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/*
LUFA Library
Copyright (C) Dean Camera, 2009.
dean [at] fourwalledcubicle [dot] com
www.fourwalledcubicle.com
*/
/*
Copyright 2009 Dean Camera (dean [at] fourwalledcubicle [dot] com)
Permission to use, copy, modify, and distribute this software
and its documentation for any purpose and without fee is hereby
granted, provided that the above copyright notice appear in all
copies and that both that the copyright notice and this
permission notice and warranty disclaimer appear in supporting
documentation, and that the name of the author not be used in
advertising or publicity pertaining to distribution of the
software without specific, written prior permission.
The author disclaim all warranties with regard to this
software, including all implied warranties of merchantability
and fitness. In no event shall the author be liable for any
special, indirect or consequential damages or any damages
whatsoever resulting from loss of use, data or profits, whether
in an action of contract, negligence or other tortious action,
arising out of or in connection with the use or performance of
this software.
*/
#define INCLUDE_FROM_DYNALLOC_C
#include "DynAlloc.h"
struct
{
char Mem_Heap[NUM_BLOCKS * BLOCK_SIZE];
void* Mem_Handles[NUM_HANDLES];
uint8_t Mem_Block_Flags[(NUM_BLOCKS / 4) + ((NUM_BLOCKS % 4) ? 1 : 0)];
uint8_t FlagMaskLookupMask[4];
uint8_t FlagMaskLookupNum[4];
} Mem_MemData = {FlagMaskLookupMask: {(3 << 0), (3 << 2), (3 << 4), (3 << 6)},
FlagMaskLookupNum: { 0, 2, 4, 6}};
static uint8_t Mem_GetBlockFlags(const Block_Number_t BlockNum)
{
const Block_Number_t BlockIndex = (BlockNum >> 2);
const uint8_t FlagMask = Mem_MemData.FlagMaskLookupMask[BlockNum & 0x03];
const uint8_t FlagMaskShift = Mem_MemData.FlagMaskLookupNum[BlockNum & 0x03];
return ((Mem_MemData.Mem_Block_Flags[BlockIndex] & FlagMask) >> FlagMaskShift);
}
static void Mem_SetBlockFlags(const Block_Number_t BlockNum, const uint8_t Flags)
{
const Block_Number_t BlockIndex = (BlockNum >> 2);
const uint8_t FlagMask = Mem_MemData.FlagMaskLookupMask[BlockNum & 0x03];
const uint8_t FlagMaskShift = Mem_MemData.FlagMaskLookupNum[BlockNum & 0x03];
Mem_MemData.Mem_Block_Flags[BlockIndex] &= ~FlagMask;
Mem_MemData.Mem_Block_Flags[BlockIndex] |= (Flags << FlagMaskShift);
}
static inline void Mem_Defrag(void)
{
Block_Number_t FreeStartBlock = 0;
char* FreeStartPtr = NULL;
char* UsedStartPtr = NULL;
Block_Number_t CurrBlock;
for (CurrBlock = 0; CurrBlock < NUM_BLOCKS; CurrBlock++)
{
if (!(Mem_GetBlockFlags(CurrBlock) & BLOCK_USED_MASK))
{
FreeStartPtr = &Mem_MemData.Mem_Heap[CurrBlock * BLOCK_SIZE];
FreeStartBlock = CurrBlock;
break;
}
}
if (FreeStartPtr == NULL)
return;
while (++CurrBlock < NUM_BLOCKS)
{
uint8_t CurrBlockFlags = Mem_GetBlockFlags(CurrBlock);
if (CurrBlockFlags & BLOCK_USED_MASK)
{
UsedStartPtr = &Mem_MemData.Mem_Heap[CurrBlock * BLOCK_SIZE];
