My Timer class: why, after 6 or 7 instances, the timeSetEvent() is NULL?

[Cambalinho]

heres my timer class:

#define  min(x, y)   __min((x), (y))
#define  max(x,y)   __max((x), (y))
class Timer
{

private:
    UINT_PTR timerid=0;
    UINT m_uResolution=0;
    unsigned int intInterval=0;

    static void CALLBACK _TimerProc(UINT wTimerID, UINT msg, DWORD dwUser, DWORD dw1, DWORD dw2)
    {
        Timer* obj=reinterpret_cast<Timer*>(dwUser);
        obj->timerprocedure();
    }

public:

    std::function<void()> timerprocedure=NULL;
    Timer(std::function<void()> tmrprocedure=NULL)
    {
        timerprocedure=tmrprocedure;
    }

    void Stop()
    {
        if(timerid!=0)
        {
            timeKillEvent(timerid);
            timeEndPeriod (m_uResolution);
        }
    }

    unsigned int GetInterval()
    {
        return intInterval;
    }

    void SetInterval(unsigned int uintInterval)
    {
        intInterval = uintInterval;
    }

    property <unsigned int> Interval{GetProperty(Timer::GetInterval),SetProperty(Timer::SetInterval)};

    void Start()
    {
        Stop();
        TIMECAPS tc;
        timeGetDevCaps(&tc, sizeof(TIMECAPS));
        m_uResolution = min(max(tc.wPeriodMin, 0), tc.wPeriodMax);
        timeBeginPeriod(m_uResolution);
        timerid = timeSetEvent(intInterval, m_uResolution, &Timer::_TimerProc, reinterpret_cast<DWORD>(this),TIME_PERIODIC);

        if (timerid==0)
            DebugText("error\t" + to_string(GetLastError()));
    }

    ~Timer()
    {
        Stop();
    }
};

or it's the 'this' or i don't know.
after 6 or 7 Timer class instances the timeSetEvent() give me NULL and GetLastError():
- 5: acess denied;
i don't have sure about the error. but maybe it's the instance pointer. can anyone explain better to me?

[Arjay]

Not sure, but when I look at the timeSetEvent in msdn, I see the following warning.

Note This function is obsolete. New applications should use CreateTimerQueueTimer to create a timer-queue timer.

I'm wondering if it's worth bothering debugging the obsolete approach?

[Igor Vartanov]

after 6 or 7 Timer class instances the timeSetEvent() give me NULL and GetLastError():
- 6: acess denied;

"Access denied" code is 5. And 6 is "The handle is invalid."

[Cambalinho]

thanks Igor. my mistake on number. sorry.

have something to do, the error, that the 6 timers instances use 200 ms(or less)? maybe i use several resources?

[Igor Vartanov]

In a situation like this I would put aside all the fancy C++ husk, entirely, and write a brand new simplistic WinAPI app that would let me see if the situation with multiple timers is reproducible (of course, in accordance with my current understanding of root cause ).

[Cambalinho]

these make me think about my multithread code. i did an array for resolve the problem, maybe i must do the same here with timerid

[VictorN]

these make me think about my multithread code. i did an array for resolve the problem, maybe i must do the same here with timerid

You did not mention multithreading inn your OP. Perhaps there is the main reason of your problem?
How do you use multithreading and your class?

[Cambalinho]

the problem is another that i didn't notice: we only can have 16 Multimedia Timers.... i was using, without notice, 16 or more. so that's natural that some of them fail. i'm resolving in a diferent way: if the interval is less than 10ms, then use timeSetEvent(), else use SetTimer(). now works. i will do another thread. Moderator: i'm so sorry, but i can't enter on these forum, again. i'm using https://eu3.proxysite.com for enter please tell me something.

[VictorN]

the problem is another that i didn't notice: we only can have 16 Multimedia Timers.... i was using, without notice, 16 or more.

Well, but you told us about "6 or 7 instances", not about "16 or more" ...

... Moderator: i'm so sorry, but i can't enter on these forum, again. i'm using https://eu3.proxysite.com for enter please tell me something.

You should report this problem in the Feedback forum: only Admin could help you, not a moderator.