Bug 765936. r=bent,peterv

content/base/public/nsContentUtils.h

@@ -1282,6 +1282,8 @@ public:
   static nsresult DropJSObjects(void* aScriptObjectHolder);
 
 #ifdef DEBUG
+  static bool AreJSObjectsHeld(void* aScriptObjectHolder); 
+
   static void CheckCCWrapperTraversal(nsISupports* aScriptObjectHolder,
                                       nsWrapperCache* aCache);
 #endif

content/base/src/nsContentUtils.cpp

@@ -4453,6 +4453,17 @@ nsContentUtils::DropJSObjects(void* aScriptObjectHolder)
   return rv;
 }
 
+#ifdef DEBUG
+/* static */
+bool
+nsContentUtils::AreJSObjectsHeld(void* aScriptHolder)
+{
+  bool isHeld = false;
+  sXPConnect->TestJSHolder(aScriptHolder, &isHeld);
+  return isHeld;
+}
+#endif
+
 /* static */
 void
 nsContentUtils::NotifyInstalledMenuKeyboardListener(bool aInstalling)

dom/indexedDB/IDBFactory.cpp

@@ -18,6 +18,7 @@
 #include "nsCharSeparatedTokenizer.h"
 #include "nsContentUtils.h"
 #include "nsDOMClassInfoID.h"
+#include "nsGlobalWindow.h"
 #include "nsHashKeys.h"
 #include "nsPIDOMWindow.h"
 #include "nsServiceManagerUtils.h"
@@ -413,6 +414,8 @@ IDBFactory::OpenCommon(const nsAString& aName,
 
   if (mWindow) {
     window = mWindow;
+    scriptOwner =
+      static_cast<nsGlobalWindow*>(window.get())->FastGetGlobalJSObject();
   }
   else {
     scriptOwner = mOwningObject;

dom/indexedDB/IDBRequest.cpp

@@ -32,7 +32,6 @@ IDBRequest::IDBRequest()
   mActorParent(nsnull),
   mErrorCode(NS_OK),
   mHaveResultOrErrorCode(false),
-  mRooted(false),
   mLineNo(0)
 {
   NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
@@ -41,8 +40,6 @@ IDBRequest::IDBRequest()
 IDBRequest::~IDBRequest()
 {
   NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
-
-  UnrootResultVal();
 }
 
 // static
@@ -74,7 +71,6 @@ IDBRequest::Reset()
   mResultVal = JSVAL_VOID;
   mHaveResultOrErrorCode = false;
   mError = nsnull;
-  UnrootResultVal();
 }
 
 nsresult
@@ -82,7 +78,6 @@ IDBRequest::NotifyHelperCompleted(HelperBase* aHelper)
 {
   NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
   NS_ASSERTION(!mHaveResultOrErrorCode, "Already called!");
-  NS_ASSERTION(!PreservingWrapper(), "Already rooted?!");
   NS_ASSERTION(JSVAL_IS_VOID(mResultVal), "Should be undefined!");
 
   // See if our window is still valid. If not then we're going to pretend that
@@ -116,7 +111,7 @@ IDBRequest::NotifyHelperCompleted(HelperBase* aHelper)
   JSAutoRequest ar(cx);
   JSAutoEnterCompartment ac;
   if (ac.enter(cx, global)) {
-    RootResultVal();
+    AssertIsRooted();
 
     rv = aHelper->GetSuccessResult(cx, &mResultVal);
     if (NS_FAILED(rv)) {
@@ -144,7 +139,6 @@ IDBRequest::NotifyHelperSentResultsToChildProcess(nsresult aRv)
 {
   NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
   NS_ASSERTION(!mHaveResultOrErrorCode, "Already called!");
-  NS_ASSERTION(!PreservingWrapper(), "Already rooted?!");
   NS_ASSERTION(JSVAL_IS_VOID(mResultVal), "Should be undefined!");
 
   // See if our window is still valid. If not then we're going to pretend that
@@ -171,7 +165,6 @@ IDBRequest::SetError(nsresult aRv)
   mErrorCode = aRv;
 
   mResultVal = JSVAL_VOID;
-  UnrootResultVal();
 }
 
 #ifdef DEBUG
@@ -239,18 +232,6 @@ IDBRequest::FillScriptErrorEvent(nsScriptErrorEvent* aEvent) const
   aEvent->fileName = mFilename.get();
 }
 
-void
-IDBRequest::RootResultValInternal()
-{
-  NS_HOLD_JS_OBJECTS(this, IDBRequest);
-}
-
-void
-IDBRequest::UnrootResultValInternal()
-{
-  NS_DROP_JS_OBJECTS(this, IDBRequest);
-}
-
 NS_IMETHODIMP
 IDBRequest::GetReadyState(nsAString& aReadyState)
 {
@@ -327,7 +308,6 @@ NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 
 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(IDBRequest, IDBWrapperCache)
   tmp->mResultVal = JSVAL_VOID;
-  tmp->UnrootResultVal();
   NS_CYCLE_COLLECTION_UNLINK_EVENT_HANDLER(success)
   NS_CYCLE_COLLECTION_UNLINK_EVENT_HANDLER(error)
   NS_IMPL_CYCLE_COLLECTION_UNLINK_NSCOMPTR(mSource)
@@ -366,8 +346,6 @@ IDBRequest::PreHandleEvent(nsEventChainPreVisitor& aVisitor)
 IDBOpenDBRequest::~IDBOpenDBRequest()
 {
   NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
-
-  UnrootResultVal();
 }
 
 // static
@@ -400,18 +378,6 @@ IDBOpenDBRequest::SetTransaction(IDBTransaction* aTransaction)
   mTransaction = aTransaction;
 }
 
