void k_timer_stop(struct k_timer *timer)
{
__ASSERT(!_is_in_isr(), "");
int key = irq_lock();
int inactive = (_abort_timeout(&timer->timeout) == _INACTIVE);
irq_unlock(key);
if (inactive) {
return;
}
if (timer->stop_fn) {
timer->stop_fn(timer);
}
key = irq_lock();
struct k_thread *pending_thread = _unpend_first_thread(&timer->wait_q);
if (pending_thread) {
_ready_thread(pending_thread);
}
if (_is_in_isr()) {
irq_unlock(key);
} else {
_reschedule_threads(key);
}
}
int k_msgq_get(struct k_msgq *q, void *data, s32_t timeout)
{
__ASSERT(!_is_in_isr() || timeout == K_NO_WAIT, "");
unsigned int key = irq_lock();
struct k_thread *pending_thread;
int result;
if (q->used_msgs > 0) {
/* take first available message from queue */
memcpy(data, q->read_ptr, q->msg_size);
q->read_ptr += q->msg_size;
if (q->read_ptr == q->buffer_end) {
q->read_ptr = q->buffer_start;
}
q->used_msgs--;
/* handle first thread waiting to write (if any) */
pending_thread = _unpend_first_thread(&q->wait_q);
if (pending_thread) {
/* add thread's message to queue */
memcpy(q->write_ptr, pending_thread->base.swap_data,
q->msg_size);
q->write_ptr += q->msg_size;
if (q->write_ptr == q->buffer_end) {
q->write_ptr = q->buffer_start;
}
q->used_msgs++;
/* wake up waiting thread */
_set_thread_return_value(pending_thread, 0);
_abort_thread_timeout(pending_thread);
_ready_thread(pending_thread);
if (!_is_in_isr() && _must_switch_threads()) {
_Swap(key);
return 0;
}
}
result = 0;
} else if (timeout == K_NO_WAIT) {
/* don't wait for a message to become available */
result = -ENOMSG;
} else {
/* wait for get message success or timeout */
_pend_current_thread(&q->wait_q, timeout);
_current->base.swap_data = data;
return _Swap(key);
}
irq_unlock(key);
return result;
}
int k_mem_pool_alloc(struct k_mem_pool *p, struct k_mem_block *block,
size_t size, s32_t timeout)
{
int ret, key;
s64_t end = 0;
__ASSERT(!(_is_in_isr() && timeout != K_NO_WAIT), "");
if (timeout > 0) {
end = _tick_get() + _ms_to_ticks(timeout);
}
while (1) {
ret = pool_alloc(p, block, size);
if (ret == 0 || timeout == K_NO_WAIT ||
ret == -EAGAIN || (ret && ret != -ENOMEM)) {
return ret;
}
key = irq_lock();
_pend_current_thread(&p->wait_q, timeout);
_Swap(key);
if (timeout != K_FOREVER) {
timeout = end - _tick_get();
if (timeout < 0) {
break;
}
}
}
return -EAGAIN;
}
void _k_thread_group_op(u32_t groups, void (*func)(struct k_thread *))
{
unsigned int key;
__ASSERT(!_is_in_isr(), "");
_sched_lock();
/* Invoke func() on each static thread in the specified group set. */
_FOREACH_STATIC_THREAD(thread_data) {
if (is_in_any_group(thread_data, groups)) {
key = irq_lock();
func(thread_data->thread);
irq_unlock(key);
}
}
/*
* If the current thread is still in a ready state, then let the
* "unlock scheduler" code determine if any rescheduling is needed.
