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+/* vmem.h
+ *
+ * (c) 1999 Microsoft Corporation. All rights reserved.
+ * Portions (c) 1999 ActiveState Tool Corp, http://www.ActiveState.com/
+ *
+ * You may distribute under the terms of either the GNU General Public
+ * License or the Artistic License, as specified in the README file.
+ *
+ * Options:
+ *
+ * Defining _USE_MSVCRT_MEM_ALLOC will cause all memory allocations
+ * to be forwarded to MSVCRT.DLL. Defining _USE_LINKED_LIST as well will
+ * track all allocations in a doubly linked list, so that the host can
+ * free all memory allocated when it goes away.
+ * If _USE_MSVCRT_MEM_ALLOC is not defined then Knuth's boundary tag algorithm
+ * is used; defining _USE_BUDDY_BLOCKS will use Knuth's algorithm R
+ * (Buddy system reservation)
+ *
+ */
+
+#ifndef ___VMEM_H_INC___
+#define ___VMEM_H_INC___
+
+#ifndef UNDER_CE
+#define _USE_MSVCRT_MEM_ALLOC
+#endif
+#define _USE_LINKED_LIST
+
+// #define _USE_BUDDY_BLOCKS
+
+// #define _DEBUG_MEM
+#ifdef _DEBUG_MEM
+#define ASSERT(f) if(!(f)) DebugBreak();
+
+inline void MEMODS(char *str)
+{
+ OutputDebugString(str);
+ OutputDebugString("\n");
+}
+
+inline void MEMODSlx(char *str, long x)
+{
+ char szBuffer[512];
+ sprintf(szBuffer, "%s %lx\n", str, x);
+ OutputDebugString(szBuffer);
+}
+
+#define WALKHEAP() WalkHeap(0)
+#define WALKHEAPTRACE() WalkHeap(1)
+
+#else
+
+#define ASSERT(f)
+#define MEMODS(x)
+#define MEMODSlx(x, y)
+#define WALKHEAP()
+#define WALKHEAPTRACE()
+
+#endif
+
+#ifdef _USE_MSVCRT_MEM_ALLOC
+
+#ifndef _USE_LINKED_LIST
+// #define _USE_LINKED_LIST
+#endif
+
+/*
+ * Pass all memory requests throught to msvcrt.dll
+ * optionaly track by using a doubly linked header
+ */
+
+typedef void (*LPFREE)(void *block);
+typedef void* (*LPMALLOC)(size_t size);
+typedef void* (*LPREALLOC)(void *block, size_t size);
+#ifdef _USE_LINKED_LIST
+class VMem;
+typedef struct _MemoryBlockHeader* PMEMORY_BLOCK_HEADER;
+typedef struct _MemoryBlockHeader {
+ PMEMORY_BLOCK_HEADER pNext;
+ PMEMORY_BLOCK_HEADER pPrev;
+ VMem *owner;
+} MEMORY_BLOCK_HEADER, *PMEMORY_BLOCK_HEADER;
+#endif
+
+class VMem
+{
+public:
+ VMem();
+ ~VMem();
+ virtual void* Malloc(size_t size);
+ virtual void* Realloc(void* pMem, size_t size);
+ virtual void Free(void* pMem);
+ virtual void GetLock(void);
+ virtual void FreeLock(void);
+ virtual int IsLocked(void);
+ virtual long Release(void);
+ virtual long AddRef(void);
+
+ inline BOOL CreateOk(void)
+ {
+ return TRUE;
+ };
+
+protected:
+#ifdef _USE_LINKED_LIST
+ void LinkBlock(PMEMORY_BLOCK_HEADER ptr)
+ {
+ PMEMORY_BLOCK_HEADER next = m_Dummy.pNext;
+ m_Dummy.pNext = ptr;
+ ptr->pPrev = &m_Dummy;
+ ptr->pNext = next;
+ ptr->owner = this;
+ next->pPrev = ptr;
+ }
+ void UnlinkBlock(PMEMORY_BLOCK_HEADER ptr)
+ {
+ PMEMORY_BLOCK_HEADER next = ptr->pNext;
+ PMEMORY_BLOCK_HEADER prev = ptr->pPrev;
+ prev->pNext = next;
+ next->pPrev = prev;
+ }
+
+ MEMORY_BLOCK_HEADER m_Dummy;
+#endif
+
+ long m_lRefCount; // number of current users
+ CRITICAL_SECTION m_cs; // access lock
+ HINSTANCE m_hLib;
+ LPFREE m_pfree;
+ LPMALLOC m_pmalloc;
+ LPREALLOC m_prealloc;
+};
+
+VMem::VMem()
+{
+ m_lRefCount = 1;
+ InitializeCriticalSection(&m_cs);
+#ifdef _USE_LINKED_LIST
+ m_Dummy.pNext = m_Dummy.pPrev = &m_Dummy;
+ m_Dummy.owner = this;
+#endif
+ m_hLib = LoadLibrary("msvcrt.dll");
+ if (m_hLib) {
+ m_pfree = (LPFREE)GetProcAddress(m_hLib, "free");
+ m_pmalloc = (LPMALLOC)GetProcAddress(m_hLib, "malloc");
