queueProcess():

runFlag(false){}

~queueProcess() {

{

std::lock_guard<std::mutex> lock{mMutex};

runFlag = true;

mCondVar.notify_one();

}

if(fut.valid())

{

fut.wait();

}

}

void addQueue(const T& process) {

{

std::lock_guard<std::mutex> lock{mMutex};

mQueue.push(process);

mCondVar.notify_one();

}

}

void processQueue() {

if(!fut.valid())

{

fut = std::async(std::launch::async, [&](){

while (!runFlag) {

std::unique_lock<std::mutex> lock{mMutex};

mCondVar.wait(

lock, [this]() { return !mQueue.empty() || runFlag; });

if(runFlag)

{

return;

}

auto process = mQueue.front();

mQueue.pop();

lock.unlock();

process();

}

});

}

}

std::future<void> fut;

std::queue<T> mQueue;

std::mutex mMutex;

bool runFlag;

std::condition_variable mCondVar;

queueProcess<std::function<void()>> processor;

processor.addQueue([]() { dummyProcess("1"); });

processor.processQueue();

processor.addQueue([]() { dummyProcess("2"); });

processor.addQueue([]() { dummyProcess("3"); });

processor.processQueue(); // no effect

processor.addQueue([]() { dummyProcess("4"); });

std::this_thread::sleep_for(std::chrono::seconds(5));

processor.addQueue([]() { dummyProcess("12"); });