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Diffstat (limited to 'src/libs/xpcom18a4/xpcom/base/nsIMemory.idl')
-rw-r--r-- | src/libs/xpcom18a4/xpcom/base/nsIMemory.idl | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/src/libs/xpcom18a4/xpcom/base/nsIMemory.idl b/src/libs/xpcom18a4/xpcom/base/nsIMemory.idl new file mode 100644 index 00000000..071aed06 --- /dev/null +++ b/src/libs/xpcom18a4/xpcom/base/nsIMemory.idl @@ -0,0 +1,126 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* ***** BEGIN LICENSE BLOCK ***** + * Version: MPL 1.1/GPL 2.0/LGPL 2.1 + * + * The contents of this file are subject to the Mozilla Public License Version + * 1.1 (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * http://www.mozilla.org/MPL/ + * + * Software distributed under the License is distributed on an "AS IS" basis, + * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License + * for the specific language governing rights and limitations under the + * License. + * + * The Original Code is mozilla.org code. + * + * The Initial Developer of the Original Code is + * Netscape Communications Corporation. + * Portions created by the Initial Developer are Copyright (C) 1998 + * the Initial Developer. All Rights Reserved. + * + * Contributor(s): + * + * Alternatively, the contents of this file may be used under the terms of + * either of the GNU General Public License Version 2 or later (the "GPL"), + * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"), + * in which case the provisions of the GPL or the LGPL are applicable instead + * of those above. If you wish to allow use of your version of this file only + * under the terms of either the GPL or the LGPL, and not to allow others to + * use your version of this file under the terms of the MPL, indicate your + * decision by deleting the provisions above and replace them with the notice + * and other provisions required by the GPL or the LGPL. If you do not delete + * the provisions above, a recipient may use your version of this file under + * the terms of any one of the MPL, the GPL or the LGPL. + * + * ***** END LICENSE BLOCK ***** */ + +#include "nsISupports.idl" + +/** + * + * nsIMemory: interface to allocate and deallocate memory. Also provides + * for notifications in low-memory situations. + * + * A client that wishes to be notified of low memory situations (for + * example, because the client maintains a large memory cache that + * could be released when memory is tight) should register with the + * observer service (see nsIObserverService) using the topic + * "memory-pressure". There are three specific types of notications + * that can occur. These types will be passed as the |aData| + * parameter of the of the "memory-pressure" notification: + * + * "low-memory" + * This will be passed as the extra data when the pressure + * observer is being asked to flush for low-memory conditions. + * + * "heap-minimize" + * This will be passed as the extra data when the pressure + * observer is being asked to flush because of a heap minimize + * call. + * + * "alloc-failure" + * This will be passed as the extra data when the pressure + * observer has been asked to flush because a malloc() or + * realloc() has failed. + * + * @status FROZEN + */ + +[scriptable, uuid(59e7e77a-38e4-11d4-8cf5-0060b0fc14a3)] +interface nsIMemory : nsISupports +{ + /** + * Allocates a block of memory of a particular size. If the memory + * cannot be allocated (because of an out-of-memory condition), null + * is returned. + * + * @param size - the size of the block to allocate + * @result the block of memory + */ + [noscript, notxpcom] voidPtr alloc(in size_t size); + + /** + * Reallocates a block of memory to a new size. + * + * @param ptr - the block of memory to reallocate + * @param size - the new size + * @result the reallocated block of memory + * + * If ptr is null, this function behaves like malloc. + * If s is the size of the block to which ptr points, the first + * min(s, size) bytes of ptr's block are copied to the new block. + * If the allocation succeeds, ptr is freed and a pointer to the + * new block returned. If the allocation fails, ptr is not freed + * and null is returned. The returned value may be the same as ptr. + */ + [noscript, notxpcom] voidPtr realloc(in voidPtr ptr, + in size_t newSize); + + /** + * Frees a block of memory. Null is a permissible value, in which case + * nothing happens. + * + * @param ptr - the block of memory to free + */ + [noscript, notxpcom] void free(in voidPtr ptr); + + /** + * Attempts to shrink the heap. + * @param immediate - if true, heap minimization will occur + * immediately if the call was made on the main thread. If + * false, the flush will be scheduled to happen when the app is + * idle. + * @return NS_ERROR_FAILURE if 'immediate' is set an the call + * was not on the application's main thread. + */ + void heapMinimize(in boolean immediate); + + /** + * This predicate can be used to determine if we're in a low-memory + * situation (what constitutes low-memory is platform dependent). This + * can be used to trigger the memory pressure observers. + */ + boolean isLowMemory(); +}; + |