  /**//**************************************************
 *
* MemMan 1.0.0.2
*
* Copyright (C) 2007 - 2008 by Len3d
* All rights reserved.
*
 *************************************************/
#ifndef __MEM_MAN__
#define __MEM_MAN__
#define DEFAULT_MEMORY_ALIGN 16 // default memory aligment set to this size
#define ALIGN_DEF __declspec( align( DEFAULT_MEMORY_ALIGN ) )
typedef int (*FreeContentFunc)( void *object, UINT requested_size, UINT & ref_count ); // can't be member function of a class
#pragma pack(push,1)
class MemoryAllocator  { // memory allocator, takes charge of all system operations, also limits the usage of memory
private:
typedef UINT MemoryHeaderBias; // biased value type of memory header
// elements of the memory priority queue, keep track of all memory blocks
  class MemoryHeader {
public:
FORCEINLINE MemoryHeader( UINT prior, void *obj, FreeContentFunc func, UINT al )
{
lchild = rchild = parent = NULL;
priority = prior;
object = obj;
free_func = func;
locked = TRUE; // we lock immediately after allocation
align = al;
ref_count = 1; // assume one block references this header at beginning
bias = sizeof(MemoryHeader);
bfact = 0; // initialize balance factor with 0
 }
// we don't need a deconstructor for this class
FORCEINLINE void lock()
{
locked = TRUE;
}
FORCEINLINE void unlock()
{
locked = FALSE;
}
FORCEINLINE MemoryHeader *insert( MemoryHeader *key )
{
MemoryHeader *root = this;
bool taller = true;
create_child( key, root, taller );
return root; // AVL may change the root, we return the new root here
}
FORCEINLINE void create_child( MemoryHeader *key, MemoryHeader * & root, bool & taller )
{
if( key->priority < priority )
{
if( lchild )
lchild->create_child( key, root, taller );
else
{
lchild = key;
lchild->parent = this;
taller = true;
}
if( taller )
{
switch( bfact )
{
case 1:
left_balance( root );
taller = false;
break;
case 0:
bfact = 1;
taller = true;
break;
case -1:
bfact = 0;
taller = false;
break;
}
}
}
else
{
if( rchild )
rchild->create_child( key, root, taller );
else
{
rchild = key;
rchild->parent = this;
taller = true;
}
if( taller )
{
switch( bfact )
{
case 1:
bfact = 0;
taller = false;
break;
case 0:
bfact = -1;
taller = true;
break;
case -1:
right_balance( root );
taller = false;
break;
}
}
}
}
FORCEINLINE void left_rotate( MemoryHeader * & root )
{
MemoryHeader *rc;
rc = rchild;
rchild = rc->lchild;
if( rchild )
rchild->parent = this;
rc->lchild = this;
rc->parent = parent;
if( parent )
{
if( parent->lchild == this )
parent->lchild = rc;
else if( parent->rchild == this )
parent->rchild = rc;
}
else
{
root = rc;
}
parent = rc;
}
FORCEINLINE void right_rotate( MemoryHeader * & root )
{
MemoryHeader *lc;
lc = lchild;
lchild = lc->rchild;
if( lchild )
lchild->parent = this;
lc->rchild = this;
lc->parent = parent;
if( parent )
{
if( parent->lchild == this )
parent->lchild = lc;
else if( parent->rchild == this )
parent->rchild = lc;
}
else
{
root = lc;
}
parent = lc;
}
FORCEINLINE void left_balance( MemoryHeader * & root )
{
MemoryHeader *lc, *rd;
lc = lchild;
switch( lc->bfact )
{
case 1:
bfact = lc->bfact = 0;
right_rotate( root );
break;
case 0:
rd = lc->rchild;
switch( rd->bfact )
{
case 1:
bfact = -1;
lc->bfact = 0;
break;
case 0:
bfact = lc->bfact = 0;
break;
case -1:
bfact = 0;
lc->bfact = 1;
break;
}
rd->bfact = 0;
lchild->left_rotate( root );
right_rotate( root );
break;
}
}
FORCEINLINE void right_balance( MemoryHeader * & root )
{
MemoryHeader *rc, *ld;
rc = rchild;
switch( rc->bfact )
{
case 1:
bfact = rc->bfact = 0;
left_rotate( root );
break;
case 0:
ld = rc->lchild;
switch( ld->bfact )
{
case 1:
bfact = -1;
rc->bfact = 0;
break;
case 0:
bfact = rc->bfact = 0;
break;
case -1:
bfact = 0;
rc->bfact = 1;
break;
}
ld->bfact = 0;
rchild->right_rotate( root );
left_rotate( root );
break;
}
}
FORCEINLINE bool search_memory( UINT search_size, int search_align, void * & search_result,
void *obj, FreeContentFunc func )
{
if( lchild && lchild->search_memory( search_size, search_align, search_result, obj, func ) )
return true;
if( align == search_align && free_content( search_size ) )
{
search_result = get_memory();
object = obj; // update the attributes of the memory block
free_func = func;
return true;
}
if( rchild && rchild->search_memory( search_size, search_align, search_result, obj, func ) )
return true;
return false;
}
FORCEINLINE void *get_memory() // the allocated memory block
{
return ((char *)this + sizeof(MemoryHeader));
}
FORCEINLINE void dec_ref_count() // decrease the reference count
{
-- ref_count;
}
FORCEINLINE UINT get_ref_count() // the reference count
{
return ref_count;
}
// try to free some content of the object for requested size,
// update the reference count and return the size of the freed memory
FORCEINLINE int free_content( UINT requested_size )
{
if( !locked && free_func && object )
return free_func( object, requested_size, ref_count );
else
return 0;
}
public:
ALIGN_DEF struct { // 48 Byte aligned including the header bias
MemoryHeader *lchild, // left child, right child and parent
*rchild,
*parent;
UINT priority; // priority for sorting the memory blocks
void *object; // the object for which the memory was allocated
FreeContentFunc free_func; // function to free the content of the object for requested size,
// memory blocks without this function will be restored to memory-mapped files.
