如何为这个linux计时器创建一个处理程序？

Question

#include <time.h>
#include <sys/time.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <unistd.h>

/*
This function is called periodically.
The actual functionality has to be provided by yourself **/
void my_handler ( timer_t timerid)
{
    printf("\nHello World\n");
}

int main()
{

 // declare some variables
 timer_t timerid;
 struct itimerspec value;
 struct sigevent sevp;

 // initalize the sigevent variable
 // the memset is necessary to avoid segmentation faults
  memset (&sevp, 0, sizeof (struct sigevent));
  sevp.sigev_notify=SIGEV_THREAD;
  sevp.sigev_notify_function=(void *)my_handler;

 // initialize the timer specification
 // currently the offset and the period is 5 seconds  // you have to adjust this to your actual 
//needs
  value.it_value.tv_sec = 5;
  value.it_value.tv_nsec = 0;
  value.it_interval.tv_sec = 5;
  value.it_interval.tv_nsec = 0;

 // create the timer
 timer_create (CLOCK_REALTIME, &sevp, &timerid);
 timer_settime (timerid, 0, &value, NULL);

 // this loop has to be adapted, so that the program ends after some time
 while(1)
 {
  sleep(100);
 }
 return 0;
}

我创建了一个计时器，用于每5秒调用一次任务并打印为hello。我是否想为另一个任务创建另一个计时器（每10ms）？如何在这种情况下创建一个处理程序？如何计算执行任务的开始时间和停止时间??