diff options
Diffstat (limited to 'engines/tinsel/heapmem.cpp')
-rw-r--r-- | engines/tinsel/heapmem.cpp | 228 |
1 files changed, 63 insertions, 165 deletions
diff --git a/engines/tinsel/heapmem.cpp b/engines/tinsel/heapmem.cpp index 31a8b97377..8b07c03da2 100644 --- a/engines/tinsel/heapmem.cpp +++ b/engines/tinsel/heapmem.cpp @@ -36,9 +36,9 @@ namespace Tinsel { // internal allocation flags #define DWM_USED 0x0001 ///< the objects memory block is in use -#define DWM_DISCARDED 0x0100 ///< the objects memory block has been discarded -#define DWM_LOCKED 0x0200 ///< the objects memory block is locked -#define DWM_SENTINEL 0x0400 ///< the objects memory block is a sentinel +#define DWM_DISCARDED 0x0002 ///< the objects memory block has been discarded +#define DWM_LOCKED 0x0004 ///< the objects memory block is locked +#define DWM_SENTINEL 0x0008 ///< the objects memory block is a sentinel struct MEM_NODE { @@ -83,8 +83,6 @@ static MEM_NODE *AllocMemNode(void); * Initialises the memory manager. */ void MemoryInit() { - MEM_NODE *pNode; - #ifdef DEBUG // clear number of nodes in use numNodes = 0; @@ -94,6 +92,7 @@ void MemoryInit() { pFreeMemNodes = mnodeList; // link all other objects after first + memset(mnodeList, 0, sizeof(mnodeList)); for (int i = 1; i < NUM_MNODES; i++) { mnodeList[i - 1].pNext = mnodeList + i; } @@ -104,53 +103,37 @@ void MemoryInit() { // clear list of fixed memory nodes memset(s_fixedMnodesList, 0, sizeof(s_fixedMnodesList)); - // allocates a big chunk of memory - uint32 size = MemoryPoolSize[0]; - if (TinselVersion == TINSEL_V1) size = MemoryPoolSize[1]; - else if (TinselVersion == TINSEL_V2) size = MemoryPoolSize[2]; - uint8 *mem = (uint8 *)malloc(size); - assert(mem); - - // allocate a mnode for this memory - pNode = AllocMemNode(); - - // make sure mnode was allocated - assert(pNode); - - // convert segment to memory address - pNode->pBaseAddr = mem; - - // set size of the memory heap - pNode->size = size; - - // clear the memory - memset(pNode->pBaseAddr, 0, size); - // set cyclic links to the sentinel - heapSentinel.pPrev = pNode; - heapSentinel.pNext = pNode; - pNode->pPrev = &heapSentinel; - pNode->pNext = &heapSentinel; + heapSentinel.pPrev = &heapSentinel; + heapSentinel.pNext = &heapSentinel; // flag sentinel as locked heapSentinel.flags = DWM_LOCKED | DWM_SENTINEL; - // store the start of the master data block in the sentinel - heapSentinel.pBaseAddr = mem; + // store the current heap size in the sentinel + uint32 size = MemoryPoolSize[0]; + if (TinselVersion == TINSEL_V1) size = MemoryPoolSize[1]; + else if (TinselVersion == TINSEL_V2) size = MemoryPoolSize[2]; + heapSentinel.size = size; } /** * Deinitialises the memory manager. */ void MemoryDeinit() { - MEM_NODE *pNode = s_fixedMnodesList; - for (int i = 0; i < ARRAYSIZE(s_fixedMnodesList); ++i, ++pNode) { - free(pNode->pBaseAddr); - pNode->pBaseAddr = 0; + const MEM_NODE *pHeap = &heapSentinel; + MEM_NODE *pCur; + + pCur = s_fixedMnodesList; + for (int i = 0; i < ARRAYSIZE(s_fixedMnodesList); ++i, ++pCur) { + free(pCur->pBaseAddr); + pCur->pBaseAddr = 0; } - // free memory used for the memory pool - free(heapSentinel.pBaseAddr); + for (pCur = pHeap->pNext; pCur != pHeap; pCur = pCur->pNext) { + free(pCur->pBaseAddr); + pCur->pBaseAddr = 0; + } } @@ -209,71 +192,11 @@ void FreeMemNode(MEM_NODE *pMemNode) { * @return true if any blocks were discarded, false otherwise */ bool HeapCompact(long size, bool bDiscard) { - MEM_NODE *pHeap = &heapSentinel; - MEM_NODE *pPrev, *pCur, *pOldest; - long largest; // size of largest free block + const MEM_NODE *pHeap = &heapSentinel; + MEM_NODE *pCur, *pOldest; uint32 oldest; // time of the oldest discardable block - while (true) { - bool bChanged; - - do { - bChanged = false; - for (pPrev = pHeap->pNext, pCur = pPrev->pNext; - pCur != pHeap; pPrev = pCur, pCur = pCur->pNext) { - if (pPrev->flags == 0 && pCur->flags == 0) { - // both blocks are free - merge them - pPrev->size += pCur->size; - - // unlink the current mnode - pPrev->pNext = pCur->pNext; - pCur->pNext->pPrev = pPrev; - - // free the current mnode - FreeMemNode(pCur); - - // set the changed flag - bChanged = true; - - // leave the loop - break; - } else if (pPrev->flags == DWM_USED && pCur->flags == 0) { - // a free block after a moveable, non-discarded, not locked block - swap them - - // set the changed flag - bChanged = true; - - // move the unlocked blocks data up (can overlap) - memmove(pPrev->pBaseAddr + pCur->size, pPrev->pBaseAddr, pPrev->size); - - // swap the order in the linked list - pPrev->pPrev->pNext = pCur; - pCur->pNext->pPrev = pPrev; - - pCur->pPrev = pPrev->pPrev; - pPrev->pPrev = pCur; - - pPrev->pNext = pCur->pNext; - pCur->pNext = pPrev; - - pCur->pBaseAddr = pPrev->pBaseAddr; - pPrev->pBaseAddr += pCur->size; - - // leave the loop - break; - } - } - } while (bChanged); - - // find the largest free block - for (largest = 0, pCur = pHeap->pNext; pCur != pHeap; pCur = pCur->pNext) { - if (pCur->flags == 0 && pCur->size > largest) - largest = pCur->size; - } - - if (largest >= size) - // we have freed enough memory - return true; + while (heapSentinel.size < size) { if (!bDiscard) // we cannot free enough without discarding blocks @@ -299,6 +222,9 @@ bool HeapCompact(long size, bool bDiscard) { // cannot discard any blocks return false; } + + // we have freed enough memory + return true; } /** @@ -307,58 +233,46 @@ bool HeapCompact(long size, bool bDiscard) { * @param size Number of bytes to allocate */ static MEM_NODE *MemoryAlloc(long size) { - const MEM_NODE *pHeap = &heapSentinel; - MEM_NODE *pNode; + MEM_NODE *pHeap = &heapSentinel; #ifdef SCUMM_NEED_ALIGNMENT const int alignPadding = sizeof(void*) - 1; size = (size + alignPadding) & ~alignPadding; //round up to nearest multiple of sizeof(void*), this ensures the addresses that are returned are alignment-safe. #endif - do { - // search the heap for a free block + // compact the heap to make up room for 'size' bytes, if necessary + if (!HeapCompact(size, true)) + return 0; - for (pNode = pHeap->pNext; pNode != pHeap; pNode = pNode->pNext) { - if (pNode->flags == 0 && pNode->size >= size) { - // a free block of the required size - pNode->flags = DWM_USED; + // success! we may allocate a new node of the right size - // update the LRU time - pNode->lruTime = DwGetCurrentTime() + 1; + // Allocate a node. + MEM_NODE *pNode = AllocMemNode(); - if (pNode->size == size) { - // an exact fit - return pNode; - } else { - // allocate a node for the remainder of the free block - MEM_NODE *pTemp = AllocMemNode(); + // Allocate memory for the node. + pNode->pBaseAddr = (byte *)malloc(size); - // calc size of the free block - long freeSize = pNode->size - size; + // Verify that we got the memory. + // TODO: If this fails, we should first try to compact the heap some further. + assert(pNode->pBaseAddr); - // set size of free block - pTemp->size = freeSize; + // Subtract size of new block from total + heapSentinel.size -= size; - // set size of node - pNode->size = size; + // Set flags, LRU time and size + pNode->flags = DWM_USED; + pNode->lruTime = DwGetCurrentTime(); + pNode->size = size; - // place the free node before pNode - pTemp->pBaseAddr = pNode->pBaseAddr; - pNode->pBaseAddr += freeSize; - pTemp->pNext = pNode; - pTemp->pPrev = pNode->pPrev; - pNode->pPrev->pNext = pTemp; - pNode->pPrev = pTemp; + // set mnode at the end of the list + pNode->pPrev = pHeap->pPrev; + pNode->pNext = pHeap; - return pNode; - } - } - } - // compact the heap if we get to here - } while (HeapCompact(size, true)); + // fix links to this mnode + pHeap->pPrev->pNext = pNode; + pHeap->pPrev = pNode; - // could not allocate a block - return 0; + return pNode; } /** @@ -371,6 +285,8 @@ MEM_NODE *MemoryNoAlloc() { // chain a discarded node onto the end of the heap MEM_NODE *pNode = AllocMemNode(); pNode->flags = DWM_USED | DWM_DISCARDED; + pNode->lruTime = DwGetCurrentTime(); + pNode->size = 0; // set mnode at the end of the list pNode->pPrev = pHeap->pPrev; @@ -406,6 +322,10 @@ MEM_NODE *MemoryAllocFixed(long size) { pNode->size = size; pNode->lruTime = DwGetCurrentTime(); pNode->flags = DWM_USED; + + // Subtract size of new block from total + heapSentinel.size -= size; + return pNode; } } @@ -427,36 +347,14 @@ void MemoryDiscard(MEM_NODE *pMemNode) { // discard it if it isn't already if ((pMemNode->flags & DWM_DISCARDED) == 0) { - // allocate a free node to replace this node - MEM_NODE *pTemp = AllocMemNode(); - - // copy node data - memcpy(pTemp, pMemNode, sizeof(MEM_NODE)); - - // flag as a free block - pTemp->flags = 0; - - // link in the free node - pTemp->pPrev->pNext = pTemp; - pTemp->pNext->pPrev = pTemp; + // free memory + free(pMemNode->pBaseAddr); + heapSentinel.size += pMemNode->size; - // discard the node + // mark the node as discarded pMemNode->flags |= DWM_DISCARDED; pMemNode->pBaseAddr = NULL; pMemNode->size = 0; - - // and place it at the end of the heap - while ((pTemp->flags & DWM_SENTINEL) != DWM_SENTINEL) - pTemp = pTemp->pNext; - - // pTemp now points to the heap sentinel - // set mnode at the end of the list - pMemNode->pPrev = pTemp->pPrev; - pMemNode->pNext = pTemp; - - // fix links to this mnode - pTemp->pPrev->pNext = pMemNode; - pTemp->pPrev = pMemNode; } } |