mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-11-24 05:11:16 +00:00
265e672179
# ignore-this-changeset --HG-- extra : amend_source : 4d301d3b0b8711c4692392aa76088ba7fd7d1022
60 lines
1.8 KiB
C++
60 lines
1.8 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
|
|
* vim: sw=2 ts=8 et :
|
|
*/
|
|
/* 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_LAYERS_MEMORYPRESSUREOBSERVER_H
|
|
#define MOZILLA_LAYERS_MEMORYPRESSUREOBSERVER_H
|
|
|
|
#include "nsIObserver.h"
|
|
|
|
namespace mozilla {
|
|
namespace layers {
|
|
|
|
// A simple memory pressure observer implementation born out of the realization
|
|
// that almost all of our memory pressure observers do exactly the same thing.
|
|
//
|
|
// The intended way to use it is to have the class that nees to react on memory
|
|
// pressure inherit the MemoryPressureListener interface and own a strong
|
|
// reference to a MemoryPressureListener object.
|
|
// Call Unregister on the listener in the destructor of your class or whenever
|
|
// you do not which to receive the notification anymore, otherwise the listener
|
|
// will be held alive by the observer service (leak) and keep a dangling pointer
|
|
// to your class.
|
|
|
|
/// See nsIMemory.idl
|
|
enum class MemoryPressureReason {
|
|
LOW_MEMORY,
|
|
LOW_MEMORY_ONGOING,
|
|
HEAP_MINIMIZE,
|
|
};
|
|
|
|
class MemoryPressureListener {
|
|
public:
|
|
virtual void OnMemoryPressure(MemoryPressureReason aWhy) = 0;
|
|
};
|
|
|
|
class MemoryPressureObserver final : public nsIObserver {
|
|
public:
|
|
NS_DECL_ISUPPORTS
|
|
NS_DECL_NSIOBSERVER
|
|
|
|
// Returns null if anything goes wrong.
|
|
static already_AddRefed<MemoryPressureObserver> Create(
|
|
MemoryPressureListener* aListener);
|
|
|
|
void Unregister();
|
|
|
|
private:
|
|
explicit MemoryPressureObserver(MemoryPressureListener* aListener);
|
|
virtual ~MemoryPressureObserver();
|
|
MemoryPressureListener* mListener;
|
|
};
|
|
|
|
} // namespace layers
|
|
} // namespace mozilla
|
|
|
|
#endif
|