asyncxx - Asynchronous backend for C++

asyncxx is a header-only library for asynchronous programming in C++. It is heavily inspired by pyhon/rust implementations of async/await features.

Features:

• Full async task backend based on setjmp and some black magic
• Futures (can be used stand-alone or incorporated into your functions)
• Events (spin lock without the spinning)
• Built-in thread pool for resource-heavy tasks to be offloaded from main thread
• Asynchronous File class
• Asynchronous Process class (with dynamic IO)
• Easy to use API
• Examples in form of comprehensive test suite

How to build

Prerequisites:

• Unix based OS (Linux/MacOS)
• gcc/clang that supports C++23
• cmake

Steps:

• cmake -B cmake-build -S .
• cmake --build cmake-build

To run the tests: ./cmake-build/async

Example

auto ev = async::Event();

async_task_r(read_file, std::string, std::string filename) {
    return async::io::File(filename, "r").readAll()->await();
}

async_task(cat, std::string input) {
    auto proc = async::io::Process::create("cat", input);
    auto res = proc->await();
    
    if (res.exit_code != 0) {
        throw std::runtime_error("cat failed");
    }
}

async_task(worker) {
    try {
        auto contents = read_file("test.txt")->await();
        cat(contents)->await();
    } catch (...) {
        ev.notifyOne();
        throw;
    }
    
    ev.notifyOne();
}

async_task(waiter) {
    std::print("Waiting for other task to cat the file...\n");
    ev.wait();
    std::print("Done!\n");
}

async::run([] {
    async::gather(waiter(), worker());
});