#include <sys/time.h>
#include <signal.h>
#include <unistd.h>
#include <stdio.h>
#include <time.h>
#include <errno.h>
#define LOOP_LIMIT  1E2
volatile int sigcount=0;
void catcher( int sig ) {
    struct itimerval value;
    int which = ITIMER_REAL;
//    printf( "Signal catcher called for signal %d\n", sig );
    sigcount++;
    if( sigcount > 1 ) {
        /*          * Disable the real time interval timer          */
        getitimer( which, &value );
        value.it_value.tv_sec = 0;
        value.it_value.tv_usec = 0;
    //    setitimer( which, &value, NULL );
    }
}
int main( int argc, char *argv[] ) {
    int result = 0;
    struct itimerval value, ovalue, pvalue;
    int which = ITIMER_REAL;
    struct sigaction sact;
    volatile double count;
    time_t t;
    sigemptyset( &sact.sa_mask );
    sact.sa_flags = 0;
    sact.sa_handler = catcher;
    sigaction( SIGALRM, &sact, NULL );
    getitimer( which, &pvalue );
    /*    * Set a real time interval timer to repeat every 200 milliseconds          */
    value.it_interval.tv_sec = 0;        /* Zero seconds */
    value.it_interval.tv_usec = 1;  /* Two hundred milliseconds */
    value.it_value.tv_sec = 0;           /* Zero seconds */
    value.it_value.tv_usec = 5;     /* Five hundred milliseconds */
    result = setitimer( which, &value, &ovalue );
    /* *      * The interval timer value returned by setitimer() should be
 *           * identical to the timer value returned by getitimer().               */
    if( ovalue.it_interval.tv_sec != pvalue.it_interval.tv_sec  ||
        ovalue.it_interval.tv_usec != pvalue.it_interval.tv_usec ||
        ovalue.it_value.tv_sec != pvalue.it_value.tv_sec ||
        ovalue.it_value.tv_usec != pvalue.it_value.tv_usec ) {
        printf( "Real time interval timer mismatch, test Failed\n" );
        result = -1;
    }
    time( &t );
    printf( "Before loop, time is %s", ctime(&t) );
//    for( count=0; ((count<LOOP_LIMIT) && (sigcount<2)); count++ );
//    printf("LOOP_LIMIT=%ld\n",LOOP_LIMIT);

    for( count=0; ((count<LOOP_LIMIT)); count++ );
    time( &t );
    printf( "After loop, time is %s\n", ctime(&t) );
    if( sigcount == 0 )
        printf( "The signal catcher never gained control\n" );
    else
        printf( "The signal catcher gained control\n" );
    printf( "The value of count is %.0f\n", count );
    return( result );
}