int pthread_rwlockattr_getpshared(const pthread_rwlockattr_t *
restrict attr, int *restrict pshared);
int pthread_rwlockattr_setpshared(pthread_rwlockattr_t *attr,
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. If the process-shared attribute is PTHREAD_PROCESS_PRIVATE, the read-write lock shall only be operated upon by threads created within the same process as the thread that initialized the read-write lock; if threads of differing processes attempt to operate on such a read-write lock, the behavior is undefined. 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.
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.
The pthread_rwlockattr_getpshared() and pthread_rwlockattr_setpshared() functions may fail if:
The pthread_rwlockattr_setpshared() function may fail if:
These functions shall not return an error code of [EINTR].
The following sections are informative.
pthread_rwlock_destroy() , pthread_rwlockattr_destroy() , pthread_rwlockattr_init() , the Base Definitions volume of IEEE Std 1003.1-2001, <pthread.h>