public boolean decRefCount() {
      int rc = refCountUpdater.decrementAndGet(this);
      if (rc < 0) {
        throw new IllegalStateException("rc=" + rc);
      }
      return rc == 0;
    }
Returns true if refCount goes to 0.
geode-core/src/main/java/org/apache/geode/internal/cache/TXManagerImpl.java