A simple heap memory manager. More...

#include <core.h>
#include <libc/string.h>
#include <kernel/mem/heap.h>
#include <kernel/mem/paging.h>

Data Structures
struct	heap_t

struct	block_header_t

struct	block_footer_t

struct	fblock_header_t

Macros
#define	ALLOC_PAGES 16

#define	FLAG_ALLOCATED (1 << 0)

#define	round16(n, r) (((((n) - (r) + 31) >> 4) << 4) + (r) - 16)

#define	total_bytes(b) ((b)->size + sizeof(block_header_t) + sizeof(block_footer_t))

Functions
heap_t *	heap_create (pagetable_t pt, void vaddr, uint64_t maxpages)
	Create a new heap from which to allocate virtual memory. More...

void	heap_destroy (heap_t *heap)
	Destroy a heap, returning its memory to page table. More...

static fblock_header_t *	next_fblock_adj (heap_t heap, block_header_t bh)
	Check the next block adjacent to 'b'. More...

static fblock_header_t *	prev_fblock_adj (heap_t heap, block_header_t bh)
	Check the preceding block adjacent to 'b'. More...

static fblock_header_t *	next_fblock (heap_t heap, block_header_t bh)
	Scan all blocks after 'b' until a free block is encountered and return it. More...

static fblock_header_t *	prev_fblock (heap_t heap, block_header_t bh)
	Scan all blocks preceding 'b' until a free block is encountered and return it. More...

static fblock_header_t *	grow_heap (heap_t *heap, uint64_t minsize)
	Grow the heap so that it's big enough to hold at least minsize newly allocated bytes (not including headers). More...

static fblock_header_t *	find_fblock (heap_t *heap, uint64_t size)

void *	heap_alloc (heap_t *heap, uint64_t size)
	Allocate memory from a heap. More...

void	heap_free (heap_t heap, void ptr)
	Free memory previously allocated with heap_alloc. More...

Detailed Description

A simple heap memory manager.

Definition in file heap.c.

Data Structure Documentation

struct heap

Definition at line 32 of file heap.c.

Data Fields
pagetable_t *	pt
void *	vaddr
uint64_t	pages
uint64_t	maxpages
struct fblock_header *	first_fblock
uint64_t	reserved

struct block_header_t

Definition at line 42 of file heap.c.

Data Fields
uint64_t	size
uint64_t	flags

struct block_footer_t

Definition at line 48 of file heap.c.

Data Fields
uint64_t	size

struct fblock_header_t

Definition at line 53 of file heap.c.

Data Fields
struct block_header	block
struct fblock_header *	next_fblock
struct fblock_header *	prev_fblock

Macro Definition Documentation

#define ALLOC_PAGES 16

Definition at line 17 of file heap.c.

Referenced by grow_heap(), and heap_create().

#define FLAG_ALLOCATED (1 << 0)

Definition at line 20 of file heap.c.

Referenced by grow_heap(), heap_alloc(), next_fblock(), next_fblock_adj(), prev_fblock(), and prev_fblock_adj().

#define round16	(	n,
		r
	)	(((((n) - (r) + 31) >> 4) << 4) + (r) - 16)

Definition at line 24 of file heap.c.

Referenced by heap_alloc().

#define total_bytes ( b ) ((b)->size + sizeof(block_header_t) + sizeof(block_footer_t))

Definition at line 29 of file heap.c.

Referenced by heap_free(), next_fblock(), next_fblock_adj(), prev_fblock(), and prev_fblock_adj().

Function Documentation

heap_t* heap_create	(	pagetable_t *	pt,
		void *	vaddr,
		uint64_t	maxpages
	)

Create a new heap from which to allocate virtual memory.

Parameters

[in]	pt	The page table from which virtual memory is to be allocated.
[in]	vaddr	The virtual address of the first byte to use for the heap.
[in]	maxpages	The maximum number of pages that the heap will grow to fill.

Returns: A pointer to a the created heap structure.

Definition at line 61 of file heap.c.

Referenced by cmd_test_heap().

void heap_destroy ( heap_t * heap )

Destroy a heap, returning its memory to page table.

Parameters

[in] heap The heap to be destroyed.

Definition at line 90 of file heap.c.

Referenced by cmd_test_heap().

static fblock_header_t* next_fblock_adj	(	heap_t *	heap,
		block_header_t *	bh
	)

static

Check the next block adjacent to 'b'.

If it's free, return a pointer to it.

Definition at line 99 of file heap.c.

Referenced by heap_free().

static fblock_header_t* prev_fblock_adj	(	heap_t *	heap,
		block_header_t *	bh
	)

static

Check the preceding block adjacent to 'b'.

If it's free, return a pointer to it.

Definition at line 114 of file heap.c.

Referenced by heap_free().

static fblock_header_t* next_fblock	(	heap_t *	heap,
		block_header_t *	bh
	)

static

Scan all blocks after 'b' until a free block is encountered and return it.

If no free blocks are found, return NULL.

Definition at line 131 of file heap.c.

Referenced by heap_free().

static fblock_header_t* prev_fblock	(	heap_t *	heap,
		block_header_t *	bh
	)

static

Scan all blocks preceding 'b' until a free block is encountered and return it.

If no free blocks are found, return NULL.

Definition at line 148 of file heap.c.

Referenced by grow_heap(), and heap_free().

static fblock_header_t* grow_heap	(	heap_t *	heap,
		uint64_t	minsize
	)

static

Grow the heap so that it's big enough to hold at least minsize newly allocated bytes (not including headers).

Return a pointer to the first new free block if successful. Otherwise return NULL.

Definition at line 168 of file heap.c.

Referenced by find_fblock().

static fblock_header_t* find_fblock	(	heap_t *	heap,
		uint64_t	size
	)

static

Definition at line 225 of file heap.c.

Referenced by heap_alloc().

void* heap_alloc	(	heap_t *	heap,
		uint64_t	size
	)

Allocate memory from a heap.

Parameters

[in]	heap	The heap from which to allocate the memory.
[in]	size	The size, in bytes, of the allocation.

Returns: A pointer to a the allocated memory.

Definition at line 239 of file heap.c.

Referenced by cmd_test_heap().

void heap_free	(	heap_t *	heap,
		void *	ptr
	)

Free memory previously allocated with heap_alloc.

Parameters

[in]	heap	The heap from which the memory was allocated.
[in]	ptr	A pointer to the memory that was allocated.

Definition at line 319 of file heap.c.

Referenced by cmd_test_heap().

Data Structures

Macros

Functions

Detailed Description

Data Structure Documentation

Macro Definition Documentation

Function Documentation