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  1. JGroups
  2. JGRP-2026

GroupRequest concurrency issue

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    • Icon: Bug Bug
    • Resolution: Done
    • Icon: Major Major
    • 3.6.9
    • 3.6.8
    • None

      GroupRequest.responsesComplete() is supposed to be called only while holding the lock (@GuardedBy("lock")). But GroupRequest.receiveResponse() calls Request.checkCompletion() outside the lock, which then calls GroupRequest.responsesComplete().

      Because this happens outside the lock, there is no happens-before relationship, and a thread can notify the request listener after another seeing the numReceived incremented by another thread, but without seeing the Rsp.value set by that other thread.

      23:22:21,328 TRACE (transport-thread-MultiNodeDistributedTest-NodeB-p8-t6) [JGroupsTransport] dests=null, command=CacheTopologyControlCommand{cache=null, type=GET_STATUS, sender=MultiNodeDistributedTest-NodeB-28202, joinInfo=null, topologyId=0, rebalanceId=0, currentCH=null, pendingCH=null, availabilityMode=null, actualMembers=null, throwable=null, viewId=4}, mode=SYNCHRONOUS, timeout=240000
      23:22:21,329 TRACE (transport-thread-MultiNodeDistributedTest-NodeB-p8-t6) [MessageDispatcher] real_dests=[MultiNodeDistributedTest-NodeC-19310, MultiNodeDistributedTest-NodeD-7096]
      23:22:21,351 TRACE (remote-thread-MultiNodeDistributedTest-NodeD-p26-t3) [CommandAwareRpcDispatcher] About to send back response SuccessfulResponse{responseValue=...}  for command CacheTopologyControlCommand{cache=null, type=GET_STATUS, sender=null, joinInfo=null, topologyId=0, rebalanceId=0, currentCH=null, pendingCH=null, availabilityMode=null, actualMembers=null, throwable=null, viewId=4}
      23:22:21,361 TRACE (remote-thread-MultiNodeDistributedTest-NodeC-p18-t6) [CommandAwareRpcDispatcher] About to send back response SuccessfulResponse{responseValue=...}  for command CacheTopologyControlCommand{cache=null, type=GET_STATUS, sender=null, joinInfo=null, topologyId=0, rebalanceId=0, currentCH=null, pendingCH=null, availabilityMode=null, actualMembers=null, throwable=null, viewId=4}
      23:22:21,418 TRACE (remote-thread-MultiNodeDistributedTest-NodeD-p26-t3) [UNICAST3] MultiNodeDistributedTest-NodeD-7096 --> DATA(MultiNodeDistributedTest-NodeB-28202: #24, conn_id=1)
      23:22:21,418 TRACE (remote-thread-MultiNodeDistributedTest-NodeC-p18-t6) [UNICAST3] MultiNodeDistributedTest-NodeC-19310 --> DATA(MultiNodeDistributedTest-NodeB-28202: #68, conn_id=1)
      23:22:21,427 TRACE (OOB-2,MultiNodeDistributedTest-NodeB-28202) [UNICAST3] MultiNodeDistributedTest-NodeB-28202: delivering MultiNodeDistributedTest-NodeD-7096#24
      23:22:21,431 TRACE (OOB-1,MultiNodeDistributedTest-NodeB-28202) [UNICAST3] MultiNodeDistributedTest-NodeB-28202: delivering MultiNodeDistributedTest-NodeC-19310#68
      23:22:21,455 TRACE (OOB-2,MultiNodeDistributedTest-NodeB-28202) [JGroupsTransport] Responses: [sender=MultiNodeDistributedTest-NodeC-19310, received=false, suspected=false]
      [sender=MultiNodeDistributedTest-NodeD-7096, retval=SuccessfulResponse{responseValue=...} , received=true, suspected=false]
      

              rhn-engineering-bban Bela Ban
              dberinde@redhat.com Dan Berindei (Inactive)
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