busybox/shell/random.h

/* vi: set sw=4 ts=4: */
/*
 * $RANDOM support.
 *
 * Copyright (C) 2009 Denys Vlasenko
 *
 * Licensed under GPLv2, see file LICENSE in this tarball for details.
 */
#ifndef SHELL_RANDOM_H
#define SHELL_RANDOM_H 1

PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN

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;

POP_SAVED_FUNCTION_VISIBILITY

#endif
1	/* vi: set sw=4 ts=4: */
2	/*
3	* $RANDOM support.
4	*
5	* Copyright (C) 2009 Denys Vlasenko
6	*
7	* Licensed under GPLv2, see file LICENSE in this tarball for details.
8	*/
9	#ifndef SHELL_RANDOM_H
10	#define SHELL_RANDOM_H 1
11
12	PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
13
14	typedef struct random_t {
15	/* Random number generators */
16	int32_t galois_LFSR; /* Galois LFSR (fast but weak). signed! */
17	uint32_t LCG; /* LCG (fast but weak) */
18	} random_t;
19
20	#define UNINITED_RANDOM_T(rnd) \
21	((rnd)->galois_LFSR == 0)
22
23	#define INIT_RANDOM_T(rnd, nonzero, v) \
24	((rnd)->galois_LFSR = (nonzero), (rnd)->LCG = (v))
25
26	#define CLEAR_RANDOM_T(rnd) \
27	((rnd)->galois_LFSR = 0)
28
29	uint32_t next_random(random_t *rnd) FAST_FUNC;
30
31	POP_SAVED_FUNCTION_VISIBILITY
32
33	#endif