00001 // $Id: cammemory.h 1492 2006-07-20 19:19:48Z alex $ 00002 /* @@tag:xara-cn@@ DO NOT MODIFY THIS LINE 00003 ================================XARAHEADERSTART=========================== 00004 00005 Xara LX, a vector drawing and manipulation program. 00006 Copyright (C) 1993-2006 Xara Group Ltd. 00007 Copyright on certain contributions may be held in joint with their 00008 respective authors. See AUTHORS file for details. 00009 00010 LICENSE TO USE AND MODIFY SOFTWARE 00011 ---------------------------------- 00012 00013 This file is part of Xara LX. 00014 00015 Xara LX is free software; you can redistribute it and/or modify it 00016 under the terms of the GNU General Public License version 2 as published 00017 by the Free Software Foundation. 00018 00019 Xara LX and its component source files are distributed in the hope 00020 that it will be useful, but WITHOUT ANY WARRANTY; without even the 00021 implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 00022 See the GNU General Public License for more details. 00023 00024 You should have received a copy of the GNU General Public License along 00025 with Xara LX (see the file GPL in the root directory of the 00026 distribution); if not, write to the Free Software Foundation, Inc., 51 00027 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 00028 00029 00030 ADDITIONAL RIGHTS 00031 ----------------- 00032 00033 Conditional upon your continuing compliance with the GNU General Public 00034 License described above, Xara Group Ltd grants to you certain additional 00035 rights. 00036 00037 The additional rights are to use, modify, and distribute the software 00038 together with the wxWidgets library, the wxXtra library, and the "CDraw" 00039 library and any other such library that any version of Xara LX relased 00040 by Xara Group Ltd requires in order to compile and execute, including 00041 the static linking of that library to XaraLX. 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All rights in these marks are reserved. 00091 00092 00093 Xara Group Ltd, Gaddesden Place, Hemel Hempstead, HP2 6EX, UK. 00094 http://www.xara.com/ 00095 00096 =================================XARAHEADEREND============================ 00097 */ 00098 00099 // This is the Camelot Memory Manager 00100 00101 00102 /******************************************************************************************** 00103 00104 < Memory Manager 00105 < Dynamic Heap 00106 00107 Comment: 00108 00109 \b Overview \b0 00110 00111 The dynamic heap or dynamic memory manager is used in Camelot to manage a shifting set 00112 of memory blocks. These memory blocks are used to hold objects which are either very 00113 large (e.g. bitmaps) or which frequently change size (e.g. paths/curves etc.). The blocks 00114 of memory are physically moved around by the memory manager to achieve the best use of the 00115 memory available. 00116 00117 00118 \b Access Restrictions \b0 00119 00120 In order for a client to access the block, a handle must be used, which is translated into 00121 a physical address when access to the block is needed. This handle is valid only as long 00122 as the block it relates to is in existence. More importantly, the physical address 00123 associated with a given handle may change across calls to the memory manager. In particular, 00124 the following memory manager functions may cause the mapping from a handle to a physical 00125 address to change: 00126 MonoOn 00127 ClaimBlock() 00128 ReleaseBlock() 00129 SplitBlock() 00130 RemoveBlockGaps() 00131 TidyMemory() 00132 MonoOff 00133 Any other functions will not change the physical address associated with a handle, so it 00134 is safe to call them, and still use the same physical address to access the block. The 00135 client should be aware that the event processing structure of Camelot means that it is not 00136 safe to assume that physical addresses remain valid across calls to Windows message 00137 processing functions, as Camelot will call the TidyMemory() function on idle events, which 00138 will cause block addresses to change. 