int32_t nano_timer_ticks_remain(struct nano_timer *timer)
{
int key = irq_lock();
int32_t remaining_ticks;
struct _nano_timeout *t = &timer->timeout_data;
sys_dlist_t *timeout_q = &_nanokernel.timeout_q;
struct _nano_timeout *iterator;
if (t->delta_ticks_from_prev == -1) {
remaining_ticks = 0;
} else {
/*
* As nanokernel timeouts are stored in a linked list with
* delta_ticks_from_prev, to get the actual number of ticks
* remaining for the timer, walk through the timeouts list
* and accumulate all the delta_ticks_from_prev values up to
* the timer.
*/
iterator =
(struct _nano_timeout *)sys_dlist_peek_head(timeout_q);
remaining_ticks = iterator->delta_ticks_from_prev;
while (iterator != t) {
iterator = (struct _nano_timeout *)sys_dlist_peek_next(
timeout_q, &iterator->node);
remaining_ticks += iterator->delta_ticks_from_prev;
}
}
irq_unlock(key);
return remaining_ticks;
}
int32_t _timeout_remaining_get(struct _timeout *timeout)
{
unsigned int key = irq_lock();
int32_t remaining_ticks;
if (timeout->delta_ticks_from_prev == _INACTIVE) {
remaining_ticks = 0;
} else {
/*
* compute remaining ticks by walking the timeout list
* and summing up the various tick deltas involved
*/
struct _timeout *t =
(struct _timeout *)sys_dlist_peek_head(&_timeout_q);
remaining_ticks = t->delta_ticks_from_prev;
while (t != timeout) {
t = (struct _timeout *)sys_dlist_peek_next(&_timeout_q,
&t->node);
remaining_ticks += t->delta_ticks_from_prev;
}
}
irq_unlock(key);
return _ticks_to_ms(remaining_ticks);
}
static inline void handle_expired_nano_timeouts(int32_t ticks)
{
struct _nano_timeout *head =
(struct _nano_timeout *)sys_dlist_peek_head(&_nanokernel.timeout_q);
_nanokernel.task_timeout = TICKS_UNLIMITED;
if (head) {
head->delta_ticks_from_prev -= ticks;
_nano_timeout_handle_timeouts();
}
}
/**
* @brief Handle expiration of a kernel timer object.
*
* @param t Timeout used by the timer.
*
* @return N/A
*/
void _timer_expiration_handler(struct _timeout *t)
{
struct k_timer *timer = CONTAINER_OF(t, struct k_timer, timeout);
struct k_thread *thread;
unsigned int key;
/*
* if the timer is periodic, start it again; don't add _TICK_ALIGN
* since we're already aligned to a tick boundary
*/
if (timer->period > 0) {
key = irq_lock();
_add_timeout(NULL, &timer->timeout, &timer->wait_q,
timer->period);
irq_unlock(key);
}
/* update timer's status */
timer->status += 1;
/* invoke timer expiry function */
if (timer->expiry_fn) {
timer->expiry_fn(timer);
}
thread = (struct k_thread *)sys_dlist_peek_head(&timer->wait_q);
if (!thread) {
return;
}
/*
* Interrupts _DO NOT_ have to be locked in this specific instance of
* calling _unpend_thread() because a) this is the only place a thread
* can be taken off this pend queue, and b) the only place a thread
* can be put on the pend queue is at thread level, which of course
* cannot interrupt the current context.
*/
_unpend_thread(thread);
key = irq_lock();
_ready_thread(thread);
irq_unlock(key);
_set_thread_return_value(thread, 0);
}
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);
}
}
/**
* @brief Prepare a working set of readers/writers
*
* Prepare a list of "working threads" into/from which the data
* will be directly copied. This list is useful as it is used to ...
*
* 1. avoid double copying
* 2. minimize interrupt latency as interrupts are unlocked
* while copying data
* 3. ensure a timeout can not make the request impossible to satisfy
*
* The list is populated with previously pended threads that will be ready to
* run after the pipe call is complete.
*
* Important things to remember when reading from the pipe ...
* 1. If there are writers int @a wait_q, then the pipe's buffer is full.
* 2. Conversely if the pipe's buffer is not full, there are no writers.
* 3. The amount of available data in the pipe is the sum the bytes used in
* the pipe (@a pipe_space) and all the requests from the waiting writers.
* 4. Since data is read from the pipe's buffer first, the working set must
* include writers that will (try to) re-fill the pipe's buffer afterwards.
*
* Important things to remember when writing to the pipe ...
* 1. If there are readers in @a wait_q, then the pipe's buffer is empty.
* 2. Conversely if the pipe's buffer is not empty, then there are no readers.
* 3. The amount of space available in the pipe is the sum of the bytes unused
* in the pipe (@a pipe_space) and all the requests from the waiting readers.
*
* @return false if request is unsatisfiable, otherwise true
*/
static bool _pipe_xfer_prepare(sys_dlist_t *xfer_list,
struct k_thread **waiter,
_wait_q_t *wait_q,
size_t pipe_space,
size_t bytes_to_xfer,
size_t min_xfer,
s32_t timeout)
{
sys_dnode_t *node;
struct k_thread *thread;
struct k_pipe_desc *desc;
size_t num_bytes = 0;
if (timeout == K_NO_WAIT) {
for (node = sys_dlist_peek_head(wait_q); node != NULL;
node = sys_dlist_peek_next(wait_q, node)) {
thread = (struct k_thread *)node;
desc = (struct k_pipe_desc *)thread->base.swap_data;
num_bytes += desc->bytes_to_xfer;
if (num_bytes >= bytes_to_xfer) {
break;
}
}
if (num_bytes + pipe_space < min_xfer) {
return false;
}
}
/*
* Either @a timeout is not K_NO_WAIT (so the thread may pend) or
* the entire request can be satisfied. Generate the working list.
*/
sys_dlist_init(xfer_list);
num_bytes = 0;
while ((thread = (struct k_thread *) sys_dlist_peek_head(wait_q))) {
desc = (struct k_pipe_desc *)thread->base.swap_data;
num_bytes += desc->bytes_to_xfer;
if (num_bytes > bytes_to_xfer) {
/*
* This request can not be fully satisfied.
* Do not remove it from the wait_q.
* Do not abort its timeout (if applicable).
* Do not add it to the transfer list
*/
break;
}
/*
* This request can be fully satisfied.
* Remove it from the wait_q.
* Abort its timeout.
* Add it to the transfer list.
*/
_unpend_thread(thread);
_abort_thread_timeout(thread);
sys_dlist_append(xfer_list, &thread->base.k_q_node);
}
*waiter = (num_bytes > bytes_to_xfer) ? thread : NULL;
return true;
}
