dom/base/nsWrapperCacheInlines.h

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef nsWrapperCacheInline_h___
   7 #define nsWrapperCacheInline_h___
   8
   9 #include "nsWrapperCache.h"
  10 #include "js/GCAPI.h"
  11 #include "js/TracingAPI.h"
  12
  13 inline JSObject*
  14 nsWrapperCache::GetWrapper() const
  15 {
  16     JSObject* obj = GetWrapperPreserveColor();
  17     if (obj) {
  18       JS::ExposeObjectToActiveJS(obj);
  19     }
  20     return obj;
  21 }
  22
  23 inline bool
  24 nsWrapperCache::IsBlack()
  25 {
  26   JSObject* o = GetWrapperPreserveColor();
  27   return o && !JS::GCThingIsMarkedGray(o);
  28 }
  29
  30 static void
  31 SearchGray(void* aGCThing, const char* aName, void* aClosure)
  32 {
  33   bool* hasGrayObjects = static_cast<bool*>(aClosure);
  34   if (!*hasGrayObjects && aGCThing && JS::GCThingIsMarkedGray(aGCThing)) {
  35     *hasGrayObjects = true;
  36   }
  37 }
  38
  39 inline bool
  40 nsWrapperCache::HasNothingToTrace(nsISupports* aThis)
  41 {
  42   nsXPCOMCycleCollectionParticipant* participant = nullptr;
  43   CallQueryInterface(aThis, &participant);
  44   bool hasGrayObjects = false;
  45   participant->Trace(aThis, TraceCallbackFunc(SearchGray), &hasGrayObjects);
  46   return !hasGrayObjects;
  47 }
  48
  49 inline bool
  50 nsWrapperCache::IsBlackAndDoesNotNeedTracing(nsISupports* aThis)
  51 {
  52   return IsBlack() && HasNothingToTrace(aThis);
  53 }
  54
  55 inline void
  56 nsWrapperCache::TraceWrapperJSObject(JSTracer* aTrc, const char* aName)
  57 {
  58   JS_CallObjectTracer(aTrc, &mWrapper, aName);
  59 }
  60
  61 #endif /* nsWrapperCache_h___ */