Unilayer Memory Layer

Simple abstract unified memory management layer designed for resource-constrained systems. More...

Files
file	memory.h
	Functions and prototypes for managing memory.
file	fakem.h
	Platform-overridden typedefs and macros for handling memory.

Data Structures
struct	FAKE_MEMORY_HANDLE
	An emulated memory handle for modern systems. Overridden on most platforms. More...

Typedefs
typedef struct FAKE_MEMORY_HANDLE *	MEMORY_HANDLE
	A reference to a block of memory which the operating system may move around on its own to free up space. MUST BE locked with memory_lock() to receive a MEMORY_PTR that can be dereferenced.
typedef void *	MEMORY_PTR
	A C-style memory pointer that can be safely dereferenced.
typedef const void *	CONST_MEMORY_PTR
	A read-only MEMORY_PTR.
typedef void *	MEMORY_FAR_PTR
	On certain platforms, a MEMORY_PTR that exists outside of the current page.
typedef const void *	CONST_MEMORY_FAR_PTR
	A read-only MEMORY_FAR_PTR.

Functions
int32_t	memory_init ()
MEMORY_HANDLE	memory_alloc (uint32_t sz, uint32_t count)
	Request dynamic memory from operating system while protecting from overflow conditions.
void	memory_free (MEMORY_HANDLE handle)
	Free a block of dynamic memory previously allocated with memory_alloc().
uint32_t	memory_sz (MEMORY_HANDLE)
uint32_t	memory_resize (MEMORY_HANDLE *, uint32_t)
void	memory_copy_ptr (MEMORY_PTR, CONST_MEMORY_PTR, uint32_t)
void	memory_zero_ptr (MEMORY_PTR ptr, uint32_t sz)
	Fill a block of memory with zeros.
WARN_UNUSED MEMORY_PTR	memory_unlock (MEMORY_HANDLE handle)
	Unlock a dynamic memory handle so the system can relocate it on the heap to relieve congestion.
char *	memory_strncpy_ptr (char *, const char *, uint16_t)
int16_t	memory_strncmp_ptr (const char *, const char *, uint16_t)
int16_t	memory_strnlen_ptr (const char *s, uint16_t l)
	Get the size of a string, up to a specified maximum.
void	memory_debug_dump ()
WARN_UNUSED MEMORY_PTR	memory_lock (MEMORY_HANDLE handle)
	Lock a dynamic memory handle and return a MEMORY_PTR that can be dereferenced safely.

Detailed Description

Simple abstract unified memory management layer designed for resource-constrained systems.

Typedef Documentation

MEMORY_PTR

typedef void* MEMORY_PTR

A C-style memory pointer that can be safely dereferenced.

Interchangeable with pointers to arbitrary types (e.g. char*, int*, etc).

Function Documentation

memory_alloc()

MEMORY_HANDLE memory_alloc	(	uint32_t	sz,
		uint32_t	count
	)

Request dynamic memory from operating system while protecting from overflow conditions.

Parameters

sz	Size of blocks to request.
count	Number of blocks to request.

Returns

A MEMORY_HANDLE to allocated memory. This handle MUST BE locked to receive a MEMORY_PTR that can be dereferenced safely.

memory_free()

void memory_free

(

MEMORY_HANDLE

handle

)

Free a block of dynamic memory previously allocated with memory_alloc().

Parameters

handle

MEMORY_HANDLE to a previously allocated memory block.

memory_lock()

WARN_UNUSED MEMORY_PTR memory_lock

(

MEMORY_HANDLE

handle

)

Lock a dynamic memory handle and return a MEMORY_PTR that can be dereferenced safely.

Parameters

handle

A handle that has been successfully allocated with memory_alloc().

Returns

A typical C-style pointer that can be dereferenced as normal.

memory_strnlen_ptr()

int16_t memory_strnlen_ptr	(	const char *	s,
		uint16_t	l
	)

Get the size of a string, up to a specified maximum.

Parameters

s	MEMORY_PTR to a string to get the size of.
l	Maximum possible size of string s.

Returns

Position of the NULL terminator in string s, or if none is found under l characters, l.

memory_unlock()

WARN_UNUSED MEMORY_PTR memory_unlock

(

MEMORY_HANDLE

handle

)

Unlock a dynamic memory handle so the system can relocate it on the heap to relieve congestion.

Parameters

handle

A handle that has been previously locked with memory_lock().

Returns

NULL if the unlock was successful.

memory_zero_ptr()

void memory_zero_ptr	(	MEMORY_PTR	ptr,
		uint32_t	sz
	)

Fill a block of memory with zeros.

Parameters

ptr	MEMORY_PTR to a block of memory to overwrite. May be on the stack or a MEMORY_PTR returned from locking a MEMORY_HANDLE.
sz	Size of the block of memory to overwrite.