My Presentation For OS class | Topic: Simulation for Dining Philosophers
Task: Simulate the Dining Philosophers problem, demonstrate three cases, explain how did they happen:
- Deadlock
- Starvation
- Without any problem
Here I will attach my presentation. Nothing fancy :) but it worked proparly. I will include couple versions, I used Keynote so there might be couple probelms with other version:
My code present is not an advanced one, and might have some mistakes. I commented everything that I tried to include, so it should be easy to understand what did I do, and why. Feel free to contribute. Here I will explain what needs to be done to demonstrate each case in the code that I have. You can find the code here
For creating a deadlock we need to change couple lines:
- Comment out lines 37 to 41
- Make sure that rIndex and lIndex are using lines 59-60
This will create a deadlock, cause everyone will pick up the fork that on their left side... And since you removed dropping the fork part they will get stuck.
For creating Starvation, same thing, we will change couple lines:
- Comment out lines 37 to 41
- Make sure that rIndex and lIndex are using lines 61-62
- Make sure the sleep_for 's are commented out. So lines: 21, 70 are commented out.
This will create a Starvation hopefully :). Since we have indexes(forks) fixed but still have stubborn philosophers(will not put the fork back till he/she eats). And there is no waiting time so they will keep trying to eat, without letting others get the fork.
For normal situation, the code itself is in this position right now, but still.. let me explain:
- Make sure that lines 37 to 41 are not commented out.
- Make sure that rIndex and lIndex are using lines 61-62
- Make sure the sleep_for 's are NOT commented out.
First bullet is because we will have open-minded philosophers, and if they cannot eat they will let others do so... I already explained rIndex, lIndex situation in Deadlock. Lastly sleep_for's will let philosophers wait before trying to eat right after finishing eating.