src/Pure/Concurrent/synchronized.scala
2014-04-24 wenzelm 2014-04-24 proper signaling after each state update (NB: ML version does this uniformly via timed_access);
2014-04-24 wenzelm 2014-04-24 synchronized access, similar to ML version;
2014-04-24 wenzelm 2014-04-24 tuned signature in accordance to ML version;
2014-04-24 wenzelm 2014-04-24 more uniform synchronized variables;