几个主要的source code路径：
/system/core/include/utils/threads.h
/system/core/include/utils/Thread.h
/system/core/include/utils/AndroidThreads.h
/system/core/include/utils/ThreadDefs.h
/system/core/include/system/thread_defs.h
/system/core/libutils/Threads.cpp
原文：http://www.cnblogs.com/roger-yu/p/6429384.html