Processes and Concurrency

reading · we frame, you read MIT or the canonical taught · we author, no canonical fits ↺ spirals back to earlier lessons

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Complete Memory Systems and I/O first.

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reading · 30 min + ~267 min canonical

The Operating System and Processes: Kernel, User Space, and the PCB

Every program you've ever run was lied to about being alone. In the last course you saw the first half of the lie — virtual memory convinces each program it owns all of memory. Th…

primary Operating Systems: Three Easy Pieces (OSTEP)

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reading · 30 min + ~267 min canonical L1

Threads and Scheduling: Concurrency Within a Process, and Who Runs Next

A process is isolated from every other process — that's its whole point. But sometimes you want concurrency inside one program: a web server handling many requests, a UI staying r…

primary Operating Systems: Three Easy Pieces (OSTEP)

after L1 locked

reading · 30 min + ~267 min canonical L1

Inter-Process Communication: Pipes, Signals, and Shared Memory

You've used inter-process communication thousands of times, probably today. Every time you typed cat access.log | grep ERROR | wc -l, you told the shell to run three separate proc…

primary Operating Systems: Three Easy Pieces (OSTEP)

after L2 locked

reading · 35 min + ~267 min canonical L1

Synchronization: Race Conditions, Locks, and the Classic Problems

Here is a program that is wrong, and you might not see why: two threads each run counter = counter + 1 a million times, starting from zero. You'd expect two million. You'll get so…

primary Operating Systems: Three Easy Pieces (OSTEP)

after L3 locked

reading · 35 min + ~267 min canonical L1

Deadlocks and the Ruby Concurrency Model: GIL, Ractors, and fork

The last lesson handed you locks to prevent race conditions. This lesson shows you how locks, used carelessly, create a bug that's arguably worse: deadlock — where threads freeze …

primary Operating Systems: Three Easy Pieces (OSTEP)

after L4 locked

exercise reading · 15 min L1

Exercises: Easy (Warm-up)

- [ ] OSTEP Ch5: Process API — Write programs using fork(), wait(), exec() in C - [ ] OSTEP Ch6: Limited Direct Execution — Measure cost of system call vs function call - [ ] OSTE…

after L5 locked

exercise reading · 30 min L1

Exercises: Medium (Core)

- [ ] OSTEP Ch8: Multi-Level Feedback Queue — Simulate MLFQ with priority boost and gaming prevention - [ ] OSTEP Ch9: Proportional Share — Implement lottery scheduling simulator …

after L6 locked

exercise reading · 45 min L1

Exercises: Hard (Stretch)

- [ ] Implement a simple shell in C — Parse commands, fork/exec, pipes (|), I/O redirect (>, <), background (&) - [ ] xv6 Lab: System calls — Add a new system call to xv6 kernel (…

after L7 locked

exercise reading · 60 min L1

Mini-Project

- [ ] Build a process manager in C — list running processes (parse /proc), send signals, display CPU/memory usage, interactive TUI like a simple htop

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L10

project reading · 300 min L1

Project: Process Launcher in C

Build a program that reads a config file listing commands, launches each as a child process with fork/exec, manages their lifecycle (wait, signal), and reports exit statuses. Supp…

after L9 locked

L11

project reading · 360 min L1

Project: Thread Pool in C

Implement a fixed-size thread pool with a work queue. Worker threads pull tasks from a shared queue protected by mutex and condition variables. Demonstrate with a batch file proce…

after L10 locked

L12

project reading · 600 min L1

Capstone: Unix Shell with Job Control

- [ ] Milestone 1: REPL loop — read input, parse command + arguments, execute with fork/exec - [ ] Milestone 2: Built-in commands — cd, pwd, exit, export, history - [ ] Milestone …

after L11 locked

L13

assessment reading · 63 min L1

Self-Assessment: Processes and Concurrency

- [ ] What is a process? What is the difference between a process and a thread? - [ ] Explain fork() and exec() in Unix. What does fork return to the parent vs the child? - [ ] Wh…

after L12 locked

13 lessons. Read in order; spiral back when you need to. By the end you'll have used the core ideas twice — once on the abstract, once on something you'll meet at work next week.