[ http://issues.apache.org/jira/browse/IBATIS-223?page=comments#action_12360731 ]
Clinton Begin commented on IBATIS-223: -------------------------------------- Okay, architecture soap box.... If that particular object is being flushed so often that it causes a thread deadlock.......why are you caching it at all? The lifespan of the object in the cache must only be milliseconds!! :-) Not that this is an excuse for the bug, we'll acknowledge that, but you really shouldn't be caching this particular object. > Thread deadlock due to CacheModel.flush() > ----------------------------------------- > > Key: IBATIS-223 > URL: http://issues.apache.org/jira/browse/IBATIS-223 > Project: iBatis for Java > Type: Bug > Components: SQL Maps > Versions: 2.1.5 > Environment: Redhat Linux ES 3.0 + Weblogic 8.1SP4+iBatis 2.1.5 + OSCache > 2.2 + JGroups 2.2.8 > Reporter: Vincent Royer > > As shown by the following thread dump, a deadlock occurs between thead 7 and > 10. As the result, almost all theads were locked due to this deadlock. > It seems that thread 10 locks the [EMAIL PROTECTED] object in > CacheModel.getObject() then is locked on [EMAIL PROTECTED] in > CacheModel.flush(). In the same time, thread 7 locks [EMAIL PROTECTED] in > CachingStatement.executeQueryForList(), then is lock on [EMAIL PROTECTED] > when calling CacheModel.getLockKey() from CacheModel.putObject(). > Of course, such deadlock occur when 2 threads work with the same cached > object and when this object is often flushed. > Thread-0xc00 "ExecuteThread: '10' for queue: > 'ExecutionAsynchroneThreadQueue'" <Active, priority=5, DAEMON> { > java/util/HashMap.get(Ljava/lang/Object;)Ljava/lang/Object;(Optimized > Method) > > com/ibatis/sqlmap/engine/cache/CacheModel.getObject(Lcom/ibatis/sqlmap/engine/cache/CacheKey;)Ljava/lang/Object;(Optimized > Method) > ^-- Holding lock: com/ibatis/sqlmap/engine/cache/[EMAIL PROTECTED] lock] > > com/ibatis/sqlmap/engine/mapping/statement/CachingStatement.executeQueryForList(Lcom/ibatis/sqlmap/engine/scope/RequestScope;Lcom/ibatis/s > > qlmap/engine/transaction/Transaction;Ljava/lang/Object;II)Ljava/util/List;(Optimized > Method) > > com/ibatis/sqlmap/engine/impl/SqlMapSessionImpl.queryForList(Ljava/lang/String;Ljava/lang/Object;)Ljava/util/List;(Optimized > Method) > > cofidis/fwk/ancestor/DaoAncestor$3.executeSqlAction(Lcom/ibatis/sqlmap/client/SqlMapSession;)Ljava/lang/Object;(Optimized > Method) > .... > Thread-0xa80 "ExecuteThread: '7' for queue: 'ExecutionAsynchroneThreadQueue'" > <Active, priority=5, DAEMON> { > -- Blocked trying to get lock: com/ibatis/sqlmap/engine/cache/[EMAIL > PROTECTED] lock] > jrockit/vm/Threads.shortNap(I)V(Native Method) > jrockit/vm/Locks.waitForThinRelease(Ljava/lang/Object;I)I(Optimized > Method) > > jrockit/vm/Locks.monitorEnterSecondStage(Ljava/lang/Object;I)Ljava/lang/Object;(Optimized > Method) > > jrockit/vm/Locks.monitorEnter(Ljava/lang/Object;)Ljava/lang/Object;(Native > Method) > > com/ibatis/sqlmap/engine/cache/CacheModel.getLock(Lcom/ibatis/sqlmap/engine/cache/CacheKey;)Ljava/lang/Object;(CacheModel.java:324) > > > com/ibatis/sqlmap/engine/cache/CacheModel.putObject(Lcom/ibatis/sqlmap/engine/cache/CacheKey;Ljava/lang/Object;)V(CacheModel.java:313) > > > com/ibatis/sqlmap/engine/mapping/statement/CachingStatement.executeQueryForList(Lcom/ibatis/sqlmap/engine/scope/RequestScope;Lcom/ibatis/s > > qlmap/engine/transaction/Transaction;Ljava/lang/Object;II)Ljava/util/List;(Optimized > Method) > ^-- Holding lock: java/lang/[EMAIL PROTECTED] lock] > > com/ibatis/sqlmap/engine/impl/SqlMapSessionImpl.queryForList(Ljava/lang/String;Ljava/lang/Object;)Ljava/util/List;(Optimized > Method) > > cofidis/fwk/ancestor/DaoAncestor$3.executeSqlAction(Lcom/ibatis/sqlmap/client/SqlMapSession;)Ljava/lang/Object;(Optimized > Method) > > cofidis/fwk/ancestor/DaoAncestor.execute(Lcofidis/fwk/ancestor/DaoAncestor$DaoCallback;)Ljava/lang/Object;(Optimized > Method) > > cofidis/fwk/ancestor/DaoAncestor.executeWithListResult(Lcofidis/fwk/ancestor/DaoAncestor$DaoCallback;)Ljava/util/List;(Optimized > Method) > > cofidis/fwk/ancestor/DaoAncestor.queryForList(Ljava/lang/String;Ljava/lang/Object;)Ljava/util/List;(Optimized > Method) > .... > Thread-0xa00 "ExecuteThread: '6' for queue: 'ExecutionAsynchroneThreadQueue'" > <Active, priority=5, DAEMON> { > -- Blocked trying to get lock: com/ibatis/sqlmap/engine/cache/[EMAIL > PROTECTED] lock] > jrockit/vm/Threads.shortNap(I)V(Native Method) > jrockit/vm/Locks.waitForThinRelease(Ljava/lang/Object;I)I(Optimized > Method) > > jrockit/vm/Locks.monitorEnterSecondStage(Ljava/lang/Object;I)Ljava/lang/Object;(Optimized > Method) > > com/ibatis/sqlmap/engine/cache/CacheModel.getObject(Lcom/ibatis/sqlmap/engine/cache/CacheKey;)Ljava/lang/Object;(Optimized > Method) > > com/ibatis/sqlmap/engine/mapping/statement/CachingStatement.executeQueryForList(Lcom/ibatis/sqlmap/engine/scope/RequestScope;Lcom/ibatis/s > > qlmap/engine/transaction/Transaction;Ljava/lang/Object;II)Ljava/util/List;(Optimized > Method) -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://issues.apache.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira
