CST 334 Week 6

This week I learned about semaphores and how they can function as a lock when used in there most basic sense but offer a number of different utilities as well. A semaphore is assigned an integer value when defined and when sem_wait is called it checks to see if the value of the semaphore is greater than 0 if it is then it is decremented by 1 if the value is 0 then the semaphore will wait until the value is greater than 0 based on a trigger from sem_post which increments the value of the semaphore by 1. Semaphores work great for allowing muliple write programs to enter a critical section at once like in the case of the producer-consumer problem. I also learned about common bugs in multi-threaded programs, deadlock bugs are the scariest as they often cause a restart or a shut down of the program however they are the least common bugs. The two most common are atomicity-bugs and order-violation bugs. Both of these bugs can be solved with careful use of semaphores or locks. Bugs are a scary part of programming but knowing how to work around them is key to implementing working computer systems. 

Comments

Post a Comment

Popular posts from this blog

CST 370 Week 5

 This week we moved from learning how to read and understand algorithms, to a more direct approach to writing some of the more advanced algorithms that explore the more common mathematical and logical problems programmers tend to face. Learning about topological ordering, tree structuring, and quick sort was very interesting as these concepts are huge throughout the computer science landscape. COming off the test last week I feel reinvogorated to keep learning. 
Read more

CST 370 Week 2

 This week was very interesting, I had learned about time efficiency and Big O, Theta and Omega notation in the past but it was great to learn formal definitions and see some examples of how they can be applied. Understanding how to evaluate recursive algorithms was new for me and pretty difficult to understand at first but after reading the text book and other required materials it started to make a little more sense. I would like to continue practicing evaluating both recursive and nonrecursive algorithms  just to continue understand the asymptotic notations a little bit more. Overall it was a good week and the homework was challenging in a great way. 
Read more

CST 370 Week 4

 This week I was able to study some of the topics I struggled with in previous weeks like recurrence relationships. In preparing for the test being able to use two sheets of paper as notes was helpful for studying but also helpful for the test. A refresher on merge sort was also a welcome experience as well as the divide and conquer techniques. 
Read more