lib/sdk/crt/math/rand.c

   1 /* Copyright (C) 1994 DJ Delorie, see COPYING.DJ for details */
   2 #include <precomp.h>
   3 #include <ntsecapi.h>
   4 #include <internal/tls.h>
   5
   6 /*
   7  * @implemented
   8  */
   9 int
  10 rand(void)
  11 {
  12   PTHREADDATA ThreadData = GetThreadData();
  13
  14   ThreadData->tnext = ThreadData->tnext * 0x5deece66dLL + 2531011;
  15   return (int)((ThreadData->tnext >> 16) & RAND_MAX);
  16 }
  17
  18 /*
  19  * @implemented
  20  */
  21 void
  22 srand(unsigned int seed)
  23 {
  24   PTHREADDATA ThreadData = GetThreadData();
  25
  26   ThreadData->tnext = (ULONGLONG)seed;
  27 }
  28
  29  /*********************************************************************
  30   *              rand_s (MSVCRT.@)
  31   */
  32 int CDECL rand_s(unsigned int *pval)
  33 {
  34     BOOLEAN (WINAPI *pSystemFunction036)(PVOID, ULONG); // RtlGenRandom
  35     HINSTANCE hadvapi32 = LoadLibraryA("advapi32.dll");
  36     pSystemFunction036 = (void*)GetProcAddress(hadvapi32, "SystemFunction036");
  37 #if 1
  38     if (!pval || (pSystemFunction036 && !pSystemFunction036(pval, sizeof(*pval))))
  39     {
  40             _invalid_parameter(NULL,_CRT_WIDE("rand_s"),_CRT_WIDE(__FILE__),__LINE__, 0);
  41         *_errno() = EINVAL;
  42         return EINVAL;
  43     }
  44 #endif
  45     if(hadvapi32) FreeLibrary(hadvapi32);
  46     return 0;
  47 }