7144086: TEST_BUG: java/nio/file/WatchService/SensitivityModifier.java failing intermittently

[Alan Bateman]

A few days I fixed the @run tag in this test because it was actually 
running a different test:

http://hg.openjdk.java.net/jdk8/tl/jdk/rev/c6d6ef8ec2bf

Now that the real test is running it turns out that it has a bug which 
causes it hang. I didn't observe this prior to pushing the above change. 
The hang is intermittent and is because the test doesn't drain events 
correctly between each iteration of the test. It is trivially fixed with 
the attached patch.

Thanks,
Alan.

diff --git a/test/java/nio/file/WatchService/SensitivityModifier.java 
b/test/java/nio/file/WatchService/SensitivityModifier.java
--- a/test/java/nio/file/WatchService/SensitivityModifier.java
+++ b/test/java/nio/file/WatchService/SensitivityModifier.java
@@ -96,6 +96,7 @@ public class SensitivityModifier {

              // drain events (to avoid interference)
              do {
+                key.pollEvents();
                  key.reset();
                  key = watcher.poll(1, TimeUnit.SECONDS);
              } while (key != null);