| 1 | /* $Id: malloc.cpp,v 1.1.1.1 2003/07/02 13:57:02 eleph Exp $ */
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| 2 |
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| 3 | /* SCCSID = %W% %E% */
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| 4 | /****************************************************************************
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| 5 | * *
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| 6 | * Copyright (c) IBM Corporation 1994 - 1997. *
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| 7 | * *
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| 8 | * The following IBM OS/2 source code is provided to you solely for the *
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| 9 | * the purpose of assisting you in your development of OS/2 device drivers. *
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| 10 | * You may use this code in accordance with the IBM License Agreement *
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| 11 | * provided in the IBM Device Driver Source Kit for OS/2. *
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| 12 | * *
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| 13 | ****************************************************************************/
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| 14 | /**@internal %W%
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| 15 | * Implementation of the driver's built in memory management.
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| 16 | * @version %I%
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| 17 | * @context
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| 18 | * Unless otherwise noted, all interfaces are Ring-3 and Ring-0, 16-bit,
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| 19 | * kernel stack.
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| 20 | * @notes
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| 21 | * @history
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| 22 | * 01-Jul-95 Timur Tabi Creation
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| 23 | */
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| 24 |
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| 25 | #include <os2.h>
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| 26 | #include <string.h> // memcpy(), memset()
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| 27 | #include <stdio.h>
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| 28 | #include <dbgos2.h>
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| 29 |
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| 30 | #include <devhelp.h>
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| 31 | #include <kee.h>
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| 32 | #include "malloc.h"
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| 33 |
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| 34 | #if !defined(min)
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| 35 | #define min(a,b) (((a) < (b)) ? (a) : (b))
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| 36 | #endif
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| 37 |
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| 38 | #define SIGNATURE 0xBEEFDEAD // "DeadBeef" when view in hex in word order.
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| 39 |
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| 40 | #pragma pack(4)
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| 41 | typedef struct _MEMBLOCK {
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| 42 | ULONG ulSignature;
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| 43 | ULONG ulSize;
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| 44 | struct _MEMBLOCK NEAR *pmbNext;
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| 45 | #ifdef DEBUGHEAP
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| 46 | char NEAR *pszFile;
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| 47 | ULONG ulLine;
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| 48 | #endif
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| 49 | char achBlock[4];
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| 50 | } MEMBLOCK, NEAR *PMEMBLOCK;
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| 51 | #pragma pack()
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| 52 |
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| 53 | #define HDR_SIZE ( sizeof(MEMBLOCK) - 4 )
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| 54 |
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| 55 | // We won't leave a hole in memory any smaller than MIN_FragSize.
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| 56 | #define MIN_FragSize 4
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| 57 |
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| 58 | //--- Global Variables used to manage the heap:
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| 59 | //
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| 60 | PMEMBLOCK pmbUsed = 0; // Points to head of list of allocated memory blocks.
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| 61 | // Newly allocated blocks are inserted into head of list.
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| 62 | PMEMBLOCK pmbFree = 0; // Points to head of list of available memory blocks.
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| 63 | unsigned uMemFree = 0; // N bytes available for allocation.
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| 64 | LINEAR acHeap = NULL;
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| 65 |
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| 66 | ULONG ulnAlloc = 0; // Current number of allocated blocks.
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| 67 | ULONG ulcAlloc = 0; // Total memory in allocated blocks incl. headers.
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| 68 | ULONG ulnAllocCalls = 0; // Cumulative total, number of malloc() calls.
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| 69 | ULONG ulnFree = 0; // Current number of free blocks.
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| 70 | ULONG ulcFree = 0; // Total memory in free blocks incl. headers.
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| 71 | ULONG ulnFreeCalls = 0; // Cumulative total, number of free() calls.
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| 72 | ULONG ulnCompact = 0; // Num of times we've joined two adjacent free
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| 73 | // blocks into a single larger block.
