NAME
pthread_condattr_destroy, pthread_condattr_init - destroy and
initialize the condition variable attributes object
SYNOPSIS
#include <pthread.h>
int pthread_condattr_destroy(pthread_condattr_t *attr);
int pthread_condattr_init(pthread_condattr_t *attr);
DESCRIPTION
The pthread_condattr_destroy() function shall destroy a condition
variable attributes object; the object becomes, in effect,
uninitialized. An implementation may cause pthread_condattr_destroy()
to set the object referenced by attr to an invalid value. A destroyed
attr attributes object can be reinitialized using
pthread_condattr_init(); the results of otherwise referencing the
object after it has been destroyed are undefined.
The pthread_condattr_init() function shall initialize a condition
variable attributes object attr with the default value for all of the
attributes defined by the implementation.
Results are undefined if pthread_condattr_init() is called specifying
an already initialized attr attributes object.
After a condition variable attributes object has been used to
initialize one or more condition variables, any function affecting the
attributes object (including destruction) shall not affect any
previously initialized condition variables.
This volume of IEEE Std 1003.1-2001 requires two attributes, the clock
attribute and the process-shared attribute.
Additional attributes, their default values, and the names of the
associated functions to get and set those attribute values are
implementation-defined.
RETURN VALUE
If successful, the pthread_condattr_destroy() and
pthread_condattr_init() functions shall return zero; otherwise, an
error number shall be returned to indicate the error.
ERRORS
The pthread_condattr_destroy() function may fail if:
EINVAL The value specified by attr is invalid.
The pthread_condattr_init() function shall fail if:
ENOMEM Insufficient memory exists to initialize the condition variable
attributes object.
These functions shall not return an error code of [EINTR].
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
See pthread_attr_init() and pthread_mutex_init() .
A process-shared attribute has been defined for condition variables for
the same reason it has been defined for mutexes.
FUTURE DIRECTIONS
None.
SEE ALSO
pthread_attr_destroy() , pthread_cond_destroy() ,
pthread_condattr_getpshared() , pthread_create() ,
pthread_mutex_destroy() , the Base Definitions volume of
IEEE Std 1003.1-2001, <pthread.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online
at http://www.opengroup.org/unix/online.html .