default boolean isLocked() {
    return hasExclusiveLock() || getSharedLockCount() > 0;
  }
Return whether this lock has already been held,
<p/>
Notice that, holding the exclusive lock or shared lock are both considered as locked, i.e, this
method usually equals to {@code hasExclusiveLock() || getSharedLockCount() > 0}.
hbase-procedure/src/main/java/org/apache/hadoop/hbase/procedure2/LockStatus.java