int task_exit(void)
{
FAR struct tcb_s *dtcb = (FAR struct tcb_s*)g_readytorun.head;
FAR struct tcb_s *rtcb;
int ret;
/* Remove the TCB of the current task from the ready-to-run list. A context
* switch will definitely be necessary -- that must be done by the
* architecture-specific logic.
*
* sched_removereadytorun will mark the task at the head of the ready-to-run
* with state == TSTATE_TASK_RUNNING
*/
(void)sched_removereadytorun(dtcb);
rtcb = (FAR struct tcb_s*)g_readytorun.head;
/* We are now in a bad state -- the head of the ready to run task list
* does not correspond to the thread that is running. Disabling pre-
* emption on this TCB and marking the new ready-to-run task as not
* running (see, for example, get_errno_ptr()).
*
* We disable pre-emption here by directly incrementing the lockcount
* (vs. calling sched_lock()).
*/
rtcb->lockcount++;
rtcb->task_state = TSTATE_TASK_READYTORUN;
/* Move the TCB to the specified blocked task list and delete it. Calling
* task_terminate with non-blocking true will suppress atexit() and on-exit()
* calls and will cause buffered I/O to fail to be flushed. The former
* is required _exit() behavior; the latter is optional _exit() behavior.
*/
sched_addblocked(dtcb, TSTATE_TASK_INACTIVE);
ret = task_terminate(dtcb->pid, true);
rtcb->task_state = TSTATE_TASK_RUNNING;
/* If there are any pending tasks, then add them to the ready-to-run
* task list now
*/
if (g_pendingtasks.head)
{
(void)sched_mergepending();
}
/* We can't use sched_unlock() to decrement the lock count because the
* sched_mergepending() call above might have changed the task at the
* head of the ready-to-run list. Furthermore, we should not need to
* perform the unlock action anyway because we know that the pending
* task list is empty. So all we really need to do is to decrement
* the lockcount on rctb.
*/
rtcb->lockcount--;
return ret;
}
void up_reprioritize_rtr(struct tcb_s *tcb, uint8_t priority)
{
/* Verify that the caller is sane */
if (tcb->task_state < FIRST_READY_TO_RUN_STATE ||
tcb->task_state > LAST_READY_TO_RUN_STATE
#if SCHED_PRIORITY_MIN > UINT8_MIN
|| priority < SCHED_PRIORITY_MIN
#endif
#if SCHED_PRIORITY_MAX < UINT8_MAX
|| priority > SCHED_PRIORITY_MAX
#endif
) {
warn("%s: task sched error\n", __func__);
return;
}
else {
struct tcb_s *rtcb = current_task;
bool switch_needed;
/* Remove the tcb task from the ready-to-run list.
* sched_removereadytorun will return true if we just
* remove the head of the ready to run list.
*/
switch_needed = sched_removereadytorun(tcb);
/* Setup up the new task priority */
tcb->sched_priority = (uint8_t)priority;
/* Return the task to the specified blocked task list.
* sched_addreadytorun will return true if the task was
* added to the new list. We will need to perform a context
* switch only if the EXCLUSIVE or of the two calls is non-zero
* (i.e., one and only one the calls changes the head of the
* ready-to-run list).
*/
switch_needed ^= sched_addreadytorun(tcb);
/* Now, perform the context switch if one is needed */
if (switch_needed && !up_interrupt_context()) {
struct tcb_s *nexttcb;
// If there are any pending tasks, then add them to the g_readytorun
// task list now. It should be the up_realease_pending() called from
// sched_unlock() to do this for disable preemption. But it block
// itself, so it's OK.
if (g_pendingtasks.head) {
warn("Disable preemption failed for reprioritize task\n");
sched_mergepending();
}
nexttcb = (struct tcb_s*)g_readytorun.head;
// context switch
up_switchcontext(rtcb, nexttcb);
}
}
}
/****************************************************************************
* Name: up_block_task
*
* Description:
* The currently executing task at the head of
* the ready to run list must be stopped. Save its context
* and move it to the inactive list specified by task_state.
