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https://issues.apache.org/jira/browse/HBASE-12431?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14233821#comment-14233821
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Jonathan Jarvis commented on HBASE-12431:
-----------------------------------------
Since the ThreadLocal buffer variable is static, it should only be allocated
once for the Result class. The actual variable stored by the thread local is
initialized (and made larger) lazily when a thread uses it.
> Use of getColumnLatestCell(byte[], int, int, byte[], int, int) is Not Thread
> Safe
> ---------------------------------------------------------------------------------
>
> Key: HBASE-12431
> URL: https://issues.apache.org/jira/browse/HBASE-12431
> Project: HBase
> Issue Type: Bug
> Components: Client
> Affects Versions: 0.98.1
> Reporter: Jonathan Jarvis
> Assignee: Jingcheng Du
> Fix For: 1.0.0, 2.0.0, 0.98.9
>
> Attachments: HBASE-12431-V2.diff, HBASE-12431-V3.diff,
> HBASE-12431.diff
>
>
> Result declares that it is NOT THREAD SAFE at the top of the source code, but
> one would assume that refers to many different threads accessing the same
> Result object. I've run into an issue when I have several different threads
> accessing their own Result object that runs into an issue because of use of
> common static member variable.
> I noticed the problem when I switched from:
> getColumnLatestCell(byte[], byte[]) to
> getColumnLatestCell(byte[], int, int, byte[], int, int)
> These methods call different binarySearch methods, the latter invoking:
> protected int binarySearch(final Cell [] kvs,
> 309 final byte [] family, final int foffset, final int flength,
> 310 final byte [] qualifier, final int qoffset, final int qlength) {
> This method utilizes a private static member variable called "buffer"
> If more than one thread is utilizing "buffer" you'll see unpredictable
> behavior unless you synchronize(Result.class) {}.
> If buffer is to remain a static variable, I would recommend changing it to a
> ThreadLocal<byte[]> instead.
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