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

Example 91 with FileLock

use of java.nio.channels.FileLock in project activemq-artemis by apache.

the class FileLockNodeManager method writeFileLockStatus.

/**
 * @param status
 * @throws IOException
 */
private void writeFileLockStatus(byte status) throws Exception {
    if (replicatedBackup && channel == null)
        return;
    logger.debug("writing status: " + status);
    ByteBuffer bb = ByteBuffer.allocateDirect(1);
    bb.put(status);
    bb.position(0);
    if (!channel.isOpen()) {
        setUpServerLockFile();
    }
    FileLock lock = null;
    try {
        lock = lock(STATE_LOCK_POS);
        channel.write(bb, 0);
        channel.force(true);
    } finally {
        if (lock != null) {
            lock.release();
        }
    }
}

Example 92 with FileLock

use of java.nio.channels.FileLock in project activemq-artemis by apache.

the class FileLockNodeManager method tryLock.

protected FileLock tryLock(final long lockPos) throws IOException {
    try {
        logger.debug("trying to lock position: " + lockPos);
        FileLock lock = channel.tryLock(lockPos, LOCK_LENGTH, false);
        if (lock != null) {
            logger.debug("locked position: " + lockPos);
        } else {
            logger.debug("failed to lock position: " + lockPos);
        }
        return lock;
    } catch (java.nio.channels.OverlappingFileLockException ex) {
        // This just means that another object on the same JVM is holding the lock
        return null;
    }
}

Example 93 with FileLock

use of java.nio.channels.FileLock in project activemq-artemis by apache.

the class FileLockNodeManager method lock.

protected FileLock lock(final long lockPosition) throws Exception {
    long start = System.currentTimeMillis();
    while (!interrupted) {
        FileLock lock = tryLock(lockPosition);
        if (lock == null) {
            try {
                Thread.sleep(500);
            } catch (InterruptedException e) {
                return null;
            }
            if (lockAcquisitionTimeout != -1 && (System.currentTimeMillis() - start) > lockAcquisitionTimeout) {
                throw new Exception("timed out waiting for lock");
            }
        } else {
            return lock;
        }
    }
    // todo this is here because sometimes channel.lock throws a resource deadlock exception but trylock works,
    // need to investigate further and review
    FileLock lock;
    do {
        lock = tryLock(lockPosition);
        if (lock == null) {
            try {
                Thread.sleep(500);
            } catch (InterruptedException e1) {
            // 
            }
        }
        if (interrupted) {
            interrupted = false;
            throw new IOException("Lock was interrupted");
        }
    } while (lock == null);
    return lock;
}

Example 94 with FileLock

use of java.nio.channels.FileLock in project jdepth by Crab2died.

the class FileLockUtil method main.

public static void main(String... args) {
    try {
        // mod 'r'  'rw'  'rws'  'rwd'
        try (RandomAccessFile fis = new RandomAccessFile("D:\\资料\\myFile.txt", "rws");
            FileChannel ch = fis.getChannel();
            FileLock fl = ch.tryLock()) {
            if (null != fl) {
                int len;
                byte[] buf = new byte[1024];
                while ((len = fis.read(buf)) != -1) {
                    System.out.println(new String(buf, 0, len));
                }
            }
            fis.seek(0);
            fis.write("aaaaddda".getBytes());
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
}

Example 95 with FileLock

use of java.nio.channels.FileLock in project maven-clean-plugin by apache.

the class CleanMojoTest method testCleanLockedFile.

/**
 * Test the removal of a locked file on Windows systems.
 * <p>
 * Note: Unix systems doesn't lock any files.
 * </p>
 *
 * @throws Exception in case of an error.
 */
public void testCleanLockedFile() throws Exception {
    if (!System.getProperty("os.name").toLowerCase().contains("windows")) {
        assertTrue("Ignored this test on none Windows based systems", true);
        return;
    }
    String pluginPom = getBasedir() + "/src/test/resources/unit/locked-file-test/plugin-pom.xml";
    // safety
    FileUtils.copyDirectory(new File(getBasedir(), "src/test/resources/unit/locked-file-test"), new File(getBasedir(), "target/test-classes/unit/locked-file-test"), null, "**/.svn,**/.svn/**");
    CleanMojo mojo = (CleanMojo) lookupMojo("clean", pluginPom);
    assertNotNull(mojo);
    File f = new File(getBasedir(), "target/test-classes/unit/locked-file-test/buildDirectory/file.txt");
    FileChannel channel = null;
    FileLock lock = null;
    try {
        channel = new RandomAccessFile(f, "rw").getChannel();
        lock = channel.lock();
        mojo.execute();
        fail("Should fail to delete a file that is locked");
    } catch (MojoExecutionException expected) {
        assertTrue(true);
    } finally {
        if (lock != null) {
            lock.release();
        }
        if (channel != null) {
            channel.close();
        }
    }
}