Deadlocks

Deadlocks

1. System Model

   • Process
     • Request
     • Use
     • Release

2. Daedlock Characterization

   • Mutual Exclusion - one process at a time
   • Hold & Wait - holding resources while waiting another resources
   • No preemption - resources released voluntarily by process holding it
   • Circular Wait waiting for resources for resources held by another process

3. Method Handling Deadlocks

   • Deadlock prevention
   • Deadlock avoidance
   • Allow the deadlock & recover
   • Ignore the deadlocks

4. Deadlock Prevention

   • Mutual Exclusion
   • Hold & Wait
   • No Preemption
   • Circular Wait