mm_malloc.h

实现一个简单的单进程内核,。该内核启用二级虚拟页表映射

/* A simple malloc implimentation from 15-213
 * mm_malloc.h
 *
 * 213 mm_malloc macros and prototypes.
 *
 */

#ifndef _MM_MALLOC_H
#define _MM_MALLOC_H

/* $begin mallocmacros */
/* Basic constants and macros */
#define WSIZE       4       /* word size (bytes) */
#define DSIZE       8       /* doubleword size (bytes) */
#define CHUNKSIZE  (1<<12)  /* initial heap size (bytes) */
#define OVERHEAD    8       /* overhead of header and footer (bytes) */

#define MAX(x, y) ((x) > (y)? (x) : (y))

/* Pack a size and allocated bit into a word */
#define PACK(size, alloc)  ((size) | (alloc))

/* Read and write a word at address p */
#define GET(p)       (*(int *)(p))
#define PUT(p, val)  (*(int *)(p) = (val))

/* Read the size and allocated fields from address p */
#define GET_SIZE(p)  (GET(p) & ~0x7)
#define GET_ALLOC(p) (GET(p) & 0x1)

/* Given block ptr bp, compute address of its header and footer */
#define HDRP(bp)       ((char *)(bp) - WSIZE)
#define FTRP(bp)       ((char *)(bp) + GET_SIZE(HDRP(bp)) - DSIZE)

/* Given block ptr bp, compute address of next and previous blocks */
#define NEXT_BLKP(bp)  ((char *)(bp) + GET_SIZE(((char *)(bp) - WSIZE)))
#define PREV_BLKP(bp)  ((char *)(bp) - GET_SIZE(((char *)(bp) - DSIZE)))
/* $end mallocmacros */

int mm_init(void);
void *mm_malloc(int size);
void mm_free(void *bp);
void *mm_realloc(void *ptr, int size);

#endif /* _MM_MALLOC_H */