/*
* Routine: wait_queue_link_internal
* Purpose:
* Insert a set wait queue into a wait queue. This
* requires us to link the two together using a wait_queue_link
* structure that was provided.
* Conditions:
* The wait queue being inserted must be inited as a set queue
* The wait_queue_link structure must already be properly typed
*/
static
kern_return_t
wait_queue_link_internal(
wait_queue_t wq,
wait_queue_set_t wq_set,
wait_queue_link_t wql)
{
wait_queue_element_t wq_element;
queue_t q;
spl_t s;
if (!wait_queue_is_valid(wq) || !wait_queue_is_set(wq_set))
return KERN_INVALID_ARGUMENT;
/*
* There are probably fewer threads and sets associated with
* the wait queue than there are wait queues associated with
* the set. So let's validate it that way.
*/
s = splsched();
wait_queue_lock(wq);
q = &wq->wq_queue;
wq_element = (wait_queue_element_t) queue_first(q);
while (!queue_end(q, (queue_entry_t)wq_element)) {
WAIT_QUEUE_ELEMENT_CHECK(wq, wq_element);
if ((wq_element->wqe_type == WAIT_QUEUE_LINK ||
wq_element->wqe_type == WAIT_QUEUE_LINK_NOALLOC) &&
((wait_queue_link_t)wq_element)->wql_setqueue == wq_set) {
wait_queue_unlock(wq);
splx(s);
return KERN_ALREADY_IN_SET;
}
wq_element = (wait_queue_element_t)
queue_next((queue_t) wq_element);
}
/*
* Not already a member, so we can add it.
*/
wqs_lock(wq_set);
WAIT_QUEUE_SET_CHECK(wq_set);
assert(wql->wql_type == WAIT_QUEUE_LINK ||
wql->wql_type == WAIT_QUEUE_LINK_NOALLOC);
wql->wql_queue = wq;
wql_clear_prepost(wql);
queue_enter(&wq->wq_queue, wql, wait_queue_link_t, wql_links);
wql->wql_setqueue = wq_set;
queue_enter(&wq_set->wqs_setlinks, wql, wait_queue_link_t, wql_setlinks);
wqs_unlock(wq_set);
wait_queue_unlock(wq);
splx(s);
return KERN_SUCCESS;
}
/*
* Routine: wait_queue_assert_wait
* Purpose:
* Insert the current thread into the supplied wait queue
* waiting for a particular event to be posted to that queue.
*
* Conditions:
* nothing of interest locked.
*/
wait_result_t
wait_queue_assert_wait(
wait_queue_t wq,
event_t event,
wait_interrupt_t interruptible,
uint64_t deadline)
{
spl_t s;
wait_result_t ret;
thread_t thread = current_thread();
/* If it is an invalid wait queue, you can't wait on it */
if (!wait_queue_is_valid(wq))
return (thread->wait_result = THREAD_RESTART);
s = splsched();
wait_queue_lock(wq);
thread_lock(thread);
ret = wait_queue_assert_wait64_locked(wq, CAST_DOWN(event64_t,event),
interruptible, deadline, thread);
thread_unlock(thread);
wait_queue_unlock(wq);
splx(s);
return(ret);
}
/*
* Routine: wait_queue_wakeup64_all_locked
* Purpose:
* Wakeup some number of threads that are in the specified
* wait queue and waiting on the specified event.
* Conditions:
* wait queue already locked (may be released).
* Returns:
* KERN_SUCCESS - Threads were woken up
* KERN_NOT_WAITING - No threads were waiting <wq,event> pair
*/
__private_extern__ kern_return_t
wait_queue_wakeup64_all_locked(
wait_queue_t wq,
event64_t event,
wait_result_t result,
boolean_t unlock)
{
queue_head_t wake_queue_head;
queue_t q = &wake_queue_head;
kern_return_t res;
assert(wait_queue_held(wq));
queue_init(q);
/*
* Select the threads that we will wake up. The threads
* are returned to us locked and cleanly removed from the
* wait queue.
*/
_wait_queue_select64_all(wq, event, q);
if (unlock)
wait_queue_unlock(wq);
/*
* For each thread, set it running.
*/
res = KERN_NOT_WAITING;
while (!queue_empty (q)) {
thread_t thread = (thread_t) dequeue(q);
res = thread_go_locked(thread, result);
assert(res == KERN_SUCCESS);
thread_unlock(thread);
}
return res;
}
/*
* Routine: wait_queue_assert_wait64
* Purpose:
* Insert the current thread into the supplied wait queue
* waiting for a particular event to be posted to that queue.