+ m_prealloc = (LPREALLOC)GetProcAddress(m_hLib, "realloc");
+ }
+}
+
+VMem::~VMem(void)
+{
+#ifdef _USE_LINKED_LIST
+ while (m_Dummy.pNext != &m_Dummy) {
+ Free(m_Dummy.pNext+1);
+ }
+#endif
+ if (m_hLib)
+ FreeLibrary(m_hLib);
+ DeleteCriticalSection(&m_cs);
+}
+
+void* VMem::Malloc(size_t size)
+{
+#ifdef _USE_LINKED_LIST
+ GetLock();
+ PMEMORY_BLOCK_HEADER ptr = (PMEMORY_BLOCK_HEADER)m_pmalloc(size+sizeof(MEMORY_BLOCK_HEADER));
+ if (!ptr) {
+ FreeLock();
+ return NULL;
+ }
+ LinkBlock(ptr);
+ FreeLock();
+ return (ptr+1);
+#else
+ return m_pmalloc(size);
+#endif
+}
+
+void* VMem::Realloc(void* pMem, size_t size)
+{
+#ifdef _USE_LINKED_LIST
+ if (!pMem)
+ return Malloc(size);
+
+ if (!size) {
+ Free(pMem);
+ return NULL;
+ }
+
+ GetLock();
+ PMEMORY_BLOCK_HEADER ptr = (PMEMORY_BLOCK_HEADER)(((char*)pMem)-sizeof(MEMORY_BLOCK_HEADER));
+ UnlinkBlock(ptr);
+ ptr = (PMEMORY_BLOCK_HEADER)m_prealloc(ptr, size+sizeof(MEMORY_BLOCK_HEADER));
+ if (!ptr) {
+ FreeLock();
+ return NULL;
+ }
+ LinkBlock(ptr);
+ FreeLock();
+
+ return (ptr+1);
+#else
+ return m_prealloc(pMem, size);
+#endif
+}
+
+void VMem::Free(void* pMem)
+{
+#ifdef _USE_LINKED_LIST
+ if (pMem) {
+ PMEMORY_BLOCK_HEADER ptr = (PMEMORY_BLOCK_HEADER)(((char*)pMem)-sizeof(MEMORY_BLOCK_HEADER));
+ if (ptr->owner != this) {
+ if (ptr->owner) {
+#if 1
+ dTHX;
+ int *nowhere = NULL;
+ Perl_warn(aTHX_ "Free to wrong pool %p not %p",this,ptr->owner);
+ *nowhere = 0; /* this segfault is deliberate,
+ so you can see the stack trace */
+#else
+ ptr->owner->Free(pMem);
+#endif
+ }
+ return;
+ }
+ GetLock();
+ UnlinkBlock(ptr);
+ ptr->owner = NULL;
+ m_pfree(ptr);
+ FreeLock();
+ }
+#else
+ m_pfree(pMem);
+#endif
+}
+
+void VMem::GetLock(void)
+{
+ EnterCriticalSection(&m_cs);
+}
+
+void VMem::FreeLock(void)
+{
+ LeaveCriticalSection(&m_cs);
+}
+
+int VMem::IsLocked(void)
+{
+#if 0
+ /* XXX TryEnterCriticalSection() is not available in some versions
+ * of Windows 95. Since this code is not used anywhere yet, we
+ * skirt the issue for now. */
+ BOOL bAccessed = TryEnterCriticalSection(&m_cs);
+ if(bAccessed) {
+ LeaveCriticalSection(&m_cs);
+ }
+ return !bAccessed;
+#else
+ ASSERT(0); /* alarm bells for when somebody calls this */
+ return 0;
+#endif
+}
+
+long VMem::Release(void)
+{
+ long lCount = InterlockedDecrement(&m_lRefCount);
+ if(!lCount)
+ delete this;
+ return lCount;
+}
+
+long VMem::AddRef(void)
+{
+ long lCount = InterlockedIncrement(&m_lRefCount);
+ return lCount;
+}
+
+#else /* _USE_MSVCRT_MEM_ALLOC */
+
+/*
+ * Knuth's boundary tag algorithm Vol #1, Page 440.
+ *
+ * Each block in the heap has tag words before and after it,
+ * TAG
+ * block
+ * TAG
+ * The size is stored in these tags as a long word, and includes the 8 bytes
+ * of overhead that the boundary tags consume. Blocks are allocated on long
+ * word boundaries, so the size is always multiples of long words. When the
+ * block is allocated, bit 0, (the tag bit), of the size is set to 1. When
+ * a block is freed, it is merged with adjacent free blocks, and the tag bit
+ * is set to 0.
+ *
+ * A linked list is used to manage the free list. The first two long words of
+ * the block contain double links. These links are only valid when the block
+ * is freed, therefore space needs to be reserved for them. Thus, the minimum
+ * block size (not counting the tags) is 8 bytes.
+ *
+ * Since memory allocation may occur on a single threaded, explict locks are not
+ * provided.