*/
if (_is_thread_ready(_current)) {
k_sched_unlock();
return;
}
/* The current thread is no longer in a ready state--reschedule. */
key = irq_lock();
_sched_unlock_no_reschedule();
_Swap(key);
}
void k_queue_insert(struct k_queue *queue, void *prev, void *data)
{
struct k_thread *first_pending_thread;
unsigned int key;
key = irq_lock();
first_pending_thread = _unpend_first_thread(&queue->wait_q);
if (first_pending_thread) {
prepare_thread_to_run(first_pending_thread, data);
if (!_is_in_isr() && _must_switch_threads()) {
(void)_Swap(key);
return;
}
} else {
sys_slist_insert(&queue->data_q, prev, data);
if (handle_poll_event(queue)) {
(void)_Swap(key);
return;
}
}
irq_unlock(key);
}
void k_queue_append_list(struct k_queue *queue, void *head, void *tail)
{
__ASSERT(head && tail, "invalid head or tail");
struct k_thread *first_thread, *thread;
unsigned int key;
key = irq_lock();
first_thread = _peek_first_pending_thread(&queue->wait_q);
while (head && ((thread = _unpend_first_thread(&queue->wait_q)))) {
prepare_thread_to_run(thread, head);
head = *(void **)head;
}
if (head) {
sys_slist_append_list(&queue->data_q, head, tail);
}
if (first_thread) {
if (!_is_in_isr() && _must_switch_threads()) {
(void)_Swap(key);
return;
}
} else {
if (handle_poll_event(queue)) {
(void)_Swap(key);
return;
}
}
irq_unlock(key);
}
uint32_t k_timer_status_sync(struct k_timer *timer)
{
__ASSERT(!_is_in_isr(), "");
unsigned int key = irq_lock();
uint32_t result = timer->status;
if (result == 0) {
if (timer->timeout.delta_ticks_from_prev != _INACTIVE) {
/* wait for timer to expire or stop */
_pend_current_thread(&timer->wait_q, K_FOREVER);
_Swap(key);
/* get updated timer status */
key = irq_lock();
result = timer->status;
} else {
/* timer is already stopped */
}
} else {
/* timer has already expired at least once */
}
timer->status = 0;
irq_unlock(key);
return result;
}
int k_msgq_put(struct k_msgq *q, void *data, s32_t timeout)
{
__ASSERT(!_is_in_isr() || timeout == K_NO_WAIT, "");
unsigned int key = irq_lock();
struct k_thread *pending_thread;
int result;
if (q->used_msgs < q->max_msgs) {
/* message queue isn't full */
pending_thread = _unpend_first_thread(&q->wait_q);
if (pending_thread) {
/* give message to waiting thread */
memcpy(pending_thread->base.swap_data, data,
q->msg_size);
/* wake up waiting thread */
_set_thread_return_value(pending_thread, 0);
_abort_thread_timeout(pending_thread);
_ready_thread(pending_thread);
if (!_is_in_isr() && _must_switch_threads()) {
_Swap(key);
return 0;
}
} else {
/* put message in queue */
memcpy(q->write_ptr, data, q->msg_size);
q->write_ptr += q->msg_size;
if (q->write_ptr == q->buffer_end) {
q->write_ptr = q->buffer_start;
}
q->used_msgs++;
}
result = 0;
} else if (timeout == K_NO_WAIT) {
/* don't wait for message space to become available */
result = -ENOMSG;
} else {
/* wait for put message success, failure, or timeout */
_pend_current_thread(&q->wait_q, timeout);
_current->base.swap_data = data;
return _Swap(key);
}
irq_unlock(key);
return result;
}
/* This implements a "fair" scheduling policy: at the end of a POSIX
* thread call that might result in a change of the current maximum
* priority thread, we always check and context switch if needed.
* Note that there is significant dispute in the community over the
* "right" way to do this and different systems do it differently by
* default. Zephyr is an RTOS, so we choose latency over
* throughput. See here for a good discussion of the broad issue:
*
* https://blog.mozilla.org/nfroyd/2017/03/29/on-mutex-performance-part-1/
*/
static void swap_or_unlock(int key)
{
/* API madness: use __ not _ here. The latter checks for our
* preemption state, but we want to do a switch here even if
* we can be preempted.
*/
if (!_is_in_isr() && __must_switch_threads()) {
_Swap(key);
} else {
irq_unlock(key);
}
}
k_tid_t k_thread_spawn(char *stack, size_t stack_size,
void (*entry)(void *, void *, void*),
void *p1, void *p2, void *p3,
int prio, u32_t options, s32_t delay)
{
__ASSERT(!_is_in_isr(), "");
struct k_thread *new_thread = (struct k_thread *)stack;
_new_thread(stack, stack_size, entry, p1, p2, p3, prio, options);
schedule_new_thread(new_thread, delay);
return new_thread;
}
void k_mem_pool_free(struct k_mem_block *block)
{
int i, key, need_sched = 0;
struct k_mem_pool *p = get_pool(block->id.pool);
size_t lsizes[p->n_levels];
/* As in k_mem_pool_alloc(), we build a table of level sizes
* to avoid having to store it in precious RAM bytes.
* Overhead here is somewhat higher because free_block()
* doesn't inherently need to traverse all the larger
* sublevels.
