deps: update v8 to 3.28.73

Reviewed-By: Fedor Indutny <fedor@indutny.com>
PR-URL: https://github.com/joyent/node/pull/8476

2 files changed, 220 insertions, 0 deletions

diff --git a/deps/v8/src/base/utils/random-number-generator.cc b/deps/v8/src/base/utils/random-number-generator.cc
new file mode 100644
index 0000000000..be79811171
--- /dev/null
+++ b/deps/v8/src/base/utils/random-number-generator.cc
@@ -0,0 +1,131 @@
+// Copyright 2013 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/base/utils/random-number-generator.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <new>
+
+#include "src/base/macros.h"
+#include "src/base/platform/mutex.h"
+#include "src/base/platform/time.h"
+
+namespace v8 {
+namespace base {
+
+static LazyMutex entropy_mutex = LAZY_MUTEX_INITIALIZER;
+static RandomNumberGenerator::EntropySource entropy_source = NULL;
+
+
+// static
+void RandomNumberGenerator::SetEntropySource(EntropySource source) {
+  LockGuard<Mutex> lock_guard(entropy_mutex.Pointer());
+  entropy_source = source;
+}
+
+
+RandomNumberGenerator::RandomNumberGenerator() {
+  // Check if embedder supplied an entropy source.
+  { LockGuard<Mutex> lock_guard(entropy_mutex.Pointer());
+    if (entropy_source != NULL) {
+      int64_t seed;
+      if (entropy_source(reinterpret_cast<unsigned char*>(&seed),
+                         sizeof(seed))) {
+        SetSeed(seed);
+        return;
+      }
+    }
+  }
+
+#if V8_OS_CYGWIN || V8_OS_WIN
+  // Use rand_s() to gather entropy on Windows. See:
+  // https://code.google.com/p/v8/issues/detail?id=2905
+  unsigned first_half, second_half;
+  errno_t result = rand_s(&first_half);
+  DCHECK_EQ(0, result);
+  result = rand_s(&second_half);
+  DCHECK_EQ(0, result);
+  SetSeed((static_cast<int64_t>(first_half) << 32) + second_half);
+#else
+  // Gather entropy from /dev/urandom if available.
+  FILE* fp = fopen("/dev/urandom", "rb");
+  if (fp != NULL) {
+    int64_t seed;
+    size_t n = fread(&seed, sizeof(seed), 1, fp);
+    fclose(fp);
+    if (n == 1) {
+      SetSeed(seed);
+      return;
+    }
+  }
+
+  // We cannot assume that random() or rand() were seeded
+  // properly, so instead of relying on random() or rand(),
+  // we just seed our PRNG using timing data as fallback.
+  // This is weak entropy, but it's sufficient, because
+  // it is the responsibility of the embedder to install
+  // an entropy source using v8::V8::SetEntropySource(),
+  // which provides reasonable entropy, see:
+  // https://code.google.com/p/v8/issues/detail?id=2905
+  int64_t seed = Time::NowFromSystemTime().ToInternalValue() << 24;
+  seed ^= TimeTicks::HighResolutionNow().ToInternalValue() << 16;
+  seed ^= TimeTicks::Now().ToInternalValue() << 8;
+  SetSeed(seed);
+#endif  // V8_OS_CYGWIN || V8_OS_WIN
+}
+
+
+int RandomNumberGenerator::NextInt(int max) {
+  DCHECK_LE(0, max);
+
+  // Fast path if max is a power of 2.
+  if (IS_POWER_OF_TWO(max)) {
+    return static_cast<int>((max * static_cast<int64_t>(Next(31))) >> 31);
+  }
+
+  while (true) {
+    int rnd = Next(31);
+    int val = rnd % max;
+    if (rnd - val + (max - 1) >= 0) {
+      return val;
+    }
+  }
+}
+
+
+double RandomNumberGenerator::NextDouble() {
+  return ((static_cast<int64_t>(Next(26)) << 27) + Next(27)) /
+      static_cast<double>(static_cast<int64_t>(1) << 53);
+}
+
+
+void RandomNumberGenerator::NextBytes(void* buffer, size_t buflen) {
+  for (size_t n = 0; n < buflen; ++n) {
+    static_cast<uint8_t*>(buffer)[n] = static_cast<uint8_t>(Next(8));
+  }
+}
+
+
+int RandomNumberGenerator::Next(int bits) {
+  DCHECK_LT(0, bits);
+  DCHECK_GE(32, bits);
+  // Do unsigned multiplication, which has the intended modulo semantics, while
+  // signed multiplication would expose undefined behavior.
+  uint64_t product = static_cast<uint64_t>(seed_) * kMultiplier;
+  // Assigning a uint64_t to an int64_t is implementation defined, but this
+  // should be OK. Use a static_cast to explicitly state that we know what we're
+  // doing. (Famous last words...)
+  int64_t seed = static_cast<int64_t>((product + kAddend) & kMask);
+  seed_ = seed;
+  return static_cast<int>(seed >> (48 - bits));
