🕒 Per-Thread Timers: Areg vs Qt vs POCO

#programming #cpp #opensource #learning

Timers are everywhere — from GUIs to embedded systems — but not all C++ frameworks handle them the same way.

If you’ve ever tried to find a Windows-like Event/Timer (WM_TIMER message) for Linux, you know the struggle: Qt ties timers to the event loop, POCO has limitations, and standard C++ doesn’t offer true per-thread timers out of the box.

That’s where Areg Framework comes in.

Areg delivers per-thread timers that are:

✅ Accurate (not bound to GUI refresh rates)
✅ Thread-aware (fires in the owning thread)
✅ Flexible (one-shot, periodic, cyclic)

🔎 Quick Comparison

Feature	Areg ⚡	Qt QTimer 🎨	POCO Timer ⚙️
Thread-Aware	✅ Target thread	⚠️ GUI/event loop needed	⚠️ Callback thread unclear
Single-Shot/Periodic	✅ Supported	✅ Supported	⚠️ Manual setup required
Cyclic/Repeated	✅ Until stopped	❌ Outside GUI limited	❌ Not native
Non-Blocking/Queue	✅ Event queue	⚠️ Event loop only	⚠️ Owner thread unclear
Central Management	✅ Timer manager	❌ Independent timers	⚠️ No central scheduler
Portability	✅ Win/Linux	⚠️ Desktop/GUI only	⚠️ Embedded support limited

👉 Full Areg timer example here: 08_timer → demonstrates 2 threads with 3 timers each.

Build & run:

git clone https://github.com/aregtech/areg-sdk.git
cd areg-sdk
cmake -B build
cmake --build build -j 12

Run the example binary (replace <compiler> and <os>-<hw>-<build-type>-<lib-type> with the real path):

./product/build/<compiler>/<os>-<hw>-<build-type>-<lib-type>/bin/08_timer

⚡ Example: One-Shot, Periodic & Cyclic in Areg

#include "areg/base/Timer.hpp"

class MyTimer : public DispatcherThread, private IETimerConsumer
{
    void processTimer(Timer &timer) override {
        std::cout << "Timer fired: " << timer.getName() << std::endl;
    }

    void startTimers() {
        mOneShot.startTimer(1000, *this, 1);   // One-shot, fires once
        mPeriodic.startTimer(2000, *this, 5);  // Periodic, fires 5 times
        mCyclic.startTimer(3000, *this);       // Cyclic, runs until stopped
    }

private:
    Timer mOneShot{ "OneShot" };
    Timer mPeriodic{ "Periodic" };
    Timer mCyclic{ "Cyclic" };
};

startTimer(timeoutMs, targetThread, 1) → one-shot
startTimer(timeoutMs, targetThread, N) → periodic (N times)
startTimer(timeoutMs, targetThread) → cyclic (stops with stopTimer())

Simple. Sharp. Reliable.

🎯 Why care?

For real-time apps, embedded systems, or distributed services, GUI-based timers (Qt) or non-thread-guaranteed callbacks (POCO) won’t cut it.
Areg provides native, thread-level control with minimal code.

⚠️ Note: Windows system timers may have ± a few ms variation. On Linux, Areg timers are more precise.

👉 Full working example here: Areg Timer Example.