+ *
+ */
+
+const long lAllocStart = 0x00020000; /* start at 128K */
+const long minBlockSize = sizeof(void*)*2;
+const long sizeofTag = sizeof(long);
+const long blockOverhead = sizeofTag*2;
+const long minAllocSize = minBlockSize+blockOverhead;
+#ifdef _USE_BUDDY_BLOCKS
+const long lSmallBlockSize = 1024;
+const size_t nListEntries = ((lSmallBlockSize-minAllocSize)/sizeof(long));
+
+inline size_t CalcEntry(size_t size)
+{
+ ASSERT((size&(sizeof(long)-1)) == 0);
+ return ((size - minAllocSize) / sizeof(long));
+}
+#endif
+
+typedef BYTE* PBLOCK; /* pointer to a memory block */
+
+/*
+ * Macros for accessing hidden fields in a memory block:
+ *
+ * SIZE size of this block (tag bit 0 is 1 if block is allocated)
+ * PSIZE size of previous physical block
+ */
+
+#define SIZE(block) (*(ULONG*)(((PBLOCK)(block))-sizeofTag))
+#define PSIZE(block) (*(ULONG*)(((PBLOCK)(block))-(blockOverhead)))
+inline void SetTags(PBLOCK block, long size)
+{
+ SIZE(block) = size;
+ PSIZE(block+(size&~1)) = size;
+}
+
+/*
+ * Free list pointers
+ * PREV pointer to previous block
+ * NEXT pointer to next block
+ */
+
+#define PREV(block) (*(PBLOCK*)(block))
+#define NEXT(block) (*(PBLOCK*)((block)+sizeof(PBLOCK)))
+inline void SetLink(PBLOCK block, PBLOCK prev, PBLOCK next)
+{
+ PREV(block) = prev;
+ NEXT(block) = next;
+}
+inline void Unlink(PBLOCK p)
+{
+ PBLOCK next = NEXT(p);
+ PBLOCK prev = PREV(p);
+ NEXT(prev) = next;
+ PREV(next) = prev;
+}
+#ifndef _USE_BUDDY_BLOCKS
+inline void AddToFreeList(PBLOCK block, PBLOCK pInList)
+{
+ PBLOCK next = NEXT(pInList);
+ NEXT(pInList) = block;
+ SetLink(block, pInList, next);
+ PREV(next) = block;
+}
+#endif
+
+/* Macro for rounding up to the next sizeof(long) */
+#define ROUND_UP(n) (((ULONG)(n)+sizeof(long)-1)&~(sizeof(long)-1))
+#define ROUND_UP64K(n) (((ULONG)(n)+0x10000-1)&~(0x10000-1))
+#define ROUND_DOWN(n) ((ULONG)(n)&~(sizeof(long)-1))
+
+/*
+ * HeapRec - a list of all non-contiguous heap areas
+ *
+ * Each record in this array contains information about a non-contiguous heap area.
+ */
+
+const int maxHeaps = 32; /* 64 was overkill */
+const long lAllocMax = 0x80000000; /* max size of allocation */
+
+#ifdef _USE_BUDDY_BLOCKS
+typedef struct _FreeListEntry
+{
+ BYTE Dummy[minAllocSize]; // dummy free block
+} FREE_LIST_ENTRY, *PFREE_LIST_ENTRY;
+#endif
+
+#ifndef _USE_BUDDY_BLOCKS
+#define USE_BIGBLOCK_ALLOC
+#endif
+/*
+ * performance tuning
+ * Use VirtualAlloc() for blocks bigger than nMaxHeapAllocSize since
+ * Windows 95/98/Me have heap managers that are designed for memory
+ * blocks smaller than four megabytes.
+ */
+
+#ifdef USE_BIGBLOCK_ALLOC
+const int nMaxHeapAllocSize = (1024*512); /* don't allocate anything larger than this from the heap */
+#endif
+
+typedef struct _HeapRec
+{
+ PBLOCK base; /* base of heap area */
+ ULONG len; /* size of heap area */
+#ifdef USE_BIGBLOCK_ALLOC
+ BOOL bBigBlock; /* was allocate using VirtualAlloc */
+#endif
+} HeapRec;
+
+class VMem
+{
+public:
+ VMem();
+ ~VMem();
+ virtual void* Malloc(size_t size);
+ virtual void* Realloc(void* pMem, size_t size);
+ virtual void Free(void* pMem);
+ virtual void GetLock(void);
+ virtual void FreeLock(void);
+ virtual int IsLocked(void);
+ virtual long Release(void);
+ virtual long AddRef(void);
+
+ inline BOOL CreateOk(void)
+ {
+#ifdef _USE_BUDDY_BLOCKS
+ return TRUE;
+#else
+ return m_hHeap != NULL;
+#endif
+ };
+
+ void ReInit(void);
+
+protected:
+ void Init(void);
+ int Getmem(size_t size);
+
+ int HeapAdd(void* ptr, size_t size
+#ifdef USE_BIGBLOCK_ALLOC
+ , BOOL bBigBlock
+#endif
+ );
+
+ void* Expand(void* block, size_t size);
+
+#ifdef _USE_BUDDY_BLOCKS
+ inline PBLOCK GetFreeListLink(int index)
+ {
+ if (index >= nListEntries)
+ index = nListEntries-1;
+ return &m_FreeList[index].Dummy[sizeofTag];
+ }
+ inline PBLOCK GetOverSizeFreeList(void)
+ {
+ return &m_FreeList[nListEntries-1].Dummy[sizeofTag];
+ }
+ inline PBLOCK GetEOLFreeList(void)
+ {
+ return &m_FreeList[nListEntries].Dummy[sizeofTag];
+ }
+
+ void AddToFreeList(PBLOCK block, size_t size)
+ {
+ PBLOCK pFreeList = GetFreeListLink(CalcEntry(size));
+ PBLOCK next = NEXT(pFreeList);
+ NEXT(pFreeList) = block;
+ SetLink(block, pFreeList, next);
+ PREV(next) = block;
+ }
+#endif
+ inline size_t CalcAllocSize(size_t size)
+ {
+ /*
+ * Adjust the real size of the block to be a multiple of sizeof(long), and add
+ * the overhead for the boundary tags. Disallow negative or zero sizes.
