Two concurrent processes P1 and P2 use four shared resources R1, R2, R3 and R4, as shown below.
P1 |
P2 |
Compute: Use R1; Use R2; Use R3; Use R4; |
Compute; Use R1; Use R2; Use R3;. Use R4; |
Both processes are started at the same time, and each resource can be accessed by only one process at a time The following scheduling constraints exist between the access of resources by the processes:
There are no other scheduling constraints between the processes. If only binary semaphores are used to enforce the above scheduling constraints, what is the minimum number of binary semaphores needed?
A |
1 |
B |
2 |
C |
3 |
D |
4 |
It needs two semaphores such as X=0; Y=0
Thank You!