Xronos C++ SDK

The Xronos C++ SDK is a programmatic interface to the Xronos library, allowing applications to be built using reactors and executed using the Xronos runtime.

System Requirements

• Ubuntu 22.04 or later
• amd64 or arm64 architecture
• GNU-compliant C++ compiler that supports the C++20 standard
  • gcc 11 or later
  • clang 16 or later
• CMake 3.28 or later

See docs.xronos.com for the most up-to-date system requirements.

Install Prerequisites

Install build dependencies

sudo apt install build-essential zlib1g-dev git

Install CMake

On systems older than Ubuntu 24.04, CMake 3.28 needs to be installed from the Kitware ppa. The following shows how to install CMake 3.28 on Ubuntu 22.04.

wget -O - https://apt.kitware.com/keys/kitware-archive-latest.asc 2>/dev/null | gpg --dearmor - | sudo tee /usr/share/keyrings/kitware-archive-keyring.gpg >/dev/null
echo "deb [signed-by=/usr/share/keyrings/kitware-archive-keyring.gpg] https://apt.kitware.com/ubuntu/ $(lsb_release -sc) main" | sudo tee /etc/apt/sources.list.d/kitware.list >/dev/null
sudo apt update

Install CMake:

sudo apt install -y cmake=3.28.6-0kitware1ubuntu22.04.1 cmake-data=3.28.6-0kitware1ubuntu22.04.1

Create a Xronos C++ application

Create the Hello World application

In a new directory, create the following source file hello_world.cc:

#include "xronos/sdk.hh"
 
namespace sdk = xronos::sdk;
 
class HelloWorld : public sdk::Reactor {
  using sdk::Reactor::Reactor;
 
  class HelloWorldReaction : public sdk::Reaction<HelloWorld> {
    using sdk::Reaction<HelloWorld>::Reaction;
    Trigger<void> startup_trigger{self().startup(), context()};
    void handler() final { std::cout << "Hello, World!\n"; }
  };
 
  void assemble() final { add_reaction<HelloWorldReaction>("hello"); }
};
 
auto main() -> int {
  sdk::Environment env{};
  HelloWorld hello_world{"hello_world", env.context()};
  env.execute();
  return 0;
}

Then create the CMake project in CMakeLists.txt:

cmake_minimum_required(VERSION 3.28)
 
project(hello_world LANGUAGES CXX)
set(CMAKE_CXX_STANDARD 20 CACHE STRING "The C++ standard." FORCE)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
include(FetchContent)
FetchContent_Declare(
  "xronos-sdk"
  GIT_REPOSITORY https://github.com/xronos-inc/xronos
  GIT_TAG main
  SOURCE_SUBDIR cpp-sdk
)
FetchContent_MakeAvailable(xronos-sdk)
 
add_executable(hello_world hello_world.cc)
target_link_libraries(hello_world xronos::xronos-sdk)

Build and Run

Generate the CMake project and build the Xronos SDK:

cmake -B build
cmake --build build --target xronos-sdk -j$(nproc)

then compile and run the hello world application:

cmake --build build --target hello_world
./build/hello_world

You should see the output

> Hello, World!

Additional Examples

See https://github.com/xronos-inc/xronos/tree/main/cpp-sdk/examples for additional examples.