#vulnerable code 
                             @Override
	public int read(ByteBuffer buffer, long offset) throws IOException {
		int requested = buffer.remaining();

		if (offset + requested > this.size) {
			throw new IllegalArgumentException("Invalid storage read request!");
		}

		int bytes = this.channel.read(buffer, offset);
		if (bytes < requested) {
			throw new IOException("Storage underrun!");
		}

		return bytes;
	} 
                            #location 9 
                            #vulnerability type THREAD_SAFETY_VIOLATION
#fixed code
                             @Override
	public int read(ByteBuffer buffer, long offset) throws IOException {
      try {
        myLock.readLock().lock();
		int requested = buffer.remaining();

		if (offset + requested > this.size) {
			throw new IllegalArgumentException("Invalid storage read request!");
		}

		int bytes = this.channel.read(buffer, offset);
		if (bytes < requested) {
			throw new IOException("Storage underrun!");
		}

		return bytes;
      } finally {
        myLock.readLock().unlock();
      }
    }