ref: 830f663db481f4566d0da79d2c29069d1e38a36d dir: /cas.c/
#include "u.h" #include "libc.h" int cas(int *x, int old, int new) { return __atomic_compare_exchange_n(x, &old, new, 0, __ATOMIC_ACQ_REL, __ATOMIC_ACQUIRE); }