Quelle nsWrapperCacheInlines.h Sprache: C

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef nsWrapperCacheInline_h___
#define nsWrapperCacheInline_h___

#include "nsWrapperCache.h"
#include "js/RootingAPI.h"
#include "js/TracingAPI.h"

inline JSObject* nsWrapperCache::GetWrapperPreserveColor() const {
  JSObject* obj = GetWrapperMaybeDead();
  if (obj && js::gc::EdgeNeedsSweepUnbarriered(&obj)) {
    // The object has been found to be dead and is in the process of being
    // finalized, so don't let the caller see it.
    // Don't clear the cache though: this happens when a new wrapper is created
    // for this native or when the wrapper is finalized.
    return nullptr;
  }
  MOZ_ASSERT(obj == mWrapper);
  return obj;
}

inline JSObject* nsWrapperCache::GetWrapper() const {
  JSObject* obj = GetWrapperPreserveColor();
  if (obj) {
    JS::ExposeObjectToActiveJS(obj);
  }
  return obj;
}

inline bool nsWrapperCache::HasKnownLiveWrapper() const {
  // If we have a wrapper and it's not gray in the GC-marking sense, that means
  // that we can't be cycle-collected.  That's because the wrapper is being kept
  // alive by the JS engine (and not just due to being traced from some
  // cycle-collectable thing), and the wrapper holds us alive, so we know we're
  // not collectable.
  JSObject* o = GetWrapperPreserveColor();
  return o && !JS::ObjectIsMarkedGray(o);
}

static void SearchGray(JS::GCCellPtr aGCThing, const char* aName,
                       void* aClosure) {
  bool* hasGrayObjects = static_cast<bool*>(aClosure);
  if (!*hasGrayObjects && aGCThing && JS::GCThingIsMarkedGray(aGCThing)) {
    *hasGrayObjects = true;
  }
}

inline bool nsWrapperCache::HasNothingToTrace(nsISupports* aThis) {
  nsXPCOMCycleCollectionParticipant* participant = nullptr;
  CallQueryInterface(aThis, &participant);
  bool hasGrayObjects = false;
  participant->Trace(aThis, TraceCallbackFunc(SearchGray), &hasGrayObjects);
  return !hasGrayObjects;
}

inline bool nsWrapperCache::HasKnownLiveWrapperAndDoesNotNeedTracing(
    nsISupports* aThis) {
  return HasKnownLiveWrapper() && HasNothingToTrace(aThis);
}

inline void nsWrapperCache::MarkWrapperLive() {
  // Just call GetWrapper and ignore the return value.  It will do the
  // gray-unmarking for us.
  GetWrapper();
}

template <typename T>
inline void nsWrapperCache::UpdateWrapperForNewGlobal(T* aScriptObjectHolder,
                                                      JSObject* aNewWrapper) {
  // If the new wrapper is in a different zone we must ensure the
  // DropJSObjects/HoldJSObjects are called to move the holder to the new zone.

  bool preserving = PreservingWrapper();
  bool zoneChanged =
      preserving && (JS::GetObjectZone(GetWrapperPreserveColor()) !=
                     JS::GetObjectZone(aNewWrapper));

  if (zoneChanged) {
    ReleaseWrapper(aScriptObjectHolder);
  } else if (preserving) {
    SetPreservingWrapper(false);
  }

  SetWrapper(aNewWrapper);

  if (zoneChanged) {
    PreserveWrapper(aScriptObjectHolder);
  } else if (preserving) {
    SetPreservingWrapper(true);
  }
}

#endif /* nsWrapperCache_h___ */

quality100%

¤ Dauer der Verarbeitung: 0.32 Sekunden (vorverarbeitet) ¤

Wurzel

Suchen

Beweissystem der NASA

Beweissystem Isabelle

NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung ist noch experimentell.