tree c061617c754014e2dae9819eab0257a204a16e21
parent 2c63eee334bca18536060eea2e4a2f7883ef8eb9
author Jeff Hao <jeffhao@google.com> 1410194298 -0700
committer Jeff Hao <jeffhao@google.com> 1410214816 -0700

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

Also adds some extra argument checking and testing for tracing.

Bug: 17412385
Change-Id: I876378d5bd17d75ab346584713b04dc0656d2120