- Circular Wait
- Cost must be consider
-one method is RAG
- Request
- Use
- Release
Safe State = No Deadlocks
System will never enter an unsafe state
Avoidance Algorithms
RAG = Single Instance
Banker's = Multiple Instances
Edges
Vertices
-Process declare Max num of R
- Ensure never be a circular wait
- RAG defined by number of available and allocated R
Process holding a resource and waiting to acquire a resource held by another process
- Prevent
- Detect and Recover
- Ignore Problem
Bankers
P->Request
- Mutual Exclusion
- Hold and Wait
- No Preemption
- Circular Wait
No cycle=No deadlock
Process Termination
1. Abort all deadlocks
2. Abort one process
Resource Preemption
1. Selecting a victim
2. Rollback
3. Starvation