pthread_rwlockattr_init or pthread_rwlockattr_destroy Subroutines

Purpose

Initializes and destroys read-write lock attributes object.

Library

Threads Library (libpthreads.a)

Syntax

#include <pthread.h>

int pthread_rwlockattr_init (attr)
pthread_rwlockattr_t *attr;

int pthread_rwlockattr_destroy (attr)
pthread_rwlockattr_t *attr;

Description

The pthread_rwlockattr_init subroutine initializes a read-write lock attributes object attr with the default value for all of the attributes defined by the implementation. Results are undefined if pthread_rwlockattr_init is called specifying an already initialized read-write lock attributes object.

After a read-write lock attributes object has been used to initialize one or more read-write locks, any function affecting the attributes object (including destruction) does not affect any previously initialized read-write locks.

The pthread_rwlockattr_destroy subroutine destroys a read-write lock attributes object. The effect of subsequent use of the object is undefined until the object is re-initialized by another call to pthread_rwlockattr_init. An implementation may cause pthread_rwlockattr_destroy to set the object referenced by attr to an invalid value.

Parameters

Return Value

If successful, the pthread_rwlockattr_init and pthread_rwlockattr_destroy subroutines return zero. Otherwise, an error number is returned to indicate the error.

Error Codes

The pthread_rwlockattr_init subroutine will fail if:

The pthread_rwlockattr_destroy subroutine will fail if: