Pthread Locks

The name that the POSIX library uses for a lock is a mutex, as it is used to provide mutual exclusion between threads, i.e., if one thread is in the critical section, it excludes the others from entering until it has completed the section. Thus, when you see the following POSIX threads code, you should understand that it is doing the same thing as above (we again use our wrappers that check for errors upon lock and unlock):