+ */
+ return (size < minBlockSize) ? minAllocSize : (size_t)ROUND_UP(size) + blockOverhead;
+ }
+
+#ifdef _USE_BUDDY_BLOCKS
+ FREE_LIST_ENTRY m_FreeList[nListEntries+1]; // free list with dummy end of list entry as well
+#else
+ HANDLE m_hHeap; // memory heap for this script
+ char m_FreeDummy[minAllocSize]; // dummy free block
+ PBLOCK m_pFreeList; // pointer to first block on free list
+#endif
+ PBLOCK m_pRover; // roving pointer into the free list
+ HeapRec m_heaps[maxHeaps]; // list of all non-contiguous heap areas
+ int m_nHeaps; // no. of heaps in m_heaps
+ long m_lAllocSize; // current alloc size
+ long m_lRefCount; // number of current users
+ CRITICAL_SECTION m_cs; // access lock
+
+#ifdef _DEBUG_MEM
+ void WalkHeap(int complete);
+ void MemoryUsageMessage(char *str, long x, long y, int c);
+ FILE* m_pLog;
+#endif
+};
+
+VMem::VMem()
+{
+ m_lRefCount = 1;
+#ifndef _USE_BUDDY_BLOCKS
+ BOOL bRet = (NULL != (m_hHeap = HeapCreate(HEAP_NO_SERIALIZE,
+ lAllocStart, /* initial size of heap */
+ 0))); /* no upper limit on size of heap */
+ ASSERT(bRet);
+#endif
+
+ InitializeCriticalSection(&m_cs);
+#ifdef _DEBUG_MEM
+ m_pLog = 0;
+#endif
+
+ Init();
+}
+
+VMem::~VMem(void)
+{
+#ifndef _USE_BUDDY_BLOCKS
+ ASSERT(HeapValidate(m_hHeap, HEAP_NO_SERIALIZE, NULL));
+#endif
+ WALKHEAPTRACE();
+
+ DeleteCriticalSection(&m_cs);
+#ifdef _USE_BUDDY_BLOCKS
+ for(int index = 0; index < m_nHeaps; ++index) {
+ VirtualFree(m_heaps[index].base, 0, MEM_RELEASE);
+ }
+#else /* !_USE_BUDDY_BLOCKS */
+#ifdef USE_BIGBLOCK_ALLOC
+ for(int index = 0; index < m_nHeaps; ++index) {
+ if (m_heaps[index].bBigBlock) {
+ VirtualFree(m_heaps[index].base, 0, MEM_RELEASE);
+ }
+ }
+#endif
+ BOOL bRet = HeapDestroy(m_hHeap);
+ ASSERT(bRet);
+#endif /* _USE_BUDDY_BLOCKS */
+}
+
+void VMem::ReInit(void)
+{
+ for(int index = 0; index < m_nHeaps; ++index) {
+#ifdef _USE_BUDDY_BLOCKS
+ VirtualFree(m_heaps[index].base, 0, MEM_RELEASE);
+#else
+#ifdef USE_BIGBLOCK_ALLOC
+ if (m_heaps[index].bBigBlock) {
+ VirtualFree(m_heaps[index].base, 0, MEM_RELEASE);
+ }
+ else
+#endif
+ HeapFree(m_hHeap, HEAP_NO_SERIALIZE, m_heaps[index].base);
+#endif /* _USE_BUDDY_BLOCKS */
+ }
+
+ Init();
+}
+
+void VMem::Init(void)
+{
+#ifdef _USE_BUDDY_BLOCKS
+ PBLOCK pFreeList;
+ /*
+ * Initialize the free list by placing a dummy zero-length block on it.
+ * Set the end of list marker.
+ * Set the number of non-contiguous heaps to zero.
+ * Set the next allocation size.
+ */
+ for (int index = 0; index < nListEntries; ++index) {
+ pFreeList = GetFreeListLink(index);
+ SIZE(pFreeList) = PSIZE(pFreeList+minAllocSize) = 0;
+ PREV(pFreeList) = NEXT(pFreeList) = pFreeList;
+ }
+ pFreeList = GetEOLFreeList();
+ SIZE(pFreeList) = PSIZE(pFreeList+minAllocSize) = 0;
+ PREV(pFreeList) = NEXT(pFreeList) = NULL;
+ m_pRover = GetOverSizeFreeList();
+#else
+ /*
+ * Initialize the free list by placing a dummy zero-length block on it.
+ * Set the number of non-contiguous heaps to zero.
+ */
+ m_pFreeList = m_pRover = (PBLOCK)(&m_FreeDummy[sizeofTag]);
+ PSIZE(m_pFreeList+minAllocSize) = SIZE(m_pFreeList) = 0;
+ PREV(m_pFreeList) = NEXT(m_pFreeList) = m_pFreeList;
+#endif
+
+ m_nHeaps = 0;
+ m_lAllocSize = lAllocStart;
+}
+
+void* VMem::Malloc(size_t size)
+{
+ WALKHEAP();
+
+ PBLOCK ptr;
+ size_t lsize, rem;
+ /*
+ * Disallow negative or zero sizes.
