Please help me get started on this. I know what semaphores are but I don\'t have

Question

Please help me get started on this. I know what semaphores are but I don't have any idea how to start this problem. Please explain step-by-step if possible.

"After each step, give the value of the updated semaphore and the content of the updated semaphore queue.

Couting Semaphores: S1, S3, S6

Binary Semaphores: S2, S4, S5

Smephore Queues: use Priority Scheduling algorithm where: Low Process ID means high priority

Semaphores initial values: S1 = 0, S2 = 1, S3 = 3, S4 = 0, S5 = 1, S6 = 0

1.) P1: P(S3)

2.) P2: P(S5)

3.) P3: P(S1)

4.) P5: P(S4)

5.) P2: V(S5)

6.) P1: P(S6)

7.) P2: P(S4)

8.) P6: V(S3)

9.) P4: V(S4)

10.) P4: P(S6)

11.) P1: V(S5)"

Explanation / Answer

Semaphores initial values: S1 = 0, S2 = 1, S3 = 3, S4 = 0, S5 = 1, S6 = 0

1.) P1: P(S3)

S1 = 0, S2 = 1, S3 = 2, S4 = 0, S5 = 1, S6 = 0

after 2.) P2: P(S5)

S1 = 0, S2 = 1, S3 = 2, S4 = 0, S5 = 0, S6 = 0

after 3.) P3: P(S1)

S1 = 0, S2 = 1, S3 = 2, S4 = 0, S5 = 0, S6 = 0 (p1 is waiting)

after 4.) P5: P(S4)

S1 = 0, S2 = 1, S3 = 2, S4 = 0, S5 = 0, S6 = 0 (p1 is waiting, p5 is waiting)

after 5.) P2: V(S5)

S1 = 0, S2 = 1, S3 = 2, S4 = 0, S5 = 1, S6 = 0 (p1 is waiting, p5 is waiting)

after 6.) P1: P(S6)

S1 = 0, S2 = 1, S3 = 2, S4 = 0, S5 = 0, S6 = 0 (p1 is waiting, p5 is waiting)

after 7.) P2: P(S4)

S1 = 0, S2 = 1, S3 = 2, S4 = 0, S5 = 0, S6 = 0 (p1 is waiting, p5 is waiting, p2 is waiting)

after 8.) P6: V(S3)

S1 = 0, S2 = 1, S3 = 3, S4 = 0, S5 = 0, S6 = 0 (p1 is waiting, p5 is waiting, p2 is waiting)

after 9.) P4: V(S4)

S1 = 0, S2 = 1, S3 = 1, S4 = 1, S5 = 0, S6 = 0 (p1 is waiting, p5 is waiting, p2 is waiting)

after 10.) P4: P(S6)

S1 = 0, S2 = 1, S3 = 1, S4 = 1, S5 = 0, S6 = 0 (p1 is waiting, p5 is waiting, p2 is waiting,p4 is waiting)

11)

S1 = 0, S2 = 1, S3 = 1, S4 = 1, S5 = 0, S6 = 0 (p1 is waiting, p5 is waiting, p2 is waiting,p4 is waiting)

after

11.) P1: V(S5)

S1 = 0, S2 = 1, S3 = 1, S4 = 1, S5 = 1, S6 = 0 (p1 is waiting, p5 is waiting, p2 is waiting,p4 is waiting)

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