busybox/shell/random.h
Denys Vlasenko 76ace254e1 ash,hush: fix $RANDOM in children being repeated
function                                             old     new   delta
next_random                                           46      68     +22
forkshell                                            248     263     +15
expand_vars_to_list                                 2118    2131     +13
run_pipe                                            1775    1782      +7
popstring                                            134     140      +6
builtin_umask                                        123     121      -2
ash_main                                            1356    1336     -20
get_local_var_value                                  125     104     -21
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 5/3 up/down: 63/-43)             Total: 20 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2009-10-12 15:25:01 +02:00

26 lines
610 B
C

/* vi: set sw=4 ts=4: */
/*
* $RANDOM support.
*
* Copyright (C) 2009 Denys Vlasenko
*
* Licensed under GPLv2, see file LICENSE in this tarball for details.
*/
typedef struct random_t {
/* Random number generators */
int32_t galois_LFSR; /* Galois LFSR (fast but weak). signed! */
uint32_t LCG; /* LCG (fast but weak) */
} random_t;
#define UNINITED_RANDOM_T(rnd) \
((rnd)->galois_LFSR == 0)
#define INIT_RANDOM_T(rnd, nonzero, v) \
((rnd)->galois_LFSR = (nonzero), (rnd)->LCG = (v))
#define CLEAR_RANDOM_T(rnd) \
((rnd)->galois_LFSR = 0)
uint32_t next_random(random_t *rnd) FAST_FUNC;