shared_unix running as the server concurrent_increment feature have atomic increment across multiple threads

[asppsa]

From Travis, running JRuby:

     Failure/Error: expect(ith_values.combination(2).map { |a, b| a & b }).to all be_empty
       expected [[], [], [276]] to all be empty
          object at index 2 failed to match:
             expected `[276].empty?` to return true, got false

This appears to be an intermittent issue. May have something to do with recent client/server changes.

[asppsa]

Another example:

  1) shared_unix runnning as the server concurrent_increment feature have atomic increment across multiple threads
     Failure/Error: expect(ith_values.combination(2).map { |a, b| a & b }).to all be_empty
       expected [[], [], [279]] to all be empty
          object at index 2 failed to match:
             expected `[279].empty?` to return true, got false

[asppsa]

• Always seems to be JRuby
• Always "running as the server"
• Always using shared_unix
• "reliably unreliable" if that makes sense - the test has failed in the same way several times now, and always seems to be fixed by re-running.