-void
-IDBOpenDBRequest::RootResultValInternal()
-{
-  NS_HOLD_JS_OBJECTS(this, IDBOpenDBRequest);
-}
-
-void
-IDBOpenDBRequest::UnrootResultValInternal()
-{
-  NS_DROP_JS_OBJECTS(this, IDBOpenDBRequest);
-}
-
 NS_IMPL_CYCLE_COLLECTION_CLASS(IDBOpenDBRequest)
 
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(IDBOpenDBRequest,

dom/indexedDB/IDBRequest.h

@@ -87,25 +87,6 @@ protected:
   IDBRequest();
   ~IDBRequest();
 
-  virtual void RootResultValInternal();
-  virtual void UnrootResultValInternal();
-
-  void RootResultVal()
-  {
-    if (!mRooted) {
-      RootResultValInternal();
-      mRooted = true;
-    }
-  }
-
-  void UnrootResultVal()
-  {
-    if (mRooted) {
-      UnrootResultValInternal();
-      mRooted = false;
-    }
-  }
-
   nsCOMPtr<nsISupports> mSource;
   nsRefPtr<IDBTransaction> mTransaction;
 
@@ -120,7 +101,6 @@ protected:
 
   nsresult mErrorCode;
   bool mHaveResultOrErrorCode;
-  bool mRooted;
 
   nsString mFilename;
   PRUint32 mLineNo;
@@ -149,9 +129,6 @@ public:
 protected:
   ~IDBOpenDBRequest();
 
-  virtual void RootResultValInternal();
-  virtual void UnrootResultValInternal();
-
   // Only touched on the main thread.
   NS_DECL_EVENT_HANDLER(blocked)
   NS_DECL_EVENT_HANDLER(upgradeneeded)

dom/indexedDB/IDBWrapperCache.cpp

@@ -48,13 +48,7 @@ IDBWrapperCache::~IDBWrapperCache()
 bool
 IDBWrapperCache::SetScriptOwner(JSObject* aScriptOwner)
 {
-  if (!aScriptOwner) {
+  NS_ASSERTION(aScriptOwner, "This should never be null!");
-    NS_ASSERTION(!mScriptOwner,
-                 "Don't null out existing owner, we need to call "
-                 "DropJSObjects!");
-
-    return true;
-  }
 
   mScriptOwner = aScriptOwner;
 
@@ -70,3 +64,12 @@ IDBWrapperCache::SetScriptOwner(JSObject* aScriptOwner)
 
   return true;
 }
+
+#ifdef DEBUG
+void
+IDBWrapperCache::AssertIsRooted() const
+{
+  NS_ASSERTION(nsContentUtils::AreJSObjectsHeld(const_cast<IDBWrapperCache*>(this)),
+               "Why aren't we rooted?!");
+}
+#endif

dom/indexedDB/IDBWrapperCache.h

@@ -46,6 +46,14 @@ public:
       nsDOMEventTargetHelper::FromSupports(aSupports));
   }
 
+#ifdef DEBUG
+  void AssertIsRooted() const;
+#else
+  inline void AssertIsRooted() const
+  {
+  }
+#endif
+
 protected:
   IDBWrapperCache()
   : mScriptOwner(nsnull)

js/xpconnect/idl/nsIXPConnect.idl

@@ -673,6 +673,13 @@ interface nsIXPConnect : nsISupports
      */
     [noscript] void removeJSHolder(in voidPtr aHolder);
 
+    /**
+     * Test to see if a JS holder is in our hashtable.
+     * Only available in debug builds.
+     * @param aHolder The object to test for.
+     */
+    [noscript] bool testJSHolder(in voidPtr aHolder);
+
     /**
      * Note aJSContext as a child to the cycle collector.
      * @param aJSContext The JSContext to note.

js/xpconnect/src/XPCJSRuntime.cpp

@@ -296,6 +296,17 @@ XPCJSRuntime::RemoveJSHolder(void* aHolder)
     return NS_OK;
 }
 
+nsresult
+XPCJSRuntime::TestJSHolder(void* aHolder, bool* aRetval)
+{
+    if (!mJSHolders.ops)
+        return NS_ERROR_OUT_OF_MEMORY;
+
+    *aRetval = !!JS_DHashTableOperate(&mJSHolders, aHolder, JS_DHASH_LOOKUP);
+
+    return NS_OK;
+}
+
 // static
 void XPCJSRuntime::TraceBlackJS(JSTracer* trc, void* data)
 {

js/xpconnect/src/nsXPConnect.cpp

@@ -2260,6 +2260,17 @@ nsXPConnect::RemoveJSHolder(void* aHolder)
     return mRuntime->RemoveJSHolder(aHolder);
 }
 
+NS_IMETHODIMP
+nsXPConnect::TestJSHolder(void* aHolder, bool* aRetval)
+{
+#ifdef DEBUG
+    return mRuntime->TestJSHolder(aHolder, aRetval);
+#else
+    MOZ_ASSERT(false);
+    return NS_ERROR_FAILURE;
+#endif
+}
+
 NS_IMETHODIMP
 nsXPConnect::SetReportAllJSExceptions(bool newval)
 {

js/xpconnect/src/xpcprivate.h

@@ -763,6 +763,7 @@ public:
 
     nsresult AddJSHolder(void* aHolder, nsScriptObjectTracer* aTracer);
     nsresult RemoveJSHolder(void* aHolder);
+    nsresult TestJSHolder(void* aHolder, bool* aRetval);
 
     static void SuspectWrappedNative(XPCWrappedNative *wrapper,
                                      nsCycleCollectionTraversalCallback &cb);