* Conditions:
* nothing of interest locked.
*/
wait_result_t
wait_queue_assert_wait64(
wait_queue_t wq,
event64_t event,
wait_interrupt_t interruptible)
{
spl_t s;
wait_result_t ret;
thread_t cur_thread = current_thread();
/* If it is an invalid wait queue, you cant wait on it */
if (!wait_queue_is_valid(wq)) {
thread_t thread = current_thread();
return (thread->wait_result = THREAD_RESTART);
}
s = splsched();
wait_queue_lock(wq);
thread_lock(cur_thread);
ret = wait_queue_assert_wait64_locked(wq, event, interruptible, cur_thread);
thread_unlock(cur_thread);
wait_queue_unlock(wq);
splx(s);
return(ret);
}
/*
* Routine: wait_queue_wakeup_one
* Purpose:
* Wakeup the most appropriate thread that is in the specified
* wait queue for the specified event.
* Conditions:
* Nothing locked
* Returns:
* KERN_SUCCESS - Thread was woken up
* KERN_NOT_WAITING - No thread was waiting <wq,event> pair
*/
kern_return_t
wait_queue_wakeup_one(
wait_queue_t wq,
event_t event,
wait_result_t result)
{
thread_t thread;
spl_t s;
if (!wait_queue_is_valid(wq)) {
return KERN_INVALID_ARGUMENT;
}
s = splsched();
wait_queue_lock(wq);
thread = _wait_queue_select64_one(wq, (event64_t)((uint32_t)event));
wait_queue_unlock(wq);
if (thread) {
kern_return_t res;
res = thread_go_locked(thread, result);
assert(res == KERN_SUCCESS);
thread_unlock(thread);
splx(s);
return res;
}
splx(s);
return KERN_NOT_WAITING;
}
/*
* Routine: wait_queue_wakeup64_thread
* Purpose:
* Wakeup the particular thread that was specified if and only
* it was in this wait queue (or one of it's set's queues)
* and waiting on the specified event.
*
* This is much safer than just removing the thread from
* whatever wait queue it happens to be on. For instance, it
* may have already been awoken from the wait you intended to
* interrupt and waited on something else (like another
* semaphore).
* Conditions:
* nothing of interest locked
* we need to assume spl needs to be raised
* Returns:
* KERN_SUCCESS - the thread was found waiting and awakened
* KERN_NOT_WAITING - the thread was not waiting here
*/
kern_return_t
wait_queue_wakeup64_thread(
wait_queue_t wq,
event64_t event,
thread_t thread,
wait_result_t result)
{
kern_return_t res;
spl_t s;
if (!wait_queue_is_valid(wq)) {
return KERN_INVALID_ARGUMENT;
}
s = splsched();
wait_queue_lock(wq);
res = _wait_queue_select64_thread(wq, event, thread);
wait_queue_unlock(wq);
if (res == KERN_SUCCESS) {
res = thread_go(thread, result);
assert(res == KERN_SUCCESS);
thread_unlock(thread);
splx(s);
return res;
}
splx(s);
return KERN_NOT_WAITING;
}
/*
* Routine: wait_queue_wakeup64_thread_locked
* Purpose:
* Wakeup the particular thread that was specified if and only
* it was in this wait queue (or one of it's set queues)
* and waiting on the specified event.
*
* This is much safer than just removing the thread from
* whatever wait queue it happens to be on. For instance, it
* may have already been awoken from the wait you intended to
* interrupt and waited on something else (like another
* semaphore).
* Conditions:
* at splsched
* wait queue already locked (may be released).
* Returns:
* KERN_SUCCESS - the thread was found waiting and awakened
* KERN_NOT_WAITING - the thread was not waiting here
*/
__private_extern__ kern_return_t
wait_queue_wakeup64_thread_locked(
wait_queue_t wq,
event64_t event,
thread_t thread,
wait_result_t result,
boolean_t unlock)
{
kern_return_t res;
assert(wait_queue_held(wq));
/*
* See if the thread was still waiting there. If so, it got
* dequeued and returned locked.