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| 74 | ULONG ulcTotalHeap = HEAP_SIZE;
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| 75 |
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| 76 |
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| 77 | #pragma off (unreferenced)
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| 78 |
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| 79 | //--- Heap methods:
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| 80 |
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| 81 | //*****************************************************************************
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| 82 | //*****************************************************************************
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| 83 | void dumpheap(void)
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| 84 | {
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| 85 | SHORT sI;
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| 86 | PMEMBLOCK pmb;
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| 87 | ULONG ulSize;
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| 88 |
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| 89 | ulSize = 0;
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| 90 | pmb=pmbUsed;
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| 91 | dprintf(("HEAP:Heap Dump acHeap=%lx Used=%p Free=%p\n", (void __far *)acHeap, pmbUsed, pmbFree));
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| 92 | dprintf((" Used blocks\n"));
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| 93 | for (sI=0; sI<10; sI++) {
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| 94 | dprintf((" pmb=%p, length=%lx\n",(void __far *) pmb, pmb->ulSize));
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| 95 | ulSize+=pmb->ulSize;
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| 96 | pmb=pmb->pmbNext;
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| 97 | if (!pmb) break;
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| 98 | }
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| 99 | dprintf((" Total used = %lx\n", ulSize));
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| 100 |
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| 101 | ulSize=0;
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| 102 | pmb=pmbFree;
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| 103 | dprintf((" Free blocks\n"));
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| 104 | for (sI=0; sI<50; sI++) {
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| 105 | dprintf((" pmb=%p, length=%lx\n",(void __far *) pmb, pmb->ulSize));
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| 106 | ulSize+=pmb->ulSize;
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| 107 | pmb=pmb->pmbNext;
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| 108 | if (!pmb) break;
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| 109 | }
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| 110 | dprintf((" Total free = %lx\n", ulSize));
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| 111 | }
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| 112 | //*****************************************************************************
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| 113 | //*****************************************************************************
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| 114 |
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| 115 | //*****************************************************************************
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| 116 | //*****************************************************************************
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| 117 | SHORT SignatureCheck ( PMEMBLOCK p, PSZ idText )
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| 118 | {
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| 119 | short sGoodPointer;
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| 120 |
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| 121 | // Set bGoodPointer to indicate whether or not 'p' points within heap.
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| 122 | sGoodPointer = ((LINEAR)p >= (acHeap))
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| 123 | && ((LINEAR)p <= (( acHeap) + HEAP_SIZE)) ;
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| 124 | //### heap might have less than HEAP_SIZE bytes
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| 125 |
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| 126 | // Check for correct signature.
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| 127 | if (sGoodPointer) sGoodPointer = (p->ulSignature == SIGNATURE) && p->ulSize < HEAP_SIZE;
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| 128 |
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| 129 | if (!sGoodPointer) {
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| 130 | dprintf(("SignatureCheck: Bad pointer %p %s\n", p, idText));
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| 131 | DebugInt3();
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| 132 | }
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| 133 | return sGoodPointer;
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| 134 | }
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| 135 | //*****************************************************************************
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| 136 | //*****************************************************************************
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| 137 | void HeapCheck ( PSZ idText )
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| 138 | {
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| 139 | PMEMBLOCK p;
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| 140 | for ( ulnAlloc = 0, ulcAlloc = 0, p = pmbUsed; p; p = p->pmbNext ) {
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| 141 | ++ulnAlloc;
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| 142 | ulcAlloc += p->ulSize + HDR_SIZE;
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| 143 | SignatureCheck( p,(PSZ) "HeapCheck() Used list" );
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| 144 | if (p == p->pmbNext) {
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| 145 | dprintf(("HeapCheck: used %p points to itself\n", p));
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| 146 | DebugInt3();
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| 147 | }
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| 148 | }
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| 149 | for ( ulnFree = 0, ulcFree = 0, p = pmbFree; p; p = p->pmbNext ) {
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| 150 | ++ulnFree;
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| 151 | ulcFree += p->ulSize + HDR_SIZE;
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| 152 | SignatureCheck( p,(PSZ) "HeapCheck() Free list" );
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| 153 | if (p == p->pmbNext) {
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| 154 | dprintf(("HeapCheck: free %p points to itself\n", p));
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| 155 | DebugInt3();
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| 156 | }
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| 157 | }
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| 158 | if (ulcAlloc + ulcFree != ulcTotalHeap) {
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| 159 | dprintf(("HeapCheck: Alloc+Free != Total\n"));
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| 160 | //dumpheap();
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| 161 | DebugInt3();
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| 162 | }
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| 163 | }
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| 164 |
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| 165 | //*****************************************************************************
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| 166 | //*****************************************************************************
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| 167 |
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| 168 | // Threshold for creating a new free block.
