bool sched_removereadytorun(FAR _TCB *rtcb)
{
bool ret = false;
/* Check if the TCB to be removed is at the head of the ready
* to run list. In this case, we are removing the currently
* active task.
*/
if (!rtcb->blink)
{
/* There must always be at least one task in the list (the idle task) */
ASSERT(rtcb->flink != NULL);
/* Inform the instrumentation layer that we are switching tasks */
sched_note_switch(rtcb, rtcb->flink);
rtcb->flink->task_state = TSTATE_TASK_RUNNING;
ret = true;
}
/* Remove the TCB from the ready-to-run list */
dq_rem((FAR dq_entry_t*)rtcb, (dq_queue_t*)&g_readytorun);
rtcb->task_state = TSTATE_TASK_INVALID;
return ret;
}
bool sched_removereadytorun(FAR struct tcb_s *rtcb)
{
FAR struct tcb_s *ntcb = NULL;
bool ret = false;
/* Check if the TCB to be removed is at the head of the ready to run list.
* In this case, we are removing the currently active task.
*/
if (!rtcb->blink)
{
/* There must always be at least one task in the list (the idle task) */
ntcb = (FAR struct tcb_s *)rtcb->flink;
DEBUGASSERT(ntcb != NULL);
/* Inform the instrumentation layer that we are switching tasks */
sched_note_switch(rtcb, ntcb);
ntcb->task_state = TSTATE_TASK_RUNNING;
ret = true;
}
/* Remove the TCB from the ready-to-run list */
dq_rem((FAR dq_entry_t *)rtcb, (FAR dq_queue_t *)&g_readytorun);
/* Since the TCB is not in any list, it is now invalid */
rtcb->task_state = TSTATE_TASK_INVALID;
return ret;
}
bool sched_addreadytorun(FAR _TCB *btcb)
{
FAR _TCB *rtcb = (FAR _TCB*)g_readytorun.head;
bool ret;
/* Check if pre-emption is disabled for the current running task and if
* the new ready-to-run task would cause the current running task to be
* preempted.
*/
if (rtcb->lockcount && rtcb->sched_priority < btcb->sched_priority)
{
/* Yes. Preemption would occur! Add the new ready-to-run task to the
* g_pendingtasks task list for now.
*/
sched_addprioritized(btcb, (FAR dq_queue_t*)&g_pendingtasks);
btcb->task_state = TSTATE_TASK_PENDING;
ret = false;
}
/* Otherwise, add the new task to the g_readytorun task list */
else if (sched_addprioritized(btcb, (FAR dq_queue_t*)&g_readytorun))
{
/* Information the instrumentation logic that we are switching tasks */
sched_note_switch(rtcb, btcb);
/* The new btcb was added at the head of the g_readytorun list. It
* is now to new active task!
*/
ASSERT(!rtcb->lockcount && btcb->flink != NULL);
btcb->task_state = TSTATE_TASK_RUNNING;
btcb->flink->task_state = TSTATE_TASK_READYTORUN;
ret = true;
}
else
{
/* The new btcb was added in the middle of the g_readytorun list */
btcb->task_state = TSTATE_TASK_READYTORUN;
ret = false;
}
return ret;
}
bool sched_mergepending(void)
{
FAR struct tcb_s *pndtcb;
FAR struct tcb_s *pndnext;
FAR struct tcb_s *rtrtcb;
FAR struct tcb_s *rtrprev;
bool ret = false;
/* Initialize the inner search loop */
rtrtcb = (FAR struct tcb_s*)g_readytorun.head;
/* Process every TCB in the g_pendingtasks list */
for (pndtcb = (FAR struct tcb_s*)g_pendingtasks.head; pndtcb; pndtcb = pndnext)
{
pndnext = pndtcb->flink;
/* Search the g_readytorun list to find the location to insert the
* new pndtcb. Each is list is maintained in ascending sched_priority
* order.
*/
for (;
(rtrtcb && pndtcb->sched_priority <= rtrtcb->sched_priority);
rtrtcb = rtrtcb->flink);
/* Add the pndtcb to the spot found in the list. Check if the
* pndtcb goes at the ends of the g_readytorun list. This would be
* error condition since the idle test must always be at the end of
* the g_readytorun list!
*/
if (!rtrtcb)
{
PANIC(OSERR_NOIDLETASK);
}
else
{
/* The pndtcb goes just before rtrtcb */
rtrprev = rtrtcb->blink;
if (!rtrprev)
{
/* Special case: Inserting pndtcb at the head of the list */
/* Inform the instrumentation layer that we are switching tasks */
sched_note_switch(rtrtcb, pndtcb);
/* Then insert at the head of the list */
pndtcb->flink = rtrtcb;
pndtcb->blink = NULL;
rtrtcb->blink = pndtcb;
g_readytorun.head = (FAR dq_entry_t*)pndtcb;
rtrtcb->task_state = TSTATE_TASK_READYTORUN;
pndtcb->task_state = TSTATE_TASK_RUNNING;
ret = true;
}
else
{
/* Insert in the middle of the list */
pndtcb->flink = rtrtcb;
pndtcb->blink = rtrprev;
rtrprev->flink = pndtcb;
rtrtcb->blink = pndtcb;
pndtcb->task_state = TSTATE_TASK_READYTORUN;
}
}
/* Set up for the next time through */
rtrtcb = pndtcb;
}
/* Mark the input list empty */
g_pendingtasks.head = NULL;
g_pendingtasks.tail = NULL;
return ret;
}
