Hi JV, Are you sure about this patch? It looks like it's adding a synchronize() that was not there before and thus all threads will be waiting on this synchronize. Since checkHibernate is called for all database access I'm worried this could lead to performance issues.

Has this been tested for performance with a tool like JMeter to simulate multiple users? Note that I haven't analyzed the patch. I'm just worried that we might be introducing a regression in term of performance. If the session factory is only created once then maybe it should be created on app init?

Thanks -Vincent On Apr 10, 2008, at 6:21 PM, jvdrean (SVN) wrote: > Author: jvdrean > Date: 2008-04-10 18:21:07 +0200 (Thu, 10 Apr 2008) > New Revision: 9071 > > Modified: > xwiki-platform/core/branches/xwiki-core-1.3/xwiki-core/src/main/ > java/com/xpn/xwiki/store/XWikiHibernateBaseStore.java > Log: > XWIKI-2300 : HibernateStore synchronization problem > > Applied patch by Raffaello Pelagalli without modification. Added > comment. > > Modified: xwiki-platform/core/branches/xwiki-core-1.3/xwiki-core/src/ > main/java/com/xpn/xwiki/store/XWikiHibernateBaseStore.java > =================================================================== > --- xwiki-platform/core/branches/xwiki-core-1.3/xwiki-core/src/main/ > java/com/xpn/xwiki/store/XWikiHibernateBaseStore.java 2008-04-10 > 14:45:54 UTC (rev 9070) > +++ xwiki-platform/core/branches/xwiki-core-1.3/xwiki-core/src/main/ > java/com/xpn/xwiki/store/XWikiHibernateBaseStore.java 2008-04-10 > 16:21:07 UTC (rev 9071) > @@ -510,13 +510,18 @@ > */ > public void checkHibernate(XWikiContext context) throws > HibernateException > { > - > + // Note : double locking is not a recommended pattern and > is not guaranteed to work on all > + // machines. See for example http://www.ibm.com/developerworks/java/library/j-dcl.html > if (getSessionFactory() == null) { > - initHibernate(); > - > - /* Check Schema */ > - if (getSessionFactory() != null) { > - updateSchema(context); > + synchronized(this) { > + if (getSessionFactory() == null) { > + > + initHibernate(); > + /* Check Schema */ > + if (getSessionFactory() != null) { > + updateSchema(context); > + } > + } > } > } > } >