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| 169 | #define MIN_Leftover (HDR_SIZE + MIN_FragSize)
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| 170 |
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| 171 | /*
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| 172 | Formats the back part of an existing free MEMBLOCK as a new, smaller
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| 173 | "Free" MEMBLOCK. Doesn't update Global vbls (caller responsibility).
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| 174 | IN: pmbOldFree - pointer to existing memory block.
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| 175 | uSize - offset, which won't be included in new allocation.
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| 176 | it's assumed HDR is not included in uSize.
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| 177 | OUT: pointer to new free MEMBLOCK, is a new block of free memory,
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| 178 | is created at pmbOldFree + uRequest. The memory block header
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| 179 | in both the new block and the old block are properly initialized
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| 180 | on return, but we don't update the Free list or Allocated list.
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| 181 | OUT: NULL if the new free memory block is smaller than the
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| 182 | framentation threshold.
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| 183 |
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| 184 | The fragmentation consideration comes into play when we find a block that's
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| 185 | big enough to hold the requested memory, but not big enough for the leftover
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| 186 | part to be useful as another free block.
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| 187 |
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| 188 | _______________________free block_______________________________________
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| 189 | | free | |
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| 190 | | block | space available |
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| 191 | | header | (pmbFree->uSize bytes long) |
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| 192 | |(HDR_SIZE | |
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| 193 | |__bytes)__|_____________________________________________________________|
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| 194 |
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| 195 | <-- HDR --> <------------------------- l -------------------------------->
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| 196 |
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| 197 | Must either be allocated in total, or must become:
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| 198 |
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| 199 | _______________________used block_______________________________________
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| 200 | | used | | free | |
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| 201 | | block | space allocated | block | space |
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| 202 | | header | == uSize (following DWORD align't) | header | available |
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| 203 | |(HDR_SIZE | (pmbUsed->uSize bytes long) |(HDR_SIZE | |
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| 204 | |__bytes)__|_____________________________________|__bytes)__|____________|
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| 205 |
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| 206 | <-- HDR --> <-------------- n ------------------><-- HDR --> <--- m ----->
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| 207 |
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| 208 | To be split into an allocated and a new, smaller free block, 'm' must be at
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| 209 | least MIN_FragSize bytes long.
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| 210 |
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| 211 | Everything should remain 4 byte aligned since the HDR_SIZE, MIN_FragSize,
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| 212 | and the space allocated (after we munge it) are all multiples of 4.
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| 213 |
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| 214 | This means that in order for a free block to be chosen, one of the following
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| 215 | equation must hold
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| 216 |
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| 217 | Case 1: n <= l < (n + HDR + MIN_FragSize)
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| 218 | Here, we'll allocate the entire block. This makes the block somewhat
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| 219 | larger than the request, but prevents some degree of fragmentation.
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| 220 |
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| 221 | Case 2: (n + HDR + MIN_FragSize) <= l
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| 222 | We split the block into an allocated part to satisfy the allocation request,
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| 223 | and a free block which can be allocated in a subsequent request.
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| 224 |
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| 225 | @internal pmbAllocateBlock
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| 226 | * Update all data structures for allocation of one memory block. It's
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| 227 | * assumed, on entry, that the block is large enough for the requested
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| 228 | * allocation.
