Description
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(25pts) Write a short program in C/C++ that creates two processes that deadlock. You MUST remove the deadlocked processes from the system (kill -9) once you have completed your experiments.
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(25) Prove the correctness or give a counter-example for each of the following statements. You must state whether the statement is true or false and then show your arguments.
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deadlock cycle
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cycle deadlock
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knot deadlock
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deadlock knot
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(25pts) Consider the following maximum-claim reusable resource system with four processes (P0, P1, P2, P3) and three resource types (R0, R1, R2). The maximum claim matrix is given by
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4
1
4
3
1
4
C =
5
6
13
1
1
6
where Cij denote maximum claim of process i for resource j. The total number of units of each resource type is given by the vector (5, 8, 15). The current allocation of resources is given by the matrix
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0
1
4
2
0
1
A =
1
2
1
1
0
3
where Ai,j denotes the units of resources of type j currently allocated to process i. For the state shown above:
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determine if the current state of the system is safe.
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determine if a request by process 1 for 1 unit of resource 1 can be safely granted.
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determine if a request by process 2 for 4 units of resource 2 can be safely granted.
(Note: Processes and Resources start with index 0). You must show your work and justify each of your answers.
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(25) Consider the following set of five processes where arrival is the time the process became ready, t is the total service time, and e is the external priority. Assume that execution starts immediately at time 0 and there is no context switch overhead.
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process
arrival
t
e
p0
0
80
9
p1
15
25
10
p2
15
15
9
p3
85
25
10
p4
90
10
11
For the following scheduling disciplines, draw a time diagram showing when each of the five processes executes. (In the case of a tie, assume that the process with the lower process number executes first.) Calculate the average waiting time for each of the scheduling disciplines.
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FIFO
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SJF
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SRT
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RR (quantum = 10)
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ML (using FIFO at each priority level)
