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

src/bootstrapper.cc

 // Copyright 2012 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
@@ skipping 1298 matching lines @@
     delegate->shared()->DontAdaptArguments();
   }
 
   // Initialize the out of memory slot.
   native_context()->set_out_of_memory(heap->false_value());
 
   // Initialize the embedder data slot.
   Handle<FixedArray> embedder_data = factory->NewFixedArray(2);
   native_context()->set_embedder_data(*embedder_data);
 
-  {
-    // Initialize the random seed slot.
-    Handle<ByteArray> zeroed_byte_array(
-        factory->NewByteArray(kRandomStateSize));
-    native_context()->set_random_seed(*zeroed_byte_array);
-    memset(zeroed_byte_array->GetDataStartAddress(), 0, kRandomStateSize);
-  }
+  // Allocate the random seed slot.
+  Handle<ByteArray> random_seed = factory->NewByteArray(kRandomStateSize);
+  native_context()->set_random_seed(*random_seed);
 }
 
 
 Handle<JSFunction> Genesis::InstallTypedArray(
     const char* name, ElementsKind elementsKind) {
   Handle<JSObject> global = Handle<JSObject>(native_context()->global_object());
   Handle<JSFunction> result = InstallFunction(global, name, JS_TYPED_ARRAY_TYPE,
       JSTypedArray::kSize, isolate()->initial_object_prototype(),
       Builtins::kIllegal, false, true);
 
@@ skipping 1304 matching lines @@
     MakeFunctionInstancePrototypeWritable();
 
     if (!ConfigureGlobalObjects(global_template)) return;
     isolate->counters()->contexts_created_from_scratch()->Increment();
   }
 
   // Initialize experimental globals and install experimental natives.
   InitializeExperimentalGlobal();
   if (!InstallExperimentalNatives()) return;
 
+  // Initially seed the per-context random number generator
+  // using the per-isolate random number generator.
+  uint32_t* state = reinterpret_cast<uint32_t*>(
+      native_context()->random_seed()->GetDataStartAddress());
+  do {
+    isolate->random_number_generator()->NextBytes(state, kRandomStateSize);
+  } while (state[0] == 0 || state[1] == 0);
+
   result_ = native_context();
 }
 
 
 // Support for thread preemption.
 
 // Reserve space for statics needing saving and restoring.
 int Bootstrapper::ArchiveSpacePerThread() {
   return sizeof(NestingCounterType);
 }
@@ skipping 13 matching lines @@
   return from + sizeof(NestingCounterType);
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   ASSERT(!IsActive());
 }
 
 } }  // namespace v8::internal