#strict_alteration #operating_system #process_synchronization

Question

In a strict alteration , we use TURN variable and turn variable is shared variable .So,my doubt is that there's synchronisation problem as it is similar to producer consumer problem. While executing turn variable  there might be preemption and it might cause inconsistency ? So how could strict alteration has this disadvantage?

Comments

If you know the concept of Test-Set-Lock, you know that updating the lock variable is a atomic operation, i.e. no preemption can occur, in turn variable(strict alteration) always ensures updating the variable turn is atomic, and adding to it, it’s a two process solution, until and unless the other process updates turn variable the process will get stuck in the while loop,

so no problem like producer consumer can arise

 

Answer 1

In strict alternation, only two processes are involved, so, when one process enters critical section, it changes value such that only other process will be able to enter. That is why the name Strict Alternation.

Comments

Yeah now I've got it .