Deadlock
Q31.
Two shared resources R_1 and R_2 are used by processes P_1 and P_2. 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_k from process P_j if T_{ik} is greater than T_{jk}. Given the following : (I). T_{11} \gt T_{21} (II). T_{12} \gt T_{22} (III). T_{11} \lt T_{21} (IV). T_{12} \lt T_{22} Which of the following conditions ensures that P_1 and P_2 can never deadlock?Q32.
In which of the following four necessary conditions for deadlock processes claim exclusive control of the resources they require?Q33.
The following are the starting and ending times of activities A,B,C,D,E,F,G and H respectively in chronological order: a_{s}\; b_{s} \; c_{s}\;a_{e}\;d_{s}\;c_{e}\;e_{s}\;f_{s}\;b_{e}\;d_{e}\;g_{s}\;e_{e}\;f_{e}\;h_{s}\;g_{e}\;h_{e} . Here, x_{s} denotes the starting time and x_{e} denotes the ending time of activity X. W need to schedule the activities in a set of rooms available to us. An activity can be scheduled in a room only if the room is reserved for the activity for its entire duration. What is the minimum number of rooms required?Q35.
In a certain operating system, deadlock prevention is attemped using the following scheme. Each process is assigned a unique timestamp, and is restarted with the same timestamp if killed. Let P_h be the process holding a resource R, P_r be a process requesting for the same resource R, and T(P_h) and T(P_r) be their timestamps respectively. The decision to wait or preempt one of the processes is based on the following algorithm. if T(Pr) < T(Ph) then kill Pr else wait Which one of the following is TRUE?Q36.
A computer has six tape drives, with n processes competing for them. Each process may need two drives. What is the maximum value of n for the system to be deadlock free?Q37.
An operating system contains 3 user processes each requiring 2 units of resource R. The minimum number of units of R such that no deadlocks will ever arise isQ39.
Consider a system having m resources of the same type. These resources are shared by 3 processes A,B, and C which have peak demands of 3, 4 and 6 respectively. For what value of m deadlock will not occur?Q40.
Choose the correct alternatives (more than one may be correct) and write the corresponding letters only: A computer system has 6 tape devices, with n processes competing for them. Each process may need 3 tape drives. The maximum value of n for which the system is guaranteed to be deadlock-free is: