@Override
  public EvictableEntry getEvictableEntry() {
    int evictionAttempts = 0;
    for (;;) {
      final EvictionNode evictionNode = unlinkHeadEntry();

      if (evictionNode == null) {
        // hit the end of the list
        return null;
      }

      if (logger.isTraceEnabled(LogMarker.LRU_CLOCK_VERBOSE)) {
        logger.trace(LogMarker.LRU_CLOCK_VERBOSE, "lru considering {}", evictionNode);
      }

      if (!isEvictable(evictionNode)) {
        continue;
      }

      if (evictionNode.isRecentlyUsed() && evictionAttempts < maxEvictionAttempts) {
        evictionAttempts++;
        evictionNode.unsetRecentlyUsed();
        appendEntry(evictionNode);
        continue;
      }

      if (logger.isTraceEnabled(LogMarker.LRU_CLOCK_VERBOSE)) {
        logger.trace(LogMarker.LRU_CLOCK_VERBOSE, "returning unused entry: {}", evictionNode);
      }
      if (evictionNode.isRecentlyUsed()) {
        scanIfNeeded();
        getStatistics().incGreedyReturns(1);
      }
      return (EvictableEntry) evictionNode;
    }
  }
Remove and return the Entry that is considered least recently used.
geode-core/src/main/java/org/apache/geode/internal/cache/eviction/LRUListWithAsyncSorting.java