*/
res = _wait_queue_select64_thread(wq, event, thread);
if (unlock)
wait_queue_unlock(wq);
if (res != KERN_SUCCESS)
return KERN_NOT_WAITING;
res = thread_go(thread, result);
assert(res == KERN_SUCCESS);
thread_unlock(thread);
return res;
}
/*
* Routine: _wait_queue_select64_one
* Purpose:
* Select the best thread off a wait queue that meet the
* supplied criteria.
* Conditions:
* at splsched
* wait queue locked
* possibly recursive
* Returns:
* a locked thread - if one found
* Note:
* This is where the sync policy of the wait queue comes
* into effect. For now, we just assume FIFO.
*/
static thread_t
_wait_queue_select64_one(
wait_queue_t wq,
event64_t event)
{
wait_queue_element_t wq_element;
wait_queue_element_t wqe_next;
thread_t t = THREAD_NULL;
queue_t q;
assert(wq->wq_fifo);
q = &wq->wq_queue;
wq_element = (wait_queue_element_t) queue_first(q);
while (!queue_end(q, (queue_entry_t)wq_element)) {
WAIT_QUEUE_ELEMENT_CHECK(wq, wq_element);
wqe_next = (wait_queue_element_t)
queue_next((queue_t) wq_element);
/*
* We may have to recurse if this is a compound wait queue.
*/
if (wq_element->wqe_type == WAIT_QUEUE_LINK) {
wait_queue_link_t wql = (wait_queue_link_t)wq_element;
wait_queue_t set_queue;
/*
* We have to check the set wait queue.
*/
set_queue = (wait_queue_t)wql->wql_setqueue;
wait_queue_lock(set_queue);
if (! wait_queue_empty(set_queue)) {
t = _wait_queue_select64_one(set_queue, event);
}
wait_queue_unlock(set_queue);
if (t != THREAD_NULL)
return t;
} else {
/*
* Otherwise, its a thread. If it is waiting on
* the event we are posting to this queue, pull
* it off the queue and stick it in out wake_queue.
*/
thread_t t = (thread_t)wq_element;
if (t->wait_event == event) {
thread_lock(t);
remqueue(q, (queue_entry_t) t);
t->wait_queue = WAIT_QUEUE_NULL;
t->wait_event = NO_EVENT64;
t->at_safe_point = FALSE;
return t; /* still locked */
}
}
wq_element = wqe_next;
}
return THREAD_NULL;
}
/*
* Routine: wait_queue_wakeup64_one_locked
* Purpose:
* Select a single thread that is most-eligible to run and set
* set it runnings.
*
* Conditions:
* at splsched
* wait queue locked
* possibly recursive
* Returns:
* KERN_SUCCESS: It was, and is, now removed.
* KERN_NOT_WAITING - No thread was waiting <wq,event> pair
*/
__private_extern__ kern_return_t
wait_queue_wakeup64_one_locked(
wait_queue_t wq,
event64_t event,
wait_result_t result,
boolean_t unlock)
{
thread_t thread;
assert(wait_queue_held(wq));
thread = _wait_queue_select64_one(wq, event);
if (unlock)
wait_queue_unlock(wq);
if (thread) {
kern_return_t res;
res = thread_go(thread, result);
assert(res == KERN_SUCCESS);
thread_unlock(thread);
return res;
}
return KERN_NOT_WAITING;
}
/*
* Routine: wait_queue_unlink
* Purpose:
* Remove the linkage between a wait queue and a set,
* freeing the linkage structure.
