PTHREAD_RWLOCKATTR_GETPSHARED(3) |
FreeBSD Library Functions Manual |
PTHREAD_RWLOCKATTR_GETPSHARED(3) |
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 *attr, int *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.
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.