4 replies to this topic

[alirezan]

Hi

I'm fairly new to many concepts in C/C++ and am just learning. I am trying to to create a timer class that can be used to check for timeouts on network operations. I was told I will need to assign a "handle" to each timer. I do know what handles are (i.e. handle to windows in visual C++) but I don't know in case of a custom timer how I should go about doing it. Can anyone help me understand this concept please?

Thanks

[Alexander]

There is a lack of information on your end. If you are working with network sockets, I would recommend looking at the Winsock select function. select Function (Windows)

[alirezan]

Sorry!
I'm working with Serial communication not network protocols. I'm trying to write a simple timer code that creates a timer and returns a handle. The timer will be used to time the packet transmission and make sure we retransmit it the ACK doesn't arrive within certain period of time. The handle is used for operations such as checking, resetting, closing etc after it was created. A system can have multiple timers running at the same time. Each timer will have a unique handle.

Thanks

[Flying Dutchman]

class Timer {

    public:

        void start() {

        #ifdef _WIN32

            ::QueryPerformanceCounter(&m_start);

        #else

            timeval time;

            gettimeofday(&time, NULL);

            m_start = time.tv_usec;

        #endif

        }


        double elapsed() const {

        #ifdef _WIN32

            LARGE_INTEGER ticksPerSecond;

            LARGE_INTEGER end;

            ::QueryPerformanceFrequency(&ticksPerSecond);

            ::QueryPerformanceCounter(&end);

            return static_cast<double>(end.QuadPart - m_start.QuadPart) / ticksPerSecond.QuadPart;

        #else

            timeval time;

            gettimeofday(&time, NULL);

            return static_cast<double>(time.tv_usec - m_start);

        #endif

        }


        void restart() {

            Timer::start();

        }


        void sleep(int milisec) {

            if (milisec > 0)

            #ifdef _WIN32

                ::Sleep(milisec);

            #else

                usleep(milisec * 1000);

            #endif

        }


        #ifndef _WIN32

        void uSleep(int microsec) {

            if (microsec > 0)

                usleep(microsec);

        }

        #endif


    private:

    #ifdef _WIN32

        LARGE_INTEGER    m_start;

    #else

        double           m_start;

    #endif

};

[fayyazlodhi]

Microsecond timer for Windows

The above explains some timers in win32 and can help to understand what is being used in the code above.