| Jens Axboe | 1fbbf72 | 2010-03-25 23:03:18 +0100 | [diff] [blame] | 1 | #ifndef FIO_RAND_H |
| 2 | #define FIO_RAND_H |
| 3 | |
| Jens Axboe | 2615cc4 | 2011-03-28 09:35:09 +0200 | [diff] [blame] | 4 | #define FRAND_MAX (-1U) |
| 5 | |
| Jens Axboe | 1fbbf72 | 2010-03-25 23:03:18 +0100 | [diff] [blame] | 6 | struct frand_state { |
| 7 | unsigned int s1, s2, s3; |
| 8 | }; |
| 9 | |
| Jens Axboe | 1fbbf72 | 2010-03-25 23:03:18 +0100 | [diff] [blame] | 10 | static inline unsigned int __rand(struct frand_state *state) |
| 11 | { |
| 12 | #define TAUSWORTHE(s,a,b,c,d) ((s&c)<<d) ^ (((s <<a) ^ s)>>b) |
| 13 | |
| 14 | state->s1 = TAUSWORTHE(state->s1, 13, 19, 4294967294UL, 12); |
| 15 | state->s2 = TAUSWORTHE(state->s2, 2, 25, 4294967288UL, 4); |
| 16 | state->s3 = TAUSWORTHE(state->s3, 3, 11, 4294967280UL, 17); |
| 17 | |
| 18 | return (state->s1 ^ state->s2 ^ state->s3); |
| 19 | } |
| 20 | |
| 21 | extern void init_rand(struct frand_state *); |
| Jens Axboe | 2615cc4 | 2011-03-28 09:35:09 +0200 | [diff] [blame] | 22 | extern void init_rand_seed(struct frand_state *, unsigned int seed); |
| Jens Axboe | 7d9fb45 | 2011-01-11 22:16:49 +0100 | [diff] [blame] | 23 | extern void __fill_random_buf(void *buf, unsigned int len, unsigned long seed); |
| Jens Axboe | 3545a10 | 2011-08-31 15:20:15 -0600 | [diff] [blame] | 24 | extern unsigned long fill_random_buf(struct frand_state *, void *buf, unsigned int len); |
| Jens Axboe | 1fbbf72 | 2010-03-25 23:03:18 +0100 | [diff] [blame] | 25 | |
| 26 | #endif |