atomic variables are the variables which can only be

manipulated atomically using atomic APIs. Linux declares

variable as atomic by using the type atomic_t. Basically

used a way to achieve synchronization.

an atomic operation is one which cannot be (or is not)

interrupted by concurrent operations and cannot be broken up

into smaller parts that could be performed by different

processors.

Atomic function is a function which is executed to

completion without interruption. Atomic function can also be

seen as a small critical section which is executed without

interruption, locking.