DOM wrappers that are not retained from Dart should be collected.

Source/WebCore/bindings/dart/DartIsolate.cpp

Index: Source/WebCore/bindings/dart/DartIsolate.cpp
diff --git a/Source/WebCore/bindings/dart/DartIsolate.cpp b/Source/WebCore/bindings/dart/DartIsolate.cpp
index 190ce1bed2935212e56b8d46f9522bd9e61de322..7609f032b9bab80034e92f9987a2f23b469e7ce5 100644
--- a/Source/WebCore/bindings/dart/DartIsolate.cpp
+++ b/Source/WebCore/bindings/dart/DartIsolate.cpp
@@ -30,7 +30,8 @@
 #include "config.h"
 #include "DartIsolate.h"
 
-#include "DartController.h"
+#include "DartDebugServer.h"
+#include "DartUtilities.h"
 
 namespace WebCore {
 
@@ -80,9 +81,24 @@ DartIsolate::DartIsolate(Dart_Isolate isolate)
 
 DartIsolate::~DartIsolate()
 {
-    DartController::shutdownIsolate(this);
+    Dart_Isolate currentIsolate = Dart_CurrentIsolate();
+    if (currentIsolate)
+        Dart_ExitIsolate();
+
+    Dart_EnterIsolate(m_isolate);
+    for (WeakCallbackMap::iterator it = m_weakCallbackMap.begin(); it != m_weakCallbackMap.end(); ++it)
+        (*it->second.weakCallback)(it->first, it->second.peer);
+    Dart_ShutdownIsolate();
+
+    *DartUtilities::recursionForIsolate(m_isolate) = 0;
+    DartUtilities::unregisterIsolate(m_isolate);
+    DartDebugServer::shared().unregisterIsolate(this);
+
     isolateMap().remove(m_isolate);
     m_isolate = 0;
+
+    if (currentIsolate)
+        Dart_EnterIsolate(currentIsolate);
 }
 
 PassRefPtr<DartIsolate> DartIsolate::current()
@@ -119,4 +135,21 @@ void DartIsolate::exit()
         Dart_EnterIsolate(previous->m_isolate);
 }
 
+Dart_Handle DartIsolate::createWeakPersistentHandle(Dart_Handle object, void* peer, Dart_WeakPersistentHandleFinalizer weakCallback)
+{
+    Dart_Handle persistentHandle = Dart_NewWeakPersistentHandle(object, peer, &DartIsolate::weakCallbackWrapper);

[Anton Muhin, 2012/03/28 18:03:23]

as another option which might be more natural: as a peer for persistent handle
you may pass something like:

struct Peer {
  void* webkitObject;
  Dart_WeakPersistentHandleFinalizer finalizer;
};

WDYT?

[podivilov, 2012/03/28 18:20:05]

That would require creating the Peer in the heap and deleting it in weak
callback. I prefer to avoid it.

[Anton Muhin, 2012/03/28 18:25:54]

What's the problem w/ it?  Allocating small objects is rather cheap w/ tcmalloc.
 And it won't lead to worst case O(size(map)) performance on insertion/removal.

On 2012/03/28 18:20:05, podivilov wrote:

+    ASSERT(!m_weakCallbackMap.contains(persistentHandle));
+    m_weakCallbackMap.set(persistentHandle, WeakCallbackData(peer, weakCallback));
+    return persistentHandle;
+}
+
+void DartIsolate::weakCallbackWrapper(Dart_Handle persistentHandle, void* peer)
+{
+    DartIsolate* isolate = current().get();
+    ASSERT(isolate->m_weakCallbackMap.contains(persistentHandle));
+    WeakCallbackData weakCallbackData = isolate->m_weakCallbackMap.take(persistentHandle);
+    ASSERT(weakCallbackData.peer == peer);
+    (*weakCallbackData.weakCallback)(persistentHandle, peer);

[Anton Muhin, 2012/03/28 18:03:23]

you allow 0 weak callback in ctor, so check here appears to be missing, but I am
not sure 0 should be allowed at all.

[podivilov, 2012/03/28 18:20:05]

0 is not allowed. Default ctor is used for denoting an empty value in
WTF::HashMap.

+}
+
 }