void *MemRealloc (void * buffer, unsigned int size, char * var, char * pszFile, int nLine)
{
void *newbuffer = NULL;
#if !DBG_MALLOC
if (!size)
MemFree (buffer);
else if (!buffer)
newbuffer = MemAlloc (size, var, pszFile, nLine, 0);
else if (!(newbuffer = realloc (buffer, size))) {
#if TRACE
con_printf (CON_MALLOC, "reallocating %d bytes in %s:%d failed.\n", size, pszFile, nLine);
#endif
}
#else
if (!bMemInitialized)
MemInit ();
if (!size)
MemFree (buffer);
else {
newbuffer = MemAlloc (size, var, pszFile, nLine, 0);
if (FindMemBlock (buffer) >= 0) {
memcpy (newbuffer, buffer, *(((int *) buffer) - 1));
MemFree (buffer);
}
}
#endif
return newbuffer;
}
/*
@ Function:
* allocate memory of specified size from memory pool for users
*
@ Arguments:
* size of wanted memory (unsigned long long)
*
@ Return:
* pointer to the allocated memory for users (void*)
* the memory has been initialized with value "0".
*
@ Basic Algorithm:
* 1) make sure enough memory left in memory pool to satify the users,
* by sometimes allocating new memory blocks from the OS.
* 2) allocate memory by changing used memory offset and updating memory pool's status.
*/
void* MemPool::Alloc( ull_t ullMemSize ) {
void* p_vdMem = NULL;
/* wrong input data range, return null pointer */
if( ullMemSize <= 0 )
return NULL;
/* find the block from which the memory will be allocated */
MemBlock* stMemBlock = FindMemBlock( ullMemSize );
if( !stMemBlock ) {
return NULL;
}
/* allocate the requested memory from the found block, and update mempool's status */
p_vdMem = ( void* ) ( ( unsigned char* ) stMemBlock->vdMem + stMemBlock->ullMemUsed );
memset( p_vdMem, 0, sizeof( unsigned char ) * ullMemSize );
stMemBlock->ullMemUsed += ullMemSize;
ullMemUsedSize += ullMemSize;
/* update maximum range of available memory blocks */
while( ullMemBlockLeftIndex < ullMemBlockRightIndex ) {
MemBlock* p_stTmpMemBlk = mpstMemBlocks[ullMemBlockLeftIndex];
ull_t ullAvailMemSz = p_stTmpMemBlk->ullMemSize - p_stTmpMemBlk->ullMemUsed;
ull_t ullDynamicThresh = ( ull_t ) ( ullMemBlockMaxSize * 0.01 );
ull_t ullStaticThresh = 256;
if( ullAvailMemSz > ullDynamicThresh || ullAvailMemSz > ullStaticThresh ) {
break;
}
++ullMemBlockLeftIndex;
}
return p_vdMem;
}
int UnregisterMemBlock (void *p)
{
int i = FindMemBlock (p);
if ((i >= 0) && (i < --nMemBlocks))
memBlocks [i] = memBlocks [nMemBlocks];
return i;
}
