# PetscMallocSet
Sets the routines used to do mallocs and frees. This routine MUST be called before `PetscInitialize()` and may be called only once. 
## Synopsis
```
#include "petscsys.h"   
PetscErrorCode PetscMallocSet(PetscErrorCode (*imalloc)(size_t, PetscBool, int, const char[], const char[], void **), PetscErrorCode (*ifree)(void *, int, const char[], const char[]), PetscErrorCode (*iralloc)(size_t, int, const char[], const char[], void **))
```
Not Collective


## Input Parameters

- ***imalloc -*** the routine that provides the malloc (also provides calloc(), which is used depends on the second argument)
- ***ifree -*** the routine that provides the free
- ***iralloc -*** the routine that provides the realloc





## See Also
 `PetscMallocClear()`

## Level
developer

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/sys/memory/mal.c.html#PetscMallocSet">src/sys/memory/mal.c</A>


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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/sys/memory/mal.c)


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