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 The snapshot can become out-of-date for a number of reasons depending on its view.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the lgroup hierarchy from dynamic reconfiguration, CPU on/offline, or other conditions can cause the snapshot to become out-of-date.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 NULL.

Attributes

See attributes(5) for descriptions of the following attributes:

See Also

lgrp_init(3LGRP), lgrp_fini(3LGRP), lgrp_view(3LGRP), liblgrp(3LIB), attributes(5)