Pranay Singh has posted comments on this change. ( http://gerrit.cloudera.org:8080/8215 )
Change subject: IMPALA-5142 EventSequence displays negative elapsed time. ...................................................................... Patch Set 1: (1 comment) http://gerrit.cloudera.org:8080/#/c/8215/1//COMMIT_MSG Commit Message: http://gerrit.cloudera.org:8080/#/c/8215/1//COMMIT_MSG@22 PS1, Line 22: value. > That's right since the code not synchronized we can read a garbage start_ w In the thread doing ClientRequestState::ClientRequestState() a) When the function AddEventSequence() is called, an EventSequence with the name is looked for, if found then the EventSequence is returned else a new event sequence gets created. b) Then after the query_events->Start(0 resets the monotonic time for the EventSequence, so say in this case a matching name for "Query Timeline" was found In another thread which is done doing AdmissionController::AdmitQuery(QuerySchedule* schedule) in the mean time will have ScopedEvent destroyed for the same EventSequence and since they are not serialized we may hit upon this issue. /// Utility class to mark an event when the object is destroyed. class ScopedEvent { ..... /// Mark the event when the object is destroyed ~ScopedEvent() { event_sequence_->MarkEvent(label_); ---> } }; -- To view, visit http://gerrit.cloudera.org:8080/8215 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I8c944396d96473b17b453da3e913ffc56680a896 Gerrit-Change-Number: 8215 Gerrit-PatchSet: 1 Gerrit-Owner: Pranay Singh Gerrit-Reviewer: Dan Hecht <[email protected]> Gerrit-Reviewer: Pranay Singh Gerrit-Comment-Date: Tue, 17 Oct 2017 21:55:54 +0000 Gerrit-HasComments: Yes
