---
name: "pthread_rwlockattr_init"
section: "3"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["freebsd", "macos"]
url: "https://new.carta.tech/pthread_rwlockattr_init"
---

# pthread\_rwlockattr\_init(3)

initialize a read/write lock attributes object

## NAME

**pthread\_rwlockattr\_init** – initialize a read/write lock attributes object

## LIBRARY

POSIX Threads Library (libpthread, -lpthread)

## SYNOPSIS

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

*int*\

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

## DESCRIPTION

The **pthread\_rwlockattr\_init**() function is used to initialize a read/write lock attributes object.

## RETURN VALUES

If successful, the **pthread\_rwlockattr\_init**() function will return zero. Otherwise an error number will be returned to indicate the error.

## ERRORS

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

- \[ENOMEM\]

  Insufficient memory exists to initialize the attributes object.

## SEE ALSO

[pthread\_rwlock\_init(3)](/pthread_rwlock_init/3.md), [pthread\_rwlockattr\_destroy(3)](/pthread_rwlockattr_destroy/3.md), [pthread\_rwlockattr\_getpshared(3)](/pthread_rwlockattr_getpshared/3.md), [pthread\_rwlockattr\_setpshared(3)](/pthread_rwlockattr_setpshared/3.md)

## STANDARDS

The **pthread\_rwlockattr\_init**() function is expected to conform to Version 2 of the Single UNIX Specification (“SUSv2”).

## HISTORY

The **pthread\_rwlockattr\_init**() function first appeared in FreeBSD 3.0.