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diff --git a/deps/v8/src/utils/random-number-generator.cc b/deps/v8/src/utils/random-number-generator.cc
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+// Copyright 2013 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+// * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following
+// disclaimer in the documentation and/or other materials provided
+// with the distribution.
+// * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived
+// from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "utils/random-number-generator.h"
+
+#include <cstdio>
+
+#include "flags.h"
+#include "platform/mutex.h"
+#include "platform/time.h"
+#include "utils.h"
+
+namespace v8 {
+namespace internal {
+
+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 --random-seed flag first.
+ if (FLAG_random_seed != 0) {
+ SetSeed(FLAG_random_seed);
+ return;
+ }
+
+ // 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;
+ }
+ }
+ }
+
+ // 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.
+ int64_t seed = Time::NowFromSystemTime().ToInternalValue() << 24;
+ seed ^= TimeTicks::HighResNow().ToInternalValue() << 16;
+ seed ^= TimeTicks::Now().ToInternalValue() << 8;
+ SetSeed(seed);
+}
+
+
+int RandomNumberGenerator::NextInt(int max) {
+ ASSERT_LE(0, max);
+
+ // Fast path if max is a power of 2.
+ if (IsPowerOf2(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) {
+ ASSERT_LT(0, bits);
+ ASSERT_GE(32, bits);
+ int64_t seed = (seed_ * kMultiplier + kAddend) & kMask;
+ seed_ = seed;
+ return static_cast<int>(seed >> (48 - bits));
+}
+
+
+void RandomNumberGenerator::SetSeed(int64_t seed) {
+ seed_ = (seed ^ kMultiplier) & kMask;
+}
+
+} } // namespace v8::internal