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| 229 | * @param PMEMBLOCK pmb - the current memory block on the Free list to
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| 230 | * allocate.
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| 231 | * @param USHORT uRequest - size of the memory request to fill, not counting
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| 232 | * memory block header.
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| 233 | * @param PMEMBLOCK pmbPrev - the memory block which precedes the block being
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| 234 | * allocated in the Free list. NULL if no predecessor (ie, pmb is pointed to
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| 235 | * by ::pmbFree).
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| 236 | * @return PMEMBLOCK - pointer to the data part of the allocated memory block,
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| 237 | * suitable for return to malloc() caller.
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| 238 | */
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| 239 | void NEAR *npvAllocateBlock( PMEMBLOCK pmb, ULONG ulRequest, PMEMBLOCK pmbPrev )
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| 240 | {
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| 241 |
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| 242 | //pmb points to the selected block.
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| 243 | //pmbPrev points to the block prior to the selected block, NULL if pmbFree.
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| 244 | PMEMBLOCK pmbOldNext; // Original free block that follows the block being allocated.
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| 245 | PMEMBLOCK pmbNewFree; // Leftover free memory from the allocated block.
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| 246 |
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| 247 | // Split this block into an allocated + free part if it's big enough.
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| 248 | pmbNewFree = 0;
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| 249 | if (pmb->ulSize >= (ulRequest + MIN_Leftover)) {
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| 250 | // We've got enough leftover to make a new free block.
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| 251 |
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| 252 | /* create the new free block */
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| 253 | pmbNewFree = (PMEMBLOCK) ((char __near *) pmb + HDR_SIZE + ulRequest );
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| 254 | pmbNewFree->ulSignature = SIGNATURE;
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| 255 | pmbNewFree->ulSize = pmb->ulSize - (ulRequest + HDR_SIZE);
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| 256 | pmbNewFree->pmbNext = pmb->pmbNext;
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| 257 |
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| 258 | // Update the size of the original free block that was passed in.
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| 259 | pmb->ulSize -= (pmbNewFree->ulSize + HDR_SIZE);
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| 260 | }
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| 261 |
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| 262 | // Update global memory counter.
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| 263 | uMemFree -= (pmb->ulSize + HDR_SIZE);
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| 264 |
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| 265 | // Add this block into the front of the Allocated list.
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| 266 | pmbOldNext = pmb->pmbNext;
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| 267 | pmb->pmbNext = pmbUsed;
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| 268 | pmbUsed = pmb;
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| 269 |
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| 270 | // Remove the new allocation from the Free list.
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| 271 | if (pmbNewFree) { // If we split off a new free block
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| 272 | pmbNewFree->pmbNext = pmbOldNext; // If we're not at head of Free list
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| 273 | if (pmbPrev) pmbPrev->pmbNext = pmbNewFree;
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| 274 | else pmbFree = pmbNewFree;
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| 275 | } else { // We allocated the entire free block.
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| 276 | if (pmbPrev) pmbPrev->pmbNext = pmbOldNext; // If we're not at head of Free list
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| 277 | else pmbFree = pmbOldNext;
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| 278 | }
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| 279 |
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| 280 | return (void NEAR *) pmb->achBlock;
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| 281 | }
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| 282 |
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| 283 |
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| 284 | /* malloc()
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| 285 | This function searches the list of free blocks until it finds one big enough
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| 286 | to hold the amount of memory requested, which is passed in uSize. The uSize
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| 287 | request is sized up for:
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| 288 | - a memory block header
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| 289 | - four byte alignment
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| 290 | - minimum fragmentation
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| 291 |
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| 292 | See helper function make_new_free() for discussion of fragmentation handling.
