c++ condition_variable wait unique_lock,cv.notifyall()

#include <atomic>
#include <chrono>
#include <cmath>
#include <condition_variable>
#include <cstddef>
#include <forward_list>
#include <fstream>
#include <functional>
#include <future>
#include <iomanip>
#include <iostream>
#include <latch>
#include <list>
#include <map>
#include <mutex>
#include <queue>
#include <random>
#include <stack>
#include <string>
#include <thread>
#include <utility>
#include <uuid/uuid.h>
#include <vector>
#include "tree.cpp"

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::string get_time_now(bool is_exact = false)
{
    std::stringstream ss;
    std::chrono::time_point<std::chrono::high_resolution_clock> 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);
    ss << std::put_time(&tm_info, "%Y%m%d%H%M%S");
    if (is_exact)
    {
        std::chrono::seconds seconds = std::chrono::duration_cast<std::chrono::seconds>(now.time_since_epoch());
        std::chrono::milliseconds mills = std::chrono::duration_cast<std::chrono::milliseconds>(now.time_since_epoch());
        std::chrono::microseconds micros = std::chrono::duration_cast<std::chrono::microseconds>(now.time_since_epoch());
        std::chrono::nanoseconds nanos = std::chrono::duration_cast<std::chrono::nanoseconds>(now.time_since_epoch());
        ss << "_" << 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();
}

std::condition_variable _cv;
std::map<int, std::string> _cv_map;
bool _is_ready = false;
std::mutex _cv_mtx;
void fill_map()
{
    static int num = 0;
    while (!_is_ready)
    {
        _cv_map.insert(std::pair<int, std::string>(++num, get_uuid_value()));
    }
}

void cv_wait_notify(const int &sleep_seconds)
{
    std::unique_lock<std::mutex> _lk(_cv_mtx);
    std::thread t1(fill_map);
    _cv.wait_for(_lk, std::chrono::seconds(sleep_seconds));
    _is_ready = true;
    _cv.notify_all();
    t1.join();
    std::cout << "Map size:" << _cv_map.size() << std::endl;
    std::cout << get_time_now(true) << ",thread id:" << std::this_thread::get_id() << ",in " << __FUNCTION__ << std::endl;
}

int main(int args, char **argv)
{
    cv_wait_notify(atoi(argv[1]));
    std::cout << get_time_now(true) << ",thread id:" << std::this_thread::get_id() << ",in " << __FUNCTION__ << std::endl;
    std::cout << "Map size:" << _cv_map.size() << std::endl;
}

Compile

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

Run

./h1 10;