simx

simx is a discrete-event simulation framework for C++20.

Processes are defined as functions receiving simx::SimX<> & as their first argument and returning simx::Promise. Each process is executed as a coroutine. Thus, this framework requires C++20. A short example simulating two clocks ticking in different time intervals looks like this:

#include <iostream>
#include <string>

#include "../core/simx.hpp"

using TimeType = long;
using Sim = simx::SimX<TimeType>;
using Promise = simx::Promise;

Promise ClockProc(Sim &sim, const std::string &name, long delay) {
    while (true) {
        std::cout<<"time: "<<sim.Now()<<", "<<name<<std::endl;
        co_await sim.Timeout(delay);
    }
}

int main(){
    Sim sim;
    auto p0 = ClockProc(sim, "slow", 5);
    auto p1 = ClockProc(sim, "fast", 3);
    sim.Run(20);
    return 0;
}

When run, the following output is generated:

time: 0, slow
time: 0, fast
time: 3, fast
time: 5, fast
time: 6, fast
time: 9, fast
time: 10, fast
time: 12, fast
time: 15, fast
time: 15, fast
time: 18, fast

Other examples can be found in the examples/ folder.

This project uses CMake. To build and execute the clocks example, run the following commands:

cmake -B build
cmake --build build
build/examples/clock

The CMake configuration has been tested with GCC (version 10 or later). If such a version is available under a different name (for example g++-10), you can try CXX=g++-10 cmake .. instead of just cmake .. to set the C++ compiler command.

If you want to use simx in your project, the easiest option is to use CMake with FetchContent. A simple configuration looks like this:

cmake_minimum_required(VERSION 3.14)

project(my_app)

include(FetchContent)

FetchContent_Declare(simx
    GIT_REPOSITORY https://github.com/wwwHui/simx
    GIT_TAG        0451e6b3f2bccfedb600dced90d956255db88e52) # replace with latest revision

FetchContent_MakeAvailable(simx)

add_executable(app app.cpp)
target_link_libraries(app PRIVATE simx)

Replace the commit hash with the latest commit hash of simx accordingly.

Reference

SimCpp20 is a discrete-event simulation framework for C++20. Actually, I developed Simx because I encountered a memory leak in a traffic project based on SimCpp20, and I didn't have the capability to solve that issue.

SimPy is a process-based discrete-event simulation framework based on standard Python.

CppCoroutines

Copyright and License

Copyright © 2023 hui.

Licensed under the MIT License. See the LICENSE file for details.