LGRP_COOKIE_STALE(3LGRP) Locality Group Library Functions

NAME

lgrp_cookie_stale - determine whether snapshot of lgroup hierarchy is
stale

SYNOPSIS

cc [ flag ... ] file... -llgrp [ library ... ]
#include <sys/lgrp_user.h>

int lgrp_cookie_stale(lgrp_cookie_t cookie);

DESCRIPTION

The lgrp_cookie_stale() function takes a cookie representing the snapshot
of the lgroup hierarchy obtained from lgrp_init(3LGRP) and returns
whether it is stale. The snapshot can become out-of-date for a number of
reasons depending on its view. If the snapshot was taken with
LGRP_VIEW_OS, changes in the lgroup hierarchy from dynamic
reconfiguration, CPU on/offline, or other conditions can cause the
snapshot to become out-of-date. A snapshot taken with LGRP_VIEW_CALLER
can be affected by the caller's processor set binding and changes in its
processor set itself, as well as changes in the lgroup hierarchy.


If the snapshot needs to be updated, lgrp_fini(3LGRP) should be called
with the old cookie and lgrp_init() should be called to obtain a new
snapshot.

RETURN VALUES

Upon successful completion, lgrp_cookie_stale() returns whether the
cookie is stale. Otherwise, it returns -1 and sets errno to indicate the
error.

ERRORS

The lgrp_cookie_stale() function will fail if:

EINVAL
The cookie is not valid.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Evolving |
+--------------------+-----------------+
|MT-Level | MT-Safe |
+--------------------+-----------------+

SEE ALSO

lgrp_fini(3LGRP), lgrp_init(3LGRP), lgrp_view(3LGRP), liblgrp(3LIB),
attributes(7)

April 16, 2003 LGRP_COOKIE_STALE(3LGRP)