* Conditions:
* The wait queue being must be a member set queue
*/
kern_return_t
wait_queue_unlink(
wait_queue_t wq,
wait_queue_set_t wq_set)
{
wait_queue_element_t wq_element;
wait_queue_link_t wql;
queue_t q;
spl_t s;
if (!wait_queue_is_valid(wq) || !wait_queue_is_set(wq_set)) {
return KERN_INVALID_ARGUMENT;
}
s = splsched();
wait_queue_lock(wq);
q = &wq->wq_queue;
wq_element = (wait_queue_element_t) queue_first(q);
while (!queue_end(q, (queue_entry_t)wq_element)) {
WAIT_QUEUE_ELEMENT_CHECK(wq, wq_element);
if (wq_element->wqe_type == WAIT_QUEUE_LINK ||
wq_element->wqe_type == WAIT_QUEUE_LINK_NOALLOC) {
wql = (wait_queue_link_t)wq_element;
if (wql->wql_setqueue == wq_set) {
boolean_t alloced;
alloced = (wql->wql_type == WAIT_QUEUE_LINK);
wqs_lock(wq_set);
wait_queue_unlink_locked(wq, wq_set, wql);
wqs_unlock(wq_set);
wait_queue_unlock(wq);
splx(s);
if (alloced)
zfree(_wait_queue_link_zone, wql);
return KERN_SUCCESS;
}
}
wq_element = (wait_queue_element_t)
queue_next((queue_t) wq_element);
}
wait_queue_unlock(wq);
splx(s);
return KERN_NOT_IN_SET;
}
kern_return_t
wait_queue_unlink_all(
wait_queue_t wq)
{
wait_queue_element_t wq_element;
wait_queue_element_t wq_next_element;
wait_queue_set_t wq_set;
wait_queue_link_t wql;
queue_head_t links_queue_head;
queue_t links = &links_queue_head;
queue_t q;
spl_t s;
if (!wait_queue_is_valid(wq)) {
return KERN_INVALID_ARGUMENT;
}
queue_init(links);
s = splsched();
wait_queue_lock(wq);
q = &wq->wq_queue;
wq_element = (wait_queue_element_t) queue_first(q);
while (!queue_end(q, (queue_entry_t)wq_element)) {
boolean_t alloced;
WAIT_QUEUE_ELEMENT_CHECK(wq, wq_element);
wq_next_element = (wait_queue_element_t)
queue_next((queue_t) wq_element);
alloced = (wq_element->wqe_type == WAIT_QUEUE_LINK);
if (alloced || wq_element->wqe_type == WAIT_QUEUE_LINK_NOALLOC) {
wql = (wait_queue_link_t)wq_element;
wq_set = wql->wql_setqueue;
wqs_lock(wq_set);
wait_queue_unlink_locked(wq, wq_set, wql);
wqs_unlock(wq_set);
if (alloced)
enqueue(links, &wql->wql_links);
}
wq_element = wq_next_element;
}
wait_queue_unlock(wq);
splx(s);
while(!queue_empty(links)) {
wql = (wait_queue_link_t) dequeue(links);
zfree(_wait_queue_link_zone, wql);
}
return(KERN_SUCCESS);
}
/*
* Routine: wait_queue_unlink
* Purpose:
* Remove the linkage between a wait queue and a set,
* freeing the linkage structure.
* Conditions:
* The wait queue being must be a member set queue
*/
kern_return_t
wait_queue_unlink(
wait_queue_t wq,
wait_queue_set_t wq_set)
{
wait_queue_element_t wq_element;
wait_queue_link_t wql;
queue_t q;
spl_t s;
if (!wait_queue_is_queue(wq) || !wait_queue_is_set(wq_set)) {
return KERN_INVALID_ARGUMENT;
}
s = splsched();
wait_queue_lock(wq);
q = &wq->wq_queue;
wq_element = (wait_queue_element_t) queue_first(q);
while (!queue_end(q, (queue_entry_t)wq_element)) {
WAIT_QUEUE_ELEMENT_CHECK(wq, wq_element);
if (wq_element->wqe_type == WAIT_QUEUE_LINK) {
wql = (wait_queue_link_t)wq_element;
if (wql->wql_setqueue == wq_set) {
wqs_lock(wq_set);
wait_queue_unlink_locked(wq, wq_set, wql);
wqs_unlock(wq_set);
wait_queue_unlock(wq);
splx(s);
kfree((vm_offset_t)wql, sizeof(struct wait_queue_link));
return KERN_SUCCESS;
}
}
wq_element = (wait_queue_element_t)
queue_next((queue_t) wq_element);
}
wait_queue_unlock(wq);
splx(s);
return KERN_NOT_IN_SET;
}
/*
* Routine: wait_queue_select64_thread
* Purpose:
* Look for a thread and remove it from the queues, if
* (and only if) the thread is waiting on the supplied
* <wait_queue, event> pair.
* Conditions:
* at splsched
* wait queue locked
* possibly recursive
* Returns:
* KERN_NOT_WAITING: Thread is not waiting here.
