title: how is it possible, 3 threads are in blocked state waiting same monitor, and there is no thread owned that monitor
body: <p>In our production environment, weblogic server hangs for half an hour, It looks like it has dead-locked threads. But after investigating thread dumps, 3 threads are blocked for the same lock, but no other threads own this lock.. Here is the <a href="https://docs.google.com/leaf?id=0B8sSS_DN3oWnNjAyMTRiMGEtZTFmMS00ZWNjLTkzMTEtNjQwNzA0MDJjMDYx&amp;hl=en_US" rel="nofollow">stacktrace</a>..</p>
  
  <p>Do you have any reasonable explanation for this stiuation?.</p>
  
  <p>Here is the blocked threads;</p>
  
  <blockquote>
    <p>"pool-1013-thread-5" prio=7 tid=600000000842be00 nid=17280
    lwp_id=518677 waiting for monitor entry
    [9fffffffe6aff000..9fffffffe6b00bd0]    java.lang.Thread.State:
    BLOCKED (on object monitor)   at
    org.apache.log4j.Category.callAppenders(Category.java:201)
      - waiting to lock &lt;9ffffffde1e7ec88> (a
    org.apache.log4j.spi.RootLogger)  at
    org.apache.log4j.Category.forcedLog(Category.java:388)    at
    org.apache.log4j.Category.log(Category.java:853)  at
    org.slf4j.impl.Log4jLoggerAdapter.debug(Log4jLoggerAdapter.java:173)
      at
    org.hibernate.jdbc.AbstractBatcher.logOpenResults(AbstractBatcher.java:426)
      at
    org.hibernate.jdbc.AbstractBatcher.getResultSet(AbstractBatcher.java:210)
      at org.hibernate.loader.Loader.getResultSet(Loader.java:1808)</p>
    
    <p>"pool-1013-thread-4" prio=7 tid=6000000008413400 nid=17279
    lwp_id=518676 waiting for monitor entry
    [9fffffffe6eff000..9fffffffe6f00b50]    java.lang.Thread.State:
    BLOCKED (on object monitor)   at
    org.apache.log4j.Category.callAppenders(Category.java:201)
      - waiting to lock &lt;9ffffffde1e7ec88> (a
    org.apache.log4j.spi.RootLogger)  at
    org.apache.log4j.Category.forcedLog(Category.java:388)    at
    org.apache.log4j.Category.log(Category.java:853)  at
    org.slf4j.impl.Log4jLoggerAdapter.debug(Log4jLoggerAdapter.java:173)
      at org.hibernate.loader.Loader.getRow(Loader.java:1197)     at
    org.hibernate.loader.Loader.getRowFromResultSet(Loader.java:603)  at
    org.hibernate.loader.Loader.doQuery(Loader.java:724)  at
    org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:259)
      at org.hibernate.loader.Loader.loadEntity(Loader.java:1881)     at
    org.hibernate.loader.entity.AbstractEntityLoader.load(AbstractEntityLoader.java:71)
      at
    org.hibernate.loader.entity.AbstractEntityLoader.load(AbstractEntityLoader.java:65)
      at
    org.hibernate.persister.entity.AbstractEntityPersister.load(AbstractEntityPersister.java:3072)
      at
    org.hibernate.event.def.DefaultLoadEventListener.loadFromDatasource(DefaultLoadEventListener.java:434)
      at
    org.hibernate.event.def.DefaultLoadEventListener.doLoad(DefaultLoadEventListener.java:415)
      at
    org.hibernate.event.def.DefaultLoadEventListener.load(DefaultLoadEventListener.java:165)
      at
    org.hibernate.event.def.DefaultLoadEventListener.proxyOrLoad(DefaultLoadEventListener.java:223)
      at
    org.hibernate.event.def.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:126)
      at org.hibernate.impl.SessionImpl.fireLoad(SessionImpl.java:905)</p>
    
    <p>"pool-1013-thread-3" prio=7 tid=6000000008411c00 nid=17278
    lwp_id=518675 waiting for monitor entry
    [9fffffffe70ff000..9fffffffe7100ad0]    java.lang.Thread.State:
    BLOCKED (on object monitor)   at
    org.apache.log4j.Category.callAppenders(Category.java:201)
      - waiting to lock &lt;9ffffffde1e7ec88> (a
    org.apache.log4j.spi.RootLogger)  at
    org.apache.log4j.Category.forcedLog(Category.java:388)    at
    org.apache.log4j.Category.log(Category.java:853)  at
    org.slf4j.impl.Log4jLoggerAdapter.debug(Log4jLoggerAdapter.java:173)
      at
    org.hibernate.jdbc.AbstractBatcher.logOpenResults(AbstractBatcher.java:426)
      at
    org.hibernate.jdbc.AbstractBatcher.getResultSet(AbstractBatcher.java:210)
      at org.hibernate.loader.Loader.getResultSet(Loader.java:1808)   at
    org.hibernate.loader.Loader.doQuery(Loader.java:697)</p>
  </blockquote>