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

#define TIMERS 16

typedef unsigned long DWORD;
static struct itimerval itval;
void timer_handler(int);


static DWORD qwtimer;
static DWORD oldtmr;

typedef void (*PFNTIMER)(void);

typedef struct XLWTIMER{

    int avail;
    int index;
    int id;
    int elapse;
    DWORD oldtmr;
    PFNTIMER timerfunc;

}XLWTIMER, *PXLWTIMER;

static XLWTIMER xlwtmr[TIMERS];
static XLWTIMER zero = { (int)0, (int)0, (int)0, (int)0, (DWORD)0UL, (PFNTIMER)NULL };

void SetTimer(int id, int elapse, PFNTIMER pfnt)
{
    int i;
    
    for(i = 0; i < 10; i++) {
    
	if(0 == xlwtmr[i].avail) {

            xlwtmr[i].avail = 1;
	    xlwtmr[i].index = i;
	    xlwtmr[i].id = id;
    	    xlwtmr[i].elapse = elapse;
            xlwtmr[i].oldtmr = qwtimer;
	    xlwtmr[i].timerfunc = pfnt;
	    return;
	}    
    }
}

void KillTimer(int id)
{
    int i;
    
    for(i = 0; i < 10; i++) {
	
	if (id == xlwtmr[i].id) {
	    xlwtmr[i] = zero;
	    return;
	}
    }

}

void test10()
{
    printf("\n10");
    return;    
}


void test150()
{
    printf("\n           150");
    return;
}

void test35()
{
    printf("\n        35");
    return;
}

void test200()
{
    printf("\n                   200");
    return;
}


int main(int argc, char **argv)
{

    qwtimer = 0UL;
    oldtmr = 0UL;
    
    memset(xlwtmr, 0, sizeof(XLWTIMER) * 10);
    
    signal(SIGALRM, timer_handler); 

    /* create the interval timer */ 
    memset(&itval, 0, sizeof(struct itimerval));
    itval.it_interval.tv_sec = 0; 
    itval.it_interval.tv_usec = 10; 
    itval.it_value.tv_sec = 0; 
    itval.it_value.tv_usec = 10;    
    setitimer(ITIMER_REAL, &itval, NULL);
    
    SetTimer(1, 10, test10);    
    SetTimer(2, 150, test150);
    SetTimer(3, 35, test35);    
    SetTimer(4, 200, test200);    

    
    getchar();
     KillTimer(1);
    getchar();
         KillTimer(2);
    getchar();
         KillTimer(4);
    getchar();
             KillTimer(3);
	     
    SetTimer(4, 200, test200);    	     


    getchar();
//while(1);
    
//   
    
//    getchar();


    return (EXIT_SUCCESS);
}

void timer_handler(int j)
{
    int i;

    signal(SIGALRM, SIG_IGN);     
    qwtimer += 10;
    
    for(i = 0; i < 10; i++) {    
    
	if(1 == (xlwtmr[i].avail)		 &&
	   0 == (qwtimer % xlwtmr[i].elapse)	 &&	    
	        (qwtimer - xlwtmr[i].oldtmr) >= xlwtmr[i].elapse) {
		
		xlwtmr[i].timerfunc();
		xlwtmr[i].oldtmr = qwtimer;
	}	
    }    
    
    signal(SIGALRM, timer_handler);
    return;
}