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| 293 | */
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| 294 |
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| 295 | #ifdef DEBUGHEAP
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| 296 | void NEAR *malloc(ULONG ulSize, const char *filename, int lineno)
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| 297 | #else
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| 298 | void NEAR *malloc( ULONG ulSize )
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| 299 | #endif
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| 300 | {
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| 301 | ULONG ulRequest; // Request size after alignment.
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| 302 | PMEMBLOCK pmb, pmbPrev; // Use to walk free lists.
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| 303 | void NEAR *npvReturn; // Return value.
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| 304 | ULONG ulCpuFlags;
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| 305 |
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| 306 | //dprintf(("malloc(). size: %d", ulSize));
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| 307 | if(acHeap == NULL) return 0;
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| 308 | if (!ulSize || ulSize > HEAP_SIZE) {
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| 309 | DebugInt3();
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| 310 | return 0;
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| 311 | }
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| 312 |
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| 313 | ulCpuFlags = DevPushfCli();
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| 314 | npvReturn = 0;
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| 315 | ++ulnAllocCalls; // Diagnostics.
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| 316 | HeapCheck((PSZ) "malloc() entry" );
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| 317 |
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| 318 | ulRequest = (ulSize + 3) & -4; // Force DWORD alignment.
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| 319 |
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| 320 | for (pmbPrev=NULL, pmb=pmbFree; pmb; pmbPrev=pmb, pmb=pmb->pmbNext) {
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| 321 | if (pmb->ulSize >= ulRequest) {
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| 322 | npvReturn = npvAllocateBlock(pmb, ulRequest, pmbPrev);
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| 323 | break;
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| 324 | }
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| 325 | }
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| 326 |
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| 327 | if (npvReturn) {
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| 328 | #ifdef DEBUGHEAP
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| 329 | PMEMBLOCK pBlock = (PMEMBLOCK) (((PUCHAR) npvReturn) - HDR_SIZE);
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| 330 |
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| 331 | pBlock->pszFile = (char *)filename;
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| 332 | pBlock->ulLine = lineno;
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| 333 | #endif
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| 334 | SignatureCheck( (PMEMBLOCK) (((PUCHAR) npvReturn) - HDR_SIZE), (PSZ) "malloc() exit, allocated block" );
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| 335 | } else {
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| 336 | dprintf(("malloc(): out of memory"));
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| 337 | DebugInt3();
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| 338 | }
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| 339 |
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| 340 | HeapCheck((PSZ) "malloc() exit" );
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| 341 | DevPopf(ulCpuFlags);
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| 342 | return npvReturn;
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| 343 | }
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| 344 |
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| 345 | /* void compact(void)
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| 346 | This function compacts the free blocks together. This function is a
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| 347 | companion to free(), and thus the algorithm is tailored to how free()
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| 348 | works. Change the algorithm in free(), and you'll have to change this
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| 349 | function too.
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| 350 |
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| 351 | When free() frees a block, it sets the head of the free list, pmbFree, to
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| 352 | point to it. Then the newly freed block points to whatever the old pmbFree
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| 353 | pointed to. In other words, each new free block is added to the head of
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| 354 | the free list.
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| 355 |
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| 356 | If compact() is always called after a block is freed, then it can be
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| 357 | guaranteed that the free list is always compacted (i.e. you won't find
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| 358 | two adjacent free blocks anywhere in the heap) _before_ each call to free().
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| 359 | Therefore, the newly freed block can be located in only one of the
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| 360 | following positions:
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| 361 | 1. Not adjacent to any other free blocks (compacting not necessary)
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| 362 | 2. Physically before another free block
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| 363 | 3. Physically after another free block
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| 364 | 4. Between two free blocks (i.e. the block occupies the entire space
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| 365 | between two free blocks)
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| 366 |
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| 367 | Since the newly freed block is the first in the free list, compact()
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| 368 | starts with the second block in the list (i.e. pmbFree->pmbNext).
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| 369 | Each free block is then compared with the newly freed block for
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| 370 | adjacency. If a given block is located before the new block, then it
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| 371 | can't possibly be also located after, and vice versa. Hence, the
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| 372 | "else if" statement in the middle of the loop.
