core/src/main/java/com/orientechnologies/common/concur/lock/ScalableRWLock.java
public boolean exclusiveTryLockNanos(long nanosTimeout) throws InterruptedException {
    final long lastTime = System.nanoTime();
    // Try to acquire the lock in write-mode
    if (stampedLock.tryWriteLock(nanosTimeout, TimeUnit.NANOSECONDS) == 0) {
      return false;
    }

    // We can only do this after writerOwner has been set to the current thread
    AtomicInteger[] localReadersStateArray = readersStateArrayRef.get();
    if (localReadersStateArray == null) {
      // Set to dummyArray before scanning the readersStateList to impose
      // a linearizability condition
      readersStateArrayRef.set(dummyArray);
      // Copy readersStateList to an array
      localReadersStateArray = readersStateList.toArray(new AtomicInteger[readersStateList.size()]);
      readersStateArrayRef.compareAndSet(dummyArray, localReadersStateArray);
    }

    // Scan the array of Reader states
    for (AtomicInteger readerState : localReadersStateArray) {
      while (readerState != null && readerState.get() == SRWL_STATE_READING) {
        if (System.nanoTime() - lastTime < nanosTimeout) {
          Thread.yield();
        } else {
          // Time has expired and there is at least one ongoing Reader so give up
          stampedLock.asWriteLock().unlock();
          return false;
        }
      }
    }

    return true;
  }
public boolean exclusiveTryLockNanos(long nanosTimeout) throws InterruptedException {
    final long lastTime = System.nanoTime();
    // Try to acquire the lock in write-mode
    if (stampedLock.tryWriteLock(nanosTimeout, TimeUnit.NANOSECONDS) == 0) {
      return false;
    }

    // We can only do this after writerOwner has been set to the current thread
    AtomicInteger[] localReadersStateArray = readersStateArrayRef.get();
    if (localReadersStateArray == null) {
      // Set to dummyArray before scanning the readersStateList to impose
      // a linearizability condition
      readersStateArrayRef.set(dummyArray);
      // Copy readersStateList to an array
      localReadersStateArray = readersStateList.toArray(new AtomicInteger[readersStateList.size()]);
      readersStateArrayRef.compareAndSet(dummyArray, localReadersStateArray);
    }

    // Scan the array of Reader states
    for (AtomicInteger readerState : localReadersStateArray) {
      while (readerState != null && readerState.get() == SRWL_STATE_READING) {
        if (System.nanoTime() - lastTime < nanosTimeout) {
          Thread.yield();
        } else {
          // Time has expired and there is at least one ongoing Reader so give up
          stampedLock.asWriteLock().unlock();
          return false;
        }
      }
    }

    return true;
  }
Acquires the write lock if it is not held by another thread
within the given waiting time.
<p>Acquires the write lock if the write lock is not
held by another thread and returns immediately with
the value {@code true} if and only if no other thread is attempting a
read lock, setting the write lock {@code reentrantWriterCount}
to one. If another thread is attempting a read lock, this
function <b>may yield until the read lock is released</b>.
<p>If the current thread already holds this lock then the
{@code reentrantWriterCount} is incremented by one and the method returns
{@code true}.
<p>If the write lock is held by another thread then the current
thread yields and lies dormant until one of two things happens:
<ul>
<li>The write lock is acquired by the current thread; or
<li>The specified waiting time elapses
</ul>
<p>If the write lock is acquired then the value {@code true} is
returned and the write lock {@code reentrantWriterCount} is set to one.

@param nanosTimeout the time to wait for the write lock in nanoseconds

@return {@code true} if the lock was free and was acquired
by the current thread, or the write lock was already held by the
current thread; and {@code false} if the waiting time
elapsed before the lock could be acquired.