Cortex Coroutine Library

Introduction

Cortex is a C++ stackful coroutine library with WebAssembly (Emscripten) support. It provides cooperative multitasking with explicit suspend/resume semantics and works across native and WASM builds through a unified API.

Highlights

• Stackful coroutines with a simple Resume / Suspend model
• Unified API for native (Boost.Context) and WASM (Emscripten fibers)
• tiny_fiber module for single-thread cooperative multitasking (native + WASM)
• Custom memory resource support for stack allocation
• Designed for deterministic, cooperative control flow

Quick Start

#include <cortex/coroutine.hpp>
 
auto co = cortex::Coroutine::Make([](cortex::CoroutineSuspendContext& ctx) {
    // Do work...
    ctx.Suspend(); // Yield back to caller
    // Resume here...
});
 
co.Resume();
co.Resume();

tiny_fiber Module

Higher-level cooperative multitasking built on Coroutine:

#include <cortex/tiny_fiber/tiny_fiber.hpp>
namespace tf = cortex::tiny_fiber;
 
tf::Scheduler::Run([] {
    auto future = tf::Spawn([] {
        tf::Yield();  // Cooperative yield
        return 42;
    });
    
    tf::Yield();
    int result = future.Get();  // Wait and get result
});

For WASM integration with JS event loop:

auto scheduler = tf::Scheduler::Create([]{
    // Spawn fibers, use Mutex, ConditionVariable, etc.
});
 
// Called from JS via setInterval
while (!scheduler.IsDone()) {
    scheduler.Step();  // Run one fiber until yield
}

Generator Example

#include <cortex/generator.hpp>
 
auto gen = cortex::Generator<int>::Make([](auto& yield) {
    yield(1);
    yield(2);
    yield(3);
});
 
while (gen.Next()) {
    int value = gen.DetachValue();
    // use value
}

API Overview

• Coroutine: low-level stackful coroutine
• BaseCoroutine: OO wrapper for coroutines
• Generator: yield values across resumes
• tiny_fiber: single-thread cooperative fibers (native + WASM)

Resources

• Live demos: https://GhevondW.github.io/cortex/
• API docs: https://GhevondW.github.io/cortex/docs/