pthread_create already includes the necessary memory barriers:
- parent at pthread_create : pthread_mutex_unlock(start_mutex)
- child at __thread_entry : pthread_mutex_lock(start_mutex)
Add lock around uses of mThread.
Added comments:
- uses of mThread require lock
- androidCreateRawThreadEtc returned ID is not safe for direct use from non-parent threads.
Change-Id: I18cb296b41ddaf64cf127b57aab31154319b5970
d9e1bb76fe