+ */
+ size_t realsize = CalcAllocSize(size);
+ if((int)realsize < minAllocSize || size == 0)
+ return NULL;
+
+#ifdef _USE_BUDDY_BLOCKS
+ /*
+ * Check the free list of small blocks if this is free use it
+ * Otherwise check the rover if it has no blocks then
+ * Scan the free list entries use the first free block
+ * split the block if needed, stop at end of list marker
+ */
+ {
+ int index = CalcEntry(realsize);
+ if (index < nListEntries-1) {
+ ptr = GetFreeListLink(index);
+ lsize = SIZE(ptr);
+ if (lsize >= realsize) {
+ rem = lsize - realsize;
+ if(rem < minAllocSize) {
+ /* Unlink the block from the free list. */
+ Unlink(ptr);
+ }
+ else {
+ /*
+ * split the block
+ * The remainder is big enough to split off into a new block.
+ * Use the end of the block, resize the beginning of the block
+ * no need to change the free list.
+ */
+ SetTags(ptr, rem);
+ ptr += SIZE(ptr);
+ lsize = realsize;
+ }
+ SetTags(ptr, lsize | 1);
+ return ptr;
+ }
+ ptr = m_pRover;
+ lsize = SIZE(ptr);
+ if (lsize >= realsize) {
+ rem = lsize - realsize;
+ if(rem < minAllocSize) {
+ /* Unlink the block from the free list. */
+ Unlink(ptr);
+ }
+ else {
+ /*
+ * split the block
+ * The remainder is big enough to split off into a new block.
+ * Use the end of the block, resize the beginning of the block
+ * no need to change the free list.
+ */
+ SetTags(ptr, rem);
+ ptr += SIZE(ptr);
+ lsize = realsize;
+ }
+ SetTags(ptr, lsize | 1);
+ return ptr;
+ }
+ ptr = GetFreeListLink(index+1);
+ while (NEXT(ptr)) {
+ lsize = SIZE(ptr);
+ if (lsize >= realsize) {
+ size_t rem = lsize - realsize;
+ if(rem < minAllocSize) {
+ /* Unlink the block from the free list. */
+ Unlink(ptr);
+ }
+ else {
+ /*
+ * split the block
+ * The remainder is big enough to split off into a new block.
+ * Use the end of the block, resize the beginning of the block
+ * no need to change the free list.
+ */
+ SetTags(ptr, rem);
+ ptr += SIZE(ptr);
+ lsize = realsize;
+ }
+ SetTags(ptr, lsize | 1);
+ return ptr;
+ }
+ ptr += sizeof(FREE_LIST_ENTRY);
+ }
+ }
+ }
+#endif
+
+ /*
+ * Start searching the free list at the rover. If we arrive back at rover without
+ * finding anything, allocate some memory from the heap and try again.
+ */
+ ptr = m_pRover; /* start searching at rover */
+ int loops = 2; /* allow two times through the loop */
+ for(;;) {
+ lsize = SIZE(ptr);
+ ASSERT((lsize&1)==0);
+ /* is block big enough? */
+ if(lsize >= realsize) {
+ /* if the remainder is too small, don't bother splitting the block. */
+ rem = lsize - realsize;
+ if(rem < minAllocSize) {
+ if(m_pRover == ptr)
+ m_pRover = NEXT(ptr);
+
+ /* Unlink the block from the free list. */
+ Unlink(ptr);
+ }
+ else {
+ /*
+ * split the block
+ * The remainder is big enough to split off into a new block.
+ * Use the end of the block, resize the beginning of the block
+ * no need to change the free list.
+ */
+ SetTags(ptr, rem);
+ ptr += SIZE(ptr);
+ lsize = realsize;
+ }
+ /* Set the boundary tags to mark it as allocated. */
+ SetTags(ptr, lsize | 1);
+ return ((void *)ptr);
+ }
+
+ /*
+ * This block was unsuitable. If we've gone through this list once already without
+ * finding anything, allocate some new memory from the heap and try again.
+ */
+ ptr = NEXT(ptr);
+ if(ptr == m_pRover) {
+ if(!(loops-- && Getmem(realsize))) {
+ return NULL;
+ }
+ ptr = m_pRover;
+ }
+ }
+}
+
+void* VMem::Realloc(void* block, size_t size)
+{
+ WALKHEAP();
+
+ /* if size is zero, free the block. */
+ if(size == 0) {
+ Free(block);
+ return (NULL);
+ }
+
+ /* if block pointer is NULL, do a Malloc(). */
+ if(block == NULL)
+ return Malloc(size);
+
+ /*
+ * Grow or shrink the block in place.
+ * if the block grows then the next block will be used if free
+ */
+ if(Expand(block, size) != NULL)
+ return block;
+
+ size_t realsize = CalcAllocSize(size);
+ if((int)realsize < minAllocSize)
+ return NULL;
+
+ /*
+ * see if the previous block is free, and is it big enough to cover the new size
+ * if merged with the current block.
