Ace Test Series: Operating System - Process Synchronization

Question

Comments

How mutual exclusion is ensured in above code ??

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what happens if flag1=true and flag2=false initially and process i starts execution

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If flag 1=true flag=false

This ensure ME

Process p1 in critical section

Answer 1

Some times deadlock free.Lets assume process i started executing, and executed until flag1=true and preempted, now process j is executing flag2=true and as flag1=true it will busy wait , again if its preempted process i will busy wait thus deadlock will occur. If process i or j executes without preemption, assuming flags values are initially false then mutual exclusion is there.

Comments

Thnx. So silly of me to miss dat :)

Answer 2

from code we can understand that sometimes deadlock is there as well ,code is not guarantee the ME so option a and b are not true and d said that "never guarantee" the ME,but code is sometimes allow the ME . so ans is option C.