Bindings: Separate WorldIdConstants into WorldTypes and WorldId

third_party/WebKit/Source/bindings/core/v8/DOMWrapperWorld.cpp

Index: third_party/WebKit/Source/bindings/core/v8/DOMWrapperWorld.cpp
diff --git a/third_party/WebKit/Source/bindings/core/v8/DOMWrapperWorld.cpp b/third_party/WebKit/Source/bindings/core/v8/DOMWrapperWorld.cpp
index 3d23c73d43c297bb6ea06936628761ccf5e5eb31..46f68642c9dd203e5909b52552e4682283178f50 100644
--- a/third_party/WebKit/Source/bindings/core/v8/DOMWrapperWorld.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/DOMWrapperWorld.cpp
@@ -46,12 +46,33 @@
 
 namespace blink {
 
+// Returns an identifier for a given world type other than WorldType::Isolated.
+// IsolatedWorld has its unique convention to allocate an identifier.
+int getWorldIdForType(WorldType worldType) {
+  switch (worldType) {
+    case WorldType::Unknown:
+      return UnknownWorldId;
+    case WorldType::Main:
+      return MainWorldId;
+    case WorldType::Isolated:
+      NOTREACHED();

[haraken, 2017/03/08 09:39:09]

Why is it not reached?

[nhiroki, 2017/03/08 10:24:52]

Because IsolatedWorld is created by DOMWrapperWorld::ensureIsolatedWorld that
doesn't call this function.

[haraken, 2017/03/08 10:27:47]

Hmm. So an ID for an isolated world is provided externally. Then who provides an
ID for a worker/worklet world?

We need to somehow make sure that there's no conflict in the IDs.

[nhiroki, 2017/03/08 10:44:22]

That's right.
I'll make a dynamic allocation mechanism for a worker/worklet world in
https://codereview.chromium.org/2735823006/ (not updated yet). It will pick up
an ID from the unused range [WorkerWorldId, INT_MAX) and getWorldIdForType()
calls it, so it never conflict with others. (Probably getWorldIdForType will be
renamed to generateWorldIdForType or something at the time)

+      return -1;
+    // Currently, WorldId for a worker/worklet is fixed value, but this doesn't

[peria, 2017/03/08 09:48:19]

*a* fixed value

[nhiroki, 2017/03/08 10:24:52]

Done.

+    // work when multiple worklets are created on a thread.
+    // TODO(nhiroki): Expand the identifier space for workers/worklets.
+    case WorldType::Worker:
+      return WorkerWorldId;
+  }
+  NOTREACHED();
+  return -1;
+}
+
 class DOMObjectHolderBase {
   USING_FAST_MALLOC(DOMObjectHolderBase);
 
  public:
   DOMObjectHolderBase(v8::Isolate* isolate, v8::Local<v8::Value> wrapper)
-      : m_wrapper(isolate, wrapper), m_world(0) {}
+      : m_wrapper(isolate, wrapper), m_world(nullptr) {}
   virtual ~DOMObjectHolderBase() {}
 
   DOMWrapperWorld* world() const { return m_world; }
@@ -84,24 +105,28 @@ class DOMObjectHolder : public DOMObjectHolderBase {
 unsigned DOMWrapperWorld::isolatedWorldCount = 0;
 
 PassRefPtr<DOMWrapperWorld> DOMWrapperWorld::create(v8::Isolate* isolate,
-                                                    int worldId) {
-  return adoptRef(new DOMWrapperWorld(isolate, worldId));
+                                                    WorldType worldType) {
+  DCHECK_NE(WorldType::Isolated, worldType);
+  return adoptRef(
+      new DOMWrapperWorld(isolate, worldType, getWorldIdForType(worldType)));
 }
 
-DOMWrapperWorld::DOMWrapperWorld(v8::Isolate* isolate, int worldId)
-    : m_worldId(worldId),
+DOMWrapperWorld::DOMWrapperWorld(v8::Isolate* isolate,
+                                 WorldType worldType,
+                                 int worldId)
+    : m_worldType(worldType),
+      m_worldId(worldId),
       m_domDataStore(
           WTF::wrapUnique(new DOMDataStore(isolate, isMainWorld()))) {
-  if (worldId == WorkerWorldId) {
+  if (isWorkerWorld())
     workerWorld() = this;
-  }
 }
 
 DOMWrapperWorld& DOMWrapperWorld::mainWorld() {
   ASSERT(isMainThread());
   DEFINE_STATIC_REF(
       DOMWrapperWorld, cachedMainWorld,
-      (DOMWrapperWorld::create(v8::Isolate::GetCurrent(), MainWorldId)));
+      (DOMWrapperWorld::create(v8::Isolate::GetCurrent(), WorldType::Main)));
   return *cachedMainWorld;
 }
 
@@ -208,7 +233,7 @@ PassRefPtr<DOMWrapperWorld> DOMWrapperWorld::ensureIsolatedWorld(
     return world.release();
   }
 
-  world = DOMWrapperWorld::create(isolate, worldId);
+  world = adoptRef(new DOMWrapperWorld(isolate, WorldType::Isolated, worldId));
   result.storedValue->value = world.get();
   isolatedWorldCount++;
   return world.release();