catch (NoSuchFileException e) {
        // file, in this case we will return immediately indicating locking failed.
        return false;
    }
    final FileLock fileLock = tryLock(channel);
    if (fileLock == null) {
        channel.close();
        return false;
    }
    globalStateChannel = channel;
    globalStateLock = fileLock;
    log.debug("{} Acquired global state dir lock", logPrefix());
    return true;
}

Example 65 with FileLock

use of java.nio.channels.FileLock in project apache-kafka-on-k8s by banzaicloud.

the class StateDirectory method lock.

/**
 * Get the lock for the {@link TaskId}s directory if it is available
 * @param taskId
 * @return true if successful
 * @throws IOException
 */
synchronized boolean lock(final TaskId taskId) throws IOException {
    final File lockFile;
    // we already have the lock so bail out here
    final LockAndOwner lockAndOwner = locks.get(taskId);
    if (lockAndOwner != null && lockAndOwner.owningThread.equals(Thread.currentThread().getName())) {
        log.trace("{} Found cached state dir lock for task {}", logPrefix(), taskId);
        return true;
    } else if (lockAndOwner != null) {
        // another thread owns the lock
        return false;
    }
    try {
        lockFile = new File(directoryForTask(taskId), LOCK_FILE_NAME);
    } catch (ProcessorStateException e) {
        // has concurrently deleted the directory
        return false;
    }
    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(channel);
    if (lock != null) {
        locks.put(taskId, new LockAndOwner(Thread.currentThread().getName(), lock));
        log.debug("{} Acquired state dir lock for task {}", logPrefix(), taskId);
    }
    return lock != null;
}