int xnsynch_flush(struct xnsynch *synch, xnflags_t reason)
{
struct xnpholder *holder;
int status;
spl_t s;
xnlock_get_irqsave(&nklock, s);
trace_mark(xn_nucleus, synch_flush, "synch %p reason %lu",
synch, reason);
status = emptypq_p(&synch->pendq) ? XNSYNCH_DONE : XNSYNCH_RESCHED;
while ((holder = getpq(&synch->pendq)) != NULL) {
struct xnthread *sleeper = link2thread(holder, plink);
xnthread_set_info(sleeper, reason);
sleeper->wchan = NULL;
xnpod_resume_thread(sleeper, XNPEND);
}
if (testbits(synch->status, XNSYNCH_CLAIMED)) {
xnsynch_clear_boost(synch, synch->owner);
status = XNSYNCH_RESCHED;
}
xnlock_put_irqrestore(&nklock, s);
xnarch_post_graph_if(synch, 0, emptypq_p(&synch->pendq));
return status;
}
static struct xnthread *
xnsynch_release_thread(struct xnsynch *synch, struct xnthread *lastowner)
{
const int use_fastlock = xnsynch_fastlock_p(synch);
xnhandle_t lastownerh, newownerh;
struct xnthread *newowner;
struct xnpholder *holder;
spl_t s;
XENO_BUGON(NUCLEUS, !testbits(synch->status, XNSYNCH_OWNER));
#ifdef CONFIG_XENO_OPT_PERVASIVE
if (xnthread_test_state(lastowner, XNOTHER)) {
if (xnthread_get_rescnt(lastowner) == 0)
xnshadow_send_sig(lastowner, SIGDEBUG,
SIGDEBUG_MIGRATE_PRIOINV, 1);
else
xnthread_dec_rescnt(lastowner);
}
#endif
lastownerh = xnthread_handle(lastowner);
if (use_fastlock &&
likely(xnsynch_fast_release(xnsynch_fastlock(synch), lastownerh)))
return NULL;
xnlock_get_irqsave(&nklock, s);
trace_mark(xn_nucleus, synch_release, "synch %p", synch);
holder = getpq(&synch->pendq);
if (holder) {
newowner = link2thread(holder, plink);
newowner->wchan = NULL;
newowner->wwake = synch;
synch->owner = newowner;
xnthread_set_info(newowner, XNWAKEN);
xnpod_resume_thread(newowner, XNPEND);
if (testbits(synch->status, XNSYNCH_CLAIMED))
xnsynch_clear_boost(synch, lastowner);
newownerh = xnsynch_fast_set_claimed(xnthread_handle(newowner),
xnsynch_pended_p(synch));
} else {
newowner = NULL;
synch->owner = NULL;
newownerh = XN_NO_HANDLE;
}
if (use_fastlock) {
xnarch_atomic_t *lockp = xnsynch_fastlock(synch);
xnarch_atomic_set(lockp, newownerh);
}
xnlock_put_irqrestore(&nklock, s);
xnarch_post_graph_if(synch, 0, emptypq_p(&synch->pendq));
return newowner;
}
struct xnthread *xnsynch_wakeup_one_sleeper(struct xnsynch *synch)
{
struct xnthread *thread = NULL;
struct xnpholder *holder;
spl_t s;
XENO_BUGON(NUCLEUS, testbits(synch->status, XNSYNCH_OWNER));
xnlock_get_irqsave(&nklock, s);
holder = getpq(&synch->pendq);
if (holder) {
thread = link2thread(holder, plink);
thread->wchan = NULL;
trace_mark(xn_nucleus, synch_wakeup_one,
"thread %p thread_name %s synch %p",
thread, xnthread_name(thread), synch);
xnpod_resume_thread(thread, XNPEND);
}
xnlock_put_irqrestore(&nklock, s);
xnarch_post_graph_if(synch, 0, emptypq_p(&synch->pendq));
return thread;
}
xnpholder_t *xnsynch_wakeup_this_sleeper(xnsynch_t *synch, xnpholder_t *holder)
{
xnthread_t *thread, *lastowner;
xnpholder_t *nholder;
spl_t s;
xnlock_get_irqsave(&nklock, s);
lastowner = synch->owner;
nholder = poppq(&synch->pendq, holder);
thread = link2thread(holder, plink);
thread->wchan = NULL;
thread->wwake = synch;
synch->owner = thread;
xnthread_set_info(thread, XNWAKEN);
trace_mark(xn_nucleus_synch_wakeup_all,
"thread %p thread_name %s synch %p",
thread, xnthread_name(thread), synch);
xnpod_resume_thread(thread, XNPEND);
if (testbits(synch->status, XNSYNCH_CLAIMED))
xnsynch_clear_boost(synch, lastowner);
xnlock_put_irqrestore(&nklock, s);