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| 373 |
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| 374 | Also, the newly freed block can only be adjacent to at most two other
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| 375 | blocks. Therefore, the operation of combining two adjacent free blocks can
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| 376 | only happen at most twice. The variable ulnFreed counts the number of times
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| 377 | two blocks are combined. The function exits if ulnFreed reaches two. ulnFreed
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| 378 | is initially 0.
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| 379 |
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| 380 | Helper macro after() takes a PMEMBLOCK (call it pmb) as a parameter,
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| 381 | and calculates where an adjacent free block would exist if it were
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| 382 | physically located after pmb.
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| 383 |
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| 384 | Helper function h_remove() removes an element from the free list.
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| 385 | */
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| 386 |
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| 387 | #define after(pmb) ((PMEMBLOCK) ((char *) pmb + pmb->ulSize + HDR_SIZE))
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| 388 |
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| 389 | void h_remove(PMEMBLOCK pmb)
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| 390 | {
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| 391 | PMEMBLOCK pmbPrev;
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| 392 |
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| 393 | if (pmb == pmbFree)
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| 394 | {
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| 395 | pmbFree = pmbFree->pmbNext;
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| 396 | return;
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| 397 | }
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| 398 |
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| 399 | for (pmbPrev=pmbFree; pmbPrev; pmbPrev=pmbPrev->pmbNext)
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| 400 | {
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| 401 | if (pmbPrev->pmbNext == pmb)
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| 402 | {
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| 403 | pmbPrev->pmbNext = pmb->pmbNext;
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| 404 | return;
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| 405 | }
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| 406 | }
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| 407 | }
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| 408 |
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| 409 | //*****************************************************************************
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| 410 | void compact(void)
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| 411 | {
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| 412 | PMEMBLOCK pmb;
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| 413 | SHORT sFreed;
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| 414 |
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| 415 | sFreed = 0;
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| 416 | for (pmb=pmbFree->pmbNext; pmb; pmb=pmb->pmbNext) {
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| 417 | if (after(pmb) == pmbFree) {
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| 418 | // dprintf(("HEAP: compact found pointer %p (size=%ui) before pmbFree %p\n", (void __far *) pmb, pmb->uSize, (void __far *) pmbFree));
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| 419 | pmb->ulSize += HDR_SIZE + pmbFree->ulSize;
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| 420 | h_remove(pmbFree);
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| 421 | if (++sFreed == 2) break;
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| 422 | } else if (after(pmbFree) == pmb) {
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| 423 | // dprintf(("HEAP: compact found pointer %p (size=%ui) after pmbFree %p\n", (void __far *) pmb, pmb->uSize, (void __far *) pmbFree);
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| 424 | pmbFree->ulSize += HDR_SIZE + pmb->ulSize;
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| 425 | h_remove(pmb);
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| 426 | if (++sFreed == 2) break;
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| 427 | }
