ex.cpp

#include <iostream>
#include <thread>
#include <ctime>

void timer_task(int interval, bool &worker_idle){
     std::thread t([=]() {
        while(1) {
            if (worker_idle == true) std::cout << "timer nha ... " << &worker_idle << "\n";
            std::this_thread::sleep_for(std::chrono::milliseconds(interval));
        }
    });
    t.detach();
}

std::string getCurrentDateTime(){
    time_t rawtime;
    struct tm * timeinfo;
    char buffer[80];
    time (&rawtime);
    timeinfo = localtime(&rawtime);
    strftime(buffer,sizeof(buffer),"%Y-%m-%d %H:%M:%S",timeinfo);
    std::string datetime(buffer);
    return datetime;
}

int main(){
    int interval = 1000;
    bool worker_idle = true;
    timer_task(interval, worker_idle);

    // main thread continue run
    int count = 0;
    while(1) {
        count++;
        if (count == 5){
            worker_idle = false;
        }
         std::cout << "worker  nha ... " << &worker_idle << "\n";
        std::this_thread::sleep_for(std::chrono::milliseconds(interval));
    }
}

log

lap60313@LAP60313:~/sources/cpp/kaldimodeloffline/kaldikiki/src/cudadecoderbin$ g++ -pthread test.cpp 
lap60313@LAP60313:~/sources/cpp/kaldimodeloffline/kaldikiki/src/cudadecoderbin$ ./a.out 
worker  nha ... 0x7ffcead80737timer nha ... 0x55cb0e042e78

timer nha ... 0x55cb0e042e78
worker  nha ... 0x7ffcead80737
timer nha ... 0x55cb0e042e78
worker  nha ... 0x7ffcead80737
timer nha ... 0x55cb0e042e78
worker  nha ... 0x7ffcead80737