@Override
  protected void setEntryHash(final int hash) {
    this.hash = hash;
  }
I needed to add this because I wanted clear to call setValue which normally can only be called
while the re is synced. But if I sync in that code it causes a lock ordering deadlock with the
disk regions because they also get a rw lock in clear. Some hardware platforms do not support
CAS on a long. If gemfire is run on one of those the AtomicLongFieldUpdater does a sync on the
RegionEntry and we will once again be deadlocked. I don't know if we support any of the
hardware platforms that do not have a 64bit CAS. If we do then we can expect deadlocks on disk
regions.
geode-core/src/main/java/org/apache/geode/internal/cache/entries/VersionedThinLRURegionEntryOffHeapObjectKey.java