pthread_rwlockattr_destroy, pthread_rwlockattr_init - destroy and initialize the read-write lock attributes object
int pthread_rwlockattr_destroy(pthread_rwlockattr_t *attr);
int pthread_rwlockattr_init(pthread_rwlockattr_t *attr);
The pthread_rwlockattr_destroy() function shall destroy a read-write lock attributes object. A destroyed attr attributes object can be reinitialized using pthread_rwlockattr_init(); the results of otherwise referencing the object after it has been destroyed are undefined. An implementation may cause pthread_rwlockattr_destroy() to set the object referenced by attr to an invalid value.
The pthread_rwlockattr_init() function shall initialize a read-write lock attributes object attr with the default value for all of the attributes defined by the implementation.
Results are undefined if pthread_rwlockattr_init() is called specifying an already initialized attr attributes object.
After a read-write lock attributes object has been used to initialize one or more read-write locks, any function affecting the attributes object (including destruction) shall not affect any previously initialized read-write locks.
The behavior is undefined if the value specified by the attr argument to pthread_rwlockattr_destroy() does not refer to an initialized read-write lock attributes object.
If successful, the pthread_rwlockattr_destroy() and pthread_rwlockattr_init() functions shall return zero; otherwise, an error number shall be returned to indicate the error.
The pthread_rwlockattr_init() function shall fail if:
- Insufficient memory exists to initialize the read-write lock attributes object.
These functions shall not return an error code of [EINTR].
If an implementation detects that the value specified by the attr argument to pthread_rwlockattr_destroy() does not refer to an initialized read-write lock attributes object, it is recommended that the function should fail and report an [EINVAL] error.
First released in Issue 5.
The following changes are made for alignment with IEEE Std 1003.1j-2000:
The margin code in the SYNOPSIS is changed to THR to indicate that the functionality is now part of the Threads option (previously it was part of the Read-Write Locks option in IEEE Std 1003.1j-2000 and also part of the XSI extension).
The SEE ALSO section is updated.
The pthread_rwlockattr_destroy() and pthread_rwlockattr_init() functions are moved from the Threads option to the Base.
The [EINVAL] error for an uninitialized read-write lock attributes object is removed; this condition results in undefined behavior.
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