int work_queue(int qid, struct work_s *work, worker_t worker, void *arg, uint32_t delay)
{
struct wqueue_s *wqueue = &g_work[qid];
//DEBUGASSERT(work != NULL && (unsigned)qid < NWORKERS);
/* First, initialize the work structure */
work->worker = worker; /* Work callback */
work->arg = arg; /* Callback argument */
work->delay = delay; /* Delay until work performed */
/* Now, time-tag that entry and put it in the work queue. This must be
* done with interrupts disabled. This permits this function to be called
* from with task logic or interrupt handlers.
*/
work_lock(qid);
work->qtime = clock_systimer(); /* Time work queued */
dq_addlast((dq_entry_t *)work, &wqueue->q);
#ifdef __PX4_QURT
px4_task_kill(wqueue->pid, SIGALRM); /* Wake up the worker thread */
#else
px4_task_kill(wqueue->pid, SIGCONT); /* Wake up the worker thread */
#endif
work_unlock(qid);
return PX4_OK;
}
static int work_qcancel(FAR struct usr_wqueue_s *wqueue, FAR struct work_s *work)
{
int ret = -ENOENT;
DEBUGASSERT(work != NULL);
/* Get exclusive access to the work queue */
while (work_lock() < 0);
/* Cancelling the work is simply a matter of removing the work structure
* from the work queue. This must be done with interrupts disabled because
* new work is typically added to the work queue from interrupt handlers.
*/
if (work->worker != NULL)
{
/* A little test of the integrity of the work queue */
DEBUGASSERT(work->dq.flink || (FAR dq_entry_t *)work == wqueue->q.tail);
DEBUGASSERT(work->dq.blink || (FAR dq_entry_t *)work == wqueue->q.head);
/* Remove the entry from the work queue and make sure that it is
* mark as available (i.e., the worker field is nullified).
*/
dq_rem((FAR dq_entry_t *)work, &wqueue->q);
work->worker = NULL;
ret = OK;
}
work_unlock();
return ret;
}
static int work_qqueue(FAR struct usr_wqueue_s *wqueue,
FAR struct work_s *work, worker_t worker,
FAR void *arg, uint32_t delay)
{
DEBUGASSERT(work != NULL);
/* First, initialize the work structure */
work->worker = worker; /* Work callback */
work->arg = arg; /* Callback argument */
work->delay = delay; /* Delay until work performed */
/* Get exclusive access to the work queue */
while (work_lock() < 0);
/* Now, time-tag that entry and put it in the work queue. */
work->qtime = clock_systimer(); /* Time work queued */
dq_addlast((FAR dq_entry_t *)work, &wqueue->q);
kill(wqueue->pid, SIGWORK); /* Wake up the worker thread */
work_unlock();
return OK;
}
static int work_qqueue(FAR struct usr_wqueue_s *wqueue,
FAR struct work_s *work, worker_t worker,
FAR void *arg, clock_t delay)
{
DEBUGASSERT(work != NULL);
/* Get exclusive access to the work queue */
while (work_lock() < 0);
/* Is there already pending work? */
if (work->worker != NULL)
{
/* Remove the entry from the work queue. It will re requeued at the
* end of the work queue.
*/
dq_rem((FAR dq_entry_t *)work, &wqueue->q);
}
/* Initialize the work structure */
work->worker = worker; /* Work callback. non-NULL means queued */
work->arg = arg; /* Callback argument */
work->delay = delay; /* Delay until work performed */
/* Now, time-tag that entry and put it in the work queue. */
work->qtime = clock(); /* Time work queued */
dq_addlast((FAR dq_entry_t *)work, &wqueue->q);
kill(wqueue->pid, SIGWORK); /* Wake up the worker thread */
work_unlock();
return OK;
}
void work_process(FAR struct usr_wqueue_s *wqueue)
{
volatile FAR struct work_s *work;
worker_t worker;
FAR void *arg;
uint32_t elapsed;
uint32_t remaining;
uint32_t stick;
uint32_t ctick;
uint32_t next;
int ret;
/* Then process queued work. Lock the work queue while we process items
* in the work list.
*/
next = wqueue->delay;
ret = work_lock();
if (ret < 0)
{
/* Break out earlier if we were awakened by a signal */
return;
}
/* Get the time that we started this polling cycle in clock ticks. */
stick = clock_systimer();
/* And check each entry in the work queue. Since we have locked the
* work queue we know: (1) we will not be suspended unless we do
* so ourselves, and (2) there will be no changes to the work queue
*/
work = (FAR struct work_s *)wqueue->q.head;
while (work)
{
/* Is this work ready? It is ready if there is no delay or if
* the delay has elapsed. qtime is the time that the work was added
* to the work queue. It will always be greater than or equal to
* zero. Therefore a delay of zero will always execute immediately.
