atomic operation function in C language

http://gcc.gnu.org/onlinedocs/gcc/Atomic-Builtins.html
http://library.gnome.org/devel/glib/2.16/glib-Atomic-Operations.html
http://java.sun.com/javase/6/docs/api/java/util/concurrent/atomic/AtomicReferenceFieldUpdater.html
https://stage.maemo.org/svn/maemo/projects/haf/branches/glib2.0/2.8.6-1osso5/glib/gatomic.c
http://www.sogou.com/labs/report/4-2.pdf