- static int first = 1;
- static u_long randseed = 1;
-
- register long x, hi, lo, t;
-
- if (first) {
- struct timeval tv;
- microtime(&tv);
- randseed = tv.tv_usec;
- if(!randseed)
- randseed=1;
- first = 0;
- }
-
- /*
- * Compute x[n + 1] = (7^5 * x[n]) mod (2^31 - 1).
- * From "Random number generators: good ones are hard to find",
- * Park and Miller, Communications of the ACM, vol. 31, no. 10,
- * October 1988, p. 1195.
- */
- x = randseed;
- hi = x / 127773;
- lo = x % 127773;
- t = 16807 * lo - 2836 * hi;
- if (t <= 0)
- t += 0x7fffffff;
- randseed = t;
- return (t);