+ */
+ PBLOCK ptr = (PBLOCK)block;
+ size_t cursize = SIZE(ptr) & ~1;
+ size_t psize = PSIZE(ptr);
+ if((psize&1) == 0 && (psize + cursize) >= realsize) {
+ PBLOCK prev = ptr - psize;
+ if(m_pRover == prev)
+ m_pRover = NEXT(prev);
+
+ /* Unlink the next block from the free list. */
+ Unlink(prev);
+
+ /* Copy contents of old block to new location, make it the current block. */
+ memmove(prev, ptr, cursize);
+ cursize += psize; /* combine sizes */
+ ptr = prev;
+
+ size_t rem = cursize - realsize;
+ if(rem >= minAllocSize) {
+ /*
+ * The remainder is big enough to be a new block. Set boundary
+ * tags for the resized block and the new block.
+ */
+ prev = ptr + realsize;
+ /*
+ * add the new block to the free list.
+ * next block cannot be free
+ */
+ SetTags(prev, rem);
+#ifdef _USE_BUDDY_BLOCKS
+ AddToFreeList(prev, rem);
+#else
+ AddToFreeList(prev, m_pFreeList);
+#endif
+ cursize = realsize;
+ }
+ /* Set the boundary tags to mark it as allocated. */
+ SetTags(ptr, cursize | 1);
+ return ((void *)ptr);
+ }
+
+ /* Allocate a new block, copy the old to the new, and free the old. */
+ if((ptr = (PBLOCK)Malloc(size)) != NULL) {
+ memmove(ptr, block, cursize-blockOverhead);
+ Free(block);
+ }
+ return ((void *)ptr);
+}
+
+void VMem::Free(void* p)
+{
+ WALKHEAP();
+
+ /* Ignore null pointer. */
+ if(p == NULL)
+ return;
+
+ PBLOCK ptr = (PBLOCK)p;
+
+ /* Check for attempt to free a block that's already free. */
+ size_t size = SIZE(ptr);
+ if((size&1) == 0) {
+ MEMODSlx("Attempt to free previously freed block", (long)p);
+ return;
+ }
+ size &= ~1; /* remove allocated tag */
+
+ /* if previous block is free, add this block to it. */
+#ifndef _USE_BUDDY_BLOCKS
+ int linked = FALSE;
+#endif
+ size_t psize = PSIZE(ptr);
+ if((psize&1) == 0) {
+ ptr -= psize; /* point to previous block */
+ size += psize; /* merge the sizes of the two blocks */
+#ifdef _USE_BUDDY_BLOCKS
+ Unlink(ptr);
+#else
+ linked = TRUE; /* it's already on the free list */
+#endif
+ }
+
+ /* if the next physical block is free, merge it with this block. */
+ PBLOCK next = ptr + size; /* point to next physical block */
+ size_t nsize = SIZE(next);
+ if((nsize&1) == 0) {
+ /* block is free move rover if needed */
+ if(m_pRover == next)
+ m_pRover = NEXT(next);
+
+ /* unlink the next block from the free list. */
+ Unlink(next);
+
+ /* merge the sizes of this block and the next block. */
+ size += nsize;
+ }
+
+ /* Set the boundary tags for the block; */
+ SetTags(ptr, size);
+
+ /* Link the block to the head of the free list. */
+#ifdef _USE_BUDDY_BLOCKS
+ AddToFreeList(ptr, size);
+#else
+ if(!linked) {
+ AddToFreeList(ptr, m_pFreeList);
+ }
+#endif
+}
+
+void VMem::GetLock(void)
+{
+ EnterCriticalSection(&m_cs);
+}
+
+void VMem::FreeLock(void)
+{
+ LeaveCriticalSection(&m_cs);
+}
+
+int VMem::IsLocked(void)
+{
+#if 0
+ /* XXX TryEnterCriticalSection() is not available in some versions
+ * of Windows 95. Since this code is not used anywhere yet, we
+ * skirt the issue for now. */
+ BOOL bAccessed = TryEnterCriticalSection(&m_cs);
+ if(bAccessed) {
+ LeaveCriticalSection(&m_cs);
+ }
+ return !bAccessed;
+#else
+ ASSERT(0); /* alarm bells for when somebody calls this */
+ return 0;
+#endif
+}
+
+
+long VMem::Release(void)
+{
+ long lCount = InterlockedDecrement(&m_lRefCount);
+ if(!lCount)
+ delete this;
+ return lCount;
+}
+
+long VMem::AddRef(void)
+{
+ long lCount = InterlockedIncrement(&m_lRefCount);
+ return lCount;
+}
+
+
+int VMem::Getmem(size_t requestSize)
+{ /* returns -1 is successful 0 if not */
+#ifdef USE_BIGBLOCK_ALLOC
+ BOOL bBigBlock;
+#endif
+ void *ptr;
+
+ /* Round up size to next multiple of 64K. */
+ size_t size = (size_t)ROUND_UP64K(requestSize);
+
+ /*
+ * if the size requested is smaller than our current allocation size
+ * adjust up
+ */
+ if(size < (unsigned long)m_lAllocSize)
+ size = m_lAllocSize;
+
+ /* Update the size to allocate on the next request */
+ if(m_lAllocSize != lAllocMax)
+ m_lAllocSize <<= 2;
+
+#ifndef _USE_BUDDY_BLOCKS
+ if(m_nHeaps != 0
+#ifdef USE_BIGBLOCK_ALLOC
+ && !m_heaps[m_nHeaps-1].bBigBlock
+#endif
+ ) {
+ /* Expand the last allocated heap */
+ ptr = HeapReAlloc(m_hHeap, HEAP_REALLOC_IN_PLACE_ONLY|HEAP_NO_SERIALIZE,
+ m_heaps[m_nHeaps-1].base,
+ m_heaps[m_nHeaps-1].len + size);
+ if(ptr != 0) {
+ HeapAdd(((char*)ptr) + m_heaps[m_nHeaps-1].len, size
+#ifdef USE_BIGBLOCK_ALLOC
+ , FALSE
+#endif
+ );
+ return -1;
+ }
+ }
+#endif /* _USE_BUDDY_BLOCKS */
+
+ /*
+ * if we didn't expand a block to cover the requested size
+ * allocate a new Heap
+ * the size of this block must include the additional dummy tags at either end
+ * the above ROUND_UP64K may not have added any memory to include this.
