NAME

pthread_attr_init, pthread_attr_destroy — thread attribute operations

LIBRARY

POSIX Threads Library (libpthread, -lpthread)

SYNOPSIS

#include <pthread.h>

int
pthread_attr_init(pthread_attr_t *attr);

int
pthread_attr_destroy(pthread_attr_t *attr);

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 the calls. The pthread_attr_t type is an opaque representation of the thread attributes; any access to the object other than via the described pthread_attr_*() functions may result in undefined behavior.

The pthread_attr_init() function initializes attr with the default thread attributes used in the implementation. Depending on the implementation, undefined behavior may follow if an uninitialized thread attribute object is used with some of the thread attribute functions. It is therefore a good practice to always use pthread_attr_init(), even if this might be unnecessary. Undefined behavior may also follow if an already initialized attr is used with pthread_attr_init().

When the attribute object is no longer needed, it should be destroyed by using pthread_attr_destroy(). The function has no effect on threads that were created by using a given attribute object. A destroyed attr can be reinitialized using pthread_attr_init(), but all other actions with the destroyed object are unspecified.

The following standard thread attribute functions are available:

Function	Description
pthread_attr_getdetachstate(3)	thread detach state
pthread_attr_getguardsize(3)	thread guard size
pthread_attr_getinheritsched(3)	inherit scheduler attribute
pthread_attr_getschedparam(3)	thread scheduling parameter
pthread_attr_getschedpolicy(3)	thread scheduling policy
pthread_attr_getscope(3)	thread contention scope
pthread_attr_getstack(3)	thread stack
pthread_attr_getstacksize(3)	thread stack size
pthread_attr_getstackaddr(3)	thread stack address

Each listed pthread_attr_get*() function contains a pthread_attr_set*() counterpart. In addition, the following NetBSD specific extensions are available:

Function	Description
pthread_attr_get_np(3)	attributes of a running thread
pthread_attr_getname_np(3)	descriptive name of an attribute

RETURN VALUES

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

ERRORS

No errors are defined for pthread_attr_init() and pthread_attr_destroy().

SEE ALSO

pthread_create(3), pthread_join(3)

STANDARDS

Both pthread_attr_init() and pthread_attr_destroy() conform to IEEE Std 1003.1-2001 (“POSIX.1”).