*
* This function is called only from the NuttX scheduling
* logic. Interrupts will always be disabled when this
* function is called.
*
* Inputs:
* tcb: Refers to a task in the ready-to-run list (normally
* the task at the head of the list). It most be
* stopped, its context saved and moved into one of the
* waiting task lists. It it was the task at the head
* of the ready-to-run list, then a context to the new
* ready to run task must be performed.
* task_state: Specifies which waiting task list should be
* hold the blocked task TCB.
*
****************************************************************************/
void up_block_task(struct tcb_s *tcb, tstate_t task_state)
{
/* Verify that the context switch can be performed */
if ((tcb->task_state < FIRST_READY_TO_RUN_STATE) ||
(tcb->task_state > LAST_READY_TO_RUN_STATE)) {
warn("%s: task sched error\n", __func__);
return;
}
else {
struct tcb_s *rtcb = current_task;
bool switch_needed;
/* Remove the tcb task from the ready-to-run list. If we
* are blocking the task at the head of the task list (the
* most likely case), then a context switch to the next
* ready-to-run task is needed. In this case, it should
* also be true that rtcb == tcb.
*/
switch_needed = sched_removereadytorun(tcb);
/* Add the task to the specified blocked task list */
sched_addblocked(tcb, (tstate_t)task_state);
/* Now, perform the context switch if one is needed */
if (switch_needed) {
struct tcb_s *nexttcb;
// this part should not be executed in interrupt context
if (up_interrupt_context()) {
panic("%s: %d\n", __func__, __LINE__);
}
// If there are any pending tasks, then add them to the g_readytorun
// task list now. It should be the up_realease_pending() called from
// sched_unlock() to do this for disable preemption. But it block
// itself, so it's OK.
if (g_pendingtasks.head) {
warn("Disable preemption failed for task block itself\n");
sched_mergepending();
}
nexttcb = (struct tcb_s*)g_readytorun.head;
// context switch
up_switchcontext(rtcb, nexttcb);
}
}
}
void up_reprioritize_rtr(struct tcb_s *tcb, uint8_t priority)
{
/* Verify that the caller is sane */
if (tcb->task_state < FIRST_READY_TO_RUN_STATE ||
tcb->task_state > LAST_READY_TO_RUN_STATE
#if SCHED_PRIORITY_MIN > 0
|| priority < SCHED_PRIORITY_MIN
#endif
#if SCHED_PRIORITY_MAX < UINT8_MAX
|| priority > SCHED_PRIORITY_MAX
#endif
)
{
PANIC();
}
else
{
struct tcb_s *rtcb = (struct tcb_s*)g_readytorun.head;
bool switch_needed;
slldbg("TCB=%p PRI=%d\n", tcb, priority);
/* Remove the tcb task from the ready-to-run list.
* sched_removereadytorun will return true if we just removed the head
* of the ready to run list.
*/
switch_needed = sched_removereadytorun(tcb);
/* Setup up the new task priority */
tcb->sched_priority = (uint8_t)priority;
/* Return the task to the ready-to-run task list. sched_addreadytorun
* will return true if the task was added to the head of ready-to-run
* list. We will need to perform a context switch only if the
* EXCLUSIVE or of the two calls is non-zero (i.e., one and only one
* the calls changes the head of the ready-to-run list).
*/
switch_needed ^= sched_addreadytorun(tcb);
/* Now, perform the context switch if one is needed (i.e. if the head
* of the ready-to-run list is no longer the same).
*/
if (switch_needed)
{
/* If we are going to do a context switch, then now is the right
* time to add any pending tasks back into the ready-to-run list.
* task list now
*/
if (g_pendingtasks.head)
{
sched_mergepending();
}
/* Are we in an interrupt handler? */
if (current_regs)
{
/* Yes, then we have to do things differently.