int locked; // this memory block was locked by a thread
int bfact; // balance factor of the AVL tree
UINT align; // aligment of the allocated memory should match
UINT ref_count; // how many blocks reference this header
UINT pad; // padded to 48 Byte, no use
MemoryHeaderBias bias; // the header bias
};
};
public:
MemoryAllocator( UINT max_size ) // max allowed memory usage
{
allocated_size = 0;
available_size = max_size;
queue = NULL;
aligned_queue = NULL;
}
~MemoryAllocator()
{
dealloc_header( queue );
dealloc_aligned_header( aligned_queue );
}
FORCEINLINE void *alloc( UINT size, UINT priority,
void *object, FreeContentFunc free_func )
{
if( size == 0 )
{
return NULL;
}
else if( size > available_size ) // searching has the complexity of O(N)
{
void *ptr = NULL;
if( queue && queue->search_memory( size, 0, ptr, object, free_func ) )
return ptr;
else
return NULL; // the system has run out of memory
}
else // the complexity is O(logN)
{
allocated_size += ( sizeof(MemoryHeader) + size );
available_size -= ( sizeof(MemoryHeader) + size );
MemoryHeader *elem;
// allocate a block
elem = new (sys_alloc( sizeof(MemoryHeader) + size )) MemoryHeader( priority, object, free_func, 0 );
if( queue )
queue = queue->insert( elem ); // insert the node
else
queue = elem; // be the root
return elem->get_memory();
}
}
FORCEINLINE void *aligned_alloc( UINT size, UINT priority,
void *object, FreeContentFunc free_func,
UINT align = DEFAULT_MEMORY_ALIGN )
{
if( size == 0 )
{
return NULL;
}
else if( size > available_size ) // searching has the complexity of O(N)
{
void *ptr = NULL;
if( aligned_queue && aligned_queue->search_memory( size, align, ptr, object, free_func ) )
return ptr;
else
return NULL; // the system has run out of memory
}
else // the complexity is O(logN)
{
allocated_size += ( sizeof(MemoryHeader) + size );
available_size -= ( sizeof(MemoryHeader) + size );
MemoryHeader *elem;
// allocate an aligned block
elem = new (sys_aligned_alloc( sizeof(MemoryHeader) + size, align )) MemoryHeader( priority, object, free_func, align );
if( aligned_queue )
aligned_queue = aligned_queue->insert( elem ); // insert the node
else
aligned_queue = elem; // be the root
return elem->get_memory();
}
}
// a lock must be used before the object being deallocated, the complexity is O(1)
FORCEINLINE void lock( void *ptr )
{
if( ptr )
{
MemoryHeader *header = get_memory_header( ptr );
header->lock();
}
}
FORCEINLINE void unlock( void *ptr )
{
if( ptr )
{
MemoryHeader *header = get_memory_header( ptr );
header->unlock();
}
}
// deallocating has the complexity of O(logN)
FORCEINLINE void dealloc( void *ptr, UINT size )
{
if( ptr )
{
MemoryHeader *header, *node, *parent;
header = get_memory_header( ptr );
header->dec_ref_count();
if( header->get_ref_count() != 0 ) // still have objects reference this
return;
parent = header->parent;
if( header->lchild && header->rchild ) // has left child and right child
{
node = find_rightmost_child( header->lchild );
// rebuild the links
if( node != header->lchild )
{
node->parent->rchild = node->lchild;
if( node->lchild )
node->lchild->parent = node->parent;
node->lchild = header->lchild;
node->lchild->parent = node;
}
node->rchild = header->rchild;
node->rchild->parent = node;
node->parent = parent;
if( parent ) // has parent
{
if( parent->lchild == header )
parent->lchild = node;
else if( parent->rchild == header )
parent->rchild = node;
}
else // it's the root
{
queue = node;
}
}
else if( header->lchild ) // has only left child
{
// rebuild the links
node = header->lchild;
node->parent = parent;
if( parent ) // has parent
{
if( parent->lchild == header )
parent->lchild = node;
else if( parent->rchild == header )
parent->rchild = node;
}
else // it's the root
{
queue = node;
}
}
else if( header->rchild ) // has only right child
{
// rebuild the links
node = header->rchild;
node->parent = parent;
if( parent ) // has parent
{
if( parent->lchild == header )
