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 mozilla_AvailableMemoryWatcher_h
8 #define mozilla_AvailableMemoryWatcher_h
9 
10 #include "nsCOMPtr.h"
11 #include "nsIAvailableMemoryWatcherBase.h"
12 
13 namespace mozilla {
14 
15 // This class implements a platform-independent part to watch the system's
16 // memory situation and invoke the registered callbacks when we detect
17 // a low-memory situation or a high-memory situation.
18 // The actual logic to monitor the memory status is implemented in a subclass
19 // of nsAvailableMemoryWatcherBase per platform.
20 class nsAvailableMemoryWatcherBase : public nsIAvailableMemoryWatcherBase {
21   static StaticRefPtr<nsAvailableMemoryWatcherBase> sSingleton;
22 
23  protected:
24   nsCOMPtr<nsITabUnloader> mTabUnloader;
25 
26   virtual ~nsAvailableMemoryWatcherBase() = default;
27 
28  public:
29   static already_AddRefed<nsAvailableMemoryWatcherBase> GetSingleton();
30 
31   nsAvailableMemoryWatcherBase();
32 
33   NS_DECL_THREADSAFE_ISUPPORTS
34   NS_DECL_NSIAVAILABLEMEMORYWATCHERBASE
35 };
36 
37 // Method to create a platform-specific object
38 already_AddRefed<nsAvailableMemoryWatcherBase> CreateAvailableMemoryWatcher();
39 
40 }  // namespace mozilla
41 
42 #endif  // ifndef mozilla_AvailableMemoryWatcher_h
43