process() {a=0; (while a0) aTESTANDSET(X) ) Critical Section X-1; true true true true false - X is a shared variable false - if X-1 was changes to X-0 could cause other false - this solution can only be used with 2 processes false - a is a shared variable processes to wait forever process() {a=0; (while a0) aTESTANDSET(X) ) Critical Section X-1; true true true true false - X is a shared variable false - if X-1 was changes to X-0 could cause other false - this solution can only be used with 2 processes false - a is a shared variable processes to wait forever