# Last edited on 1999-03-31 00:03:32 by stolfi
# Variant of read_clock that gets the CPU time from getrusage()
# instead of times()

void read_clock(double *etime, double *ptime)
  { struct tms buf;
    clock_t et;
    double tck;

    et = times(&buf);
    tck = (double)sysconf(_SC_CLK_TCK);
    affirm(tck != 0, "bad tck!");
    (*etime) = ((double) et)/tck;
    
    { struct rusage ru; double psec, pusec;
      int s = getrusage(RUSAGE_CHILDREN, &ru);
      check_return(s == 0, "getrusage failed");
      psec = (double) ru.ru_utime.tv_sec;
      pusec = (double) ru.ru_utime.tv_usec;
      (*ptime) = psec + pusec/1000000.0;
    }
  }