deadlock

1.Deadlock Characterization

necessary conditions:

1) Mutual exclusion:
• at least one shared resource is held

2) Hold and wait:
• a process must be holding at least one resource andwaiting for another

3) No preemption:
• cannot steal a resource away from a process

4) Circular wait:
• E.g., A is waiting for B who is waiting for C who iswaiting for A.