/**
* Block until we can acquire a non-exclusive mutator lock on the servers 's persistent state.
* This lock should be acquired in a <code>try</code> block and a <code>releaseMutatorLock</code>
* call should be placed in a <code>finally</code> block.
*/
public void acquireMutatorLock() {
// Do we already hold a lock?
Long lockStateVal = lockState.get();
if (lockStateVal == null) lockStateVal = zero;
final long longVal = lockStateVal;
if (longVal == 0) {
// No, this thread currently does not hold a lock,
// grab non-exclusive lock (which for mutatorLock is a
// read lock)
mutatorLock.readLock();
}
// Ether way, bump the lock count and update our thread state
lockState.set(longVal + 1);
}
