dart::Random Class Reference

#include <random.h>

Public Member Functions
	Random ()
	Random (uint64_t seed)
	~Random ()
uint32_t	NextUInt32 ()
uint64_t	NextUInt64 ()
uint64_t	NextJSInt ()
double	NextDouble ()

Static Public Member Functions
static uint64_t	GlobalNextUInt64 ()
static void	Init ()
static void	Cleanup ()

Detailed Description

Definition at line 18 of file random.h.

Constructor & Destructor Documentation

Random() [1/2]

dart::Random::Random

(

)

Definition at line 17 of file random.cc.

               {
  uint64_t seed = FLAG_random_seed;
  if (seed == 0) {
    Dart_EntropySource callback = Dart::entropy_source_callback();
    if (callback != nullptr) {
      if (!callback(reinterpret_cast<uint8_t*>(&seed), sizeof(seed))) {
        // Callback failed. Reset the seed to 0.
        seed = 0;
      }
    }
  }
  if (seed == 0) {
    // We did not get a seed so far. As a fallback we do use the current time.
    seed = OS::GetCurrentTimeMicros();
  }
  Initialize(seed);
}

Random() [2/2]

dart::Random::Random ( uint64_t  seed )

explicit

Definition at line 45 of file random.cc.

                            {
  Initialize(seed);
}

~Random()

dart::Random::~Random

(

)

Definition at line 49 of file random.cc.

                {
  // Nothing to be done here.
}

Member Function Documentation

Cleanup()

void dart::Random::Cleanup ( )

static

Definition at line 88 of file random.cc.

                     {
  delete global_random_mutex;
  global_random_mutex = nullptr;
  delete global_random;
  global_random = nullptr;
}

GlobalNextUInt64()

uint64_t dart::Random::GlobalNextUInt64 ( )

static

Definition at line 95 of file random.cc.

                                  {
  MutexLocker locker(global_random_mutex);
  return global_random->NextUInt64();
}

Init()

void dart::Random::Init ( )

static

Definition at line 81 of file random.cc.

                  {
  ASSERT(global_random_mutex == nullptr);
  global_random_mutex = new Mutex(NOT_IN_PRODUCT("global_random_mutex"));
  ASSERT(global_random == nullptr);
  global_random = new Random();
}

NextDouble()

double dart::Random::NextDouble

(

)

Definition at line 100 of file random.cc.

                          {
  uint64_t mantissa = NextUInt64() & 0xFFFFFFFFFFFFF;
  // The exponent value 0 in biased form.
  const uint64_t exp = 1023;
  return bit_cast<double>(exp << 52 | mantissa) - 1.0;
}

NextJSInt()

uint64_t dart::Random::NextJSInt ( )

inline

Definition at line 37 of file random.h.

                       {
    // Number.MAX_SAFE_INTEGER (2 ^ 53 - 1)
    const uint64_t kMaxJsInt = 0x1FFFFFFFFFFFFF;
    return NextUInt64() & kMaxJsInt;
  }

NextUInt32()

uint32_t dart::Random::NextUInt32

(

)

Definition at line 73 of file random.cc.

                            {
  const uint64_t MASK_32 = 0xffffffff;
  return static_cast<uint32_t>(NextState() & MASK_32);
}

NextUInt64()

uint64_t dart::Random::NextUInt64 ( )

inline

Definition at line 26 of file random.h.

                        {
    return (static_cast<uint64_t>(NextUInt32()) << 32) |
           static_cast<uint64_t>(NextUInt32());
  }

---

The documentation for this class was generated from the following files:

• third_party/dart-lang/sdk/runtime/vm/random.h
• third_party/dart-lang/sdk/runtime/vm/random.cc