+ */
+ if(size == requestSize)
+ size = (size_t)ROUND_UP64K(requestSize+(blockOverhead));
+
+Restart:
+#ifdef _USE_BUDDY_BLOCKS
+ ptr = VirtualAlloc(NULL, size, MEM_COMMIT, PAGE_READWRITE);
+#else
+#ifdef USE_BIGBLOCK_ALLOC
+ bBigBlock = FALSE;
+ if (size >= nMaxHeapAllocSize) {
+ bBigBlock = TRUE;
+ ptr = VirtualAlloc(NULL, size, MEM_COMMIT, PAGE_READWRITE);
+ }
+ else
+#endif
+ ptr = HeapAlloc(m_hHeap, HEAP_NO_SERIALIZE, size);
+#endif /* _USE_BUDDY_BLOCKS */
+
+ if (!ptr) {
+ /* try to allocate a smaller chunk */
+ size >>= 1;
+ if(size > requestSize)
+ goto Restart;
+ }
+
+ if(ptr == 0) {
+ MEMODSlx("HeapAlloc failed on size!!!", size);
+ return 0;
+ }
+
+#ifdef _USE_BUDDY_BLOCKS
+ if (HeapAdd(ptr, size)) {
+ VirtualFree(ptr, 0, MEM_RELEASE);
+ return 0;
+ }
+#else
+#ifdef USE_BIGBLOCK_ALLOC
+ if (HeapAdd(ptr, size, bBigBlock)) {
+ if (bBigBlock) {
+ VirtualFree(ptr, 0, MEM_RELEASE);
+ }
+ }
+#else
+ HeapAdd(ptr, size);
+#endif
+#endif /* _USE_BUDDY_BLOCKS */
+ return -1;
+}
+
+int VMem::HeapAdd(void* p, size_t size
+#ifdef USE_BIGBLOCK_ALLOC
+ , BOOL bBigBlock
+#endif
+ )
+{ /* if the block can be succesfully added to the heap, returns 0; otherwise -1. */
+ int index;
+
+ /* Check size, then round size down to next long word boundary. */
+ if(size < minAllocSize)
+ return -1;
+
+ size = (size_t)ROUND_DOWN(size);
+ PBLOCK ptr = (PBLOCK)p;
+
+#ifdef USE_BIGBLOCK_ALLOC
+ if (!bBigBlock) {
+#endif
+ /*
+ * Search for another heap area that's contiguous with the bottom of this new area.
+ * (It should be extremely unusual to find one that's contiguous with the top).
+ */
+ for(index = 0; index < m_nHeaps; ++index) {
+ if(ptr == m_heaps[index].base + (int)m_heaps[index].len) {
+ /*
+ * The new block is contiguous with a previously allocated heap area. Add its
+ * length to that of the previous heap. Merge it with the dummy end-of-heap
+ * area marker of the previous heap.
+ */
+ m_heaps[index].len += size;
+ break;
+ }
+ }
+#ifdef USE_BIGBLOCK_ALLOC
+ }
+ else {
+ index = m_nHeaps;
+ }
+#endif
+
+ if(index == m_nHeaps) {
+ /* The new block is not contiguous, or is BigBlock. Add it to the heap list. */
+ if(m_nHeaps == maxHeaps) {
+ return -1; /* too many non-contiguous heaps */
+ }
+ m_heaps[m_nHeaps].base = ptr;
+ m_heaps[m_nHeaps].len = size;
+#ifdef USE_BIGBLOCK_ALLOC
+ m_heaps[m_nHeaps].bBigBlock = bBigBlock;
+#endif
+ m_nHeaps++;
+
+ /*
+ * Reserve the first LONG in the block for the ending boundary tag of a dummy
+ * block at the start of the heap area.
+ */
+ size -= blockOverhead;
+ ptr += blockOverhead;
+ PSIZE(ptr) = 1; /* mark the dummy previous block as allocated */
+ }
+
+ /*
+ * Convert the heap to one large block. Set up its boundary tags, and those of
+ * marker block after it. The marker block before the heap will already have
+ * been set up if this heap is not contiguous with the end of another heap.
+ */
+ SetTags(ptr, size | 1);
+ PBLOCK next = ptr + size; /* point to dummy end block */
+ SIZE(next) = 1; /* mark the dummy end block as allocated */
+
+ /*
+ * Link the block to the start of the free list by calling free().
+ * This will merge the block with any adjacent free blocks.
+ */
+ Free(ptr);
+ return 0;
+}
+
+
+void* VMem::Expand(void* block, size_t size)
+{
+ /*
+ * Disallow negative or zero sizes.
