---
name: "erl_malloc"
section: "3erl"
platform: "linux"
package: "erlang-manpages"
version: "1:21.2.6+dfsg-1"
release: "Debian 10 (Buster)"
platforms: ["linux"]
url: "https://new.carta.tech/erl_malloc"
---

# erl\_malloc(3erl)

Memory allocation functions.

## NAME

erl\_malloc - Memory allocation functions.

## DESCRIPTION

This module provides functions for allocating and deallocating memory.

## EXPORTS

**ETERM \*erl\_alloc\_eterm(etype)**\

Types:

unsigned char etype;\

Allocates an *(ETERM)* structure.

Specify *etype* as one of the following constants:

- \*

  *ERL\_INTEGER*

- \*

  *ERL\_U\_INTEGER* (unsigned integer)

- \*

  *ERL\_ATOM*

- \*

  *ERL\_PID* (Erlang process identifier)

- \*

  *ERL\_PORT*

- \*

  *ERL\_REF* (Erlang reference)

- \*

  *ERL\_LIST*

- \*

  *ERL\_EMPTY\_LIST*

- \*

  *ERL\_TUPLE*

- \*

  *ERL\_BINARY*

- \*

  *ERL\_FLOAT*

- \*

  *ERL\_VARIABLE*

- \*

  *ERL\_SMALL\_BIG* (bignum)

- \*

  *ERL\_U\_SMALL\_BIG* (bignum)

*ERL\_SMALL\_BIG* and *ERL\_U\_SMALL\_BIG* are for creating Erlang *bignums*, which can contain integers of any size. The size of an integer in Erlang is machine-dependent, but any integer \> 2^28 requires a bignum.

**void erl\_eterm\_release(void)**\

Clears the freelist, where blocks are placed when they are released by *erl\_free\_term()* and *erl\_free\_compound()*.

**void erl\_eterm\_statistics(allocated, freed)**\

Types:

long \*allocated;\
 long \*freed;\

Reports term allocation statistics.

*allocated* and *freed* are initialized to contain information about the fix-allocator used to allocate *ETERM* components.

- \*

  *allocated* is the number of blocks currently allocated to *ETERM* objects.

- \*

  *freed* is the length of the freelist, where blocks are placed when they are released by *erl\_free\_term()* and *erl\_free\_compound()*.

**void erl\_free(ptr)**\

Types:

void \*ptr;\

Calls the standard *free()* function.

**void erl\_free\_array(array, size)**\

Types:

ETERM \*\*array;\
 int size;\

Frees an array of Erlang terms.

- \*

  *array* is an array of ETERM\* objects.

- \*

  *size* is the number of terms in the array.

**void erl\_free\_compound(t)**\

Types:

ETERM \*t;\

Normally it is the programmer's responsibility to free each Erlang term that has been returned from any of the *Erl\_Interface* functions. However, as many of the functions that build new Erlang terms in fact share objects with other existing terms, it can be difficult for the programmer to maintain pointers to all such terms to free them individually.

*erl\_free\_compound()* recursively frees all of the subterms associated with a specified Erlang term, regardless of whether we are still holding pointers to the subterms.

For an example, see section **Building Terms and Patterns** in the User's Guide.

**void erl\_free\_term(t)**\

Types:

ETERM \*t;\

Frees an Erlang term.

**void erl\_malloc(size)**\

Types:

long size;\

Calls the standard *malloc()* function.