Manual Pages  — PTHREAD_RWLOCKATTR_GETPSHARED

pthread_rwlockattr_getpshared – get the process shared attribute

LIBRARY SYNOPSIS DESCRIPTION RETURN VALUES ERRORS SEE ALSO STANDARDS HISTORY

POSIX Threads Library (libpthread, -lpthread)

#include <pthread.h>

int
pthread_rwlockattr_getpshared(const pthread_rwlockattr_t *restrict attr, int *restrict pshared);

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.

If successful, the pthread_rwlockattr_getpshared() function will return zero. Otherwise an error number will be returned to indicate the error.

The pthread_rwlockattr_getpshared() function may fail if:

[EINVAL]
	The value specified by attr is invalid.

The pthread_rwlockattr_getpshared() function is expected to conform to Version 2 of the Single UNIX Specification.

The pthread_rwlockattr_getpshared() function first appeared in FreeBSD 3.0 .