static void mdlUpdate(SimStruct *S, int_T tid)
{
UNUSED(tid);
struct timeval tv;
gettimeofday(&tv, NULL);
double *wall_t0 = (double*) ssGetDWork(S,0);
if (*wall_t0 == TIME_NOT_YET_SET) {
// t0 not set yet, set it now. (note: used to set this in mdlStart, but there can be a big pause between mdlStart and the full simulation start)
*wall_t0 = timevalToDouble(tv);
return;
}
double wall_t = timevalToDouble(tv),
simtime = ssGetT(S),
realtime_factor = mxGetScalar(ssGetSFcnParam(S, 1));
double t_diff = (wall_t - *wall_t0)*realtime_factor - simtime;
// mexPrintf("wall time: %f, sim time: %f, (scaled) diff: %f\n", wall_t-*wall_t0, simtime, t_diff);
if (t_diff<0.0) { // then simtime > scaled wall_time
timespec tosleep;
tv = doubleToTimeval(-t_diff);
tosleep.tv_sec = tv.tv_sec;
tosleep.tv_nsec = tv.tv_usec * 1000;
// mexPrintf("sleeping... %d sec, %d nsec\n", tosleep.tv_sec, tosleep.tv_nsec);
nanosleep(&tosleep, NULL);
} else if (t_diff>1.0) { // then I'm behind by more than 1 second
mexPrintf("at time %f, I'm behind by %f sec\n", simtime, t_diff);
ssSetErrorStatus(S, "Simulink is not keeping up with real time. Consider reducing demands on your ODE solver, or optimizing your code.");
}
}
int main ( int argc, char **argv) {
assert(argc > 1);
double d = atof(argv[1]);
printf("double: %f\n", d);
struct timeval t;
doubleToTimeval(d, &t);
printf("before add; secs: %d, usecs: %d\n", t.tv_sec, t.tv_usec);
struct timeval t2;
t2.tv_usec = 2;
t.tv_usec += t2.tv_usec;
printf("after add; secs: %d, usecs: %d\n", t.tv_sec, t.tv_usec);
if ( t.tv_usec >= 1000000 )
{
t.tv_sec++;
t.tv_usec-=1000000;
}
printf("after clean; secs: %d, usecs: %d\n", t.tv_sec, t.tv_usec);
return 0;
}
