memory.c File Reference

A simple and preforment memory allocator. More...

#include "variables.c"
#include "errors.c"

Data Structures
struct	HeapItem

Macros
#define	HEAP_SIZE   1024
	The size of the calculator variable the heap is stored as. You can set this to a larger (or smaller) value if you want.
#define	CUSTOM_HEAP_NAME   "ConHeap"
	allows setting a custom heap variable name
#define	purge_heap()   delete(HEAP_VAR_NAME)
	Cleans up the heap for when the program is closing.
#define	__hs   #
#define	auto_purge_heap()
	Automaticlly runs purge_heap() for you.
Heap memory locations
#define	HEAP_LOCATION   0x83E5
	Memory location of heap related information.
#define	HEAP_CONSTANT   HEAP_LOCATION
#define	HEAP_CONSTANT2   ( HEAP_CONSTANT+1)
#define	HEAP_LOCATION_PTR   (HEAP_CONSTANT2+1)
#define	HEAP_TEMP   (HEAP_LOCATION_PTR+2)

Functions
void	initHeap ()
	Create the heap for you.
void	_malloc () __naked
	Assembly malloc implementation.
void *	malloc (int size) __naked
	Request to allocate an amount of memory from the heap (filled undefined random data)
void	_free () __naked
	Assembly free() implementation.
void	free (void *ptr) __naked
	Frees an allocated memory address from the heap.
void	_calloc () __naked
	Assembly function for calloc()
void *	calloc (int size) __naked
	Request to allocate an amount of memory from the heap (filled zeros)
void	copy (void *dst, void *source, int size) __naked
	Copy a region of memory.

Variables
const char	HEAP_VAR_NAME [] = addAppVarObj(CUSTOM_HEAP_NAME)
	Name of heap variable in calculator.

Detailed Description

A simple and preforment memory allocator.

This file allows for a psuedo-heap, it is a lot like how the heap works in the typical c std. This works by creating a calculator variable typically called "ConHeap" where the data is stored. It should be noted that initHeap() uses getOrCreateVar() so if somebody forgets to purge_heap() and you are using a custom HEAP_SIZE you might run into some error. So always call purge_heap() or make use of auto_purge_heap() !

It should be noted that auto_purge_heap() seems not to run correctly in programs

Optional #defines

• HEAP_SIZE - A number that is the size of varible to create for the heap.
• CUSTOM_HEAP_NAME - Sets the heap variable to a custom name

Macro Definition Documentation

auto_purge_heap

#define auto_purge_heap

(

)

Value:

   __asm                  \
   ld hl, __hs AUTO_CLOSE_HEAP_LOCATION          \
   push hl                                       \
   jp AFTER_AUTO_CLOSE_HEAP                      \
AUTO_CLOSE_HEAP_LOCATION:                        \
   __endasm; purge_heap(); __asm        \
   ret                                           \
  AFTER_AUTO_CLOSE_HEAP: __endasm

Automaticlly runs purge_heap() for you.

This must be called in main, this is because it will automaticlly run purge_heap() when the current function returns. This also must be called before ANY variables are set, it will destroy the hl register. If you call auto_purge_heap() in main before any variables are set, it will automaticlly call purge_heap() for you as main returns.

Also doesn't seem to run currectly programs.

purge_heap

#define purge_heap

(

)

delete(HEAP_VAR_NAME)

Cleans up the heap for when the program is closing.

Call this before you exit the program if you initialized the heap

Function Documentation

_calloc()

void _calloc

(

)

Assembly function for calloc()

Parameters

[bc]	Size of memory to be requested

Returns

hl = memory location

_free()

void _free

(

)

Assembly free() implementation.

Parameters

[hl]	Location of memory to be freed

See free()

_malloc()

void _malloc

(

)

Assembly malloc implementation.

Parameters

[bc]	Size of memory to be requested

Returns

hl = memory location

See malloc() and all error conditions apply.

calloc()

void * calloc

(

int

size

)

Request to allocate an amount of memory from the heap (filled zeros)

Parameters

[size]

Amount of memory to be allocated

Returns

A pointer to free memory

Same as malloc() except fills data buffer with zeros

copy()

void copy	(	void *	dst,
		void *	source,
		int	size )

Copy a region of memory.

Parameters

[dst]	Location to copy to
[source]	Location to copy from
[size]	Amount of ram to copy.

This is not strncpy and will disregard null termination.

free()

void free

(

void *

ptr

)

Frees an allocated memory address from the heap.

Parameters

[ptr]

Memory to be freed

initHeap()

void initHeap

(

)

Create the heap for you.

Call this to create/reset the heap. You can call this a secound time to reset the heap for you. But don't use any pointers you got from malloc/calloc or you might get undefined outputs.

malloc()

void * malloc

(

int

size

)

Request to allocate an amount of memory from the heap (filled undefined random data)

Parameters

[size]

Amount of memory to be allocated

Returns

A pointer to free memory

This should be identical to the normal malloc function. But be warned that if you write to bytes past what you have allocated you can cause undefined behavior!

If NO_MEMMORY_ERRORS is defined instead of raising an error, malloc will return NULL. Malloc can error for two reasons, if you pass in zero, or if you allocate too much memory for the heap variable.