Atomic Operations in OS

Advantage and Disadvantage of Atomic Operations

Advantage

Atomic operations are usually faster when compared to locks. Also, they do not suffer from issues of deadlocks and convoying.

Disadvantage

One restraining factor of atomic operations is that they only execute a limited number of processes and cannot function efficiently when complicated processes are to be executed.

Example of Atomic Operation

• Consider a process in which the value of temp is to be fetched and incremented by 1.
• Let initially, the value of temp be 0.
• Now after the execution of the process the value of temp is increased by 1 and it becomes equal to 1.
• However, now this processes is pre-empted and a new process is initiated, which also use the value of temp and increase its value by 5.
• Now, the value of temp becomes 6 as the initial value was 1, which is then increased by 5.
• After, completion of this process, when the first process starts its execution again, the value of temp becomes 5+1=6.
• However, the expected result, in this case, was 1+1=2. Hence, a wrong solution is generated.
• Nevertheless, in the case of atomic operations, the value of temp can neither be read nor modified, thereby ensuring the accuracy of results.