* Copyright 2013 Haiku, Inc. All rights reserved.
* Distributed under the terms of the MIT License.
*
* Authors:
* Paweł Dziepak, pdziepak@quarnos.org
*/
#ifndef KERNEL_UTIL_RANDOM_H
#define KERNEL_UTIL_RANDOM_H
#include <smp.h>
#include <SupportDefs.h>
#define MAX_FAST_RANDOM_VALUE 0x7fff
#define MAX_RANDOM_VALUE 0x7fffffffu
#define MAX_SECURE_RANDOM_VALUE 0xffffffffu
static const int kFastRandomShift = 15;
static const int kRandomShift = 31;
static const int kSecureRandomShift = 32;
#ifdef __cplusplus
extern "C" {
#endif
unsigned int fast_random_value(void);
unsigned int random_value(void);
unsigned int secure_random_value(void);
#ifdef __cplusplus
}
#endif
#ifdef __cplusplus
template<typename T>
T
fast_get_random()
{
size_t shift = 0;
T random = 0;
while (shift < sizeof(T) * 8) {
random |= (T)fast_random_value() << shift;
shift += kFastRandomShift;
}
return random;
}
template<typename T>
T
get_random()
{
size_t shift = 0;
T random = 0;
while (shift < sizeof(T) * 8) {
random |= (T)random_value() << shift;
shift += kRandomShift;
}
return random;
}
template<typename T>
T
secure_get_random()
{
size_t shift = 0;
T random = 0;
while (shift < sizeof(T) * 8) {
random |= (T)secure_random_value() << shift;
shift += kSecureRandomShift;
}
return random;
}
#endif
#endif
