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https://issues.apache.org/jira/browse/MAHOUT-409?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12875362#action_12875362
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Jake Mannix commented on MAHOUT-409:
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So as the creator of the not-correctly-synchronizing bug, the original
intention of it is actually improperly used in
o.a.m.math.decomposer.AsyncEigenVerifier, which sync's on an EigenStatus: one
thread is doing computation, and another thread is doing computation in a loop.
The latter thread after each iteration, checks the EigenStatus to see if it's
still "inProgress()", which the first thread sets to false when it's done.
Unfortunately, I don't think even that is being done correctly, if you look at
how it's done, it's not synchronizing on a proper final lock object.
So while yes, removing the lock on the boolean is correct, it reminds me that
the way thread synchronization was coded (by me), it appears to have been done
completely unsafely. As it turns out, the synchronization in practice is
between two different threads who only make checks once every couple 10's of
seconds up to once every 10's of minutes (depending on the data set), and so
collisions on updating a single reference are basically infinitessimal.
Doesn't make it any more correct, but fairly innocuous, at least.
> Find bugs finds some bugs in our code
> -------------------------------------
>
> Key: MAHOUT-409
> URL: https://issues.apache.org/jira/browse/MAHOUT-409
> Project: Mahout
> Issue Type: Bug
> Reporter: Ted Dunning
> Attachments: MAHOUT-409.patch, MAHOUT-409.patch
>
>
> I will produce a patch shortly that fixes some low hanging fruit highlighted
> by findbugs.
> Notably this:
> http://hudson.zones.apache.org/hudson/job/Mahout-Quality/48/findbugsResult/HIGH/type.-1824009442/source.8285/#44
> and
> http://hudson.zones.apache.org/hudson/job/Mahout-Quality/48/findbugsResult/HIGH/type.-694648638/
> and
> http://hudson.zones.apache.org/hudson/job/Mahout-Quality/48/findbugsResult/HIGH/type.-1787470473/
> and
> http://hudson.zones.apache.org/hudson/job/Mahout-Quality/48/findbugsResult/HIGH/type.921339475/
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