[jboss-dev-forums] [Design of Messaging on JBoss (Messaging/JBoss)] - Contention on MINA? WAS: Combined codec and packet

Yesterday... Just because I wanted to have a little better understanding of the packages.. I navigated through the code with a debugger :-) And I had seen one interesting thing. org.apache.mina.common.DefaultIoSessionDataStructureFactory has few synchronized collections: | private static class DefaultIoSessionAttributeMap implements IoSessionAttributeMap { | | private final Map<Object, Object> attributes = | Collections.synchronizedMap(new HashMap<Object, Object>(4)); | And on a test I executed today, this appeared in few threads: pool-3-thread-2" prio=1 tid=0x00007f611431de00 nid=0x32aa waiting for monitor entry [0x000000004444b000..0x000000004444be20] | at java.util.Collections$SynchronizedMap.get(Collections.java:1979) | - waiting to lock <0x00007f61296c47c8> (a java.util.Collections$SynchronizedMap) | at org.apache.mina.common.DefaultIoSessionDataStructureFactory$DefaultIoSessionAttributeMap.getAttribute(DefaultIoSessionDataStructureFactory.java:63) | at org.apache.mina.common.AbstractIoSession.getAttribute(AbstractIoSession.java:343) | at org.apache.mina.common.AbstractIoSession.getAttribute(AbstractIoSession.java:339) | at org.apache.mina.common.SimpleIoProcessorPool.getProcessor(SimpleIoProcessorPool.java:236) | at org.apache.mina.common.SimpleIoProcessorPool.flush(SimpleIoProcessorPool.java:181) | at org.apache.mina.common.SimpleIoProcessorPool.flush(SimpleIoProcessorPool.java:1) | at org.apache.mina.common.DefaultIoFilterChain$HeadFilter.filterWrite(DefaultIoFilterChain.java:644) | at org.apache.mina.common.DefaultIoFilterChain.callPreviousFilterWrite(DefaultIoFilterChain.java:467) | at org.apache.mina.common.DefaultIoFilterChain.access$7(DefaultIoFilterChain.java:464) | at org.apache.mina.common.DefaultIoFilterChain$EntryImpl$1.filterWrite(DefaultIoFilterChain.java:835) | Shouldn't this be using concurrent? Are we (including Trustin) aware of that specific possible contention? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4149774#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...