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

[Alex Menkov]

Hi Sergey,

Most of the fix looks good to me, but I'm not sure change in 
Sequence.deleteTrack is correct.
As far as I understand synchronized(track) are to make safe 
getTickLength method (otherwise we can get 
ArrayIndexOutOfBoundsException there)

--alex

On 17.05.2016 17:30, Sergey Bylokhov wrote:
> 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
>
>