Deadlock
Q31.
In which of the following four necessary conditions for deadlock processes claim exclusive control of the resources they require?Q32.
When a process is rolled back as a result of deadlock the difficulty which arises isQ33.
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 isQ38.
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: