gecko-dev/dom/abort/AbortFollower.h

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/* -*- 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 mozilla_dom_AbortFollower_h
#define mozilla_dom_AbortFollower_h
#include "nsISupportsImpl.h"
#include "nsTObserverArray.h"
namespace mozilla {
namespace dom {
class AbortSignal;
class AbortSignalImpl;
// This class must be implemented by objects who want to follow an
// AbortSignalImpl.
class AbortFollower : public nsISupports {
public:
virtual void RunAbortAlgorithm() = 0;
void Follow(AbortSignalImpl* aSignal);
void Unfollow();
bool IsFollowing() const;
AbortSignalImpl* Signal() const { return mFollowingSignal; }
protected:
// Subclasses of this class must call these Traverse and Unlink functions
// during corresponding cycle collection operations.
static void Traverse(AbortFollower* aFollower,
nsCycleCollectionTraversalCallback& cb);
static void Unlink(AbortFollower* aFollower) { aFollower->Unfollow(); }
virtual ~AbortFollower();
friend class AbortSignalImpl;
RefPtr<AbortSignalImpl> mFollowingSignal;
};
class AbortSignalImpl : public nsISupports {
public:
explicit AbortSignalImpl(bool aAborted);
bool Aborted() const;
virtual void SignalAbort();
protected:
// Subclasses of this class must call these Traverse and Unlink functions
// during corresponding cycle collection operations.
static void Traverse(AbortSignalImpl* aSignal,
nsCycleCollectionTraversalCallback& cb);
static void Unlink(AbortSignalImpl* aSignal) {
// To be filled in shortly.
}
virtual ~AbortSignalImpl() = default;
private:
friend class AbortFollower;
// Raw pointers. |AbortFollower::Follow| adds to this array, and
// |AbortFollower::Unfollow| (also callbed by the destructor) will remove
// from this array. Finally, calling |SignalAbort()| will (after running all
// abort algorithms) empty this and make all contained followers |Unfollow()|.
nsTObserverArray<AbortFollower*> mFollowers;
bool mAborted;
};
} // namespace dom
} // namespace mozilla
#endif // mozilla_dom_AbortFollower_h