Core Code

Sometimes is quite interesting to measure the run time of a given snippet your code. In C++11 is very simple and in my case I’m using just like that.

In my .h file I define

#ifndef __PROFILER__H
#define __PROFILER__H

#include <chrono>

using namespace std::chrono;

high_resolution_clock::time_point start(void);
high_resolution_clock::time_point end(void);
void finished(high_resolution_clock::time_point, high_resolution_clock::time_point);

#endif

And in my .cpp file

#include <iostream>
#include "profiler.h"


high_resolution_clock::time_point start(void) 
{
    return high_resolution_clock::now();
}

high_resolution_clock::time_point end(void)
{
    return high_resolution_clock::now();
}

void finished(high_resolution_clock::time_point start, high_resolution_clock::time_point end)
{
    duration<double> elapse = end - start;
    std::cout << "Elapsed time for function " << __FUNCTION__ << " :"<< elapse.count() << "s" << std::endl;
}

In order to use the code you just need to add the code ‘surrounded’ by start and finished functions, passing end as parameter. Like that:

#include <iostream>

// It's not often that you'll profiling your code so just add a D flag
// See Makefile
#if PROFILER 
#include "profiler.h"
#endif

// Some function to measure
void initLoad(void) {
    cout << "Initializing data in memory..." << endl;

#if PROFILER
    high_resolution_clock::time_point s = start();
#endif

    for (int i = 0; i < 100000000000; i++)
        cout << i << endl;

#if PROFILER
    finished(s, end());
#endif
}

In your Makefile you can use a D flag to optionally compile your code to use the profiling, such as:

SRC = $(wildcard src/*.cpp)
PROG_NAME = test
INCLUDE = -Iinclude 
LIBS = -Ilibs
FLAGS = -std=c++0x
DFLAGS = -q -nx -tui
PROFILER ?= 0

# To use profiler just add: make PROFILER=1
ifeq ($(PROFILER), 1)
	FLAGS += -DPROFILER
endif

test:
	g++ -o $(PROG_NAME) $(SRC) $(INCLUDE) $(LIBS) $(FLAGS)

Now you can use this ‘lib’ for any source you want to measure the run time typing: make PROFILER=1 🙂

That’s all folks!

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