Symmetric Coroutine Worker

A C++ worker implementation based on symmetric coroutine provided by boost::context.

It's a very thin wrapper around boost::context, relying on the callcc/continuation module.

It's just a couple of lines, so why not read the source code?

How to Use

int main()
{
    symcoro::CoroWorker worker;

    // register a job
    worker.Register([&](symcoro::cc_t &&sink) {
        std::cout << "from job 1" << std::endl;
        return std::move(sink);
    });
    // register yet another job
    worker.Register([&](symcoro::cc_t &&sink) {
        std::cout << "from job 2" << std::endl;
        // Switch away and go back here later
        sink = sink.resume();
        std::cout << "from job 2 again" << std::endl;
        return std::move(sink);
    });
    // register yet another job.
    worker.Register([&](symcoro::cc_t &&sink) {
        std::cout << "from job 3" << std::endl;
        return std::move(sink);
    });

    // block until all the jobs are finished.
    worker.Serve();
}

... and the output is

from job 1
from job 2
from job 3
from job 2 again

Prerequisite

C++ compiler supports at least c++11
Boost >= 1.4
- An earlier version of Boost may work, as long as it supports callcc/continuation. But it's not tested.

Compile

mkdir build; cd build
cmake -DCMAKE_BUILD_TYPE=Release ..
# or cmake -DCMAKE_BUILD_TYPE=Debug ..
# for more options, see CMakeLists.txt
make -j8

Run the example

$ ./bin/main
from job 1
from job 2
from job 3
from job 2 again

Benchmarking

It takes two context switch to schedule the next working coroutine (one switch from the working coroutine to the coordinating coroutine, and another to switch to the next working coroutine).

It takes ~40 ns in total to schedule to the next working coroutine.

Install & Uninstall

# to install libs and headers
sudo make install
# to uninstall
cat install_manifest.txt | sudo xargs rm -rf

clang-format

clang-format is an opt-in if you would like to use.

sudo apt install clang-format

YanB25/symcoro