[HADOOP-11786] Fix Javadoc typos in org.apache.hadoop.fs.FileSystem

• Type: Bug
• Status: Resolved
• Priority: Trivial
• Resolution: Fixed
• Affects Version/s: 2.6.0
• Fix Version/s: 2.9.0, 3.0.0-alpha1
• Component/s: documentation
• Labels: newbie++
• Hadoop Flags: Reviewed
• Assignee: Andras Bokor
• Reporter: Chen He
• Created: 01/Apr/15 18:10
• Updated: 17/Nov/16 11:55
• Resolved: 17/Aug/16 22:05

Description

/**

• 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.