malloc.c File Reference

#include "threads/malloc.h"
#include <debug.h>
#include <list.h>
#include <round.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include "threads/palloc.h"
#include "threads/synch.h"
#include "threads/vaddr.h"

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Data Structures
struct	desc
	A simple implementation of malloc(). More...
struct	arena
	Arena. More...
struct	block
	A block device. More...

Macros
#define	ARENA_MAGIC   0x9a548eed
	Magic number for detecting arena corruption. More...

Functions
static struct arena *	block_to_arena (struct block *b)
	Returns the arena that block B is inside. More...
static struct block *	arena_to_block (struct arena *a, size_t idx)
	Returns the (IDX - 1)'th block within arena A. More...
void	malloc_init (void)
	Initializes the malloc() descriptors. More...
void *	malloc (size_t size)
	Obtains and returns a new block of at least SIZE bytes. More...
void *	calloc (size_t a, size_t b)
	Allocates and return A times B bytes initialized to zeroes. More...
static size_t	block_size (void *block)
	Returns the number of bytes allocated for BLOCK. More...
void *	realloc (void *old_block, size_t new_size)
	Attempts to resize OLD_BLOCK to NEW_SIZE bytes, possibly moving it in the process. More...
void	free (void *p)
	Frees block P, which must have been previously allocated with malloc(), calloc(), or realloc(). More...

Variables
static struct desc	descs [10]
	Our set of descriptors. More...
static size_t	desc_cnt
	Number of descriptors. More...

Macro Definition Documentation

ARENA_MAGIC

#define ARENA_MAGIC   0x9a548eed

Magic number for detecting arena corruption.

Definition at line 47 of file malloc.c.

Function Documentation

arena_to_block()

static struct block * arena_to_block ( struct arena *  a, size_t  idx  )

static

Returns the (IDX - 1)'th block within arena A.

Definition at line 286 of file malloc.c.

References ARENA_MAGIC, ASSERT, desc::block_size, desc::blocks_per_arena, arena::desc, arena::magic, and NULL.

Referenced by free(), and malloc().

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block_size()

static size_t block_size ( void *  block )

static

Returns the number of bytes allocated for BLOCK.

Definition at line 179 of file malloc.c.

References desc::block_size, block_to_arena(), arena::desc, arena::free_cnt, NULL, pg_ofs(), and PGSIZE.

Referenced by malloc_init(), and realloc().

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block_to_arena()

static struct arena * block_to_arena ( struct block *  b )

static

Returns the arena that block B is inside.

Definition at line 268 of file malloc.c.

References ARENA_MAGIC, ASSERT, desc::block_size, arena::desc, arena::magic, NULL, pg_ofs(), and pg_round_down().

Referenced by block_size(), free(), and malloc().

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calloc()

void * calloc	(	size_t	a,
		size_t	b
	)

Allocates and return A times B bytes initialized to zeroes.

Returns a null pointer if memory is not available.

Definition at line 159 of file malloc.c.

References malloc(), memset(), NULL, and block::size.

Referenced by dir_open(), file_open(), and inode_create().

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free()

void free

(

void *

p

)

Frees block P, which must have been previously allocated with malloc(), calloc(), or realloc().

threads/malloc.h

Definition at line 219 of file malloc.c.

References arena_to_block(), ASSERT, desc::block_size, block_to_arena(), desc::blocks_per_arena, arena::desc, arena::free_cnt, block::free_elem, desc::free_list, list_push_front(), list_remove(), desc::lock, lock_acquire(), lock_release(), memset(), NULL, palloc_free_multiple(), and palloc_free_page().

Referenced by bitmap_create(), bitmap_destroy(), dir_close(), dir_open(), file_close(), file_open(), fsutil_append(), fsutil_extract(), hash_destroy(), inode_close(), inode_create(), inode_read_at(), inode_write_at(), read_partition_table(), realloc(), rehash(), and test_sleep().

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malloc()

void * malloc

(

size_t

size

)

Obtains and returns a new block of at least SIZE bytes.

Returns a null pointer if memory is not available.

Definition at line 90 of file malloc.c.

References ARENA_MAGIC, arena_to_block(), desc::block_size, block_to_arena(), desc::blocks_per_arena, arena::desc, desc_cnt, descs, DIV_ROUND_UP, arena::free_cnt, block::free_elem, desc::free_list, list_empty(), list_entry, list_pop_front(), list_push_back(), desc::lock, lock_acquire(), lock_release(), arena::magic, NULL, palloc_get_multiple(), palloc_get_page(), and PGSIZE.

Referenced by bitmap_create(), block_register(), calloc(), found_partition(), fsutil_append(), fsutil_extract(), hash_init(), inode_open(), inode_read_at(), inode_write_at(), read_partition_table(), realloc(), rehash(), and test_sleep().

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malloc_init()

void malloc_init

(

void

)

Initializes the malloc() descriptors.

Definition at line 72 of file malloc.c.

References ASSERT, desc::block_size, block_size(), desc::blocks_per_arena, desc_cnt, descs, desc::free_list, list_init(), desc::lock, lock_init(), and PGSIZE.

Referenced by pintos_init().

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realloc()

void * realloc	(	void *	old_block,
		size_t	new_size
	)

Attempts to resize OLD_BLOCK to NEW_SIZE bytes, possibly moving it in the process.

If successful, returns the new block; on failure, returns a null pointer. A call with null OLD_BLOCK is equivalent to malloc(NEW_SIZE). A call with zero NEW_SIZE is equivalent to free(OLD_BLOCK).

Definition at line 195 of file malloc.c.

References block_size(), free(), malloc(), memcpy(), and NULL.

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Variable Documentation

desc_cnt

size_t desc_cnt

static

Number of descriptors.

Definition at line 65 of file malloc.c.

Referenced by malloc(), and malloc_init().

descs

struct desc descs[10]

static

Our set of descriptors.

Descriptors.

Definition at line 64 of file malloc.c.

Referenced by malloc(), and malloc_init().