Run CPU utilization very high

README.md

Dependencies

• Boost Program Options Library
• CMake
• C++14

Building

mkdir build
cd build
cmake .. && make
./evil --help

build.sh

#!/bin/bash
# vim: set ts=4 sw=4 noet fileencoding=utf-8:

targetBuildDIR=$(dirname $0)/build

if [[ ! -d $targetBuildDIR ]]; then
	echo "Creating build output directory at $targetBuildDIR"
	mkdir $targetBuildDIR
else
	echo "Build output directory $targetBuildDIR already exists"
fi

cd $targetBuildDIR

if [[ ! $(type -P cmake) ]]; then
	echo "CMake was not found in your path. It must be installed."
	exit -1
fi

################################################################################

if cmake .. && make; then
	cd -     # leave the build directory if we are successful
else
	echo "Failed"
	exit -1  # ensure we propagate the exit code for callers
fi

CMakeLists.txt

# vim: set ts=4 sw=4 noet fileencoding=utf-8:
#
# cmake -DCMAKE_BUILD_TYPE=Debug ..
# cmake -DCMAKE_BUILD_TYPE=Release ..

cmake_minimum_required(VERSION 2.8)

set(PACKAGE_NAME      "evil")
set(PACKAGE_VERSION   "0.0.1-dev")
set(PACKAGE_STRING    "${PACKAGE_NAME} ${PACKAGE_VERSION}")
set(PACKAGE_TARNAME   "${PACKAGE_NAME}-${PACKAGE_VERSION}")
project(${PACKAGE_NAME} CXX)

# essential language (C++) specific features & debug / production build
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++14")
set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -O0 -g -Wall")
set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -O2")

set(Boost_USE_STATIC_LIBS ON)
set(Boost_USE_MULTITHREADED OFF)
find_package(Boost 1.42 REQUIRED COMPONENTS program_options)

add_executable(evil evil.c++)
target_link_libraries(evil ${Boost_LIBRARIES})

evil.c++

// vim: set ts=4 sw=4 noet fileencoding=utf-8:

#include <iostream>
#include <string>
#include <sstream>
#include <thread>

#include <boost/program_options.hpp>
namespace po = boost::program_options;

int main(int argc, char const *argv[]) {
	unsigned threads;

	try {
		po::options_description desc("Allowed options");
		desc.add_options()
			("help", "print this help message and exit")
			("threads,t", po::value<unsigned>(&threads)->default_value(0),
				"Threads")
		;

		po::positional_options_description p;
		p.add("threads", -1);

		po::variables_map vm;
		po::store(
			po::command_line_parser(argc, argv)
			.options(desc)
			.positional(p)
			.run(),
		vm);
		po::notify(vm);

		if (vm.count("help") || !threads) {
			std::cout
				<< "Usage: evil [options]" << std::endl
				<< desc << std::endl;
			return 1;
		}

	} catch (std::exception& e) {
		std::cerr << e.what() << std::endl;
		return 1;
	}

	////////////////////////////////////////////////////////////////////////////

	auto evil = [](void) -> void { int i; while (1) ++i; };
	std::vector<std::thread*> threadList;
	for (int i = 0; i < threads; ++i)
		threadList.push_back(new std::thread(*evil));

	for (auto t : threadList) t->join();
}