зеркало из https://github.com/mozilla/gecko-dev.git
63 строки
2.2 KiB
C++
63 строки
2.2 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* vim: set ts=8 sts=2 et sw=2 tw=80: */
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#ifndef nsMemory_h__
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#define nsMemory_h__
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#include "nsError.h"
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/**
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*
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* A client that wishes to be notified of low memory situations (for
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* example, because the client maintains a large memory cache that
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* could be released when memory is tight) should register with the
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* observer service (see nsIObserverService) using the topic
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* "memory-pressure". There are specific types of notifications
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* that can occur. These types will be passed as the |aData|
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* parameter of the of the "memory-pressure" notification:
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*
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* "low-memory"
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* This will be passed as the extra data when the pressure
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* observer is being asked to flush for low-memory conditions.
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*
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* "low-memory-ongoing"
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* This will be passed when we continue to be in a low-memory
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* condition and we want to flush caches and do other cheap
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* forms of memory minimization, but heavy handed approaches like
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* a GC are unlikely to succeed.
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*
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* "heap-minimize"
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* This will be passed as the extra data when the pressure
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* observer is being asked to flush because of a heap minimize
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* call.
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*/
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// This is implemented in nsMemoryImpl.cpp.
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namespace nsMemory {
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/**
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* Attempts to shrink the heap.
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* @param immediate - if true, heap minimization will occur
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* immediately if the call was made on the main thread. If
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* false, the flush will be scheduled to happen when the app is
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* idle.
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* @throws NS_ERROR_FAILURE if 'immediate' is set and the call
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* was not on the application's main thread.
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*/
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nsresult HeapMinimize(bool aImmediate);
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/**
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* This predicate can be used to determine if the platform is a "low-memory"
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* platform. Callers may use this to dynamically tune their behaviour
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* to favour reduced memory usage at the expense of performance. The value
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* returned by this function will not change over the lifetime of the process.
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*/
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bool IsLowMemoryPlatform();
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} // namespace nsMemory
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#endif // nsMemory_h__
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