operating systems

Question

a system has 6 processes sharing 7 resourses if each process needs maximum 3 units then

a) deadlock can never occur

b)deadlock may occur

c)starvation will occur

d)none of these

Answer 1

Option B :

Refer to Galvin : If (no. of processes * max need of each process) < (no of processes + total no of resources), the deadlock will not occur .

Therefore, in our question, 6*3 < 6+7 ? Which is false , which implies deadlock may occur.

Or if you see it as allocation of resources, assume that :

Process Id	No of resources allocated
P1	1+1
P2	1
P3	1
P4	1
P5	1
P6	1

If resources are allocated ike this, its a deadlock.

Answer 2

deadlock will occur

No of process in system = 6

Total resouces = 7

At the worst case if give 2 resouces each Process = 2*6 =12 and then 1 resources more so that we can break and start one process and so on . So min of no resources required to be deadlock free is 13

but Resources in system = 7

Since 7<13 ( MIN required )

So the condition is a deadlock .

Comments

No no deadlock and starvation arent same .

Starvation is a long waiting which will end at some time

But Deadlock is an infinite waiting

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give explanation to u r answer

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"will" is wrong. Because a process can release a resource after use - we are not told that hold and wait condition is satisfied here.

Answer 3

answer is option b) Deadlock may occur

example :  the allocation sequence of resources = (2, 2, 2, 1, 0, 0) means deadlock

Answer 4

deadlock May occur so the answer is B