Message:

  A new issue has been created in JIRA.

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View the issue:
  http://issues.apache.org/jira/browse/GERONIMO-288

Here is an overview of the issue:
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        Key: GERONIMO-288
    Summary: NIO Network code might send unordered messages
       Type: Bug

     Status: Unassigned
   Priority: Major

    Project: Apache Geronimo
 Components: 
             core

   Assignee: 
   Reporter: Bulent Erdemir

    Created: Tue, 24 Aug 2004 8:15 AM
    Updated: Tue, 24 Aug 2004 8:15 AM

Description:
Hi, 
Geronimo network code might deliver messages out of order. 

To be more specific, the network code tries to write a buffer and if 
remaining()>0, registers an OP_WRITE interest in order to drain the buffer 
contents later (when the channel is available for write). When the server is 
loaded, things can get hairy and we might receive another write event which 
might get scheduled to run before the OP_WRITE is processed. 

More specifically, SocketProtocol.serviceWrite reads:

 long count = socketChannel.write(sendBuffer);
            log.trace("Wrote " + count);
if (sendBuffer[i].hasRemaining()) {
                    // not all was delivered in this call setup selector
                    // so we setup to finish sending async.
                    log.trace("+OP_WRITE " + selectionKey);
                    selectorManager.addInterestOps(selectionKey, 
SelectionKey.OP_WRITE);

                    return;
                }

Since there's no synchronization, in a situation where the selector returns 
with OP_WRITE (in SelectorManager) but not yet finds the chance to process the 
event, another thread loaded with a read event might sneak in and call the 
above lines, the result of which would be sending data out of order. 

Regards,
Bulent Erdemir


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