Expert · Module 10 · Lesson 7 of 12
Cooperative Synchronization: Fiber Mutexes, Semaphores, and Channels
Construct user-space synchronization primitives without kernel locks, engineer wait-queue fiber mutexes, implement counting semaphores, and design CSP channels with backpressure.
By the end you can
- Diagnose why pthread_mutex_lock and kernel futexes freeze entire cooperative fiber runtimes
- Implement user-space fiber mutexes using intrusive wait-queues and voluntary stack suspension
- Construct cooperative counting semaphores to throttle concurrent fiber resource access
- Design bounded Go-style channels with dual wait-queues for sender and receiver backpressure
Builds on Asynchronous Event Integration: Cooperative I/O with epoll and timerfd.
01 · A question first
Why does calling pthread_mutex_lock() inside a coroutine freeze thousands of innocent tasks on the same thread, and how can we build user-space mutexes and Go-style channels that suspend only the contended fiber in under 10 nanoseconds?
Make a guess before you read on.
02 · The idea
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What's inside
- Start with the problem
- How the idea works
- Complete Working Implementation: Synchronization Engine
- Why it is correct
- Pitfalls and variations
- Where it is used
03 · Practice
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