+}
+
+
+void RandomNumberGenerator::SetSeed(int64_t seed) {
+  seed_ = (seed ^ kMultiplier) & kMask;
+}
+
+} }  // namespace v8::base
diff --git a/deps/v8/src/base/utils/random-number-generator.h b/deps/v8/src/base/utils/random-number-generator.h
new file mode 100644
index 0000000000..5955d66597
--- /dev/null
+++ b/deps/v8/src/base/utils/random-number-generator.h
@@ -0,0 +1,89 @@
+// Copyright 2013 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_BASE_UTILS_RANDOM_NUMBER_GENERATOR_H_
+#define V8_BASE_UTILS_RANDOM_NUMBER_GENERATOR_H_
+
+#include "src/base/macros.h"
+
+namespace v8 {
+namespace base {
+
+// -----------------------------------------------------------------------------
+// RandomNumberGenerator
+//
+// This class is used to generate a stream of pseudorandom numbers. The class
+// uses a 48-bit seed, which is modified using a linear congruential formula.
+// (See Donald Knuth, The Art of Computer Programming, Volume 3, Section 3.2.1.)
+// If two instances of RandomNumberGenerator are created with the same seed, and
+// the same sequence of method calls is made for each, they will generate and
+// return identical sequences of numbers.
+// This class uses (probably) weak entropy by default, but it's sufficient,
+// because it is the responsibility of the embedder to install an entropy source
+// using v8::V8::SetEntropySource(), which provides reasonable entropy, see:
+// https://code.google.com/p/v8/issues/detail?id=2905
+// This class is neither reentrant nor threadsafe.
+
+class RandomNumberGenerator V8_FINAL {
+ public:
+  // EntropySource is used as a callback function when V8 needs a source of
+  // entropy.
+  typedef bool (*EntropySource)(unsigned char* buffer, size_t buflen);
+  static void SetEntropySource(EntropySource entropy_source);
+
+  RandomNumberGenerator();
+  explicit RandomNumberGenerator(int64_t seed) { SetSeed(seed); }
+
+  // Returns the next pseudorandom, uniformly distributed int value from this
+  // random number generator's sequence. The general contract of |NextInt()| is
+  // that one int value is pseudorandomly generated and returned.
+  // All 2^32 possible integer values are produced with (approximately) equal
+  // probability.
+  V8_INLINE int NextInt() V8_WARN_UNUSED_RESULT {
+    return Next(32);
+  }
+
+  // Returns a pseudorandom, uniformly distributed int value between 0
+  // (inclusive) and the specified max value (exclusive), drawn from this random
+  // number generator's sequence. The general contract of |NextInt(int)| is that
+  // one int value in the specified range is pseudorandomly generated and
+  // returned. All max possible int values are produced with (approximately)
+  // equal probability.
+  int NextInt(int max) V8_WARN_UNUSED_RESULT;
+
+  // Returns the next pseudorandom, uniformly distributed boolean value from
+  // this random number generator's sequence. The general contract of
+  // |NextBoolean()| is that one boolean value is pseudorandomly generated and
+  // returned. The values true and false are produced with (approximately) equal
+  // probability.
+  V8_INLINE bool NextBool() V8_WARN_UNUSED_RESULT {
+    return Next(1) != 0;
+  }
+
+  // Returns the next pseudorandom, uniformly distributed double value between
+  // 0.0 and 1.0 from this random number generator's sequence.
+  // The general contract of |NextDouble()| is that one double value, chosen
+  // (approximately) uniformly from the range 0.0 (inclusive) to 1.0
+  // (exclusive), is pseudorandomly generated and returned.
+  double NextDouble() V8_WARN_UNUSED_RESULT;
+
+  // Fills the elements of a specified array of bytes with random numbers.
+  void NextBytes(void* buffer, size_t buflen);
+
+  // Override the current ssed.
+  void SetSeed(int64_t seed);
+
+ private:
+  static const int64_t kMultiplier = V8_2PART_UINT64_C(0x5, deece66d);
+  static const int64_t kAddend = 0xb;
+  static const int64_t kMask = V8_2PART_UINT64_C(0xffff, ffffffff);
+
+  int Next(int bits) V8_WARN_UNUSED_RESULT;
+
+  int64_t seed_;
+};
+
+} }  // namespace v8::base
+
+#endif  // V8_BASE_UTILS_RANDOM_NUMBER_GENERATOR_H_