*/
ctick = clock_systimer();
elapsed = ctick - work->qtime;
if (elapsed >= work->delay)
{
/* Remove the ready-to-execute work from the list */
(void)dq_rem((struct dq_entry_s *)work, &wqueue->q);
/* Extract the work description from the entry (in case the work
* instance by the re-used after it has been de-queued).
*/
worker = work->worker;
/* Check for a race condition where the work may be nullified
* before it is removed from the queue.
*/
if (worker != NULL)
{
/* Extract the work argument (before unlocking the work queue) */
arg = work->arg;
/* Mark the work as no longer being queued */
work->worker = NULL;
/* Do the work. Unlock the the work queue while the work is being
* performed... we don't have any idea how long this will take!
*/
work_unlock();
worker(arg);
/* Now, unfortunately, since we unlocked the work queue we don't
* know the state of the work list and we will have to start
* back at the head of the list.
*/
ret = work_lock();
if (ret < 0)
{
/* Break out earlier if we were awakened by a signal */
return;
}
work = (FAR struct work_s *)wqueue->q.head;
}
else
{
/* Cancelled.. Just move to the next work in the list with
* the work queue still locked.
*/
work = (FAR struct work_s *)work->dq.flink;
}
}
else /* elapsed < work->delay */
{
/* This one is not ready.
*
* NOTE that elapsed is relative to the the current time,
* not the time of beginning of this queue processing pass.
* So it may need an adjustment.
*/
elapsed += (ctick - stick);
if (elapsed > work->delay)
{
/* The delay has expired while we are processing */
elapsed = work->delay;
}
/* Will it be ready before the next scheduled wakeup interval? */
remaining = work->delay - elapsed;
if (remaining < next)
{
/* Yes.. Then schedule to wake up when the work is ready */
next = remaining;
}
/* Then try the next in the list. */
work = (FAR struct work_s *)work->dq.flink;
}
}
/* Get the delay (in clock ticks) since we started the sampling */
elapsed = clock_systimer() - stick;
if (elapsed < wqueue->delay && next > 0)
{
/* How must time would we need to delay to get to the end of the
* sampling period? The amount of time we delay should be the smaller
* of the time to the end of the sampling period and the time to the
* next work expiry.
*/
remaining = wqueue->delay - elapsed;
next = MIN(next, remaining);
/* Wait awhile to check the work list. We will wait here until
* either the time elapses or until we are awakened by a signal.
* Interrupts will be re-enabled while we wait.
*/
usleep(next * USEC_PER_TICK);
}
work_unlock();
}
static void work_process(struct wqueue_s *wqueue, int lock_id)
{
volatile struct work_s *work;
worker_t worker;
void *arg;
uint64_t elapsed;
uint32_t remaining;
uint32_t next;
/* Then process queued work. We need to keep interrupts disabled while
* we process items in the work list.
*/
next = CONFIG_SCHED_WORKPERIOD;
work_lock(lock_id);
work = (struct work_s *)wqueue->q.head;
while (work) {
/* Is this work ready? It is ready if there is no delay or if
* the delay has elapsed. qtime is the time that the work was added
* to the work queue. It will always be greater than or equal to
* zero. Therefore a delay of zero will always execute immediately.
*/
elapsed = USEC2TICK(clock_systimer() - work->qtime);
//printf("work_process: in ticks elapsed=%lu delay=%u\n", elapsed, work->delay);
if (elapsed >= work->delay) {
/* Remove the ready-to-execute work from the list */
(void)dq_rem((struct dq_entry_s *)work, &wqueue->q);
/* Extract the work description from the entry (in case the work
* instance by the re-used after it has been de-queued).
*/
worker = work->worker;
arg = work->arg;
/* Mark the work as no longer being queued */
work->worker = NULL;
/* Do the work. Re-enable interrupts while the work is being
* performed... we don't have any idea how long that will take!
*/
work_unlock(lock_id);
if (!worker) {
PX4_WARN("MESSED UP: worker = 0\n");
} else {
worker(arg);
}
/* Now, unfortunately, since we re-enabled interrupts we don't
* know the state of the work list and we will have to start
* back at the head of the list.
*/
work_lock(lock_id);
work = (struct work_s *)wqueue->q.head;
} else {
/* This one is not ready.. will it be ready before the next
* scheduled wakeup interval?
*/
/* Here: elapsed < work->delay */
remaining = USEC_PER_TICK * (work->delay - elapsed);
if (remaining < next) {
/* Yes.. Then schedule to wake up when the work is ready */
next = remaining;
}
/* Then try the next in the list. */
work = (struct work_s *)work->dq.flink;
}
}
/* Wait awhile to check the work list. We will wait here until either
* the time elapses or until we are awakened by a signal.
*/
work_unlock(lock_id);
usleep(next);
}
