std::atomic store load std::memory_order_seq_cst

#include <atomic>
#include <chrono>
#include <ctime>
#include <fstream>
#include <future>
#include <iomanip>
#include <iostream>
#include <map>
#include <memory>
#include <mutex>
#include <sstream>
#include <thread>
#include <uuid/uuid.h>

std::string get_time_now()
{
    auto now = std::chrono::high_resolution_clock::now();
    time_t raw_time = std::chrono::high_resolution_clock::to_time_t(now);
    struct tm tm_info = *localtime(&raw_time);
    std::chrono::seconds seconds = std::chrono::duration_cast<std::chrono::seconds>(now.time_since_epoch());
    auto mills = std::chrono::duration_cast<std::chrono::milliseconds>(now.time_since_epoch());
    auto micros = std::chrono::duration_cast<std::chrono::microseconds>(now.time_since_epoch());
    auto nanos = std::chrono::duration_cast<std::chrono::nanoseconds>(now.time_since_epoch());
    std::stringstream ss;
    ss << std::put_time(&tm_info, "%Y%m%d%H%M%S") << "_"
       << std::setw(3) << std::setfill('0') << (mills.count() - seconds.count() * 1000)
       << std::setw(3) << std::setfill('0') << (micros.count() - mills.count() * 1000)
       << std::setw(3) << std::setfill('0') << (nanos.count() - micros.count() * 1000);
    return ss.str();
}

char *uuid_value = (char *)malloc(40);
char *get_uuid_value()
{
    uuid_t new_uuid;
    uuid_generate(new_uuid);
    uuid_unparse(new_uuid, uuid_value);
    return uuid_value;
}
 
std::atomic<bool> _is_finish(false);
void atomic_write_log(const std::string &file_name)
{
    std::fstream w_file(file_name, std::ios::app);
    if (!w_file.is_open())
    {
        std::cout << "Create or open " << file_name << " failed!" << std::endl;
        return;
    }
    std::stringstream ss;
    std::uint64_t num = 0;
    while (!_is_finish.load(std::memory_order_seq_cst))
    {
        for (int i = 0; i < 1000000; i++)
        {
            ss << ++num << "," << get_uuid_value() << std::endl;
        }
        w_file << ss.str();
        ss = std::stringstream();
        std::cout << "Num:" << num << "," << get_time_now() << std::endl;
    }
    w_file.close();
    std::cout << get_time_now() << ",thread id:" << std::this_thread::get_id() << ",finish in " << __FUNCTION__ << std::endl;
}

void atomic_store_for_seconds(const std::string file_name, const int &run_seconds)
{
    std::future<void> fut=std::async(atomic_write_log,std::cref(file_name));
    fut.wait_for(std::chrono::seconds(run_seconds));
    _is_finish.store(true,std::memory_order_seq_cst);
    std::cout << get_time_now() << ",thread id:" << std::this_thread::get_id() << ",finish in " << __FUNCTION__ << std::endl;
}

int main(int args, char **argv)
{
    atomic_store_for_seconds(argv[1], atoi(argv[2]));
    std::cout << get_time_now() << ",finish in " << __FUNCTION__ << std::endl;
}

 

Compile

g++-12 -std=c++2a -I. *.cpp -o h1 -luuid -lpthread

 

Run

./h1 log3.txt 100;