Assigning a member function to signal callback function pointer

From:
Ramesh <rramesh1@gmail.com>
Newsgroups:
comp.lang.c++
Date:
Wed, 24 Dec 2008 16:04:00 -0800 (PST)
Message-ID:
<c6eb707c-817a-4e99-9b26-506237386a34@e3g2000vbe.googlegroups.com>
Hello,

I am writing an application in linux using timer_create API to create
timers in my application, I have registered a call back routine which
would be called when the timer timesout. I get the following error:

-------

test.cpp: In member function 'unsigned long
testMgr::addConfigChangeTimer(unsigned long)':
test.cpp:125: error: argument of type 'void (testMgr::)(sigval_t)'
does not match 'void (*)(sigval_t)'

------

The compiler expects a function returning void and taking a sigval_t
as argument, in my case the only difference is that the linkage is C++
style and its a member function.

Is there a way I can assign a member function to the notify_function
pointer?

Thanks
/R

Here is the code snippet:

---

// Actual point of assignment of the callback function to the signal
handler

unsigned long testMgr::addConfigChangeTimer(unsigned long interval) {

    timer_t id = 0;
    int count = 0;
    struct sigevent sig;
    struct itimerspec timerspec;

    memset(&timerspec, 0, sizeof(struct itimerspec));
    memset(&sig, 0, sizeof(struct sigevent));

    sig.sigev_notify = SIGEV_THREAD;
    sig.sigev_notify_function = ConfigChangeHandler;
 
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    sig.sigev_value.sival_ptr = (void*)&count

-------

// Actual function

void testMgr::ConfigChangeHandler(sigval_t value) {

    ACE_Guard<ACE_Thread_Mutex> guard(tMutex);

    if (ConfigChange == TRUE) {
        Notifythreads();
        ConfigChange = FALSE;
    }
    trace("Config change timeout process completed");
}

----

// Class definition

class testMgr {

    private:

        timestamp ChangeTime;
        BOOL ConfigChange;
        ACE_Thread_Mutex tMutex;

    public:

        testMgr();
        ~testMgr();
        UINT32 addConfigChangeTimer(UINT32);
        void entConfigChangeHandler(sigval_t );
};

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