Memory API

The memory module implements efficient memory management systems, with a focus on the Arena Allocator.

Arena Allocator

The Arena Allocator is a powerful, region-based memory allocator that simplifies memory management in C applications.

Types

type myrtx_arena_t

Opaque structure representing an arena allocator.

typedef struct myrtx_arena {
    // Internal details
} myrtx_arena_t;

type myrtx_scratch_arena_t

Container for temporary arena memory regions with automatic reset.

typedef struct myrtx_scratch_arena {
    myrtx_arena_t* arena;     // Arena being used
    myrtx_arena_t* parent;    // Parent arena, if any
    size_t marker;            // Position for reset
} myrtx_scratch_arena_t;

Initialization and Cleanup

bool myrtx_arena_init(myrtx_arena_t *arena, size_t block_size)

Initializes an arena allocator.

Parameters:

arena – Pointer to an uninitialized arena structure
block_size – Size of each memory block in bytes (0 for default size)

Returns:

true on success, false on error

void myrtx_arena_reset(myrtx_arena_t *arena)

Resets an arena by freeing all allocated memory blocks.

Parameters:

arena – Pointer to an initialized arena

void myrtx_arena_free(myrtx_arena_t *arena)

Frees all resources used by the arena.

Parameters:

arena – Pointer to an initialized arena

Memory Allocation

void *myrtx_arena_alloc(myrtx_arena_t *arena, size_t size)

Allocates memory from the arena.

Parameters:

arena – Pointer to an initialized arena
size – Number of bytes to allocate

Returns:

Pointer to the allocated memory or NULL on error

void *myrtx_arena_calloc(myrtx_arena_t *arena, size_t size)

Allocates memory from the arena and initializes it to zero.

Parameters:

arena – Pointer to an initialized arena
size – Number of bytes to allocate

Returns:

Pointer to the allocated memory or NULL on error

void *myrtx_arena_realloc(myrtx_arena_t *arena, void *ptr, size_t old_size, size_t new_size)

Resizes a previously allocated memory block.

Parameters:

arena – Pointer to an initialized arena
ptr – Pointer to previously allocated memory
old_size – Size of the previously allocated memory block
new_size – New size in bytes

Returns:

Pointer to the newly allocated memory or NULL on error

void *myrtx_arena_alloc_aligned(myrtx_arena_t *arena, size_t size, size_t alignment)

Allocates aligned memory from the arena.

Parameters:

arena – Pointer to an initialized arena
size – Number of bytes to allocate
alignment – Alignment in bytes (must be a power of two)

Returns:

Pointer to the allocated aligned memory or NULL on error

Temporary Arenas

size_t myrtx_arena_temp_begin(myrtx_arena_t *arena)

Marks the current state of an arena for temporary use.

Parameters:

arena – Pointer to an initialized arena

Returns:

Marker for the current position

void myrtx_arena_temp_end(myrtx_arena_t *arena, size_t marker)

Resets an arena to a previously marked state.

Parameters:

arena – Pointer to an initialized arena
marker – Marker position returned by myrtx_arena_temp_begin

Scratch Arenas

void myrtx_scratch_begin(myrtx_scratch_arena_t *scratch, myrtx_arena_t *parent)

Begins a scratch arena session with an existing arena.

Parameters:

scratch – Pointer to an uninitialized scratch arena structure
parent – Pointer to a parent arena (or NULL for a new arena)

void myrtx_scratch_end(myrtx_scratch_arena_t *scratch)

Ends a scratch arena session and frees temporary memory.

Parameters:

scratch – Pointer to an initialized scratch arena structure

Helper Functions

char *myrtx_arena_strdup(myrtx_arena_t *arena, const char *str)

Duplicates a string into arena memory.

Parameters:

arena – Pointer to an initialized arena
str – Null-terminated string to duplicate

Returns:

Pointer to the duplicated string or NULL on error

char *myrtx_arena_strndup(myrtx_arena_t *arena, const char *str, size_t n)

Duplicates the first n characters of a string into arena memory.

Parameters:

arena – Pointer to an initialized arena
str – String to duplicate
n – Maximum number of characters to duplicate

Returns:

Pointer to the duplicated string or NULL on error

void *myrtx_arena_memdup(myrtx_arena_t *arena, const void *ptr, size_t size)

Duplicates a memory block into arena memory.

Parameters:

arena – Pointer to an initialized arena
ptr – Memory block to duplicate
size – Size of the memory block in bytes

Returns:

Pointer to the duplicated memory block or NULL on error

Statistics and Information

size_t myrtx_arena_total_allocated(const myrtx_arena_t *arena)

Returns the total size of memory allocated by an arena.

Parameters:

arena – Pointer to an initialized arena

Returns:

Total size in bytes