NAME

pthread_attr_init, pthread_attr_destroy - initialize or destroy threads attribute object

SYNOPSIS

cc -mt [ flag... ] file... -lpthread [ library... ]
#include <pthread.h>
int pthread_attr_init(pthread_attr_t *attr);

int pthread_attr_destroy(pthread_attr_t *attr);

DESCRIPTION

The function pthread_attr_init() initializes a thread attributes object attr with the default value for all of the individual attributes used by a given implementation.

The resulting attribute object (possibly modified by setting individual attribute values), when used by pthread_create(), defines the attributes of the thread created. A single attributes object can be used in multiple simultaneous calls to pthread_create().

The pthread_attr_init() function initializes a thread attributes object ( attr) with the default value for each attribute as follows:

Attribute	Default Value	Meaning of Default
contentionscope	PTHREAD_SCOPE_PROCESS	resource competition within process
detachstate	PTHREAD_CREATE_JOINABLE	joinable by other threads
stackaddr	NULL	stack allocated by system
stacksize	0	1 or 2 megabyte
priority	0	priority of the thread
policy	SCHED_OTHER	traditional time-sharing policy
inheritsched	PTHREAD_INHERIT_SCHED	scheduling policy and parameters are inherited from the creating thread
guardsize	PAGESIZE	size of guard area for a thread's created stack

The pthread_attr_destroy() function destroys a thread attributes object ( attr), which cannot be reused until it is reinitialized. An implementation may cause pthread_attr_destroy() to set attr to an implementation-dependent invalid value. The behavior of using the attribute after it has been destroyed is undefined.

RETURN VALUES

Upon successful completion, pthread_attr_init() and pthread_attr_destroy() return a value of 0. Otherwise, an error number is returned to indicate the error.

ERRORS

The pthread_attr_init() function will fail if:

ENOMEM

Insufficient memory exists to initialize the thread attributes object.

The pthread_attr_destroy() function may fail if:

EINVAL

attr is invalid.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:

ATTRIBUTE TYPE	ATTRIBUTE VALUE
Interface Stability	Committed
MT-Level	MT-Safe
Standard	See standards(7).