SU04: Process & Memory Management

Question 1

Deadlock Conditions

Answer 1

1. Mutual Exclusion: resource to one process only
2. Hold and wait: Process can hold resource while waiting for other resources
3. No pre-emption: resorces cannot be removed from process (halting not allowed)
4. **Circular wait: **the cruicial condition

Question 2

Deadlock Prevention

Answer 2

1. Mutual exclusion: Not possible - necessary for reource to have this chracteristic
2. Hold & wait: Possible - Process need to have all required resources, Will be blocked until all resources are allocated
3. No pre-emption: Possible - Process to release withheld resources if other process needs it
4. Circular wait: Possible - Define Linear ordering of resource type

Question 3

Deadlock Avoidance

Answer 3

Process not started if demands lead to deadlock
Process not **granted incremental resource if allocation ** lead to deadlock

Question 4

Deadlock Detection & Recovery

Answer 4

OS periodically checks for deadlock, to employ strategy to resolve deadlock (abort & restart deadlock process)