pentaho/mondrian — pull request #88 by mkambol (2013-06-10 20:58:12+00:00)
Title: [MONDRIAN-1471]  Switched RolapSchemaReader.getMemberReader() from being...

... synchronized at the method level to using a double-checked lock instead. getMemberReader() is called frequently inside of nested loops;
this approach should reduce some amount of thread contention.