+ */
+ size_t realsize = CalcAllocSize(size);
+ if((int)realsize < minAllocSize || size == 0)
+ return NULL;
+
+ PBLOCK ptr = (PBLOCK)block;
+
+ /* if the current size is the same as requested, do nothing. */
+ size_t cursize = SIZE(ptr) & ~1;
+ if(cursize == realsize) {
+ return block;
+ }
+
+ /* if the block is being shrunk, convert the remainder of the block into a new free block. */
+ if(realsize <= cursize) {
+ size_t nextsize = cursize - realsize; /* size of new remainder block */
+ if(nextsize >= minAllocSize) {
+ /*
+ * Split the block
+ * Set boundary tags for the resized block and the new block.
+ */
+ SetTags(ptr, realsize | 1);
+ ptr += realsize;
+
+ /*
+ * add the new block to the free list.
+ * call Free to merge this block with next block if free
+ */
+ SetTags(ptr, nextsize | 1);
+ Free(ptr);
+ }
+
+ return block;
+ }
+
+ PBLOCK next = ptr + cursize;
+ size_t nextsize = SIZE(next);
+
+ /* Check the next block for consistency.*/
+ if((nextsize&1) == 0 && (nextsize + cursize) >= realsize) {
+ /*
+ * The next block is free and big enough. Add the part that's needed
+ * to our block, and split the remainder off into a new block.
+ */
+ if(m_pRover == next)
+ m_pRover = NEXT(next);
+
+ /* Unlink the next block from the free list. */
+ Unlink(next);
+ cursize += nextsize; /* combine sizes */
+
+ size_t rem = cursize - realsize; /* size of remainder */
+ if(rem >= minAllocSize) {
+ /*
+ * The remainder is big enough to be a new block.
+ * Set boundary tags for the resized block and the new block.
+ */
+ next = ptr + realsize;
+ /*
+ * add the new block to the free list.
+ * next block cannot be free
+ */
+ SetTags(next, rem);
+#ifdef _USE_BUDDY_BLOCKS
+ AddToFreeList(next, rem);
+#else
+ AddToFreeList(next, m_pFreeList);
+#endif
+ cursize = realsize;
+ }
+ /* Set the boundary tags to mark it as allocated. */
+ SetTags(ptr, cursize | 1);
+ return ((void *)ptr);
+ }
+ return NULL;
+}
+
+#ifdef _DEBUG_MEM
+#define LOG_FILENAME ".\\MemLog.txt"
+
+void VMem::MemoryUsageMessage(char *str, long x, long y, int c)
+{
+ char szBuffer[512];
+ if(str) {
+ if(!m_pLog)
+ m_pLog = fopen(LOG_FILENAME, "w");
+ sprintf(szBuffer, str, x, y, c);
+ fputs(szBuffer, m_pLog);
+ }
+ else {
+ if(m_pLog) {
+ fflush(m_pLog);
+ fclose(m_pLog);
+ m_pLog = 0;
+ }
+ }
+}
+
+void VMem::WalkHeap(int complete)
+{
+ if(complete) {
+ MemoryUsageMessage(NULL, 0, 0, 0);
+ size_t total = 0;
+ for(int i = 0; i < m_nHeaps; ++i) {
+ total += m_heaps[i].len;
+ }
+ MemoryUsageMessage("VMem heaps used %d. Total memory %08x\n", m_nHeaps, total, 0);
+
+ /* Walk all the heaps - verify structures */
+ for(int index = 0; index < m_nHeaps; ++index) {
+ PBLOCK ptr = m_heaps[index].base;
+ size_t size = m_heaps[index].len;
+#ifndef _USE_BUDDY_BLOCKS
+#ifdef USE_BIGBLOCK_ALLOC
+ if (!m_heaps[m_nHeaps].bBigBlock)
+#endif
+ ASSERT(HeapValidate(m_hHeap, HEAP_NO_SERIALIZE, ptr));
+#endif
+
+ /* set over reserved header block */
+ size -= blockOverhead;
+ ptr += blockOverhead;
+ PBLOCK pLast = ptr + size;
+ ASSERT(PSIZE(ptr) == 1); /* dummy previous block is allocated */
+ ASSERT(SIZE(pLast) == 1); /* dummy next block is allocated */
+ while(ptr < pLast) {
+ ASSERT(ptr > m_heaps[index].base);
+ size_t cursize = SIZE(ptr) & ~1;
+ ASSERT((PSIZE(ptr+cursize) & ~1) == cursize);
+ MemoryUsageMessage("Memory Block %08x: Size %08x %c\n", (long)ptr, cursize, (SIZE(ptr)&1) ? 'x' : ' ');
+ if(!(SIZE(ptr)&1)) {
+ /* this block is on the free list */
+ PBLOCK tmp = NEXT(ptr);
+ while(tmp != ptr) {
+ ASSERT((SIZE(tmp)&1)==0);
+ if(tmp == m_pFreeList)
+ break;
+ ASSERT(NEXT(tmp));
+ tmp = NEXT(tmp);
+ }
+ if(tmp == ptr) {
+ MemoryUsageMessage("Memory Block %08x: Size %08x free but not in free list\n", (long)ptr, cursize, 0);
+ }
+ }
+ ptr += cursize;
+ }
+ }
+ MemoryUsageMessage(NULL, 0, 0, 0);
+ }
+}
+#endif /* _DEBUG_MEM */
+
+#endif /* _USE_MSVCRT_MEM_ALLOC */
+
+#endif /* ___VMEM_H_INC___ */