hadoop-mapreduce-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Gera Shegalov (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (MAPREDUCE-4844) Counters.java doesn't obey Java Memory Model
Date Tue, 31 Mar 2015 05:43:53 GMT

    [ https://issues.apache.org/jira/browse/MAPREDUCE-4844?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14388048#comment-14388048
] 

Gera Shegalov commented on MAPREDUCE-4844:
------------------------------------------

Thanks for working on this old  JIRA, [~brahmareddy]! Changes to {{mapred.Counters}} look
fine to me. Can you also add a final qualifier to a bunch maps towards the top of the {{counters.AbstractCounters}}
class?

> Counters.java doesn't obey Java Memory Model
> --------------------------------------------
>
>                 Key: MAPREDUCE-4844
>                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-4844
>             Project: Hadoop Map/Reduce
>          Issue Type: Bug
>    Affects Versions: 3.0.0, 2.6.0
>            Reporter: Gera Shegalov
>            Assignee: Brahma Reddy Battula
>         Attachments: MAPREDUCE-4844-002.patch, MAPREDUCE-4844-branch-1.patch
>
>
> Counters have a number of immutable fields that have not been declared 'final'.
> For example, the field groups is not final. It is, however, accessed in a couple of methods
that are declared 'synchronized'. While there is a happens-before relationship between these
methods calls, there is none between the Counters object initialization and these synchronized
methods.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Mime
View raw message