C :: Implement Mutex Lock Using Atomic Hardware Instruction

Consider how to implement a mutex lock using an atomic hardware instruction. Assume that the following structure defining the mutex lock is available:

Code:

typedef struct {
int available;
}
lock; (available == 0)

indicates that the lock is available, and a value of 1 indicates that the lock is unavailable. Using this struct, illustrate how the following functions can be implemented using the test and set() and compare and swap() instructions:

void acquire(lock *mutex)
void release(lock *mutex)

Be sure to include any initialization that may be necessary.