void acquireReadLock(DiskRegion dr) {
    dr.basicAcquireReadLock();
    synchronized (closeRegionGuard) {
      entryOpsCount.incrementAndGet();
      if (dr.isRegionClosed()) {
        dr.releaseReadLock();
        throw new RegionDestroyedException("The DiskRegion has been closed or destroyed",
            dr.getName());
      }
    }
  }
All callers must have {@link #releaseReadLock(DiskRegion)} in a matching finally block. Note
that this is no longer implemented by getting a read lock but instead locks the same lock that
acquireWriteLock does.

@since GemFire 5.1
geode-core/src/main/java/org/apache/geode/internal/cache/DiskStoreImpl.java