* KERN_SUCCESS: It was, and is now removed (returned locked)
*/
static kern_return_t
_wait_queue_select64_thread(
wait_queue_t wq,
event64_t event,
thread_t thread)
{
wait_queue_element_t wq_element;
wait_queue_element_t wqe_next;
kern_return_t res = KERN_NOT_WAITING;
queue_t q = &wq->wq_queue;
thread_lock(thread);
if ((thread->wait_queue == wq) && (thread->wait_event == event)) {
remqueue(q, (queue_entry_t) thread);
thread->at_safe_point = FALSE;
thread->wait_event = NO_EVENT64;
thread->wait_queue = WAIT_QUEUE_NULL;
/* thread still locked */
return KERN_SUCCESS;
}
thread_unlock(thread);
/*
* The wait_queue associated with the thread may be one of this
* wait queue's sets. Go see. If so, removing it from
* there is like removing it from here.
*/
wq_element = (wait_queue_element_t) queue_first(q);
while (!queue_end(q, (queue_entry_t)wq_element)) {
WAIT_QUEUE_ELEMENT_CHECK(wq, wq_element);
wqe_next = (wait_queue_element_t)
queue_next((queue_t) wq_element);
if (wq_element->wqe_type == WAIT_QUEUE_LINK) {
wait_queue_link_t wql = (wait_queue_link_t)wq_element;
wait_queue_t set_queue;
set_queue = (wait_queue_t)wql->wql_setqueue;
wait_queue_lock(set_queue);
if (! wait_queue_empty(set_queue)) {
res = _wait_queue_select64_thread(set_queue,
event,
thread);
}
wait_queue_unlock(set_queue);
if (res == KERN_SUCCESS)
return KERN_SUCCESS;
}
wq_element = wqe_next;
}
return res;
}
/*
* Routine: wait_queue_set_unlink_all
* Purpose:
* Remove the linkage between a set wait queue and all its
* member wait queues. The link structures are freed for those
* links which were dynamically allocated.
* Conditions:
* The wait queue must be a set
*/
kern_return_t
wait_queue_set_unlink_all(
wait_queue_set_t wq_set)
{
wait_queue_link_t wql;
wait_queue_t wq;
queue_t q;
queue_head_t links_queue_head;
queue_t links = &links_queue_head;
spl_t s;
if (!wait_queue_is_set(wq_set)) {
return KERN_INVALID_ARGUMENT;
}
queue_init(links);
retry:
s = splsched();
wqs_lock(wq_set);
q = &wq_set->wqs_setlinks;
wql = (wait_queue_link_t)queue_first(q);
while (!queue_end(q, (queue_entry_t)wql)) {
WAIT_QUEUE_SET_LINK_CHECK(wq_set, wql);
wq = wql->wql_queue;
if (wait_queue_lock_try(wq)) {
boolean_t alloced;
alloced = (wql->wql_type == WAIT_QUEUE_LINK);
wait_queue_unlink_locked(wq, wq_set, wql);
wait_queue_unlock(wq);
if (alloced)
enqueue(links, &wql->wql_links);
wql = (wait_queue_link_t)queue_first(q);
} else {
wqs_unlock(wq_set);
splx(s);
delay(1);
goto retry;
}
}
wqs_unlock(wq_set);
splx(s);
while (!queue_empty (links)) {
wql = (wait_queue_link_t) dequeue(links);
zfree(_wait_queue_link_zone, wql);
}
return(KERN_SUCCESS);
}
/*
* Routine: wait_queue_unlink_one
* Purpose:
* Find and unlink one set wait queue
* Conditions:
* Nothing of interest locked.
