reactos/sdk/lib/crt/math/rand.c

73 lines
1.8 KiB
C

/* Copyright (C) 1994 DJ Delorie, see COPYING.DJ for details */
#include <precomp.h>
#include <ntsecapi.h>
#include <internal/tls.h>
/*
* @implemented
*/
int
rand(void)
{
thread_data_t *data = msvcrt_get_thread_data();
/* this is the algorithm used by MSVC, according to
* http://en.wikipedia.org/wiki/List_of_pseudorandom_number_generators */
data->random_seed = data->random_seed * 214013 + 2531011;
return (data->random_seed >> 16) & RAND_MAX;
}
/*
* @implemented
*/
void
srand(unsigned int seed)
{
thread_data_t *data = msvcrt_get_thread_data();
data->random_seed = seed;
}
/*********************************************************************
* rand_s (MSVCRT.@)
*/
int CDECL rand_s(unsigned int *pval)
{
BOOLEAN (WINAPI *pSystemFunction036)(PVOID, ULONG); // RtlGenRandom
HINSTANCE hadvapi32;
if (!pval)
{
_invalid_parameter(NULL,_CRT_WIDE("rand_s"),_CRT_WIDE(__FILE__),__LINE__, 0);
*_errno() = EINVAL;
return EINVAL;
}
*pval = 0;
hadvapi32 = LoadLibraryA("advapi32.dll");
if (!hadvapi32)
{
_invalid_parameter(NULL,_CRT_WIDE("rand_s"),_CRT_WIDE(__FILE__),__LINE__, 0);
*_errno() = EINVAL;
return EINVAL;
}
pSystemFunction036 = (void*)GetProcAddress(hadvapi32, "SystemFunction036");
if (!pSystemFunction036)
{
_invalid_parameter(NULL,_CRT_WIDE("rand_s"),_CRT_WIDE(__FILE__),__LINE__, 0);
*_errno() = EINVAL;
FreeLibrary(hadvapi32);
return EINVAL;
}
if (!pSystemFunction036(pval, sizeof(*pval)))
{
_invalid_parameter(NULL,_CRT_WIDE("rand_s"),_CRT_WIDE(__FILE__),__LINE__, 0);
*_errno() = EINVAL;
FreeLibrary(hadvapi32);
return EINVAL;
}
FreeLibrary(hadvapi32);
return 0;
}