Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17


Dining Philosophers problem - easy questions

Posted on 2004-10-13
Medium Priority
Last Modified: 2012-08-14
Could anyone tell me what the pros and cons of the following three solutions to the dining
philosophers problem are?

Algorithm 1:
Wait for left stick to be free.
Pick up left stick.
Wait for right stick to be free.
Pick up right stick.

Algorithm 2:
All philosophers run Algorithm 1,
except philosopher number 5 who runs:

Wait for right stick to be free.
Pick up right stick.
Wait for left stick to be free.
Pick up left stick.

Algorithm 3: Wait for both sticks to be free.
Pick up both sticks (as an atomic operation)
Question by:killer455
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions

Expert Comment

ID: 12304083
The issues that are generally present in multiprogramming systems like this are:
- Deadlock: it wont get to a state where some threads can never run because they are waiting on each other.
- Starvation: a thread doesnt get blocked 'forever' becaue other threads always have the resources it needs
- Fairness: threads get blocked evenly, and no thread is 'favored' over others.  
And like everything, there is also ease of implementation, memory required, overhead, speed, etc.

this page might give you a good guide

Author Comment

ID: 12304627
This is more of a general answer, could be be more specific to my question regarding those algorithms rather than general info.
LVL 84

Accepted Solution

ozo earned 120 total points
ID: 12305123
Algorithm 1 suffers from deadlock.
Algorithm 3 can suffer from starvation.
Build and deliver software with DevOps

A digital transformation requires faster time to market, shorter software development lifecycles, and the ability to adapt rapidly to changing customer demands. DevOps provides the solution.


Author Comment

ID: 12305325
What about algorithm 2?

Assisted Solution

Mistobaan earned 80 total points
ID: 12306143
Alghoritm 2 is the same as 1
it suffers deadlock, Starvation and fairness.
It depends also on how the stick are released.
LVL 84

Expert Comment

ID: 12315807
Algorithm 2 does not suffer deadlock

Expert Comment

ID: 12691147
Algorithm 2 looks like the good one to me :)

Featured Post

What does it mean to be "Always On"?

Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Although it can be difficult to imagine, someday your child will have a career of his or her own. He or she will likely start a family, buy a home and start having their own children. So, while being a kid is still extremely important, it’s also …
Q&A with Course Creator, Mark Lassoff, on the importance of HTML5 in the career of a modern-day developer.
In this fourth video of the Xpdf series, we discuss and demonstrate the PDFinfo utility, which retrieves the contents of a PDF's Info Dictionary, as well as some other information, including the page count. We show how to isolate the page count in a…
Introduction to Processes

705 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question