parent->lchild = node;
else if( parent->rchild == header )
parent->rchild = node;
}
else // it's the root
{
queue = node;
}
}
else // has no child
{
if( parent ) // has parent
{
if( parent->lchild == header )
parent->lchild = NULL;
else if( parent->rchild == header )
parent->rchild = NULL;
}
else // it's the root, clear it
{
queue = NULL;
}
}
allocated_size -= ( sizeof(MemoryHeader) + size );
available_size += ( sizeof(MemoryHeader) + size );
sys_dealloc( header ); // deallocate the block
}
}
FORCEINLINE void aligned_dealloc( void *ptr, UINT size )
{
if( ptr )
{
MemoryHeader *header, *node, *parent;
header = get_memory_header( ptr );
header->dec_ref_count();
if( header->get_ref_count() != 0 ) // still have objects reference this
return;
parent = header->parent;
if( header->lchild && header->rchild ) // has left child and right child
{
node = find_rightmost_child( header->lchild );
// rebuild the links
if( node != header->lchild )
{
node->parent->rchild = node->lchild;
if( node->lchild )
node->lchild->parent = node->parent;
node->lchild = header->lchild;
node->lchild->parent = node;
}
node->rchild = header->rchild;
node->rchild->parent = node;
node->parent = parent;
if( parent ) // has parent
{
if( parent->lchild == header )
parent->lchild = node;
else if( parent->rchild == header )
parent->rchild = node;
}
else // it's the root
{
aligned_queue = node;
}
}
else if( header->lchild ) // has only left child
{
// rebuild the links
node = header->lchild;
node->parent = parent;
if( parent ) // has parent
{
if( parent->lchild == header )
parent->lchild = node;
else if( parent->rchild == header )
parent->rchild = node;
}
else // it's the root
{
aligned_queue = node;
}
}
else if( header->rchild ) // has only right child
{
// rebuild the links
node = header->rchild;
node->parent = parent;
if( parent ) // has parent
{
if( parent->lchild == header )
parent->lchild = node;
else if( parent->rchild == header )
parent->rchild = node;
}
else // it's the root
{
aligned_queue = node;
}
}
else // has no child
{
if( parent ) // has parent
{
if( parent->lchild == header )
parent->lchild = NULL;
else if( parent->rchild == header )
parent->rchild = NULL;
}
else // it's the root, clear it
{
aligned_queue = NULL;
}
}
allocated_size -= ( sizeof(MemoryHeader) + size );
available_size += ( sizeof(MemoryHeader) + size );
sys_aligned_dealloc( header ); // deallocate the block
}
}
private:
// help functions
FORCEINLINE void dealloc_header( MemoryHeader *node )
{
if( node )
{
if( node->lchild )
dealloc_header( node->lchild );
if( node->rchild )
dealloc_header( node->rchild );
sys_dealloc( node );
}
}
FORCEINLINE void dealloc_aligned_header( MemoryHeader *node )
{
if( node )
{
if( node->lchild )
dealloc_aligned_header( node->lchild );
if( node->rchild )
dealloc_aligned_header( node->rchild );
sys_aligned_dealloc( node );
}
}
FORCEINLINE MemoryHeader *find_rightmost_child( MemoryHeader *node )
{
while( node && node->rchild )
{
node = node->rchild;
}
return node;
}
FORCEINLINE MemoryHeader *get_memory_header( void *ptr )
{
// get the biased value first
MemoryHeaderBias *pb = (MemoryHeaderBias *)((char *) ptr - sizeof(MemoryHeaderBias));
// then get the header using the biased value
MemoryHeader *header = (MemoryHeader *)((char *) ptr - (*pb));
return header;
}
private:
// encapsulate system operations
FORCEINLINE void *sys_alloc( UINT size )
{
return malloc( size );
}
FORCEINLINE void *sys_aligned_alloc( UINT size, UINT align )
{
return _mm_malloc( size, align );
}
FORCEINLINE void sys_dealloc( void *ptr )
{
free( ptr );
}
FORCEINLINE void sys_aligned_dealloc( void *ptr )
{
_mm_free( ptr );
}
private:
// memory statistics
UINT allocated_size,
available_size;
// implement priority queues to record all the allocations
MemoryHeader *queue;
MemoryHeader *aligned_queue;
};
#pragma pack(pop)
#endif // __MEM_MAN__
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