# pthread_rwlockattr_getpshared

## PROLOG



           This manual page is part of the POSIX Programmer's Manual.  The
           Linux implementation of this interface may differ (consult the
           corresponding Linux manual page for details of Linux behavior), or
           the interface may not be implemented on Linux.
    


## NAME



           pthread_rwlockattr_getpshared, pthread_rwlockattr_setpshared — get
           and set the process-shared attribute of the read-write lock
           attributes object
    


## SYNOPSIS



           #include <pthread.h>
    
           int pthread_rwlockattr_getpshared(const pthread_rwlockattr_t
               *restrict _attr_ , int *restrict _pshared_);
           int pthread_rwlockattr_setpshared(pthread_rwlockattr_t *_attr_ ,
               int _pshared_);
    


## DESCRIPTION



           The _pthread_rwlockattr_getpshared_() function shall obtain the
           value of the _process-shared_ attribute from the initialized
           attributes object referenced by _attr_.  The
           _pthread_rwlockattr_setpshared_() function shall set the _process-_
           _shared_ attribute in an initialized attributes object referenced by
           _attr_.
    
           The _process-shared_ attribute shall be set to
           PTHREAD_PROCESS_SHARED to permit a read-write lock to be operated
           upon by any thread that has access to the memory where the read-
           write lock is allocated, even if the read-write lock is allocated
           in memory that is shared by multiple processes. See _Section 2.9.9_ ,
           _Synchronization Object Copies and Alternative Mappings_ for further
           requirements. The default value of the _process-shared_ attribute
           shall be PTHREAD_PROCESS_PRIVATE.
    
           Additional attributes, their default values, and the names of the
           associated functions to get and set those attribute values are
           implementation-defined.
    
           The behavior is undefined if the value specified by the _attr_
           argument to _pthread_rwlockattr_getpshared_() or
           _pthread_rwlockattr_setpshared_() does not refer to an initialized
           read-write lock attributes object.
    


## RETURN VALUE



           Upon successful completion, the _pthread_rwlockattr_getpshared_()
           function shall return zero and store the value of the _process-_
           _shared_ attribute of _attr_ into the object referenced by the _pshared_
           parameter. Otherwise, an error number shall be returned to
           indicate the error.
    
           If successful, the _pthread_rwlockattr_setpshared_() function shall
           return zero; otherwise, an error number shall be returned to
           indicate the error.
    


## ERRORS



           The _pthread_rwlockattr_setpshared_() function may fail if:
    
           **EINVAL** The new value specified for the attribute is outside the
                  range of legal values for that attribute.
    
           These functions shall not return an error code of **[EINTR]**.
    
           _The following sections are informative._
    


## EXAMPLES



           None.
    


## APPLICATION USAGE



           None.
    


## RATIONALE



           None.
    


## FUTURE DIRECTIONS



           None.
    


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