A system is in a safe state only if there exists a safe sequence of processes P1, P2, …, Pn where:
- For each Pi, the resources that Pi can still request can be satisfied by the currently available resources plus the resources help by all Pj, j<i.
If a system is in safe state, there is no deadlock.
If the system is deadlocked, it is in an unsafe state.
If a system is in unsafe state, there is a possibility for a deadlock.
Avoidance: making sure the system will not enter an unsafe state.