static void xnsynch_clear_boost(struct xnsynch *synch,
struct xnthread *owner)
{
struct xnthread *target;
struct xnsynch *hsynch;
struct xnpholder *h;
int wprio;
removepq(&owner->claimq, &synch->link);
__clrbits(synch->status, XNSYNCH_CLAIMED);
wprio = w_bprio(owner);
if (emptypq_p(&owner->claimq)) {
xnthread_clear_state(owner, XNBOOST);
target = owner;
} else {
/* Find the highest priority needed to enforce the PIP. */
hsynch = link2synch(getheadpq(&owner->claimq));
h = getheadpq(&hsynch->pendq);
XENO_BUGON(NUCLEUS, h == NULL);
target = link2thread(h, plink);
if (w_cprio(target) > wprio)
wprio = w_cprio(target);
else
target = owner;
}
if (w_cprio(owner) != wprio &&
!xnthread_test_state(owner, XNZOMBIE))
xnsynch_renice_thread(owner, target);
}
void xnsynch_release_all_ownerships(xnthread_t *thread)
{
xnpholder_t *holder, *nholder;
for (holder = getheadpq(&thread->claimq); holder != NULL;
holder = nholder) {
/* Since xnsynch_wakeup_one_sleeper() alters the claim
queue, we need to be conservative while scanning
it. */
xnsynch_t *synch = link2synch(holder);
nholder = nextpq(&thread->claimq, holder);
xnsynch_wakeup_one_sleeper(synch);
if (synch->cleanup)
synch->cleanup(synch);
}
}
void xnsynch_release_all_ownerships(struct xnthread *thread)
{
struct xnpholder *holder, *nholder;
struct xnsynch *synch;
for (holder = getheadpq(&thread->claimq); holder != NULL;
holder = nholder) {
/*
* Since xnsynch_release() alters the claim queue, we
* need to be conservative while scanning it.
*/
synch = link2synch(holder);
nholder = nextpq(&thread->claimq, holder);
xnsynch_release_thread(synch, thread);
if (synch->cleanup)
synch->cleanup(synch);
}
}
/*
* Detect when a thread is about to relax while holding a
* synchronization object currently claimed by another thread, which
* bears the TWARNSW bit (thus advertising a concern about potential
* spurious relaxes and priority inversion). By relying on the claim
* queue, we restrict the checks to PIP-enabled objects, but that
* already covers most of the use cases anyway.
*/
void xnsynch_detect_claimed_relax(struct xnthread *owner)
{
struct xnpholder *hs, *ht;
struct xnthread *sleeper;
struct xnsynch *synch;
for (hs = getheadpq(&owner->claimq); hs != NULL;
hs = nextpq(&owner->claimq, hs)) {
synch = link2synch(hs);
for (ht = getheadpq(&synch->pendq); ht != NULL;
ht = nextpq(&synch->pendq, ht)) {
sleeper = link2thread(ht, plink);
if (xnthread_test_state(sleeper, XNTRAPSW)) {
xnthread_set_info(sleeper, XNSWREP);
xnshadow_send_sig(sleeper, SIGDEBUG,
SIGDEBUG_MIGRATE_PRIOINV, 1);
}
}
}
}
