Jump to content United States-English
HP.com Home Products and Services Support and Drivers Solutions How to Buy
» Contact HP
More options
HP.com home
HP-UX Reference > P


Pthread Library
HP-UX 11i Version 3: February 2007

Technical documentation

» Feedback
Content starts here

 » Table of Contents

 » Index


pthread_rwlockattr_init(), pthread_rwlockattr_destroy() — initialize or destroy a read-write lock attributes object


#include <pthread.h>

int pthread_rwlockattr_init( pthread_rwlockattr_t *attr );

int pthread_rwlockattr_destroy( pthread_rwlockattr_t *attr );



Pointer to the read-write lock attributes object to be initialized or destroyed.


pthread_rwlockattr_init() initializes the read-write lock attributes object attr with the default value for all attributes. The attributes object describes a read-write lock in detail and is passed to the read-write lock initialization function.

When a read-write lock attributes object is used to initialize a read-write lock, the values of the individual attributes determine the characteristics of the new read-write lock. Attributes objects act like additional parameters to object initialization.

After a read-write lock attributes object has been used to initialize one or more read-write lock, any function affecting the attributes object does not affect the previously initialized read-write locks.

The read-write lock attributes and their default values are:


The default value is PTHREAD_PROCESS_PRIVATE.

If an initialized read-write lock attributes object is reinitialized, undefined behavior results.

pthread_rwlockattr_destroy() destroys the read-write lock attributes object attr. The destroyed read-write lock attributes object ceases to exist and its resources are reclaimed. Referencing the object after it has been destroyed results in undefined behavior. A destroyed read-write lock attributes object can be reinitialized using the function pthread_rwlockattr_init().

Read-write locks which have been already initialized using this attributes object are not affected by the destruction of the read-write lock attributes object.


Upon successful completion, pthread_rwlockattr_init() and pthread_rwlockattr_destroy() return zero. Otherwise, an error number is returned to indicate the error (the errno variable is not set).


For each of the following conditions, if the condition is detected, the pthread_rwlockattr_init() and pthread_rwlockattr_destroy() functions return the corresponding error number:


There is insufficient memory available in which to initialize attr.


The value specified by attr is invalid.


pthread_rwlockattr_init() and pthread_rwlockattr_destroy() were developed by X/Open.


pthread_rwlockattr_init(): X/Open. pthread_rwlockattr_destroy(): X/Open.

Printable version
Privacy statement Using this site means you accept its terms Feedback to webmaster
© 1983-2007 Hewlett-Packard Development Company, L.P.