Operating System MCQs

Resource preemption removes ownership from a blocked process and makes the resource available elsewhere.
The process may need to roll back and retry when its required resources can be reacquired.

A process-to-resource edge is a request edge showing an outstanding demand.
An assignment edge points in the opposite direction, from a resource instance to a process.

A resource-to-process edge is an assignment edge.
It records current ownership rather than a pending request.

With one instance per resource type, a graph cycle means each process in the cycle waits on the next.
No process in that cycle can obtain the needed resource and proceed.

A safe state has a safe sequence that permits each process to obtain its remaining needs and complete.
An unsafe state is not necessarily deadlocked, but it can lead to deadlock.

The ostrich approach assumes deadlocks are sufficiently rare or recoverable through manual intervention.
General-purpose systems may choose this trade-off for some resource classes.

The problem tests selective signaling among several waiting processes based on a combination of resources.
Correct synchronization wakes the one eligible smoker without deadlock or incorrect consumption.

Priority inheritance temporarily raises the lock holder's priority to that of the blocked high-priority thread.
The holder can then run, release the lock, and reduce priority inversion.

Deadlocked processes cannot progress because each depends on resources or events held by another in the set.
External scheduling alone cannot resolve the circular dependency.

Mutual exclusion applies when a resource cannot be shared concurrently among requesting processes.
If every resource were freely shareable, resource deadlock would not arise.

Hold and wait allows a process to retain allocated resources while waiting for others.
This retained ownership can participate in a cycle of dependencies.

No preemption means resources are released only voluntarily by the process holding them.
A process may therefore remain blocked while retaining resources needed elsewhere.