linux performance tracking utility

sample.cpp

#include <iostream>
#include <thread>
#include <chrono>
#include <sys/times.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/resource.h>
#include <unistd.h>
#include <fstream>

using namespace std::chrono;

rusage prevUsage = {0};
rusage curUsage = {0};
high_resolution_clock::time_point prevWall, curWall;
size_t frameNumber = 0;

void logProcessStatistics(std::ostream &os) {
	const double elapsedCpu = curUsage.ru_utime.tv_sec + curUsage.ru_stime.tv_sec
		- (prevUsage.ru_utime.tv_sec + prevUsage.ru_stime.tv_sec)
		+ 1e-6f * (curUsage.ru_utime.tv_usec + curUsage.ru_stime.tv_usec
				- (prevUsage.ru_utime.tv_usec + prevUsage.ru_stime.tv_usec));

	const double elapsedWall = duration_cast<duration<double>>(curWall - prevWall).count();
	os << "\tCPU: " << elapsedCpu / elapsedWall * 100.0 << "%\n";


	std::ifstream procStatus("/proc/" + std::to_string(getpid()) + "/status");
	std::string line;
	const static std::string threadPrefix = "Threads:";
	const static std::string cpusPrefix = "Cpus_allowed_list:";
	while (std::getline(procStatus, line)) {
		if (line.compare(0, threadPrefix.size(), threadPrefix) == 0) {
			os << "\t" << line << "\n";
		} else if (line.compare(0, cpusPrefix.size(), cpusPrefix) == 0) {
			os << "\t" << line << "\n";
		}
	}
}

int main() {
	getrusage(RUSAGE_SELF, &prevUsage);
	prevWall = high_resolution_clock::now();

	// Do something expensive that you want to profile
	std::this_thread::sleep_for(seconds(1));

	getrusage(RUSAGE_SELF, &curUsage);
	curWall = high_resolution_clock::now();

	logProcessStatistics(std::cout);

	return 0;
}