allocator.h File Reference

Interface for custom allocators. More...

#include "common.h"

Go to the source code of this file.

Data Structures
struct	cx_allocator_class
	The class definition for an allocator. More...
struct	cx_allocator_s
	Structure holding the data for an allocator. More...

Typedefs
typedef struct cx_allocator_s	CxAllocator
	High-Level type alias for the allocator type.
typedef void(*	cx_destructor_func) (void *memory)
	Function pointer type for destructor functions.
typedef void(*	cx_destructor_func2) (void *data, void *memory)
	Function pointer type for destructor functions.

Functions
int	cx_reallocate (void **mem, size_t n)
	Re-allocate a previously allocated block and changes the pointer in-place, if necessary.
void *	cxMalloc (CxAllocator const *allocator, size_t n)
	Allocate n bytes of memory.
void *	cxRealloc (CxAllocator const *allocator, void *mem, size_t n)
	Re-allocate the previously allocated block in mem, making the new block n bytes long.
int	cxReallocate (CxAllocator const *allocator, void **mem, size_t n)
	Re-allocate a previously allocated block and changes the pointer in-place, if necessary.
void *	cxCalloc (CxAllocator const *allocator, size_t nelem, size_t n)
	Allocate nelem elements of n bytes each, all initialized to zero.
void	cxFree (CxAllocator const *allocator, void *mem)
	Free a block allocated by this allocator.

Variables
CxAllocator *	cxDefaultAllocator
	A default allocator using standard library malloc() etc.

Detailed Description

Interface for custom allocators.

Typedef Documentation

cx_destructor_func

typedef void(* cx_destructor_func) (void *memory)

Function pointer type for destructor functions.

A destructor function deallocates possible contents and MAY free the memory pointed to by memory. Read the documentation of the respective function pointer to learn if a destructor SHALL, MAY, or MUST NOT free the memory in that particular implementation.

Parameters

memory

a pointer to the object to destruct

cx_destructor_func2

typedef void(* cx_destructor_func2) (void *data, void *memory)

Function pointer type for destructor functions.

A destructor function deallocates possible contents and MAY free the memory pointed to by memory. Read the documentation of the respective function pointer to learn if a destructor SHALL, MAY, or MUST NOT free the memory in that particular implementation.

Parameters

data	an optional pointer to custom data
memory	a pointer to the object to destruct

Function Documentation

cx_reallocate()

int cx_reallocate	(	void **	mem,
		size_t	n
	)

Re-allocate a previously allocated block and changes the pointer in-place, if necessary.

Error handling

errno will be set by realloc() on failure.

Parameters

mem	pointer to the pointer to allocated block
n	the new size in bytes

Returns

zero on success, non-zero on failure

cxCalloc()

void * cxCalloc	(	CxAllocator const *	allocator,
		size_t	nelem,
		size_t	n
	)

Allocate nelem elements of n bytes each, all initialized to zero.

Parameters

allocator	the allocator
nelem	the number of elements
n	the size of each element in bytes

Returns

a pointer to the allocated memory

cxFree()

void cxFree	(	CxAllocator const *	allocator,
		void *	mem
	)

Free a block allocated by this allocator.

Note

Freeing a block of a different allocator is undefined.

Parameters

allocator	the allocator
mem	a pointer to the block to free

cxMalloc()

void * cxMalloc	(	CxAllocator const *	allocator,
		size_t	n
	)

Allocate n bytes of memory.

Parameters

allocator	the allocator
n	the number of bytes

Returns

a pointer to the allocated memory

cxRealloc()

void * cxRealloc	(	CxAllocator const *	allocator,
		void *	mem,
		size_t	n
	)

Re-allocate the previously allocated block in mem, making the new block n bytes long.

This function may return the same pointer that was passed to it, if moving the memory was not necessary.

Note

Re-allocating a block allocated by a different allocator is undefined.

Parameters

allocator	the allocator
mem	pointer to the previously allocated block
n	the new size in bytes

Returns

a pointer to the re-allocated memory

cxReallocate()

int cxReallocate	(	CxAllocator const *	allocator,
		void **	mem,
		size_t	n
	)

Re-allocate a previously allocated block and changes the pointer in-place, if necessary.

This function acts like cxRealloc() using the pointer pointed to by mem.

Note

Re-allocating a block allocated by a different allocator is undefined.

Error handling

errno will be set, if the underlying realloc function does so.

Parameters

allocator	the allocator
mem	pointer to the pointer to allocated block
n	the new size in bytes

Returns

zero on success, non-zero on failure