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| 428 | }
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| 429 |
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| 430 | ulnCompact += sFreed;
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| 431 | }
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| 432 | //*****************************************************************************
|
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| 433 | //*****************************************************************************
|
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| 434 | #ifdef DEBUGHEAP
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| 435 | void free(void NEAR *pvBlock, const char *filename, int lineno)
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| 436 | #else
|
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| 437 | void free(void NEAR *pvBlock)
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| 438 | #endif
|
|---|
| 439 | {
|
|---|
| 440 | PMEMBLOCK pmb,pmbPrev,pmbBlock;
|
|---|
| 441 | ULONG ulCpuFlags;
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| 442 |
|
|---|
| 443 | if(acHeap == NULL) {
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| 444 | DebugInt3();
|
|---|
| 445 | return;
|
|---|
| 446 | }
|
|---|
| 447 |
|
|---|
| 448 | ++ulnFreeCalls;
|
|---|
| 449 | if (!pvBlock) return; // support freeing of NULL
|
|---|
| 450 |
|
|---|
| 451 | ulCpuFlags = DevPushfCli();
|
|---|
| 452 | pmbBlock=(PMEMBLOCK) ((char NEAR *) pvBlock - HDR_SIZE);
|
|---|
| 453 |
|
|---|
| 454 | SignatureCheck( pmbBlock,(PSZ) "free() entry, Block to be freed" );
|
|---|
| 455 | HeapCheck((PSZ) "free() entry" );
|
|---|
| 456 |
|
|---|
| 457 | uMemFree += pmbBlock->ulSize + HDR_SIZE;
|
|---|
| 458 |
|
|---|
| 459 | /* find the block on the used chain */
|
|---|
| 460 | for (pmbPrev=NULL, pmb=pmbUsed; pmb; pmbPrev=pmb, pmb=pmb->pmbNext) {
|
|---|
| 461 | if (pmb == pmbBlock) { /* found the block */
|
|---|
| 462 | if (pmbPrev) { /* it is in the middle of the chain */
|
|---|
| 463 | pmbPrev->pmbNext = pmb->pmbNext; /* delete this block from the chain */
|
|---|
| 464 | } else { /* it is the first block on the used list */
|
|---|
| 465 | pmbUsed = pmbUsed->pmbNext; // the 2nd block is now the head
|
|---|
| 466 | }
|
|---|
| 467 | pmbBlock->pmbNext = pmbFree; /* This block is now free, so it points to the first free block */
|
|---|
| 468 | pmbFree = pmbBlock; /* This is now the first free block */
|
|---|
| 469 | break;
|
|---|
| 470 | }
|
|---|
| 471 | }
|
|---|
| 472 | if (pmb == 0) {
|
|---|
| 473 | dprintf(("free: block not found %x\n", pmb));
|
|---|
| 474 | DebugInt3();
|
|---|
| 475 | }
|
|---|
| 476 | compact();
|
|---|
| 477 |
|
|---|
| 478 | HeapCheck((PSZ) "free() exit" );
|
|---|
| 479 | DevPopf(ulCpuFlags);
|
|---|
| 480 | }
|
|---|
| 481 | //*****************************************************************************
|
|---|
| 482 | //*****************************************************************************
|
|---|
| 483 | unsigned _memfree(void)
|
|---|
| 484 | {
|
|---|
| 485 | return uMemFree;
|
|---|
| 486 | }
|
|---|
| 487 | //*****************************************************************************
|
|---|
| 488 | //*****************************************************************************
|
|---|
| 489 | /**@internal _msize
|
|---|
| 490 | */
|
|---|
| 491 | unsigned _msize(void NEAR *pvBlock)
|
|---|
| 492 | {
|
|---|
| 493 | PMEMBLOCK pmb;
|
|---|
| 494 |
|
|---|
| 495 | if (!pvBlock)
|
|---|
| 496 | return 0;
|
|---|
| 497 |
|
|---|
| 498 | pmb = (PMEMBLOCK) ((char NEAR *) pvBlock - HDR_SIZE);
|
|---|
| 499 |
|
|---|
| 500 | return pmb->ulSize;
|
|---|
| 501 | }
|
|---|
| 502 |
|
|---|
| 503 |
|
|---|
| 504 | #ifdef DEBUGHEAP
|
|---|
| 505 | void NEAR *realloc(void NEAR *pvBlock, ULONG ulLength, const char *filename, int lineno)
|
|---|
| 506 | #else
|
|---|
| 507 | void NEAR *realloc(void NEAR *pvBlock, ULONG ulLength)
|
|---|
| 508 | #endif
|
|---|
| 509 | {
|
|---|
| 510 | void NEAR *pv;
|
|---|
| 511 |
|
|---|
| 512 | if (!pvBlock) // if ptr is null, alloc block
|
|---|
| 513 | #ifdef DEBUGHEAP
|
|---|
| 514 | return malloc(ulLength, filename, lineno);
|
|---|
| 515 | #else
|
|---|
| 516 | return malloc(ulLength);
|
|---|
| 517 | #endif
|
|---|
| 518 |
|
|---|
| 519 | if (!ulLength) { // if length is 0, free block
|
|---|
| 520 | #ifdef DEBUGHEAP
|
|---|
| 521 | free(pvBlock, filename, lineno);
|
|---|
| 522 | #else
|
|---|
| 523 | free(pvBlock);
|
|---|
| 524 | #endif
|
|---|
| 525 | return 0;
|
|---|
| 526 | }
|
|---|
| 527 |
|
|---|
| 528 | #ifdef DEBUGHEAP
|
|---|
| 529 | pv = malloc(ulLength, filename, lineno); // attempt to allocate the new block
|
|---|
| 530 | #else
|
|---|
| 531 | pv = malloc(ulLength); // attempt to allocate the new block
|
|---|
| 532 | #endif
|
|---|
| 533 | if (!pv) // can't do it?
