---
name: "pthread_attr"
section: "3"
platform: "macos"
package: "libpthread"
version: "539.100.4"
release: "macOS 26.5"
platforms: ["freebsd", "macos"]
url: "https://new.carta.tech/pthread_attr"
---

# pthread\_attr(3)

thread attribute operations

## NAME

**pthread\_attr\_init**, **pthread\_attr\_destroy**, **pthread\_attr\_setstack**, **pthread\_attr\_getstack**, **pthread\_attr\_setguardsize**, **pthread\_attr\_getguardsize** – thread attribute operations

## SYNOPSIS

**#include \<pthread.h\>**

*int*\

**pthread\_attr\_init**(*pthread\_attr\_t \*attr*);

*int*\

**pthread\_attr\_destroy**(*pthread\_attr\_t \*attr*);

*int*\

**pthread\_attr\_setstack**(*pthread\_attr\_t \*attr*,  *void \*stackaddr*, *size\_t stacksize*);

*int*\

**pthread\_attr\_getstack**(*const pthread\_attr\_t \* restrict attr*, *void \*\* restrict stackaddr*, *size\_t \* restrict stacksize*);

*int*\

**pthread\_attr\_setstacksize**(*pthread\_attr\_t \*attr*, *size\_t stacksize*);

*int*\

**pthread\_attr\_getstacksize**(*const pthread\_attr\_t \*attr*, *size\_t \*stacksize*);

*int*\

**pthread\_attr\_setguardsize**(*pthread\_attr\_t \*attr*, *size\_t guardsize*);

*int*\

**pthread\_attr\_getguardsize**(*const pthread\_attr\_t \*attr*, *size\_t \*guardsize*);

*int*\

**pthread\_attr\_setstackaddr**(*pthread\_attr\_t \*attr*, *void \*stackaddr*);

*int*\

**pthread\_attr\_getstackaddr**(*const pthread\_attr\_t \*attr*, *void \*\*stackaddr*);

*int*\

**pthread\_attr\_setdetachstate**(*pthread\_attr\_t \*attr*, *int detachstate*);

*int*\

**pthread\_attr\_getdetachstate**(*const pthread\_attr\_t \*attr*, *int \*detachstate*);

*int*\

**pthread\_attr\_setinheritsched**(*pthread\_attr\_t \*attr*, *int inheritsched*);

*int*\

**pthread\_attr\_getinheritsched**(*const pthread\_attr\_t \*attr*, *int \*inheritsched*);

*int*\

**pthread\_attr\_setschedparam**(*pthread\_attr\_t \*attr*, *const struct sched\_param \*param*);

*int*\

**pthread\_attr\_getschedparam**(*const pthread\_attr\_t \*attr*, *struct sched\_param \*param*);

*int*\

**pthread\_attr\_setschedpolicy**(*pthread\_attr\_t \*attr*, *int policy*);

*int*\

**pthread\_attr\_getschedpolicy**(*const pthread\_attr\_t \*attr*, *int \*policy*);

*int*\

**pthread\_attr\_setscope**(*pthread\_attr\_t \*attr*, *int contentionscope*);

*int*\

**pthread\_attr\_getscope**(*const pthread\_attr\_t \*attr*, *int \*contentionscope*);

## DESCRIPTION

Thread attributes are used to specify parameters to **pthread\_create**(). One attribute object can be used in multiple calls to **pthread\_create**(), with or without modifications between calls.

The **pthread\_attr\_init**() function initializes *attr* with all the default thread attributes.

The **pthread\_attr\_destroy**() function destroys *attr*.

The **pthread\_attr\_set\***() functions set the attribute that corresponds to each function name.

The **pthread\_attr\_get\***() functions copy the value of the attribute that corresponds to each function name to the location pointed to by the second function parameter.

## RETURN VALUES

If successful, these functions return 0. Otherwise, an error number is returned to indicate the error.

## ERRORS

The **pthread\_attr\_init**() function will fail if:

- \[ENOMEM\]

  Out of memory.

The **pthread\_attr\_destroy**() function will fail if:

- \[EINVAL\]

  Invalid value for *attr*.

## SEE ALSO

[pthread\_attr\_affinity\_np(3)](/pthread_attr_affinity_np/3.md), [pthread\_attr\_get\_np(3)](/pthread_attr_get_np/3.md), [pthread\_create(3)](/pthread_create/3.md)

## STANDARDS

**pthread\_attr\_init**(), **pthread\_attr\_destroy**(), **pthread\_attr\_setstacksize**(), **pthread\_attr\_getstacksize**(), **pthread\_attr\_setstackaddr**(), **pthread\_attr\_getstackaddr**(), **pthread\_attr\_setdetachstate**(), and **pthread\_attr\_getdetachstate**() functions conform to ISO/IEC 9945-1:1996 (“POSIX.1”)

The **pthread\_attr\_setinheritsched**(), **pthread\_attr\_getinheritsched**(), **pthread\_attr\_setschedparam**(), **pthread\_attr\_getschedparam**(), **pthread\_attr\_setschedpolicy**(), **pthread\_attr\_getschedpolicy**(), **pthread\_attr\_setscope**(), and **pthread\_attr\_getscope**() functions conform to Version 2 of the Single UNIX Specification (“SUSv2”)