*/
void
wait_queue_unlink_one(
wait_queue_t wq,
wait_queue_set_t *wq_setp)
{
wait_queue_element_t wq_element;
queue_t q;
spl_t s;
s = splsched();
wait_queue_lock(wq);
q = &wq->wq_queue;
wq_element = (wait_queue_element_t) queue_first(q);
while (!queue_end(q, (queue_entry_t)wq_element)) {
if (wq_element->wqe_type == WAIT_QUEUE_LINK) {
wait_queue_link_t wql = (wait_queue_link_t)wq_element;
wait_queue_set_t wq_set = wql->wql_setqueue;
wqs_lock(wq_set);
wait_queue_unlink_locked(wq, wq_set, wql);
wqs_unlock(wq_set);
wait_queue_unlock(wq);
splx(s);
kfree((vm_offset_t)wql,sizeof(struct wait_queue_link));
*wq_setp = wq_set;
return;
}
wq_element = (wait_queue_element_t)
queue_next((queue_t) wq_element);
}
wait_queue_unlock(wq);
splx(s);
*wq_setp = WAIT_QUEUE_SET_NULL;
}
kern_return_t
wait_queue_unlink_all(
wait_queue_t wq)
{
wait_queue_element_t wq_element;
wait_queue_element_t wq_next_element;
wait_queue_set_t wq_set;
wait_queue_link_t wql;
queue_head_t links_queue_head;
queue_t links = &links_queue_head;
queue_t q;
spl_t s;
if (!wait_queue_is_queue(wq)) {
return KERN_INVALID_ARGUMENT;
}
queue_init(links);
s = splsched();
wait_queue_lock(wq);
q = &wq->wq_queue;
wq_element = (wait_queue_element_t) queue_first(q);
while (!queue_end(q, (queue_entry_t)wq_element)) {
WAIT_QUEUE_ELEMENT_CHECK(wq, wq_element);
wq_next_element = (wait_queue_element_t)
queue_next((queue_t) wq_element);
if (wq_element->wqe_type == WAIT_QUEUE_LINK) {
wql = (wait_queue_link_t)wq_element;
wq_set = wql->wql_setqueue;
wqs_lock(wq_set);
wait_queue_unlink_locked(wq, wq_set, wql);
wqs_unlock(wq_set);
enqueue(links, &wql->wql_links);
}
wq_element = wq_next_element;
}
wait_queue_unlock(wq);
splx(s);
while(!queue_empty(links)) {
wql = (wait_queue_link_t) dequeue(links);
kfree((vm_offset_t) wql, sizeof(struct wait_queue_link));
}
return(KERN_SUCCESS);
}
/*
* Routine: wait_queue_set_unlink_all
* Purpose:
* Remove the linkage between a set wait queue and all its
* member wait queues. The link structures are freed.
* Conditions:
* The wait queue must be a set
*/
kern_return_t
wait_queue_set_unlink_all(
wait_queue_set_t wq_set)
{
wait_queue_link_t wql;
wait_queue_t wq;
queue_t q;
queue_head_t links_queue_head;
queue_t links = &links_queue_head;
kern_return_t kret;
spl_t s;
if (!wait_queue_is_set(wq_set)) {
return KERN_INVALID_ARGUMENT;
}
queue_init(links);
retry:
s = splsched();
wqs_lock(wq_set);
q = &wq_set->wqs_setlinks;
wql = (wait_queue_link_t)queue_first(q);
while (!queue_end(q, (queue_entry_t)wql)) {
WAIT_QUEUE_SET_LINK_CHECK(wq_set, wql);
wq = wql->wql_queue;
if (wait_queue_lock_try(wq)) {
wait_queue_unlink_locked(wq, wq_set, wql);
wait_queue_unlock(wq);
enqueue(links, &wql->wql_links);
wql = (wait_queue_link_t)queue_first(q);
} else {
wqs_unlock(wq_set);
splx(s);
delay(1);
goto retry;
}
}
wqs_unlock(wq_set);
splx(s);
while (!queue_empty (links)) {
wql = (wait_queue_link_t) dequeue(links);
kfree((vm_offset_t)wql, sizeof(struct wait_queue_link));
}
return(KERN_SUCCESS);
}
/*
* Routine: wait_queue_pull_thread_locked
* Purpose:
* Pull a thread off its wait queue and (possibly) unlock
* the waitq.
* Conditions:
* at splsched
* wait queue locked
* thread locked
* Returns:
* with the thread still locked.
