v8/test/cctest/test-random-number-generator.cc

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#include "src/v8.h"
#include "test/cctest/cctest.h"

#include "src/base/utils/random-number-generator.h"
#include "src/isolate-inl.h"

using namespace v8::internal;


static const int kMaxRuns = 12345;
static const int kRandomSeeds[] = {
  -1, 1, 42, 100, 1234567890, 987654321
};


TEST(RandomSeedFlagIsUsed) {
  for (unsigned n = 0; n < arraysize(kRandomSeeds); ++n) {
    FLAG_random_seed = kRandomSeeds[n];
    v8::Isolate* i = v8::Isolate::New();
    v8::base::RandomNumberGenerator& rng1 =
        *reinterpret_cast<Isolate*>(i)->random_number_generator();
    v8::base::RandomNumberGenerator rng2(kRandomSeeds[n]);
    for (int k = 1; k <= kMaxRuns; ++k) {
      int64_t i1, i2;
      rng1.NextBytes(&i1, sizeof(i1));
      rng2.NextBytes(&i2, sizeof(i2));
      CHECK_EQ(i2, i1);
      CHECK_EQ(rng2.NextInt(), rng1.NextInt());
      CHECK_EQ(rng2.NextInt(k), rng1.NextInt(k));
      CHECK_EQ(rng2.NextDouble(), rng1.NextDouble());
    }
    i->Dispose();
  }
}