14 #define atomic_read(atomic)	((atomic)->value)   // 读取原子变量
15 #define atomic_set(atomic,val)	(((atomic)->value) = (val)) // 设置原子变量的初始值
19     volatile long value;  member
31                  : "=m"(ato->value)  in atomic_add()
45                  : "=m"(ato->value)  in atomic_sub()
58                  : "=m"(ato->value)  in atomic_inc()
59                  : "m"(ato->value)  in atomic_inc()
71                  : "=m"(ato->value)  in atomic_dec()
72                  : "m"(ato->value)  in atomic_dec()
84                          : "=m"(ato->value)  in atomic_set_mask()
97                          : "=m"(ato->value)  in atomic_clear_mask()
105     bool success = arch_try_cmpxchg(&ato->value, &oldval, newval);  in atomic_cmpxchg()