/gecko_api/include/nsMemory.h
C Header | 169 lines | 45 code | 17 blank | 107 comment | 1 complexity | 15cebacbb9568fd6652d54d2ebeabf6e MD5 | raw file
1/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ 2/* ***** BEGIN LICENSE BLOCK ***** 3 * Version: MPL 1.1/GPL 2.0/LGPL 2.1 4 * 5 * The contents of this file are subject to the Mozilla Public License Version 6 * 1.1 (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * http://www.mozilla.org/MPL/ 9 * 10 * Software distributed under the License is distributed on an "AS IS" basis, 11 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License 12 * for the specific language governing rights and limitations under the 13 * License. 14 * 15 * The Original Code is mozilla.org code. 16 * 17 * The Initial Developer of the Original Code is 18 * Netscape Communications Corporation. 19 * Portions created by the Initial Developer are Copyright (C) 1998 20 * the Initial Developer. All Rights Reserved. 21 * 22 * Contributor(s): 23 * 24 * Alternatively, the contents of this file may be used under the terms of 25 * either of the GNU General Public License Version 2 or later (the "GPL"), 26 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"), 27 * in which case the provisions of the GPL or the LGPL are applicable instead 28 * of those above. If you wish to allow use of your version of this file only 29 * under the terms of either the GPL or the LGPL, and not to allow others to 30 * use your version of this file under the terms of the MPL, indicate your 31 * decision by deleting the provisions above and replace them with the notice 32 * and other provisions required by the GPL or the LGPL. If you do not delete 33 * the provisions above, a recipient may use your version of this file under 34 * the terms of any one of the MPL, the GPL or the LGPL. 35 * 36 * ***** END LICENSE BLOCK ***** */ 37 38#ifndef nsMemory_h__ 39#define nsMemory_h__ 40 41#include "nsXPCOM.h" 42#include "nsIMemory.h" 43 44#define NS_MEMORY_CONTRACTID "@mozilla.org/xpcom/memory-service;1" 45#define NS_MEMORY_CLASSNAME "Global Memory Service" 46#define NS_MEMORY_CID \ 47{ /* 30a04e40-38e7-11d4-8cf5-0060b0fc14a3 */ \ 48 0x30a04e40, \ 49 0x38e7, \ 50 0x11d4, \ 51 {0x8c, 0xf5, 0x00, 0x60, 0xb0, 0xfc, 0x14, 0xa3} \ 52} 53 54 55/** 56 * Static helper routines to manage memory. These routines allow easy access 57 * to xpcom's built-in (global) nsIMemory implementation, without needing 58 * to go through the service manager to get it. However this requires clients 59 * to link with the xpcom DLL. 60 * 61 * This class is not threadsafe and is intented for use only on the main 62 * thread. 63 */ 64class nsMemory 65{ 66public: 67 static NS_HIDDEN_(void*) Alloc(size_t size) 68 { return NS_Alloc(size); } 69 70 static NS_HIDDEN_(void*) Realloc(void* ptr, PRSize size) 71 { return NS_Realloc(ptr, size); } 72 73 static NS_HIDDEN_(void) Free(void* ptr) 74 { NS_Free(ptr); } 75 76 static NS_COM_GLUE nsresult HeapMinimize(PRBool aImmediate); 77 static NS_COM_GLUE void* Clone(const void* ptr, PRSize size); 78 static NS_COM_GLUE nsIMemory* GetGlobalMemoryService(); // AddRefs 79}; 80 81/** 82 * Macro to free all elements of an XPCOM array of a given size using 83 * freeFunc, then frees the array itself using nsMemory::Free(). 84 * 85 * Note that this macro (and its wrappers) can be used to deallocate a 86 * partially- or completely-built array while unwinding an error 87 * condition inside the XPCOM routine that was going to return the 88 * array. For this to work on a partially-built array, your code 89 * needs to be building the array from index 0 upwards, and simply 90 * pass the number of elements that have already been built (and thus 91 * need to be freed) as |size|. 92 * 93 * Thanks to <alecf@netscape.com> for suggesting this form, which 94 * allows the macro to be used with NS_RELEASE / NS_RELEASE_IF in 95 * addition to nsMemory::Free. 96 * 97 * @param size Number of elements in the array. If not a constant, this 98 * should be a PRInt32. Note that this means this macro 99 * will not work if size >= 2^31. 100 * @param array The array to be freed. 101 * @param freeFunc The function or macro to be used to free it. 102 * For arrays of nsISupports (or any class derived 103 * from it), NS_IF_RELEASE (or NS_RELEASE) should be 104 * passed as freeFunc. For most (all?) other pointer 105 * types (including XPCOM strings and wstrings), 106 * nsMemory::Free should be used, since the 107 * shared-allocator (nsMemory) is what will have been 108 * used to allocate the memory. 109 */ 110#define NS_FREE_XPCOM_POINTER_ARRAY(size, array, freeFunc) \ 111 PR_BEGIN_MACRO \ 112 PRInt32 iter_ = PRInt32(size); \ 113 while (--iter_ >= 0) \ 114 freeFunc((array)[iter_]); \ 115 NS_Free((array)); \ 116 PR_END_MACRO 117 118// convenience macros for commonly used calls. mmmmm. syntactic sugar. 119 120/** 121 * Macro to free arrays of non-refcounted objects allocated by the 122 * shared allocator (nsMemory) such as strings and wstrings. A 123 * convenience wrapper around NS_FREE_XPCOM_POINTER_ARRAY. 124 * 125 * @param size Number of elements in the array. If not a constant, this 126 * should be a PRInt32. Note that this means this macro 127 * will not work if size >= 2^31. 128 * @param array The array to be freed. 129 */ 130#define NS_FREE_XPCOM_ALLOCATED_POINTER_ARRAY(size, array) \ 131 NS_FREE_XPCOM_POINTER_ARRAY((size), (array), NS_Free) 132 133/** 134 * Macro to free an array of pointers to nsISupports (or classes 135 * derived from it). A convenience wrapper around 136 * NS_FREE_XPCOM_POINTER_ARRAY. 137 * 138 * Note that if you know that none of your nsISupports pointers are 139 * going to be 0, you can gain a bit of speed by calling 140 * NS_FREE_XPCOM_POINTER_ARRAY directly and using NS_RELEASE as your 141 * free function. 142 * 143 * @param size Number of elements in the array. If not a constant, this 144 * should be a PRInt32. Note that this means this macro 145 * will not work if size >= 2^31. 146 * @param array The array to be freed. 147 */ 148#define NS_FREE_XPCOM_ISUPPORTS_POINTER_ARRAY(size, array) \ 149 NS_FREE_XPCOM_POINTER_ARRAY((size), (array), NS_IF_RELEASE) 150 151/** 152 * Helpful array length function for calculating the length of a 153 * statically declared array. 154 */ 155 156#define NS_ARRAY_LENGTH(array_) \ 157 (sizeof(array_)/sizeof(array_[0])) 158 159/** 160 * An enumeration type used to represent a method of assignment. 161 */ 162enum nsAssignmentType { 163 NS_ASSIGNMENT_COPY, // copy by value 164 NS_ASSIGNMENT_DEPEND, // copy by reference 165 NS_ASSIGNMENT_ADOPT // copy by reference (take ownership of resource) 166}; 167 168#endif // nsMemory_h__ 169