[ https://issues.apache.org/jira/browse/LUCENE-8720?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Michael McCandless resolved LUCENE-8720. ---------------------------------------- Resolution: Fixed Fix Version/s: (was: 7.1.1) 8.1 master (9.0) > Integer overflow bug in NameIntCacheLRU.makeRoomLRU() > ----------------------------------------------------- > > Key: LUCENE-8720 > URL: https://issues.apache.org/jira/browse/LUCENE-8720 > Project: Lucene - Core > Issue Type: Bug > Components: core/search > Affects Versions: 7.7.1 > Environment: Mac OS X 10.11.6 but this bug is not affected by the > environment because it is a straightforward integer overflow bug. > Reporter: Russell A Brown > Priority: Major > Labels: easyfix, patch > Fix For: master (9.0), 8.1 > > Attachments: LUCENE-NNNN.patch > > > The NameIntCacheLRU.makeRoomLRU() method has an integer overflow bug because > if maxCacheSize >= Integer.MAX_VALUE/2, 2*maxCacheSize will overflow to > -(2^30) and the value of n will overflow to a negative integer as well, which > will prevent any clearing of the cache whatsoever. Hence, performance will > degrade once the cache becomes full because it will be impossible to remove > any entries in order to add new entries to the cache. > Moreover, comments in NameIntCacheLRU.java and LruTaxonomyWriterCache.java > indicate that 2/3 of the cache will be cleared, whereas in fact only 1/3 of > the cache is cleared. So as not to change the behavior of the > NameIntCacheLRU.makeRoomLRU() method, I have not changed the code to clear > 2/3 of the cache but instead I have changed the comments to indicate that 1/3 > of the cache is cleared. -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org For additional commands, e-mail: dev-h...@lucene.apache.org