tree 98399fb92eaeefab47daf6ce9b77f03ffb8841d8
parent 5bc47ebe278af65e8e2a2d6b603ac94a020285f7
author Jeff Hao <jeffhao@google.com> 1410194298 -0700
committer Jeff Hao <jeffhao@google.com> 1410287978 -0700

Change when sampling thread is reset during shutdown to prevent races.

Also adds some extra argument checking and testing for tracing.

Bug: 17412385

(cherry picked from commit f8bdd4e783842577e49f418a0b5962ba49dfdd93)

Change-Id: Ifc4f1a296155d73255b29d264b5475024e6419da