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Chen He commented on HADOOP-11786: ---------------------------------- Thank you for the patch, [~boky01]. I will review it this week. > Fix Javadoc typos in org.apache.hadoop.fs.FileSystem > ---------------------------------------------------- > > Key: HADOOP-11786 > URL: https://issues.apache.org/jira/browse/HADOOP-11786 > Project: Hadoop Common > Issue Type: Bug > Components: documentation > Affects Versions: 2.6.0 > Reporter: Chen He > Assignee: Yanjun Wang > Priority: Trivial > Labels: newbie++ > Attachments: HADOOP-11786.patch > > > /** > * Resets all statistics to 0. > * > * In order to reset, we add up all the thread-local statistics data, and > * set rootData to the negative of that. > * > * This may seem like a counterintuitive way to reset the statsitics. Why > * can't we just zero out all the thread-local data? Well, thread-local > * data can only be modified by the thread that owns it. If we tried to > * modify the thread-local data from this thread, our modification might > get > * interleaved with a read-modify-write operation done by the thread that > * owns the data. That would result in our update getting lost. > * > * The approach used here avoids this problem because it only ever reads > * (not writes) the thread-local data. Both reads and writes to rootData > * are done under the lock, so we're free to modify rootData from any > thread > * that holds the lock. > */ > etc. -- This message was sent by Atlassian JIRA (v6.3.4#6332)