*/
void
wait_queue_pull_thread_locked(
wait_queue_t waitq,
thread_t thread,
boolean_t unlock)
{
assert(thread->wait_queue == waitq);
remqueue((queue_entry_t)thread );
thread->wait_queue = WAIT_QUEUE_NULL;
thread->wait_event = NO_EVENT64;
thread->at_safe_point = FALSE;
if (unlock)
wait_queue_unlock(waitq);
}
/*
* Routine: wait_queue_member
* Purpose:
* Indicate if this set queue is a member of the queue
* Conditions:
* The set queue is just that, a set queue
*/
boolean_t
wait_queue_member(
wait_queue_t wq,
wait_queue_set_t wq_set)
{
boolean_t ret;
spl_t s;
if (!wait_queue_is_set(wq_set))
return FALSE;
s = splsched();
wait_queue_lock(wq);
ret = wait_queue_member_locked(wq, wq_set);
wait_queue_unlock(wq);
splx(s);
return ret;
}
kern_return_t
wait_queue_set_unlink_one(
wait_queue_set_t wq_set,
wait_queue_link_t wql)
{
wait_queue_t wq;
spl_t s;
assert(wait_queue_is_set(wq_set));
retry:
s = splsched();
wqs_lock(wq_set);
WAIT_QUEUE_SET_CHECK(wq_set);
/* Already unlinked, e.g. by selclearthread() */
if (wql->wql_type == WAIT_QUEUE_UNLINKED) {
goto out;
}
WAIT_QUEUE_SET_LINK_CHECK(wq_set, wql);
/* On a wait queue, and we hold set queue lock ... */
wq = wql->wql_queue;
if (wait_queue_lock_try(wq)) {
wait_queue_unlink_locked(wq, wq_set, wql);
wait_queue_unlock(wq);
} else {
wqs_unlock(wq_set);
splx(s);
delay(1);
goto retry;
}
out:
wqs_unlock(wq_set);
splx(s);
return KERN_SUCCESS;
}
/*
* Routine: wait_queue_set_unlink_all_nofree
* Purpose:
* Remove the linkage between a set wait queue and all its
* member wait queues. The link structures are not freed, nor
* returned. It is the caller's responsibility to track and free
* them.
* Conditions:
* The wait queue being must be a member set queue
*/
kern_return_t
wait_queue_set_unlink_all_nofree(
wait_queue_set_t wq_set)
{
wait_queue_link_t wql;
wait_queue_t wq;
queue_t q;
kern_return_t kret;
spl_t s;
if (!wait_queue_is_set(wq_set)) {
return KERN_INVALID_ARGUMENT;
}
retry:
s = splsched();
wqs_lock(wq_set);
q = &wq_set->wqs_setlinks;
wql = (wait_queue_link_t)queue_first(q);
while (!queue_end(q, (queue_entry_t)wql)) {
WAIT_QUEUE_SET_LINK_CHECK(wq_set, wql);
wq = wql->wql_queue;
if (wait_queue_lock_try(wq)) {
wait_queue_unlink_locked(wq, wq_set, wql);
wait_queue_unlock(wq);
wql = (wait_queue_link_t)queue_first(q);
} else {
wqs_unlock(wq_set);
splx(s);
delay(1);
goto retry;
}
}
wqs_unlock(wq_set);
splx(s);
return(KERN_SUCCESS);
}
/*
* Routine: wait_queue_wakeup_one
* Purpose:
* Wakeup the most appropriate thread that is in the specified
* wait queue for the specified event.
* Conditions:
* Nothing locked
* Returns:
* KERN_SUCCESS - Thread was woken up
* KERN_NOT_WAITING - No thread was waiting <wq,event> pair
*/
kern_return_t
wait_queue_wakeup_one(
wait_queue_t wq,
event_t event,
wait_result_t result,
int priority)
{
thread_t thread;
spl_t s;
if (!wait_queue_is_valid(wq)) {
return KERN_INVALID_ARGUMENT;
}
s = splsched();
wait_queue_lock(wq);
thread = _wait_queue_select64_one(wq, CAST_DOWN(event64_t,event));
wait_queue_unlock(wq);
if (thread) {
kern_return_t res;
if (thread->sched_pri < priority) {
if (priority <= MAXPRI) {
set_sched_pri(thread, priority);
thread->was_promoted_on_wakeup = 1;
thread->sched_flags |= TH_SFLAG_PROMOTED;
}
}
res = thread_go(thread, result);
assert(res == KERN_SUCCESS);
thread_unlock(thread);
splx(s);
return res;
}
splx(s);
return KERN_NOT_WAITING;
}
/*
* Routine: wait_queue_wakeup64_identity_locked
* Purpose:
* Select a single thread that is most-eligible to run and set
* set it running. But return the thread locked.
*
* Conditions:
* at splsched
* wait queue locked
* possibly recursive
* Returns:
* a pointer to the locked thread that was awakened
*/
__private_extern__ thread_t
wait_queue_wakeup64_identity_locked(
wait_queue_t wq,
event64_t event,
wait_result_t result,
boolean_t unlock)
{
kern_return_t res;
thread_t thread;
assert(wait_queue_held(wq));
thread = _wait_queue_select64_one(wq, event);
if (unlock)
wait_queue_unlock(wq);
if (thread) {
res = thread_go(thread, result);
assert(res == KERN_SUCCESS);
}
return thread; /* still locked if not NULL */
}
/*
* Routine: wait_queue_peek64_locked
* Purpose:
* Select the best thread from a wait queue that meet the
* supplied criteria, but leave it on the queue it was
* found on. The thread, and the actual wait_queue the
* thread was found on are identified.
