Operating System Questions

1) Process P0 requires a resource held by process P1 while P1 requires a resource held by P0. When does this scenario imply a deadlocked state?

2) Consider a system consisting of four instances of a resource type that are shared by three processes. Each process requires at most two instances of the resource. Show that deadlocks cannot occur in this system. Hint: There will never be circular waiting.

3) Consider the following snapshot of a system. Determine if the system is in a deadlocked state.

How is a page fault detected?

Allocation Request Available Poll 0 1 011 0 101120 2 0 Ps 0 0 1 DI bl-C0 VB 2 Al D00211 st c 10210 RB 01230 A10-22 D00210 ion 1020 IO C 10201 ll-B 0 0 1 10 A-1100 01234