xnarch_post_graph_if(synch, 0, emptypq_p(&synch->pendq));
return nholder;
}
struct xnthread *xnsynch_release(struct xnsynch *synch)
{
const int use_fastlock = xnsynch_fastlock_p(synch);
struct xnthread *newowner, *lastowner;
xnhandle_t lastownerh, newownerh;
struct xnpholder *holder;
spl_t s;
XENO_BUGON(NUCLEUS, !testbits(synch->status, XNSYNCH_OWNER));
lastownerh = xnthread_handle(xnpod_current_thread());
if (use_fastlock &&
likely(xnsynch_fast_release(xnsynch_fastlock(synch), lastownerh)))
return NULL;
xnlock_get_irqsave(&nklock, s);
trace_mark(xn_nucleus, synch_release, "synch %p", synch);
holder = getpq(&synch->pendq);
if (holder) {
newowner = link2thread(holder, plink);
newowner->wchan = NULL;
newowner->wwake = synch;
lastowner = synch->owner;
synch->owner = newowner;
xnthread_set_info(newowner, XNWAKEN);
xnpod_resume_thread(newowner, XNPEND);
if (testbits(synch->status, XNSYNCH_CLAIMED))
xnsynch_clear_boost(synch, lastowner);
newownerh = xnsynch_fast_set_claimed(xnthread_handle(newowner),
xnsynch_pended_p(synch));
} else {
newowner = NULL;
synch->owner = NULL;
newownerh = XN_NO_HANDLE;
}
if (use_fastlock) {
xnarch_atomic_t *lockp = xnsynch_fastlock(synch);
xnarch_atomic_set(lockp, newownerh);
}
xnlock_put_irqrestore(&nklock, s);
xnarch_post_graph_if(synch, 0, emptypq_p(&synch->pendq));
return newowner;
}
void xnsynch_forget_sleeper(struct xnthread *thread)
{
struct xnsynch *synch = thread->wchan;
struct xnthread *owner, *target;
struct xnpholder *h;
trace_mark(xn_nucleus, synch_forget,
"thread %p thread_name %s synch %p",
thread, xnthread_name(thread), synch);
xnthread_clear_state(thread, XNPEND);
thread->wchan = NULL;
removepq(&synch->pendq, &thread->plink);
if (testbits(synch->status, XNSYNCH_CLAIMED)) {
/* Find the highest priority needed to enforce the PIP. */
owner = synch->owner;
if (emptypq_p(&synch->pendq))
/* No more sleepers: clear the boost. */
xnsynch_clear_boost(synch, owner);
else {
target = link2thread(getheadpq(&synch->pendq), plink);
h = getheadpq(&owner->claimq);
if (w_cprio(target) != h->prio) {
/*
* Reorder the claim queue, and lower
* the priority to the required
* minimum needed to prevent priority
* inversion.
*/
removepq(&owner->claimq, &synch->link);
insertpqf(&owner->claimq, &synch->link,
w_cprio(target));
h = getheadpq(&owner->claimq);
if (h->prio < w_cprio(owner))
xnsynch_renice_thread(owner, target);
}
}
}
xnarch_post_graph_if(synch, 0, emptypq_p(&synch->pendq));
}
void xnsynch_forget_sleeper(xnthread_t *thread)
{
xnsynch_t *synch = thread->wchan;
trace_mark(xn_nucleus_synch_forget,
"thread %p thread_name %s synch %p",
thread, xnthread_name(thread), synch);
xnthread_clear_state(thread, XNPEND);
thread->wchan = NULL;
removepq(&synch->pendq, &thread->plink);
if (testbits(synch->status, XNSYNCH_CLAIMED)) {
/* Find the highest priority needed to enforce the PIP. */
xnthread_t *owner = synch->owner;
int rprio;
if (emptypq_p(&synch->pendq))
/* No more sleepers: clear the boost. */
xnsynch_clear_boost(synch, owner);
else if (getheadpq(&synch->pendq)->prio !=
getheadpq(&owner->claimq)->prio) {
/* Reorder the claim queue, and lower the priority to the
required minimum needed to prevent priority
inversion. */
removepq(&owner->claimq, &synch->link);
insertpqf(&owner->claimq,
&synch->link, getheadpq(&synch->pendq)->prio);
rprio = getheadpq(&owner->claimq)->prio;
if (rprio < owner->cprio)
xnsynch_renice_thread(owner, rprio);
}
}
xnarch_post_graph_if(synch, 0, emptypq_p(&synch->pendq));
}