cc65/include/_heap.h

54 lines
1.1 KiB
C

/*
** _heap.h
**
** Ullrich von Bassewitz, 1998-06-03, 2004-12-19
**
*/
#ifndef __HEAP_H
#define __HEAP_H
/* Structure that preceeds a user block in most cases.
** The aligned_malloc function may generate blocks where the start pointer
** and size are splitted to handle a memory hole that is needed for
** alignment.
*/
struct usedblock {
unsigned size;
struct usedblock* start;
};
/* Space needed for administering used blocks */
#define HEAP_ADMIN_SPACE sizeof (struct usedblock)
/* The data type used to implement the free list.
** Beware: Field order is significant!
*/
struct freeblock {
unsigned size;
struct freeblock* next;
struct freeblock* prev;
};
/* Variables that describe the heap */
extern unsigned* _heaporg; /* Bottom of heap */
extern unsigned* _heapptr; /* Current top */
extern unsigned* _heapend; /* Upper limit */
extern struct freeblock* _heapfirst; /* First free block in list */
extern struct freeblock* _heaplast; /* Last free block in list */
/* End of _heap.h */
#endif