Total time in different parts of recursive function-CodePudding

I am new to C and I need to measure the total time for different parts of a recursive function. A simple example to show where I get so far is:

#include <iostream>
#include <unistd.h>
#include <chrono>
using namespace std;
using namespace std::chrono;

int recursive(int);
void foo();
void bar();

int main() {
    int n = 5;  // this value is known only at runtime
    int result = recursive(n);
    return 0;
}

int recursive(int n) {
    auto start = high_resolution_clock::now();
    if (n > 1) { recursive(n - 1); n = n - 1; }
    auto stop = high_resolution_clock::now();
    auto duration_recursive = duration_cast<microseconds>(stop - start); 

    cout << "time in recursive: " << duration_recursive.count() << endl;
    //
    // .. calls to other functions and computations parts I don't want to time
    //
    start = high_resolution_clock::now();
    foo();
    stop = high_resolution_clock::now();
    auto duration_foo = duration_cast<seconds>(stop - start);
    cout << "time in foo: " << duration_foo.count() << endl;
    //
    // .. calls to other functions and computations parts I don't want to time
    //
    start = high_resolution_clock::now();
    bar();
    stop = high_resolution_clock::now();
    auto duration_bar = duration_cast<seconds>(stop - start);
    cout << "time in bar: " << duration_bar.count() << endl;

    return 0;
}

void foo() { // a complex function
sleep(1);
}

void bar() { // another complex function
sleep(2);
}

I want the total time for each of the functions, for instance, for foo() it is 5 seconds, while now I always get 1 second. The number of iterations is known only at runtime (n=5 here is fixed just for simplicity).

To compute the total time for each of the functions I did try replacing the type above by using static and accumulate the results but didn't work.

CodePudding user response：

You can use some container to store the times, pass it by reference and accumulate the times. For example with a std::map<std::string,unsinged> to have labels:

int recursive(int n, std::map<std::string,unsigned>& times) { 
    if (n >= 0) return;
    // measure time of foo
    times["foo"]  = duration_foo;
    // measure time of bar
    times["bar"]  = duration_bar;
    // recurse
    recursive(n-1,times);
}

Then

std::map<std::string,unsigned> times;
recursive(200,times);
for (const auto& t : times) {
    std::cout << t.first << " took total : " << t.second << "\n";
}