|
|---|
| 534 | return 0; // just fail. Version 2 will try harder
|
|---|
| 535 |
|
|---|
| 536 | memcpy(pv, pvBlock, min( _msize(pvBlock), ulLength));
|
|---|
| 537 |
|
|---|
| 538 | #ifdef DEBUGHEAP
|
|---|
| 539 | free(pvBlock, filename, lineno);
|
|---|
| 540 | #else
|
|---|
| 541 | free(pvBlock);
|
|---|
| 542 | #endif
|
|---|
| 543 | return pv;
|
|---|
| 544 | }
|
|---|
| 545 | //*****************************************************************************
|
|---|
| 546 | //*****************************************************************************
|
|---|
| 547 | BOOL IsHeapAddr(ULONG addr)
|
|---|
| 548 | {
|
|---|
| 549 | int bGoodPointer;
|
|---|
| 550 |
|
|---|
| 551 | bGoodPointer = ((LINEAR)addr >= acHeap)
|
|---|
| 552 | && ((LINEAR)addr <= (acHeap + HEAP_SIZE)) ;
|
|---|
| 553 |
|
|---|
| 554 | return bGoodPointer;
|
|---|
| 555 | }
|
|---|
| 556 | //*****************************************************************************
|
|---|
| 557 | extern APIRET VMAlloc(ULONG size, ULONG flags, LINEAR *pAddr) ;
|
|---|
| 558 | //*****************************************************************************
|
|---|
| 559 | ULONG HeapInit(ULONG ulSize)
|
|---|
| 560 | {
|
|---|
| 561 | LINEAR addr;
|
|---|
| 562 | SHORT sel;
|
|---|
| 563 |
|
|---|
| 564 | if (!ulSize) ulSize = DEFAULT_HEAP;
|
|---|
| 565 |
|
|---|
| 566 | if (ulSize > HEAP_SIZE) ulSize = HEAP_SIZE;
|
|---|
| 567 |
|
|---|
| 568 | if(VMAlloc(ulSize, VMDHA_FIXED, &addr)) {
|
|---|
| 569 | DebugInt3();
|
|---|
| 570 | return 0;
|
|---|
| 571 | }
|
|---|
| 572 | acHeap = addr;
|
|---|
| 573 | //dprintf(("HeapInit(): addr: %x", acHeap));
|
|---|
| 574 |
|
|---|
| 575 | pmbFree = (PMEMBLOCK) acHeap;
|
|---|
| 576 | pmbFree->ulSize = ulSize - HDR_SIZE;
|
|---|
| 577 | pmbFree->ulSignature = SIGNATURE;
|
|---|
| 578 | pmbFree->pmbNext = 0;
|
|---|
| 579 | uMemFree = pmbFree->ulSize;
|
|---|
| 580 | return pmbFree->ulSize;
|
|---|
| 581 | }
|
|---|
| 582 | //*****************************************************************************
|
|---|
| 583 | //*****************************************************************************
|
|---|
