<Sound Dev> [9] Review Request: 8156169 Some sound tests rarely hangs because of incorrect synchronization

[Sergey Bylokhov]

Hello, Audio Guru.

Please review the fix for jdk9.
While working on some bugs reported by the mach5 project, I found that 
some of our tests are quite unstable, and the reason was in this(or 
similar) pattern:
....
clip.start();
while(clip.isRunning());
....
The status of the clip is run or not is updated on a different thread, 
but our clip implementation lacks of synchronization of getters and the 
hotspot inline such methods to while(true). There are some other flags 
which have the similar issue, I tried to fix all of them in the proposed 
version of the fix.

Also I propose the small cleanup of Sequence.java
  - It is not necessary to sync tracks.removeElement() on tracks, 
because this is synchronized method.
  - tracks.toArray(new Track[tracks.size()]) should be synchronized on 
tracks, because the problem can occurs between tracks.size() and 
tracks.toArray(). But I decided to pass the empty array, so all the work 
will be done in toArray() which is synchronized method.

Bug: https://bugs.openjdk.java.net/browse/JDK-8156169
Webrev can be found at: http://cr.openjdk.java.net/~serb/8156169/webrev.01


-- 
Best regards, Sergey.