* Conditions:
* at splsched
* wait queue locked
* possibly recursive
* Returns:
* a locked thread - if one found
* a locked waitq - the one the thread was found on
* Note:
* Both the waitq the thread was actually found on, and
* the supplied wait queue, are locked after this.
*/
__private_extern__ void
wait_queue_peek64_locked(
wait_queue_t wq,
event64_t event,
thread_t *tp,
wait_queue_t *wqp)
{
wait_queue_element_t wq_element;
wait_queue_element_t wqe_next;
thread_t t;
queue_t q;
assert(wq->wq_fifo);
*tp = THREAD_NULL;
q = &wq->wq_queue;
wq_element = (wait_queue_element_t) queue_first(q);
while (!queue_end(q, (queue_entry_t)wq_element)) {
WAIT_QUEUE_ELEMENT_CHECK(wq, wq_element);
wqe_next = (wait_queue_element_t)
queue_next((queue_t) wq_element);
/*
* We may have to recurse if this is a compound wait queue.
*/
if (wq_element->wqe_type == WAIT_QUEUE_LINK) {
wait_queue_link_t wql = (wait_queue_link_t)wq_element;
wait_queue_t set_queue;
/*
* We have to check the set wait queue.
*/
set_queue = (wait_queue_t)wql->wql_setqueue;
wait_queue_lock(set_queue);
if (! wait_queue_empty(set_queue)) {
wait_queue_peek64_locked(set_queue, event, tp, wqp);
}
if (*tp != THREAD_NULL) {
if (*wqp != set_queue)
wait_queue_unlock(set_queue);
return; /* thread and its waitq locked */
}
wait_queue_unlock(set_queue);
} else {
/*
* Otherwise, its a thread. If it is waiting on
* the event we are posting to this queue, return
* it locked, but leave it on the queue.
*/
thread_t t = (thread_t)wq_element;
if (t->wait_event == event) {
thread_lock(t);
*tp = t;
*wqp = wq;
return;
}
}
wq_element = wqe_next;
}
}
/*
* Routine: _wait_queue_select64_all
* Purpose:
* Select all threads off a wait queue that meet the
* supplied criteria.
* Conditions:
* at splsched
* wait queue locked
* wake_queue initialized and ready for insertion
* possibly recursive
* Returns:
* a queue of locked threads
*/
static void
_wait_queue_select64_all(
wait_queue_t wq,
event64_t event,
queue_t wake_queue)
{
wait_queue_element_t wq_element;
wait_queue_element_t wqe_next;
queue_t q;
q = &wq->wq_queue;
wq_element = (wait_queue_element_t) queue_first(q);
while (!queue_end(q, (queue_entry_t)wq_element)) {
WAIT_QUEUE_ELEMENT_CHECK(wq, wq_element);
wqe_next = (wait_queue_element_t)
queue_next((queue_t) wq_element);
/*
* We may have to recurse if this is a compound wait queue.
*/
if (wq_element->wqe_type == WAIT_QUEUE_LINK) {
wait_queue_link_t wql = (wait_queue_link_t)wq_element;
wait_queue_t set_queue;
/*
* We have to check the set wait queue.
*/
set_queue = (wait_queue_t)wql->wql_setqueue;
wait_queue_lock(set_queue);
if (set_queue->wq_isprepost) {
wait_queue_set_t wqs = (wait_queue_set_t)set_queue;
/*
* Preposting is only for sets and wait queue
* is the first element of set
*/
wqs->wqs_refcount++;
}
if (! wait_queue_empty(set_queue))
_wait_queue_select64_all(set_queue, event, wake_queue);
wait_queue_unlock(set_queue);
} else {
/*
* Otherwise, its a thread. If it is waiting on
* the event we are posting to this queue, pull
* it off the queue and stick it in out wake_queue.
*/
thread_t t = (thread_t)wq_element;
if (t->wait_event == event) {
thread_lock(t);
remqueue(q, (queue_entry_t) t);
enqueue (wake_queue, (queue_entry_t) t);
t->wait_queue = WAIT_QUEUE_NULL;
t->wait_event = NO_EVENT64;
t->at_safe_point = FALSE;
/* returned locked */
}
}
wq_element = wqe_next;
}
}
