Introduce a RandonNumberGenerator class. Refactor the random/private_random uses in Isolate/Context.

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

Index: test/cctest/test-random-number-generator.cc
diff --git a/test/cctest/test-cpu.cc b/test/cctest/test-random-number-generator.cc
similarity index 52%
copy from test/cctest/test-cpu.cc
copy to test/cctest/test-random-number-generator.cc
index 06966c68c86296e510edb8899f4d7deb0343f108..d9fadfacb8fa1bd3e26e8b9ed9aed93dd7920fc3 100644
--- a/test/cctest/test-cpu.cc
+++ b/test/cctest/test-random-number-generator.cc
@@ -28,28 +28,65 @@
 #include "v8.h"
 
 #include "cctest.h"
-#include "cpu.h"
+#include "utils/random-number-generator.h"
 
 using namespace v8::internal;
 
 
-TEST(FeatureImplications) {
-  // Test for features implied by other features.
-  CPU cpu;
+static const int kMaxRuns = 12345;
+static const int kRandomSeeds[] = {
+  -1, 1, 42, 100, 1234567890, 987654321, 0xdeadbeef
+};
 
-  // ia32 and x64 features
-  CHECK(!cpu.has_sse() || cpu.has_mmx());
-  CHECK(!cpu.has_sse2() || cpu.has_sse());
-  CHECK(!cpu.has_sse3() || cpu.has_sse2());
-  CHECK(!cpu.has_ssse3() || cpu.has_sse3());
-  CHECK(!cpu.has_sse41() || cpu.has_sse3());
-  CHECK(!cpu.has_sse42() || cpu.has_sse41());
 
-  // arm features
-  CHECK(!cpu.has_vfp3_d32() || cpu.has_vfp3());
+TEST(NextIntWithMaxValue) {
+  for (unsigned n = 0; n < ARRAY_SIZE(kRandomSeeds); ++n) {
+    RandomNumberGenerator rng(kRandomSeeds[n]);
+    for (int max = 1; max <= kMaxRuns; ++max) {
+      int n = rng.NextInt(max);
+      CHECK_LE(0, n);
+      CHECK_LT(n, max);
+    }
+  }
 }
 
 
-TEST(NumberOfProcessorsOnline) {
-  CHECK_GT(CPU::NumberOfProcessorsOnline(), 0);
+TEST(NextBoolReturnsBooleanValue) {
+  for (unsigned n = 0; n < ARRAY_SIZE(kRandomSeeds); ++n) {
+    RandomNumberGenerator rng(kRandomSeeds[n]);
+    for (int k = 0; k < kMaxRuns; ++k) {
+      bool b = rng.NextBool();
+      CHECK(b == false || b == true);
+    }
+  }
+}
+
+
+TEST(NextDoubleRange) {
+  for (unsigned n = 0; n < ARRAY_SIZE(kRandomSeeds); ++n) {
+    RandomNumberGenerator rng(kRandomSeeds[n]);
+    for (int k = 0; k < kMaxRuns; ++k) {
+      double d = rng.NextDouble();
+      CHECK_LE(0.0, d);
+      CHECK_LT(d, 1.0);
+    }
+  }
+}
+
+
+TEST(RandomSeedFlagIsUsed) {
+  for (unsigned n = 0; n < ARRAY_SIZE(kRandomSeeds); ++n) {
+    FLAG_random_seed = kRandomSeeds[n];
+    RandomNumberGenerator rng1;
+    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());
+    }
+  }
 }