*/
lsizes[0] = _ALIGN4(p->max_sz);
for (i = 1; i <= block->id.level; i++) {
lsizes[i] = _ALIGN4(lsizes[i-1] / 4);
}
free_block(get_pool(block->id.pool), block->id.level,
lsizes, block->id.block);
/* Wake up anyone blocked on this pool and let them repeat
* their allocation attempts
*/
key = irq_lock();
while (!sys_dlist_is_empty(&p->wait_q)) {
struct k_thread *th = (void *)sys_dlist_peek_head(&p->wait_q);
_unpend_thread(th);
_abort_thread_timeout(th);
_ready_thread(th);
need_sched = 1;
}
if (need_sched && !_is_in_isr()) {
_reschedule_threads(key);
} else {
irq_unlock(key);
}
}
/* must be called with interrupts locked */
static int _signal_poll_event(struct k_poll_event *event, u32_t state,
int *must_reschedule)
{
*must_reschedule = 0;
if (!event->poller) {
goto ready_event;
}
struct k_thread *thread = event->poller->thread;
__ASSERT(event->poller->thread, "poller should have a thread\n");
clear_polling_state(thread);
if (!_is_thread_pending(thread)) {
goto ready_event;
}
if (_is_thread_timeout_expired(thread)) {
return -EAGAIN;
}
_unpend_thread(thread);
_abort_thread_timeout(thread);
_set_thread_return_value(thread, 0);
if (!_is_thread_ready(thread)) {
goto ready_event;
}
_add_thread_to_ready_q(thread);
*must_reschedule = !_is_in_isr() && _must_switch_threads();
ready_event:
set_event_ready(event, state);
return 0;
}
/**
* @brief Check if a memory address range falls within the stack
*
* Given a memory address range, ensure that it falls within the bounds
* of the faulting context's stack.
*
* @param addr Starting address
* @param size Size of the region, or 0 if we just want to see if addr is
* in bounds
* @param cs Code segment of faulting context
* @return true if addr/size region is not within the thread stack
*/
static bool check_stack_bounds(u32_t addr, size_t size, u16_t cs)
{
u32_t start, end;
if (_is_in_isr()) {
/* We were servicing an interrupt */
start = (u32_t)_ARCH_THREAD_STACK_BUFFER(_interrupt_stack);
end = start + CONFIG_ISR_STACK_SIZE;
} else if ((cs & 0x3) != 0 ||
(_current->base.user_options & K_USER) == 0) {
/* Thread was in user mode, or is not a user mode thread.
* The normal stack buffer is what we will check.
*/
start = _current->stack_info.start;
end = STACK_ROUND_DOWN(_current->stack_info.start +
_current->stack_info.size);
} else {
/* User thread was doing a syscall, check kernel stack bounds */
start = _current->stack_info.start - MMU_PAGE_SIZE;
end = _current->stack_info.start;
}
return (addr <= start) || (addr + size > end);
}
int k_is_in_isr(void)
{
return _is_in_isr();
}
int k_poll(struct k_poll_event *events, int num_events, s32_t timeout)
{
__ASSERT(!_is_in_isr(), "");
__ASSERT(events, "NULL events\n");
__ASSERT(num_events > 0, "zero events\n");
int last_registered = -1, in_use = 0, rc;
unsigned int key;
key = irq_lock();
set_polling_state(_current);
irq_unlock(key);
/*
* We can get by with one poller structure for all events for now:
* if/when we allow multiple threads to poll on the same object, we
* will need one per poll event associated with an object.
*/
struct _poller poller = { .thread = _current };
/* find events whose condition is already fulfilled */
for (int ii = 0; ii < num_events; ii++) {
u32_t state;
key = irq_lock();
if (is_condition_met(&events[ii], &state)) {
set_event_ready(&events[ii], state);
clear_polling_state(_current);
} else if (timeout != K_NO_WAIT && is_polling() && !in_use) {
rc = register_event(&events[ii]);
if (rc == 0) {
events[ii].poller = &poller;
++last_registered;
} else if (rc == -EADDRINUSE) {
/* setting in_use also prevents any further
* registrations by the current thread
*/
in_use = -EADDRINUSE;
events[ii].state = K_POLL_STATE_EADDRINUSE;
clear_polling_state(_current);
} else {
__ASSERT(0, "unexpected return code\n");
}
}
irq_unlock(key);
}
key = irq_lock();
/*
* If we're not polling anymore, it means that at least one event
* condition is met, either when looping through the events here or
* because one of the events registered has had its state changed, or
* that one of the objects we wanted to poll on already had a thread
* polling on it. We can remove all registrations and return either
* success or a -EADDRINUSE error. In the case of a -EADDRINUSE error,
* the events that were available are still flagged as such, and it is
* valid for the caller to consider them available, as if this function
* returned success.
*/
if (!is_polling()) {
clear_event_registrations(events, last_registered, key);
irq_unlock(key);
return in_use;
}
clear_polling_state(_current);
if (timeout == K_NO_WAIT) {
irq_unlock(key);
return -EAGAIN;
}
_wait_q_t wait_q = _WAIT_Q_INIT(&wait_q);
_pend_current_thread(&wait_q, timeout);
int swap_rc = _Swap(key);
/*
* Clear all event registrations. If events happen while we're in this
* loop, and we already had one that triggered, that's OK: they will
* end up in the list of events that are ready; if we timed out, and
* events happen while we're in this loop, that is OK as well since
* we've already know the return code (-EAGAIN), and even if they are
* added to the list of events that occurred, the user has to check the
* return code first, which invalidates the whole list of event states.
*/
key = irq_lock();
clear_event_registrations(events, last_registered, key);
irq_unlock(key);
return swap_rc;
}