pthread_attr_getukeyset_np or pthread_attr_setukeyset_np Subroutine

Purpose

Gets and sets the value of the active user-key-set attribute of a thread attributes object.

Library

Threads library (libpthreads.a)

Syntax

#include <pthread.h>
#include <sys/ukeys.h>

int pthread_attr_getukeyset_np (attr, ukeyset)
const pthread_attr_t *  attr;
ukeyset_t *  ukeyset;

Description

The ukeyset parameter specifies the active user-key-set for a thread that is created with this attributes object. By default, newly-created threads can only access (both read and write) memory pages that have been assigned the default user-key UKEY_PUBLIC. User-key-sets are not inherited across the pthread_create subroutine.

The pthread_attr_getukeyset_np subroutine gets the user-key-set attribute, while the pthread_attr_setukeyset_np subroutine sets the user-key-set attribute in the thread attributes object specified by the attr parameter.

Both the pthread_attr_getukeyset_np and the pthread_attr_setukeyset_np subroutines fail unless the ukey_enable subroutine has been previously successfully run by a thread in the process. Refer to the Storage Protect Keys article for more details.

Parameters

Table 1. Parameters
Item	Description
`attr`	Specifies the thread attributes object.
`ukeyset`	Points to a location where the user-key-set attribute value is stored.

Return Values

The pthread_attr_getukeyset_np and pthread_attr_setukeyset_np subroutines return a value of 0 on success. Otherwise, an error code is returned.

Errors Codes

The pthread_attr_getukeyset_np and pthread_attr_setukeyset_np subroutines are unsuccessful if the following are true:

Table 2. Error Codes
Item	Description
`EINVAL`	The attribute object specified by the `attr` parameter is invalid or the address pointed to by the `ukeyset` parameter is not aligned to hold a user-key-set.
`ENOSYS`	Process is not a user-key-enabled process.

In addition, the pthread_attr_setukeyset_np subroutine is unsuccessful if the following is true:

Item	Description
`EINVAL`	The user-key-set value that is specified by the `ukeyset` parameter is not valid.

These functions will not return an error code of EINTR.