for (Handle_Number_t HandleNum = 0; HandleNum < NUM_HANDLES; HandleNum++)
{
if (Mem_MemData.Mem_Handles[HandleNum] == UsedStartPtr)
{
Mem_MemData.Mem_Handles[HandleNum] = FreeStartPtr;
break;
}
}
memcpy(FreeStartPtr, UsedStartPtr, BLOCK_SIZE);
FreeStartPtr += BLOCK_SIZE;
Mem_SetBlockFlags(FreeStartBlock++, CurrBlockFlags);
Mem_SetBlockFlags(CurrBlock, 0);
}
}
}
static inline bool Mem_FindFreeBlocks(Block_Number_t* const RetStartPtr, const Block_Number_t Blocks)
{
Block_Number_t FreeInCurrSec = 0;
for (Block_Number_t CurrBlock = 0; CurrBlock < NUM_BLOCKS; CurrBlock++)
{
if (Mem_GetBlockFlags(CurrBlock) & BLOCK_USED_MASK)
FreeInCurrSec = 0;
else
FreeInCurrSec++;
if (FreeInCurrSec >= Blocks)
{
*RetStartPtr = CurrBlock;
return true;
}
}
return false;
}
Mem_Handle_t Mem_Alloc(const Alloc_Size_t Bytes)
{
Block_Number_t ReqBlocks = (Bytes / BLOCK_SIZE);
Block_Number_t StartBlock;
if (Bytes % BLOCK_SIZE)
ReqBlocks++;
if (!(Mem_FindFreeBlocks(&StartBlock, ReqBlocks)))
{
Mem_Defrag();
if (!(Mem_FindFreeBlocks(&StartBlock, ReqBlocks)))
return NULL;
}
for (Block_Number_t UsedBlock = 0; UsedBlock < (ReqBlocks - 1); UsedBlock++)
Mem_SetBlockFlags((StartBlock + UsedBlock), (BLOCK_USED_MASK | BLOCK_LINKED_MASK));
Mem_SetBlockFlags((StartBlock + (ReqBlocks - 1)), BLOCK_USED_MASK);
for (Handle_Number_t AllocEntry = 0; AllocEntry < NUM_HANDLES; AllocEntry++)
{
Mem_Handle_t CurrHdl = (Mem_Handle_t)&Mem_MemData.Mem_Handles[AllocEntry];
if (DEREF(CurrHdl, void*) == NULL)
{
DEREF(CurrHdl, void*) = &Mem_MemData.Mem_Heap[StartBlock * BLOCK_SIZE];
return CurrHdl;
}
}
return NULL;
}
Mem_Handle_t Mem_Realloc(Mem_Handle_t CurrAllocHdl, const Alloc_Size_t Bytes)
{
Mem_Free(CurrAllocHdl);
return Mem_Alloc(Bytes);
}
Mem_Handle_t Mem_Calloc(const Alloc_Size_t Bytes)
{
Mem_Handle_t AllocHdl = Mem_Alloc(Bytes);
if (AllocHdl != NULL)
memset(DEREF(AllocHdl, void*), 0x00, Bytes);
return AllocHdl;
}
void Mem_Free(Mem_Handle_t CurrAllocHdl)
{
char* MemBlockPtr = DEREF(CurrAllocHdl, char*);
Block_Number_t CurrBlock = ((uint16_t)(MemBlockPtr - Mem_MemData.Mem_Heap) / BLOCK_SIZE);
uint8_t CurrBlockFlags;
if ((CurrAllocHdl == NULL) || (MemBlockPtr == NULL))
return;
do
{
CurrBlockFlags = Mem_GetBlockFlags(CurrBlock);
Mem_SetBlockFlags(CurrBlock, 0);
CurrBlock++;
}
while (CurrBlockFlags & BLOCK_LINKED_MASK);
DEREF(CurrAllocHdl, void*) = NULL;
}
Block_Number_t Mem_TotalFreeBlocks(void)
{
Block_Number_t FreeBlocks = 0;
for (Block_Number_t CurrBlock = 0; CurrBlock < NUM_BLOCKS; CurrBlock++)
{
if (!(Mem_GetBlockFlags(CurrBlock) & BLOCK_USED_MASK))
FreeBlocks++;
}
return FreeBlocks;
}
Handle_Number_t Mem_TotalFreeHandles(void)
{
Handle_Number_t FreeHandles = 0;
for (Handle_Number_t CurrHandle = 0; CurrHandle < NUM_HANDLES; CurrHandle++)
{
if (Mem_MemData.Mem_Handles[CurrHandle] == NULL)
FreeHandles++;
}
return FreeHandles;
}
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