NAME
pthread_rwlockattr_getpshared – get the process shared attribute
LIBRARY
POSIX Threads Library (libpthread, -lpthread)
SYNOPSIS
#include <pthread.h>
int
pthread_rwlockattr_getpshared(const pthread_rwlockattr_t *restrict attr, int *restrict pshared);
DESCRIPTION
The pthread_rwlockattr_getpshared() function is used to get the process shared setting of a read/write lock attribute object. The setting is returned via pshared, and may be one of two values:
- PTHREAD_PROCESS_SHARED
-
Any thread of any process that has access to the memory where the read/write lock resides can manipulate the lock.
- PTHREAD_PROCESS_PRIVATE
-
Only threads created within the same process as the thread that initialized the read/write lock can manipulate the lock. This is the default value.
RETURN VALUES
If successful, the pthread_rwlockattr_getpshared() function will return zero. Otherwise an error number will be returned to indicate the error.
ERRORS
The pthread_rwlockattr_getpshared() function may fail if:
- [EINVAL]
-
The value specified by attr is invalid.
SEE ALSO
pthread_rwlock_init(3), pthread_rwlockattr_init(3), pthread_rwlockattr_setpshared(3)
STANDARDS
The pthread_rwlockattr_getpshared() function is expected to conform to Version 2 of the Single UNIX Specification (“SUSv2”).
HISTORY
The pthread_rwlockattr_getpshared() function first appeared in FreeBSD 3.0.