NAME

pthread_mutexattr_init pthread_mutexattr_destroy — initialise and destroy mutex attributes object

SYNOPSIS

#include <pthread.h>

int pthread_mutexattr_init(pthread_mutexattr_t *attr);
int pthread_mutexattr_destroy(pthread_mutexattr_t *attr);

DESCRIPTION

The function pthread_mutexattr_init() initialises a mutex attributes object attr with the default value for all of the attributes defined by the implementation.

The effect of initialising an already initialised mutex attributes object is undefined.

After a mutex attributes object has been used to initialise one or more mutexes, any function affecting the attributes object (including destruction) does not affect any previously initialised mutexes.

The pthread_mutexattr_destroy() function destroys a mutex attributes object; the object becomes, in effect, uninitialised. An implementation may cause pthread_mutexattr_destroy() to set the object referenced by attr to an invalid value. A destroyed mutex attributes object can be re-initialised using pthread_mutexattr_init(); the results of otherwise referencing the object after it has been destroyed are undefined.

RETURN VALUE

Upon successful completion, pthread_mutexattr_init() and pthread_mutexattr_destroy() return zero. Otherwise, an error number is returned to indicate the error.

ERRORS

The pthread_mutexattr_init() function may fail if:

[ENOMEM]

Insufficient memory exists to initialise the mutex attributes object.

The pthread_mutexattr_destroy() function may fail if:

[EINVAL]

The value specified by attr is invalid.

These functions will not return an error code of [EINTR].

EXAMPLES

None.

APPLICATION USAGE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

pthread_create(3) , pthread_mutex_init(3) , pthread_mutexattr_init() , pthread_cond_init(3) , <pthread.h> .

DERIVATION

Derived from the POSIX Threads Extension (1003.1c-1995)