Commit 6f8dfd30 authored by Olli Pettay's avatar Olli Pettay
Browse files

Bug 794694 - Make sure to trace all the gray GCthings, not only wrapper, r=mccr8

parent 86c3d29f

content/base/src/nsXMLHttpRequest.cpp

+2 −1
Original line number Diff line number Diff line
@@ -529,7 +529,8 @@ NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_BEGIN(nsXMLHttpRequest) 
NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_END



NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_BEGIN(nsXMLHttpRequest)

  return tmp->IsBlack();

  return tmp->

    IsBlackAndDoesNotNeedTracing(static_cast<nsDOMEventTargetHelper*>(tmp));

NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_END



NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_BEGIN(nsXMLHttpRequest)

content/events/src/nsDOMEventTargetHelper.cpp

+1 −1
Original line number Diff line number Diff line
@@ -53,7 +53,7 @@ NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_BEGIN(nsDOMEventTargetHelper) 
NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_END



NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_BEGIN(nsDOMEventTargetHelper)

  return tmp->IsBlack();

  return tmp->IsBlackAndDoesNotNeedTracing(tmp);

NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_END



NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_BEGIN(nsDOMEventTargetHelper)

dom/base/nsWrapperCache.h

+6 −0
Original line number Diff line number Diff line
@@ -159,6 +159,12 @@ public: 
   */

  bool IsBlack();



  /**

   * Returns true if the object has a black wrapper,

   * and all the GC things it is keeping alive are black too.

   */

  bool IsBlackAndDoesNotNeedTracing(nsISupports* aThis);



  // Only meant to be called by code that preserves a wrapper.

  void SetPreservingWrapper(bool aPreserve)

  {

dom/base/nsWrapperCacheInlines.h

+22 −0
Original line number Diff line number Diff line
@@ -24,4 +24,26 @@ nsWrapperCache::IsBlack() 
  return o && !xpc_IsGrayGCThing(o);

}



static void

SearchGray(void* aGCThing, const char* aName, void* aClosure)

{

  bool* hasGrayObjects = static_cast<bool*>(aClosure);

  if (!*hasGrayObjects && aGCThing && xpc_IsGrayGCThing(aGCThing)) {

    *hasGrayObjects = true;

  }

}



inline bool

nsWrapperCache::IsBlackAndDoesNotNeedTracing(nsISupports* aThis)

{

  if (IsBlack()) {

    nsXPCOMCycleCollectionParticipant* participant = nullptr;

    CallQueryInterface(aThis, &participant);

    bool hasGrayObjects = false;

    participant->Trace(aThis, SearchGray, &hasGrayObjects);

    return !hasGrayObjects;

  }

  return false;

}



#endif /* nsWrapperCache_h___ */