Need help in implementation of a timer/ticker class in C++ - c++

Question

Need help in implementing a ticker class with start/stop/pause functionality, assignable callback (onTick) with execution on a separate thread every interval span. Interval span is specifiable and update-able. Hopefully it should be cross-platform.
Here is my naive attempt, but it's not good (the while loop in start() is blocking currently, but ideally it should run on a separate thread but I can't figure out how to achieve it) as I'm pretty noob in C++ multithreading model:
#include <cstdint>
#include <functional>
#include <chrono>
#include <thread>
#include <future>
class Ticker {
public:
typedef std::chrono::duration<int64_t, std::nano> tick_interval_t;
typedef std::function<void()> on_tick_t;
Ticker (std::function<void()> onTick, std::chrono::duration<int64_t, std::nano> tickInterval)
: _onTick (onTick)
, _tickInterval (tickInterval)
, _running (false) {}
~Ticker () {}
void start () {
if (_running) return;
_running = true;
while (_running) {
std::async( std::launch::async, _onTick );
std::this_thread::sleep_for( _tickInterval );
}
}
void stop () { _running = false; }
private:
on_tick_t _onTick;
tick_interval_t _tickInterval;
bool _running;
};
I'm a completely wrong in my attempt or it's pretty close?

Answer 1

Consider the following code with example of usage. I hope I understood you correctly.
Just run your while loop in a separate thread.
#include <cstdint>
#include <functional>
#include <chrono>
#include <thread>
#include <future>
#include <condition_variable>
#include <iostream>
#include <mutex>
class Ticker {
public:
typedef std::chrono::duration<int64_t, std::nano> tick_interval_t;
typedef std::function<void()> on_tick_t;
Ticker (std::function<void()> onTick, std::chrono::duration<int64_t, std::nano> tickInterval)
: _onTick (onTick)
, _tickInterval (tickInterval)
, _running (false) {}
~Ticker () {}
void start () {
if (_running) return;
_running = true;
std::thread run(&Ticker::timer_loop, this);
run.detach();
}
void stop () { _running = false; }
void setDuration(std::chrono::duration<int64_t, std::nano> tickInterval)
{
_tickIntervalMutex.lock();
_tickInterval = tickInterval;
_tickIntervalMutex.unlock();
}
private:
void timer_loop()
{
while (_running) {
std::thread run(_onTick );
run.detach();
_tickIntervalMutex.lock();
std::chrono::duration<int64_t, std::nano> tickInterval = _tickInterval;
_tickIntervalMutex.unlock();
std::this_thread::sleep_for( tickInterval );
}
}
on_tick_t _onTick;
tick_interval_t _tickInterval;
volatile bool _running;
std::mutex _tickIntervalMutex;
};
void tick()
{
std::cout << "tick\n";
}
void main()
{
std::chrono::duration<int, std::milli> timer_duration1(1000);
std::chrono::duration<int, std::milli> timer_duration2(500);
std::chrono::duration<int> main_wait(5);
Ticker ticker(std::function<void()>(tick), timer_duration1);
ticker.start();
std::this_thread::sleep_for(main_wait);
ticker.setDuration(timer_duration2);
std::this_thread::sleep_for(main_wait);
ticker.stop();
}