CS Learning Journal

From this past week in CST-334, we spent more time focusing on virtual memory and translations. It helped to solidify my understanding of concepts like paging from last week, and elaborated on concepts like Memory Allocation in C.   Recap  One of the first things we went over was free space management, which focuses specifically on how C functions like  malloc()  and  free()  work under the hood: the operating system tracks a large block of all the free space, and as memory-allocation is called then a header is set at the beginning position tracking how much space it takes up. The chunks of free space separated by chunks of allocated space ends up in a data structure called the  free list , which keeps track of the starting address of the unallocated memory and its size (how many bytes it has available adjacent to it). When the allocation function is called, it can either grab from the free region it finds first ( first fit ), from the region with the ...

 From this past week in CST-334, we spent some time learning about how memory in managed in the operating system, and specifically about the concept of Virtual Memory. I learned that the operating system doesn't let programs directly access real physical memory, but rather only a virtual slot of memory, and then the Memory Management Unit built in the CPU translates the virtual memory address into a real memory address. With the concept of memory in mind, we also went over how the C programming language gives us tools to interact with memory using functions like malloc()  to manually allocate memory and  free()  to manually designate memory as freed. We also spent time investigating deeper into how the MMU actually translates virtual memory into physical memory using processes like  Base and Bounds  which denotes the start point of an address and how much space it can cover, as well as the strategy of  Segmentation  which splits up the memory into...

 In the past week, I've learned a lot of new interesting topics that relate to Operating Systems. We're now digging into the specifics of how the Operating System interacts with different processes. We went over how a program -- which is really just a string of data -- is only made useful by the operating system, which can turn it into a running program, called a process. There isn't only one process, however, and the operating system is responsible for ensuring that every process (including the Operating System) is given adequate time to run. We went over the concept of multi-programming, which is the strategy used to make running programs appear concurrent, especially on a device that can only technically process one thing at a time. We learned about concepts like yielding and switching to move from one process to another and how to emulate this in the C programming language, as well as how policies are introduced to enforce how much time each process gets, such as First ...

 During this past week of CST334, there was a few new topics I was excited to dive into. The lectures covered specifically: A brief introduction of operating systems How an operating system chooses to allocate resources for all of its programs, what is important to it (such as protecting certain files and also giving the user an easy-to-use interface), and how a computer's resources are managed by the operating system.  Computer Architecture  Discussing the core components of a computer, such as the central processor and memory, as well as going over the hierarchy of computer storage (registers, cache, main memory, etc.). This lecture connects a computer's hardware to software and how the two interact in a low-level.  Linux and Shell A history and overview of the Unix operating system, as well as its derivatives like GNU/Linux and OSX (MacOS). This lecture also briefs over how an operating system splits permissions, such as User modes and Kernel modes, for inter...

 Project in Review      As we approach our final week of the semester, I'm feeling the small bit of pressure but also excitement of finishing up our project with my team. The project we've been working on has been rewarding, and having a group of our size has been an overall fun learning experience on how it feels to work with a small team. I've built several healthy communication habits, as well as gotten very familiar with using Git, GitHub, Android Studio, and even navigating documentation and online resources to troubleshoot issues and inspire me to implement solutions we didn't even learn from our class. Our project is due later this week, and even though there is still quite a bit to do on our project, it has been rewarding to see our collective hard work pay off. In my learning journal for next week, I'll go further into detail on what I accomplished as I recap what I've learned from this course. I can't wait to showcase it all!   First Homework in Re...

 Markov Project Review Recently I completed an assignment that emulates a Markov chain and creates a predictive text algorithm based on text files it reads in. This is actually similar to a project I've attempted in the past in C++, so giving it a shot in Java was a fun exercise.   For this review, I partnered up with one of my teammates Jessica Sandoval.  My strategy for solving the problem was similar to my solution solving my first Project. I began by reading the prompt thoroughly, and laying out the class variables as outlined by the provided UML diagram. I also took note of the suggestion to split off my code into two branches: one for reading text input and one for generating sentences. I set the first branch, and after reading through the prompt more and getting a full understanding of the requirements, I began to layout my starting method for file reading. I laid out pseudocode in the form of code comments to show my line of thinking to ground myself on what the m...

Project 1 Review      After completing my first Java project, Legally-Distinct Pocket Monsters, I spent some time reviewing my solution with my classmates. I decided to team up with Jessica and Emmanuel from my team and we looked over each other's code.       My strategy for solving the problems was to review the provided project prompt which outlines all the details of the program, including what methods and attributes were expected as well as the output, and I would comment through my Java file to lay out my thought process. Although I never had to reach for scratch paper to solve this problem, commenting out pseudocode accomplishes the same goal while never having to leave the IDE and I've gotten used to the method quite a bit.      After planning out my code, I would write my real code underneath the comments I had left, and sometimes I would make additional comments that I felt were helpful breaking down certain lines. For example, ...