io_context poll latency

io_context_latency.cpp

#include <iostream>
#include <chrono>

#include <boost/asio/io_context.hpp>
#include <boost/asio/spawn.hpp>
#include <boost/asio/steady_timer.hpp>

int main(int argc, char* argv[])
{
    boost::asio::io_context io_context(BOOST_ASIO_CONCURRENCY_HINT_1);
    std::uint64_t counter = 0;
    std::uint64_t fire_count = 0;

    for (int i = 0; i < 1; ++i) {
        boost::asio::spawn(io_context, [&] (boost::asio::yield_context yield) {
            boost::asio::steady_timer timer(io_context);
            
            while (true) {
                timer.expires_after(std::chrono::seconds(1));
                timer.async_wait(yield);
                // std::cout << "fired " << std::endl;
                fire_count++;
            }
        });
    }

    auto begin = std::chrono::high_resolution_clock::now();
    while(fire_count < 10) {
        counter++;
        io_context.poll();
    }
    auto end = std::chrono::high_resolution_clock::now();
    auto nanos = std::chrono::duration_cast<std::chrono::nanoseconds>(end - begin).count();

    std::cout << "Polled count: " << counter << std::endl;
    std::cout << "Fired: " << fire_count << std::endl;
    std::cout << "ns per poll: " << nanos / double(counter) << std::endl;

    return 0;
}