[PATCH] Review quest for bug 8023878 TEST_BUG java/nio/file/WatchService/SensitivityModifier.java fails intermittently

[Eric Wang]

Hi,

Please help to review the fix 
http://cr.openjdk.java.net/~ewang/8023878/webrev.00/ for bug 
https://bugs.openjdk.java.net/browse/JDK-8023878.

There's a defect in the loop of old test as below, if the eventRecived 
is true, the while loop is broken which causes keys of watcher are not 
reset, it causes the watcher.take() is hung in next execution in the for 
loop.

for (int i=0; i<10; i++) {
     ......
     boolean eventReceived = false;
     WatchKey key = watcher.take();
     do {
         for (WatchEvent<?> event: key.pollEvents()) {
             if (event.kind() != ENTRY_MODIFY)
                 throw new RuntimeException("Unexpected event: " + event);
             Path name = ((WatchEvent<Path>)event).context();
             if (name.equals(file.getFileName())) {
                 eventReceived = true;
                 break; // jump out to while loop and the events of the 
key is not reset
             }
         }
         key.reset();
         key = watcher.poll(1, TimeUnit.SECONDS);
     } while (key != null && !eventReceived)

Thanks,
Eric