What is Dispatcher...

Dispatcher is a short time scheduler simulator for use in studying operating systems principles, developed at Università degli studi di Napoli "Federico II".

Features

Dispatcher executes a set of processes, using one of the available schedulers and collecting times foreach process.

Processes

• Processes are randomly created as sets of interrupts and SVCs
• Two kind of processes can be added to simulator: CPU-BOUND and I/O-BOUND
• You may choose processes's length, to verify scheduler's equity (fcfs scheduler penalizes short processes).
  • short (10-50 istructions)
  • normal (50-150 istrutions)
  • long (150-200 istructions)
• If you choose the priority scheduler, you can add to the simulation processes that suffer starvartion
• You can test memory protection, adding process that tryes to violate memory. Those processes will be killed when memory violation is detected.
• Processes can forks.
• Forked processes can execute other program.

Schedulers available

• First come first served (fcfs) scheduler. Convoy effect can be tested.
• Round Robin scheduler.
• Virtual Round Robin scheduler.
• Priority scheduler.
  Two policy are available to manage lesser priority queue
  • first come first served policy
  • processes are moved to higher priority queue
  startvation cat be tested.

Collected times

• Arrival time
• Start time
• Finish time
• Turnaround time
• Service time
• Normalized turnaround

Thanks

I wish to thanks prof. Domenico Cotroneo for his suggestions.

This software is released under the term of GNU GPL, see file COPYING for more informations.