Kernel heap

Allocations from the kernel heap. More...

Functions
void	pbl_malloc_init (void)
	Initialize the kernel heap.
struct pbl_heap *	pbl_malloc_heap (void)
	Get the kernel heap.
void *	pbl_malloc (size_t size)
	Allocate memory.
void *	pbl_malloc_check (size_t size)
	Allocate memory, or fail with pbl_heap_oom().
void *	pbl_zalloc (size_t size)
	Allocate zeroed memory.
void *	pbl_zalloc_check (size_t size)
	Allocate zeroed memory, or fail with pbl_heap_oom().
void *	pbl_calloc (size_t count, size_t size)
	Allocate a zeroed array.
void *	pbl_calloc_check (size_t count, size_t size)
	Allocate a zeroed array, or fail with pbl_heap_oom().
void *	pbl_realloc (void *ptr, size_t size)
	Reallocate memory.
char *	pbl_strdup (const char *s)
	Duplicate a string.
char *	pbl_strdup_check (const char *s)
	Duplicate a string, or fail with pbl_heap_oom().
void	pbl_free (void *ptr)
	Free memory.

Detailed Description

Allocations from the kernel heap.

The kernel heap sits in kernel RAM, between the linker symbols _heap_start and _heap_end. Every function here allocates from it, whatever thread calls it, and can be used before the scheduler starts and from interrupts that may call the kernel. Other heaps are reached through their own struct pbl_heap.

The _check variants never return NULL: they call pbl_heap_oom() instead.

struct entry *e = pbl_zalloc(sizeof(*e));
if (e == NULL) {
  return -ENOMEM;
}
...
pbl_free(e);

Function Documentation

pbl_calloc()

void * pbl_calloc	(	size_t	count,
		size_t	size
	)

Allocate a zeroed array.

Parameters

count	Number of elements.
size	Size of an element in bytes.

Returns

Allocated memory, or NULL.

pbl_calloc_check()

void * pbl_calloc_check	(	size_t	count,
		size_t	size
	)

Allocate a zeroed array, or fail with pbl_heap_oom().

Parameters

count	Number of elements.
size	Size of an element in bytes.

Returns

Allocated memory; NULL only if the total size is 0.

pbl_free()

void pbl_free

(

void *

ptr

)

Free memory.

Parameters

ptr	Memory from the kernel heap, or NULL (no-op). Anything else is a fatal error.

pbl_malloc()

void * pbl_malloc

(

size_t

size

)

Allocate memory.

Parameters

size	Number of bytes.

Returns

Allocated memory, or NULL.

pbl_malloc_check()

void * pbl_malloc_check

(

size_t

size

)

Allocate memory, or fail with pbl_heap_oom().

Parameters

size	Number of bytes.

Returns

Allocated memory; NULL only if size is 0.

pbl_malloc_heap()

struct pbl_heap * pbl_malloc_heap

(

void

)

Get the kernel heap.

Returns

Kernel heap.

pbl_malloc_init()

void pbl_malloc_init

(

void

)

Initialize the kernel heap.

Called once at boot, before any allocation.

pbl_realloc()

void * pbl_realloc	(	void *	ptr,
		size_t	size
	)

Reallocate memory.

Parameters

ptr	Memory from the kernel heap, or NULL.
size	New size in bytes.

Returns

New memory, or NULL on failure (ptr is then left untouched).

pbl_strdup()

char * pbl_strdup

(

const char *

s

)

Duplicate a string.

Parameters

s

String.

Returns

Copy of s, or NULL.

pbl_strdup_check()

char * pbl_strdup_check

(

const char *

s

)

Duplicate a string, or fail with pbl_heap_oom().

Parameters

s

String.

Returns

Copy of s.

pbl_zalloc()

void * pbl_zalloc

(

size_t

size

)

Allocate zeroed memory.

Parameters

size	Number of bytes.

Returns

Allocated memory, or NULL.

pbl_zalloc_check()

void * pbl_zalloc_check

(

size_t

size

)

Allocate zeroed memory, or fail with pbl_heap_oom().

Parameters

size	Number of bytes.

Returns

Allocated memory; NULL only if size is 0.