What are the requirements for solution of critical section problems?
Mutual exclusion: If process p is implementing in its critical section then no other processes can be executing in their critical sections.
Progress : if no process is implementing in its critical section and some process wish to enter their critical section then only those processes that are not executing in their remainder section can participate in the decision on which will enter its critical section next and this selection can't be postponed indefinitely.
Bounded waiting: there subsist a bound on the number of times that other processes are allowed to enter their critical section after a process has made a request to enter its critical section and previous to that request is granted.