Introduction

Peterson's synchronization mechanism is a classic algorithm used to provide mutual exclusion in concurrent programming. It was proposed by Gary L. Peterson in 1981 and is widely used in operating systems and parallel computing.

A. Progress is guaranteed

Progress is guaranteed in Peterson's synchronization mechanism. This means that if a process is trying to enter the critical section, it will eventually be able to do so. This guarantee is achieved through the use of the turn variable, which ensures that processes take turns entering the critical section. The turn variable is updated in a specific order, allowing each process to have a fair chance of entering the critical section.

B. Busy waiting solution

Peterson's synchronization mechanism is a busy waiting solution. Busy waiting refers to the technique where a process repeatedly checks for a condition to become true in a loop. In Peterson's algorithm, processes spin in a loop while waiting for their turn to enter the critical section. This can lead to high CPU utilization, as the process keeps executing instructions in the loop without any productive work. However, busy waiting ensures that the process can immediately enter the critical section once it is their turn.

C. Uses semaphore variable

Peterson's synchronization mechanism does not use semaphore variables. Instead, it relies on two shared variables: turn and flag. The turn variable determines which process gets to enter the critical section, while the flag variable indicates if a process is ready to enter the critical section or not. The absence of semaphore variables simplifies the implementation of Peterson's algorithm.

D. Mutual exclusion is guaranteed

Mutual exclusion is guaranteed in Peterson's synchronization mechanism. Mutual exclusion means that only one process can be in the critical section at a time. Peterson's algorithm achieves this by using the turn variable and the flag variable. The turn variable ensures that processes take turns entering the critical section, while the flag variable is used to indicate if a process is ready to enter or not. By properly updating these variables, Peterson's algorithm guarantees that only one process can be in the critical section at a time.

Conclusion

In summary, Peterson's synchronization mechanism guarantees progress, provides a busy waiting solution, and ensures mutual exclusion. It achieves these properties through the use of shared variables, specifically the turn and flag variables. While busy waiting can lead to high CPU utilization, Peterson's algorithm is a simple and effective solution for providing mutual exclusion in concurrent programming.