source/libs/poppler/poppler-0.37.0/goo/grandom.cc

   1 /*
   2  * grandom.cc
   3  *
   4  * This file is licensed under the GPLv2 or later
   5  *
   6  * Pseudo-random number generation
   7  *
   8  * Copyright (C) 2012 Fabio D'Urso <fabiodurso@hotmail.it>
   9  */
  10
  11 #include <config.h>
  12 #include "grandom.h"
  13 #include "gtypes.h"
  14
  15 #ifdef HAVE_RAND_R // rand_r backend (POSIX)
  16
  17 static GBool initialized = gFalse;
  18
  19 #include <stdlib.h>
  20 #include <time.h>
  21 static unsigned int seed;
  22
  23 static void initialize() {
  24   if (!initialized) {
  25     seed = time(NULL);
  26     initialized = gTrue;
  27   }
  28 }
  29
  30 void grandom_fill(Guchar *buff, int size)
  31 {
  32   initialize();
  33   while (size--)
  34     *buff++ = rand_r(&seed) % 256;
  35 }
  36
  37 double grandom_double()
  38 {
  39   initialize();
  40   return rand_r(&seed) / (1 + (double)RAND_MAX);
  41 }
  42
  43 #else // srand+rand backend (unsafe, because it may interfere with the application)
  44
  45 static GBool initialized = gFalse;
  46
  47 #include <stdlib.h>
  48 #include <time.h>
  49
  50 static void initialize() {
  51   if (!initialized) {
  52     srand(time(NULL));
  53     initialized = gTrue;
  54   }
  55 }
  56
  57 void grandom_fill(Guchar *buff, int size)
  58 {
  59   initialize();
  60   while (size--)
  61     *buff++ = rand() % 256;
  62 }
  63
  64 double grandom_double()
  65 {
  66   initialize();
  67   return rand() / (1 + (double)RAND_MAX);
  68 }
  69
  70 #endif