On Fri, 21 May 2021 08:15:25 GMT, Sergey Bylokhov <s...@openjdk.org> wrote:
> In the fix for JDK-8207150 I have updated the synchronization of some code > paths under one "lock", before that code was synchronized only on some > threads and missing on others. Old review: > http://mail.openjdk.java.net/pipermail/sound-dev/2018-August/000650.html > > That fix introduced this order of locks: "lock"->"synchronized(this)", I have > checked other places and did not found where we use the opposite order. > Unfortunately, one such place exists in the private subclass DirectClip. > > I have checked both usages of synchronized which caused deadlock: > - In the DirectClip class the method setMicrosecondPosition is marked as > "synchronized" but it is unclear why. This method is implemented as a call to > another public method setFramePosition which is not "synchronized" and use > some internal synchronization. So I have removed this keyword. > - In a few places we have the code like this: > > boolean sendEvents = false; > synchronized (this) { > if (this.started != started) { > this.started = started; > sendEvents = true; > } > } > if (sendEvents) {..... > > I doubt that this type of synchronization may help something - the fields are > volatile and we use sendEvents flag after synchronisation block, so I removed > it as well. Any thoughts? This pull request has now been integrated. Changeset: f6f82c31 Author: Sergey Bylokhov <s...@openjdk.org> URL: https://git.openjdk.java.net/jdk/commit/f6f82c31689e68f4263bbbe2314033d69f9049f5 Stats: 128 lines in 4 files changed: 106 ins; 11 del; 11 mod 8266421: Deadlock in Sound System Reviewed-by: prr, azvegint ------------- PR: https://git.openjdk.java.net/jdk/pull/4141
