GATE - 2005 | OS | Two shared resources R1 and R2 are used by processes P1 and P2.

GATE - 2005 [Operating System]

Question:

Two shared resources R₁ and R₂ are used by processes P₁ and P₂. Each process has a certain priority for accessing each resource. Let T_ij denote the priority of P_i for accessing  R_j. A process P_i can snatch a resource R_h from process P_j if T_ik is greater than T_jk. Given the following :

1. T₁₁> T₂₁
2. T₁₂> T₂₂
3. T₁₁< T₂₁
4. T₁₂< T₂₂

Which of the following conditions ensures that P₁ and P₂ can never deadlock?

A	(I) and (IV)
B	(II) and (III)
C	(I) and (II)
D	None of the above

   

Solution:

Option (C) is Correct.

If all resources are allocated to one process then deadlock will never occur.

So, if we allocate both R₁ and R₂ to process P₁ or both R₁ and R₂ to process P₂ then deadlock will never occur.

So when one process will complete its execution then both the resources are allocated to the other process.

So, either condition (I) and (II) or (III) and (IV) ensures that deadlock will never occur.

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