dom/base/nsCCUncollectableMarker.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef nsCCUncollectableMarker_h_
   8 #define nsCCUncollectableMarker_h_
   9
  10 #include "js/TracingAPI.h"
  11 #include "mozilla/Attributes.h"
  12 #include "nsIObserver.h"
  13
  14 class nsCCUncollectableMarker final : public nsIObserver {
  15   NS_DECL_ISUPPORTS
  16   NS_DECL_NSIOBSERVER
  17
  18   /**
  19    * Inits a global nsCCUncollectableMarker. Should only be called once.
  20    */
  21   static nsresult Init();
  22
  23   /**
  24    * Checks if we're collecting during a given generation
  25    */
  26   static bool InGeneration(uint32_t aGeneration) {
  27     return aGeneration && aGeneration == sGeneration;
  28   }
  29
  30   template <class CCCallback>
  31   static bool InGeneration(CCCallback& aCb, uint32_t aGeneration) {
  32     return InGeneration(aGeneration) && !aCb.WantAllTraces();
  33   }
  34
  35   static uint32_t sGeneration;
  36
  37  private:
  38   nsCCUncollectableMarker() = default;
  39   ~nsCCUncollectableMarker() = default;
  40 };
  41
  42 namespace mozilla::dom {
  43 void TraceBlackJS(JSTracer* aTrc);
  44 }  // namespace mozilla::dom
  45
  46 #endif