README.md



CS 11 Asynchronous Programming track (FA 2020)

Course description
This CS 11 track introduces asynchronous programming, an increasingly common paradigm for I/O-heavy applications.
Learn how highly concurrent servers and responsive webpages can be built without multithreading.
We will cover techniques including callback functions, promises, and streams, and apply them to file I/O, networking, user interfaces, and more.
Examples and projects will be in modern JavaScript, running both in the browser and as server-side programs in Node.js.
Projects include building your own Minesweeper, concurrent make, and git-like version control software.
CS 2-level programming knowledge is a soft prerequisite for this course.
No JavaScript experience is needed; the necessary language features will be introduced for the projects.

About me
Hi, I'm Caleb!
I'm a Computer Science/Economics major and I really enjoy low-level software design and abstractions.
I've TAed for CS 2, 3, 21, 24, and 124.
I designed this course as a year-long CS 81 project.
I chose to teach about asynchronous programming because it is a powerful tool leveraged in industry for its unique approach to I/O, yet the Caltech CS curriculum doesn't cover it in depth.
This course was taught for the first time in SP 2020.
You can contact me via:

Email: csander@caltech.edu

DM on Campuswire (see Resources)
Zoom during office hours (W 16:00-18:00; R 20:00-22:00): (see Resources)


Schedule


Weeks
Topic and notes
Project
Due on Friday at 11 PM PDT/PST


1-2
Callbacks
Minesweeper
2020-10-09


3-4
Promises
make
2020-10-23


5-6
Streams
grep
2020-11-06


7-8
HTTP
Wiki Game
2020-11-20


9-10
async-await
MiniVC
2020-12-04


JavaScript reference
There is a description of the important parts of the JavaScript language in notes/js/js.md.
It also has information specific to running JS in the browser and through Node.js.
Feel free to read as much of it as you want, but it's quite long.
I will point out sections that may be useful on each project.

Resources

Campuswire
We will be using Campuswire as a class forum.
You can join the class here.
If you haven't used it before, Campuswire is similar to Piazza, but the interface is much better and you can also use it for chat.
If you have a question about a project or the course in general, please post there first!
I will answer questions as soon as I can, but other students are also welcome to respond.
If you have a question, you are probably not the only one; hopefully answers to Campuswire posts will help other students too.
I only ask that you do not post code from your project.
If you want me to take a look at your code, push it to your GitLab repository and leave a link to the repository.
You can DM me if you have an individual concern (e.g. asking about an extension on a project), but please make a post instead if someone else might have a similar question.

Zoom office hours
This online-only term is new for me too, so I'm not sure what formats are the most convenient for helping you.
I think Campuswire will be the easiest for most questions, but I'd like to be available to answer questions or discuss confusing concepts face-to-face as well.
To that end, I'll be available for Zoom office hours during the following times (PDT/PST) each week:

Wednesday 4-6 PM
Thursday 8-10 PM

My personal meeting ID is 586-773-0238.

Course policies

Student wellbeing
Asynchronous programming is an unusal way to write programs, so I hope the course challenges you a bit.
However, please remember that it is P/F and only 3 units.
I do not want the course to take up too much of your time or cause you stress.
If there is anything I can do to make the course more manageable for you, please let me know!

Material
This course is meant to help you learn asynchronous programming at your own pace, so there are no lectures.
There are readings linked above that provide background for the projects.
If you have questions about the material or want me to discuss another topic, please Zoom me during my OH or make a Campuswire post.

Extensions
I realize this unusual term may present obstacles to completing projects on time.
I also don't really care when projects are submitted, but I want to make sure that they do not pile up towards the end of the term (both for your sake and so I can grade them in a timely manner).
If you have an extenuating circumstance, e.g. a family emergency, please email me; I am happy to grant an extension.
Aside from extensions, I am also giving you 5 total late days to apply to any of the projects.
You may use at most 3 late days on a single project.
If you are taking late days, please email/DM me to let me know before the project is due so that I can hold off on grading your submission.
The late day policy is pretty generous, so I will not grade any projects that are submitted late without an accompanying extension or late days.

Submitting projects
Projects will be distributed and submitted on GitLab.
If you don't have an SSH key registered with GitLab, please add one:

If you don't have an SSH key, make a new one by running the command ssh-keygen -t rsa in a terminal (on macOS or Linux) or in Git Bash or Windows Subsystem for Linux (on Windows)
Run cat ~/.ssh/id_rsa.pub to print out the public key
Go to the GitLab SSH keys page, paste the entire key, and click "Add key"

To get your copy of a project, you should fork its repository:

Go to the cs11-async group on GitLab
Click on the repository for the project you want to work on
If you're not signed in, click "Sign in" in the upper-right corner and log in with your Access Caltech credentials
Fork the repository by clicking on "Fork" in the upper-right of the page.
This should take you to your forked copy of the repository.
Click on "Clone" in the upper-right and copy the address under "Clone with SSH", i.e. git@gitlab.caltech.edu:USERNAME/PROJECT.git

Run git clone ADDRESS (replacing ADDRESS with the address you just copied) in a terminal to download the repository
Make your code private: click on "Settings" in the left sidebar, click "Expand" next to "Permissions", change "Project visibility" to "Private", and click "Save changes"
Share your code with me (so I can grade it and provide help): click "Members" under "Settings" in the sidebar, select "csander" as the user to invite, select "Maintainer" as the role, and click "Add to project"

To submit a project, you just need to push your changes to GitLab.
If you haven't used Git before, these are the basic commands you'll need:


git status: show which files are tracked by Git (i.e. they were previously committed)

git add .: if you add new files, you need to run this so they will be included in future commits

git commit -am "COMMIT MESSAGE": make a new Git commit containing all the changes

git push: push the commit to GitLab

It is easy to forget to run git push or git add when committing.
I suggest you always check GitLab to ensure your commits were pushed and include all the files you changed.

Grading
Your grade will be the unweighted average of your grades on all the projects.
The passing threshold is 70%.
For the projects with tests, your grade will be primarily determined from whether you are passing the tests.
However, I will deduct points for not writing code in an asynchronous style, e.g. using Node.js's synchronous I/O functions or performing I/O tasks in sequence when they can be done in parallel.
If you write your code to defeat the test cases but not to work in general (e.g. hard-coding the outputs that the tests expect), I will not give credit for passing those tests.
For the browser-side projects without tests, I will try using your project and check that it implements the functionality outlined in the project spec.
Your versions of these projects do not have to look exactly like mine!
The specs are intended to be specific about what they expect, but please ask questions if anything is unclear.

Feedback
This is the second time this CS 11 track is being taught, and I hope it will stick around!
I really value your constructive feedback on the course so I can improve it for the future.
Please let me know:

If my notes on any topic are helpful or unhelpful
If there are topics I should add or remove from the course
If you found a project too much or too little work
If you particularly liked or disliked a project
Ideas for other projects you think would be fun
Any other ideas on how to make the course more interesting, useful, or accessible