MATLAB Application Program Interface Reference

C Syntax

#include "matrix.h"
#include <stdlib.h>
void mxSetAllocFcns(calloc_proc callocfcn, free_proc freefcn, 
  realloc_proc reallocfcn, malloc_proc mallocfcn);

Arguments

callocfcn

The name of the function that mxCalloc uses to perform memory allocation operations. The function you specify is ordinarily a wrapper around the ANSI C calloc function. The callocfcn you write must have the prototype:

void * callocfcn(size_t nmemb, size_t size);
nmemb
The number of contiguous elements that you want the matrix library to allocate on your behalf.

size
The size of each element. To get the size, you typically use the sizeof operator or the mxGetElementSize routine.

`void * callocfcn(size_t nmemb, size_t size);`
`nmemb`	The number of contiguous elements that you want the matrix library to allocate on your behalf.
`size`	The size of each element. To get the size, you typically use the `sizeof` operator or the `mxGetElementSize` routine.

The callocfcn you specify must create memory in which all allocated memory has been initialized to zero.

freefcn

The name of the function that mxFree uses to perform memory deallocation (freeing) operations. The freefcn you write must have the prototype:

void freefcn(void *ptr);
ptr
Pointer to beginning of the memory parcel to deallocate.

`void freefcn(void *ptr);`
`ptr`	Pointer to beginning of the memory parcel to deallocate.

The freefcn you specify must contain code to determine if ptr is NULL. If ptr is NULL, then your freefcn must not attempt to deallocate it.

reallocfcn

The name of the function that mxRealloc uses to perform memory reallocation operations. The reallocfcn you write must have the prototype:

void * reallocfcn(void *ptr, size_t size);
ptr
Pointer to beginning of the memory parcel to reallocate.

size
The size of each element. To get the size, you typically use the sizeof operator or the mxGetElementSize routine.

`void * reallocfcn(void *ptr, size_t size);`
`ptr`	Pointer to beginning of the memory parcel to reallocate.
`size`	The size of each element. To get the size, you typically use the `sizeof` operator or the `mxGetElementSize` routine.

mallocfcn

The name of the function the API functions should call in place of malloc to perform memory reallocation operations. The mallocfcn you write must have the prototype:

void * mallocfcn(size_t size);
size
The size of each element. To get the size, you typically use the sizeof operator or the mxGetElementSize routine.

`void * mallocfcn(size_t size);`
`size`	The size of each element. To get the size, you typically use the `sizeof` operator or the `mxGetElementSize` routine.

The mallocfcn you specify doesn't necessarily need to initialize the memory it allocates.

Description

Call mxSetAllocFcns to establish your own memory allocation and deallocation routines in a stand-alone (nonMEX) application.

It is illegal to call mxSetAllocFcns from a MEX-file; doing so causes a compiler error.

In a stand-alone application, if you do not call mxSetAllocFcns, then

mxCalloc simply calls the ANSI C calloc routine.
mxFree simply calls the ANSI C free routine.
mxRealloc simply calls the ANSI C realloc routine.

Writing your own callocfcn, freefcn, and reallocfcn allows you to customize memory allocation and deallocation.

Example

See mxSetAllocFcns.c in the mx subdirectory of the examples directory.