pthread_rwlockattr_setpshared(3P)

NAME
     pthread_rwlockattr_setpshared, pthread_rwlockattr_getpshared - set/get a
     read-write lock attribute object's process-shared attribute

C SYNOPSIS
     #include <pthread.h>

     int pthread_rwlockattr_setpshared(pthread_rwlockattr_t *attr,
          int pshared);

     int pthread_rwlockattr_getpshared(const pthread_rwlockattr_t *attr,
          int *opshared);

DESCRIPTION
     These functions manipulate the initialized read-write lock attribute
     object attr [see pthread_rwlockattr_init()].

     The function pthread_rwlockattr_setpshared() sets the process-shared
     attribute value of the read-write lock.  The attribute value may be
     PTHREAD_PROCESS_PRIVATE or PTHREAD_PROCESS_SHARED.

     The function pthread_rwlockattr_getpshared() returns the process-shared
     attribute value of attr via opshared.  The default value is
     PTHREAD_PROCESS_PRIVATE.

     A read-write lock with a process-shared attribute of
     PTHREAD_PROCESS_PRIVATE may only be operated on by threads created within
     the same process as the thread which initialized the read-write lock.

     A read-write lock with a process-shared attribute of
     PTHREAD_PROCESS_SHARED may be operated on 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.

DIAGNOSTICS
     The read-write lock attribute process-shared functions return zero on
     success; otherwise, an error number is returned:

     [EINVAL]       The attribute value specified by pshared is invalid.

SEE ALSO
     pthread_rwlock_rdlock(3P), pthread_rwlock_unlock(3P),
     pthread_rwlock_wrlock(3P), pthread_rwlockattr_init(3P).