Add support for per-isolate private symbols

src/runtime.cc

Index: src/runtime.cc
diff --git a/src/runtime.cc b/src/runtime.cc
index b4c34ef76922cf8b997b6ecd72f34c88d85e3587..b313185db0fcd17c8d09053862daa2722d9966d5 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -621,6 +621,34 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_CreatePrivateSymbol) {
 }
 
 
+RUNTIME_FUNCTION(MaybeObject*, Runtime_CreateGlobalPrivateSymbol) {
+  HandleScope scope(isolate);
+  ASSERT(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(String, name, 0);
+  Handle<JSObject> registry = handle(isolate->heap()->symbol_registry());
+  Handle<String> part = handle(isolate->heap()->private_intern_string());
+  Handle<Object> privates_val = JSReceiver::GetProperty(registry, part);
+  Handle<JSObject> privates;
+  if (privates_val->IsJSObject()) {
+    privates = Handle<JSObject>::cast(privates_val);
+  } else {
+    ASSERT(privates_val->IsUndefined());
+    privates =
+        isolate->factory()->NewJSObject(isolate->object_function(), TENURED);

[Michael Starzinger, 2014/03/24 10:04:33]

As discussed offline: This will create a JSObject bound to a specific context
(i.e. obj->map->constructor) and hence keep the native context which happened to
trigger this lazy initialization alive forever.

And you are right, we have the same problem already in the lazy initialization
in the symbol.js file.

[rossberg, 2014/03/24 15:09:49]

I moved the whole registry creation and initialization to a new method
Isolate::GetSymbolRegistry, which is now shared by all relevant code sites.

+    JSObject::SetPrototype(privates, isolate->factory()->null_value());
+    JSObject::SetProperty(registry, part, privates, NONE, STRICT);
+  }
+  Handle<Object> symbol = JSObject::GetProperty(privates, name);
+  if (!symbol->IsSymbol()) {
+    ASSERT(symbol->IsUndefined());
+    symbol = isolate->factory()->NewPrivateSymbol();
+    Handle<Symbol>::cast(symbol)->set_name(*name);
+    JSObject::SetProperty(privates, name, symbol, NONE, STRICT);
+  }
+  return *symbol;
+}
+
+
 RUNTIME_FUNCTION(MaybeObject*, Runtime_NewSymbolWrapper) {
   ASSERT(args.length() == 1);
   CONVERT_ARG_CHECKED(Symbol, symbol, 0);