00139 00140 These restrictions are also relevant when using the handle manager directly to point into 00141 arbitrary positions in dynamic heap blocks. Using the handle manager, a client can obtain 00142 a handle which points to any part of their dynamic heap block. While obtaining this handle, 00143 the client must follow the same constraints as when using a physical address obtained via a 00144 block handle. 00145 00146 00147 \b General Use \b0 00148 00149 The ClaimBlock() function should be used when allocating a block of memory from the dynamic 00150 heap. This will return a handle for this block, which can be converted to a physical address 00151 using DescribeBlock(). The client can then access the contents of the block using this 00152 address. It is also possible to use the Handle Manager to obtain extra handles which 00153 refer to arbitrary areas within blocks - such handles are automatically deallocated when the 00154 block itself is deallocated. This is because the Memory Manager is itself a client of the 00155 Handle Manager, and when deallocating blocks, it instructs the Handle Manager to release any 00156 handles which point into the block in question. 00157 00158 To deallocate a block, use the ReleaseBlock() function, passing the handle of the block 00159 you wish to deallocate. Clients should \i not \i0 pass in a handle that has been allocated 00160 by the Handle Manager directly - the Memory Manager will not deallocate the correct block, 00161 and an error will usually occur. 00162 00163 The remaining function for manipulation of blocks is SplitBlock(). This is a general 00164 purpose function which can remove or insert memory at an arbitrary point within a block. 00165 The heap block is resized to accomodate the increase or reduction in the size of the block 00166 as a result. This will usually cause heap blocks to move, as mentioned above, and any 00167 physical addresses obtained from handles should be considered invalid, and new versions 00168 should be obtained with DescribeBlock() (or DescribeHandle() if the handle has been obtained 00169 directly from the Handle Manager rather than via the Memory Manager). 00170 00171 00172 \b Debugging \b0 00173 00174 There are two debugging functions (which are only present in the DEBUG build of Camelot). 00175 The first is CheckMemory(), which walks the heap and examines special debugging information 00176 to ensure that the heap structure has not been corrupted. If the heap has been corrupted, 00177 an assertion failure will occur, with the usual consequences. The other function is 00178 DumpMemory() which outputs to the debugging stream (DBWIN) the overall structure of the 00179 heap - how many blocks, what size they are, whether they are in use or designated as 'holes', 00180 and how much free memory is available at the time. 00181 00182 00183 SeeAlso: InitMemory;DeinitMemory;ClaimBlock;DescribeBlock;ReleaseBlock 00184 SeeAlso: SplitBlock;RemoveBlockGaps;TidyMemory;DumpMemory;CheckMemory 00185 SeeAlso: Handle Manager 00186 00187 00188 ********************************************************************************************/ 00189 00190 #ifndef INC_MEMORY 00191 #define INC_MEMORY 00192 00193 #include "handles.h" 00194 00195 extern BOOL InitMemory(); 00196 extern void DeinitMemory(); 00197 extern MHANDLE ClaimBlock(size_t Size, BOOL Heavy = FALSE); 00198 extern BOOL DescribeBlock(MHANDLE Handle, ADDR *Address, size_t *Size); 00199 extern BOOL ReleaseBlock(MHANDLE Handle); 00200 extern BOOL SplitBlock(MHANDLE Handle, INT32 SplitSize, UINT32 Offset); 00201 extern BOOL IncreaseBlock(MHANDLE Handle, UINT32 NumBytes); 00202 extern BOOL DecreaseBlock(MHANDLE Handle, UINT32 NumBytes); 00203 extern BOOL InsertMemory(MHANDLE Handle, UINT32 Offset, UINT32 NumBytes); 00204 extern BOOL RemoveMemory(MHANDLE Handle, UINT32 Offset, UINT32 NumBytes); 00205 extern BOOL TidyMemory(); 00206 extern void GetMemoryStatus(UINT64* pPhysRam = NULL, UINT32* pLoadPercent = NULL); 00207 00208 #ifdef _DEBUG 00209 extern void DumpMemory(); 00210 extern void SetMemoryFailFlag(BOOL DenyRequests); 00211 00212 #else 00213 #define DumpMemory() 00214 #define SetMemoryFailFlag(x) 00215 00216 #endif // _DEBUG 00217 00218 #endif // INC_MEMORY