Thursday, August 20, 2009
at
3:48 AM
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- Mutual Exclusion – not required for sharable resources; must hold for nonsharable resources.
- Hold and Wait – must guarantee that whenever a process requests a resource, it does not hold any other resources.
- Require process to request and be allocated all its resources before it begins execution, or allow process to request resources only when the process has none.
- Low resource utilization; starvation possible.Restrain the ways request can be made.
- No Preemption :
- If a process that is holding some resources requests another resource that cannot be immediately allocated to it, then all resources currently being held are released.
- Preempted resources are added to the list of resources for whichthe process is waiting.
- Process will be restarted only when it can regain its old resourcesas well as the new ones that it is requesting.
- Circular Wait – impose a total ordering of all resource types, and require that each process requests resources in an increasing order of enumeration.
Posted by
Roger
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os 8
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