Drekar Launch Process C++

This library contains client utility functions for processes launched using drekar-launch, although they may also be used without drekar-launch. Currently this package provides a reliable way for processes to receive shutdown signals from a process manager or the user using ctrl-c. This package contains C++ implementations, analogous to drekar-launch-process for Python. See https://github.com/johnwason/drekar-launch-process for more information.

Building

Use cmake to build the library.

git clone https://github.com/johnwason/drekar-launch-process-process-cpp
mkdir build
cd build
cmake ..
cmake --build .

Alternatively build using vcpkg:

git clone https://github.com/microsoft/vcpkg.git
cd vcpkg
git clone https://github.com/robotraconteur/vcpkg-robotraconteur.git
vcpkg --overlay-ports=vcpkg-robotraconteur\ports install drekar-launch-process-cpp:x64-windows

Usage

The class CWaitForExit provides utility functions to wait for program exit. The WaitForExit() function will block until the exit signal is received, or the CallbackWaitForExit() function will asynchronously trigger a callback when the exit signal is received.

Blocking example:

#include "drekar_launch_process_cpp/drekar_launch_process_cpp.h"
#include <iostream>

int main()
{
    drekar_launch_process_cpp::CWaitForExit wait_for_exit;
    std::cout << "Press Ctrl+C to exit" << std::endl;
    wait_for_exit.WaitForExit();
    std::cout << "Exit" << std::endl;
    return 0;
}

Callback example:

#include "drekar_launch_process_cpp/drekar_launch_process_cpp.h"
#include <iostream>
#include <condition_variable>
#include <functional>

std::condition_variable cv;
std::mutex cv_mutex;
bool exit_received = false;

void exit_callback()
{
    std::unique_lock<std::mutex> lock(cv_mutex);
    exit_received = true;
    cv.notify_all();
}

int main()
{
    drekar_launch_process_cpp::CWaitForExit wait_for_exit;
    wait_for_exit.CallbackWaitForExit(exit_callback);
    std::unique_lock<std::mutex> lock(cv_mutex);
    std::cout << "Press Ctrl+C to exit" << std::endl;
    cv.wait(lock, [] {return exit_received; });
    std::cout << "Exit" << std::endl;
    return 0;
}

Acknowledgment

Research was sponsored in part by the ARM (Advanced Robotics for Manufacturing) Institute through a grant from the Office of the Secretary of Defense and was accomplished under Agreement Number W911NF-17-3-0004. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of the Office of the Secretary of Defense or the U.S. Government. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation herein.

This work was supported in part by the New York State Empire State Development Division of Science, Technology and Innovation (NYSTAR) under contract C160142.