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

Example 21 with FileLock

use of java.nio.channels.FileLock in project platform_frameworks_base by android.

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 22 with FileLock

use of java.nio.channels.FileLock in project CoreNLP by stanfordnlp.

the class FileBackedCache method acquireFileLock.

@SuppressWarnings("SynchronizationOnLocalVariableOrMethodParameter")
protected FileSemaphore acquireFileLock(File f) throws IOException {
    assert canonicalFile.intern(f.getCanonicalFile()) == f;
    synchronized (f) {
        // Check semaphore
        synchronized (fileLocks) {
            if (fileLocks.containsKey(f)) {
                FileSemaphore sem = fileLocks.get(f);
                if (sem.isActive()) {
                    sem.take();
                    return sem;
                } else {
                    fileLocks.remove(f);
                }
            }
        }
        // Get the channel
        FileChannel channel = new RandomAccessFile(f, "rw").getChannel();
        FileLock lockOrNull = null;
        // Try the lock
        for (int i = 0; i < 1000; ++i) {
            lockOrNull = channel.tryLock();
            if (lockOrNull == null || !lockOrNull.isValid()) {
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    log(e);
                    throw new RuntimeInterruptedException(e);
                }
                if (i % 60 == 59) {
                    warn("FileBackedCache", "Lock still busy after " + ((i + 1) / 60) + " minutes");
                }
                //noinspection UnnecessaryContinue
                continue;
            } else {
                break;
            }
        }
        if (lockOrNull == null) {
            warn("FileBackedCache", "Could not acquire file lock! Continuing without lock");
        }
        // Return
        FileSemaphore sem = new FileSemaphore(lockOrNull, channel);
        synchronized (fileLocks) {
            fileLocks.put(f, sem);
        }
        return sem;
    }
}

Example 23 with FileLock

use of java.nio.channels.FileLock in project syncany by syncany.

the class LockFile method execute.

@Override
public void execute() throws Exception {
    if (state.containsKey("lockedFile")) {
        throw new Exception("Currently only one file can be locked at a time.");
    }
    File file = pickFile(7878);
    log(this, file.getAbsolutePath());
    RandomAccessFile randomAccessFile = new RandomAccessFile(file, "rw");
    FileLock fileLock = randomAccessFile.getChannel().lock();
    state.put(STATE_KEY_RANDOM_ACCESS_FILE, randomAccessFile);
    state.put(STATE_KEY_FILE_LOCK, fileLock);
// Do not (!) close this file
}

Example 24 with FileLock

use of java.nio.channels.FileLock in project syncany by syncany.

the class FileUtilTest method testFileLocked.

@Test
public void testFileLocked() throws Exception {
    // Setup
    File tempDir = TestFileUtil.createTempDirectoryInSystemTemp();
    // Run
    File lockedFile = TestFileUtil.createRandomFileInDirectory(tempDir, 50 * 1024);
    // Test
    assertFalse("File should not be locked: " + lockedFile, FileUtil.isFileLocked(lockedFile));
    RandomAccessFile fileLock = new RandomAccessFile(lockedFile, "rw");
    FileLock lockedFileLock = fileLock.getChannel().lock();
    assertTrue("File should be locked: " + lockedFile, FileUtil.isFileLocked(lockedFile));
    // Tear down
    lockedFileLock.release();
    fileLock.close();
    Path bFilePath = Paths.get(lockedFile.getAbsolutePath());
    if (EnvironmentUtil.isWindows()) {
        Files.setAttribute(bFilePath, "dos:readonly", true);
    } else if (EnvironmentUtil.isUnixLikeOperatingSystem()) {
        Files.setPosixFilePermissions(bFilePath, PosixFilePermissions.fromString("r--r--r--"));
    }
    assertFalse("File should not be locked if read-only: " + lockedFile, FileUtil.isFileLocked(lockedFile));
    // Tear down
    TestFileUtil.deleteDirectory(tempDir);
}

Example 25 with FileLock

use of java.nio.channels.FileLock in project syncany by syncany.

the class FileUtil method isFileLocked.

public static boolean isFileLocked(File file) {
    if (!file.exists()) {
        return false;
    }
    if (file.isDirectory()) {
        return false;
    }
    if (isSymlink(file)) {
        return false;
    }
    RandomAccessFile randomAccessFile = null;
    boolean fileLocked = false;
    try {
        // Test 1 missing permissions or locked file parts. If File is not readable == locked
        randomAccessFile = new RandomAccessFile(file, "r");
        randomAccessFile.close();
    } catch (Exception e) {
        fileLocked = true;
    }
    if (!fileLocked && file.canWrite()) {
        try {
            // Test 2:Locked file parts
            randomAccessFile = new RandomAccessFile(file, "rw");
            // Test 3: Set lock and release it again
            FileLock fileLock = randomAccessFile.getChannel().tryLock();
            if (fileLock == null) {
                fileLocked = true;
            } else {
                try {
                    fileLock.release();
                } catch (Exception e) {
                /* Nothing */
                }
            }
        } catch (Exception e) {
            fileLocked = true;
        }
        if (randomAccessFile != null) {
            try {
                randomAccessFile.close();
            } catch (IOException e) {
            /* Nothing */
            }
        }
    }
    return fileLocked;
}