C++: How to Implement Chrono in this code

I am new to using chrono so any suggestions at all would be appreciated. The following program takes in a vector and passes each element as a single thread. Now, the chrono should take each thread object and perform a computation of it. I'm not well-versed with the syntax so am not sure how to implement it properly.

Here is the code. The variable half_life is supposed to run the function whenever lifetime is half its original size.

#include <iostream>
#include <thread>
#include <string>
#include <sstream>
#include<vector>
#include <chrono>
#include <mutex>
#include <stdlib.h>
using namespace std;
vector<int> inputs;

int total = 0, counter=0;
int totally= 0;
thread thread_obj;
int total_cells= 0;
class Counter
{
    int number;
    mutex mute;
public:
    Counter() :number(0){}
    int getNumber() { return number; }
    int increase()
    {
        mute.lock();
        number++;
        mute.unlock();
        return number;
    }
    void decrease()
{
        mute.lock();
        number--;
        mute.unlock();
}

};
Counter timer;

void thread_function(int x)
{   using namespace std::chrono;
    int lifeTime= (0.1 + x % 8);
    int y = (x-x%8) / 8 ;
    int half_life;


    timer.increase();


    half_life = std::thread_function::sleep_for(std::chrono::milliseconds((int)(0.5 * 1000 * lifeTime))); 
//this is the chrono function

    if (timer.getNumber() == half_life){

        totally=totally+y;
        thread_function(y);
    }
    cout<<"[Monitor] Total cells: "<< totally << " [ " << timer.getNumber() <<" s ] "<<endl;
    if(totally == 0){
        exit(0);
    }


}


int main()
{   
    cout<<"[Main] Please input a list of gene seeds: "<<endl;
    int value;
    string line;
    getline(cin, line);
    istringstream iss(line);
    while(iss >> value){

       inputs.push_back(value);
    }

    cout<<"[Monitor] Started [ 0 s ]"<<endl;
    for (int unsigned i = 0; i < inputs.size(); i++) {
        thread thread_obj(thread_function, inputs.at(i));
        thread_obj.join();
     }



    return 0;

}