RFR: 8178698: javax/sound/midi/Sequencer/MetaCallback.java failed with timeout [v4]

[Alexander Zuev]

> On m1 mac sometimes (in very rare instance) it takes a long time to get the sequencer so increasing timeout helps with that.
> Also on m1 mac sequencer got notified about the first MetaMessage twice. The reason is unclear but watching for that fixes the problem. Also on Linux sometimes process hangs indefinitely without finishing hold by the com.sun.media.sound.MediaDispatcher. Closing the sequencer at the end of the test helps with that.

Alexander Zuev has updated the pull request incrementally with one additional commit since the last revision:

  Making variables that accessed across different threads volatile
  The workaround for duplicate messages now changed to collect more data instead of making test to pass

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Changes:
  - all: https://git.openjdk.org/jdk/pull/11157/files
  - new: https://git.openjdk.org/jdk/pull/11157/files/791065fb..5647db2e

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=11157&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=11157&range=02-03

  Stats: 17 lines in 1 file changed: 13 ins; 0 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/11157.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11157/head:pull/11157

PR: https://git.openjdk.org/jdk/pull/11157