RFR of JDK-8049316: TEST_BUG: java/nio/channels/Selector/Wakeup.java fails in same binary run b19

[Roger Riggs]

Hi Hamlin,

Wakeup.java:

  - Some refactoring may make it easier to understand.
    Perhaps moving waitSleeper to be a method on Sleeper.
    The use of cyclicBarrier seems fine but could use a comment 
somewhere saying what
threads/functions are being coordinated; putting them both in Sleeper 
would make it easier to see.

- line 126,127:  Add a Sleeper constructor to initialize these as needed.

- Some of the test stimulus is buried in the newSleeper methods that was 
previously
   in line in main.  It seemed clearer what case was being tested in the 
original.
   They are buried in static factory 'newSleeper' functions with 
uninformative names.
    lines 112, 116, 120.

  - If I read it right, some cases where events don't happen that used 
to be reported as exceptions
    ("Interrupt never delivered") will now be reported as the test 
timing out.  (infinite loop at line 85).

Thanks, Roger

On 11/29/2016 4:23 AM, Hamlin Li wrote:
> Would you please review the below patch?
>
> bug: https://bugs.openjdk.java.net/browse/JDK-8049316
> webrev: http://cr.openjdk.java.net/~mli/8049316/webrev.00/
>
> Root cause:
> 1. it depends on sleeping time to check failure, which is not reliable 
> in some extreme situation
> 2. it mix several tests together with a loop in Sleeper
>
> Solution:
> 1. synchronize between threads.
> 2. isolate tests.
>
> Thank you
> Hamlin