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00033 #include <stdlib.h>
00034 #include <math.h>
00035 #include <stdio.h>
00036 #include "RandomUtil.h"
00037 #include "TimeUtil.h"
00038 #include "maceConfig.h"
00039
00040 void RandomUtil::seedRandom(unsigned int s) {
00041 if (!srandInit) {
00042 #ifdef HAVE_DRAND48
00043 srand48(s);
00044 #else
00045 #ifdef HAVE_RAND_S
00046 #else
00047 #ifdef HAVE_RAND
00048 srand(s);
00049 #endif
00050 #endif
00051 #endif
00052 srandInit = true;
00053 }
00054 }
00055
00056 RandomUtil& RandomUtil::Instance() {
00057 if(_inst == NULL) {
00058 seedRandom(TimeUtil::timeu());
00059 _inst = new RandomUtil();
00060 }
00061 return *_inst;
00062 }
00063
00064 unsigned RandomUtil::randIntImpl() {
00065 #ifdef HAVE_DRAND48
00066 return (unsigned)lrand48();
00067 #else
00068 #ifdef HAVE_RAND_S
00069
00070 unsigned int n;
00071 ASSERT(rand_s(&n) == 0);
00072 return n;
00073 #else
00074 #ifdef HAVE_RAND
00075 #if RAND_MAX != 32767
00076 #error "unexpected randmax!"
00077 #endif
00078 unsigned n1 = rand();
00079 unsigned n2 = rand();
00080 unsigned n3 = rand();
00081 return (n1 << 17) | (n2 << 2) | (n3 & 0x3);
00082 #endif
00083 #endif
00084 #endif
00085 }
00086
00087 unsigned RandomUtil::randIntImpl(unsigned max) {
00088
00089 #ifdef HAVE_DRAND48
00090 double value = drand48();
00091 value *= max;
00092 unsigned r = (unsigned)floor(value);
00093 if (r == max) {
00094 r--;
00095 }
00096 return r;
00097 #else
00098 #ifdef HAVE_RAND_S
00099 unsigned int n;
00100 ASSERT(rand_s(&n) == 0);
00101 return (unsigned int)((double)n / (double)UINT_MAX * max);
00102 #else
00103 #ifdef HAVE_RAND
00104 unsigned int n = randIntImpl();
00105 return (unsigned int)((double)n / (double)UINT_MAX * max);
00106 #endif
00107 #endif
00108 #endif
00109 }
00110
00111 unsigned RandomUtil::randIntImpl(unsigned max, unsigned first, va_list ap) {
00112 va_list copy;
00113 va_copy(copy, ap);
00114
00115 unsigned newMax = first;
00116 for (size_t i = 0; i < max - 1; i++) {
00117 unsigned t = va_arg(ap, unsigned);
00118 newMax += t;
00119 }
00120
00121 unsigned rand = randIntImpl(newMax);
00122 unsigned r = 0;
00123 while (r < max - 1 && rand >= first) {
00124 r++;
00125 first += va_arg(copy, unsigned);
00126 }
00127 va_end(copy);
00128
00129 return r;
00130 }
00131
00132
00133 RandomUtil* RandomUtil::_inst = NULL;
00134 bool RandomUtil::srandInit = false;