* Just copy the current_regs into the OLD rtcb.
*/
up_savestate(rtcb->xcp.regs);
/* Restore the exception context of the rtcb at the (new) head
* of the g_readytorun task list.
*/
rtcb = (struct tcb_s*)g_readytorun.head;
slldbg("New Active Task TCB=%p\n", rtcb);
/* Then switch contexts */
up_restorestate(rtcb->xcp.regs);
}
/* No, then we will need to perform the user context switch */
else
{
/* Switch context to the context of the task at the head of the
* ready to run list.
*/
struct tcb_s *nexttcb = (struct tcb_s*)g_readytorun.head;
up_switchcontext(rtcb->xcp.regs, nexttcb->xcp.regs);
/* up_switchcontext forces a context switch to the task at the
* head of the ready-to-run list. It does not 'return' in the
* normal sense. When it does return, it is because the blocked
* task is again ready to run and has execution priority.
*/
}
}
}
}
void up_block_task(struct tcb_s *tcb, tstate_t task_state)
{
struct tcb_s *rtcb = this_task();
bool switch_needed;
/* Verify that the context switch can be performed */
DEBUGASSERT((tcb->task_state >= FIRST_READY_TO_RUN_STATE) &&
(tcb->task_state <= LAST_READY_TO_RUN_STATE));
/* Remove the tcb task from the ready-to-run list. If we
* are blocking the task at the head of the task list (the
* most likely case), then a context switch to the next
* ready-to-run task is needed. In this case, it should
* also be true that rtcb == tcb.
*/
switch_needed = sched_removereadytorun(tcb);
/* Add the task to the specified blocked task list */
sched_addblocked(tcb, (tstate_t)task_state);
/* If there are any pending tasks, then add them to the ready-to-run
* task list now
*/
if (g_pendingtasks.head)
{
switch_needed |= sched_mergepending();
}
/* Now, perform the context switch if one is needed */
if (switch_needed)
{
/* Update scheduler parameters */
sched_suspend_scheduler(rtcb);
/* Are we in an interrupt handler? */
if (g_current_regs)
{
/* Yes, then we have to do things differently.
* Just copy the g_current_regs into the OLD rtcb.
*/
up_copystate(rtcb->xcp.regs, g_current_regs);
/* Restore the exception context of the rtcb at the (new) head
* of the ready-to-run task list.
*/
rtcb = this_task();
/* Reset scheduler parameters */
sched_resume_scheduler(rtcb);
/* Then switch contexts. Any necessary address environment
* changes will be made when the interrupt returns.
*/
g_current_regs = rtcb->xcp.regs;
}
/* Copy the user C context into the TCB at the (old) head of the
* ready-to-run Task list. if up_saveusercontext returns a non-zero
* value, then this is really the previously running task restarting!
*/
else if (!up_saveusercontext(rtcb->xcp.regs))
{
/* Restore the exception context of the rtcb at the (new) head
* of the ready-to-run task list.
*/
rtcb = this_task();
#ifdef CONFIG_ARCH_ADDRENV
/* Make sure that the address environment for the previously
* running task is closed down gracefully (data caches dump,
* MMU flushed) and set up the address environment for the new
* thread at the head of the ready-to-run list.
*/
(void)group_addrenv(rtcb);
#endif
/* Reset scheduler parameters */
sched_resume_scheduler(rtcb);
/* Then switch contexts */
up_fullcontextrestore(rtcb->xcp.regs);
}
}
}
void up_reprioritize_rtr(struct tcb_s *tcb, uint8_t priority)
{
/* Verify that the caller is sane */
if (tcb->task_state < FIRST_READY_TO_RUN_STATE ||
tcb->task_state > LAST_READY_TO_RUN_STATE
#if SCHED_PRIORITY_MIN > 0
|| priority < SCHED_PRIORITY_MIN
#endif
#if SCHED_PRIORITY_MAX < UINT8_MAX
|| priority > SCHED_PRIORITY_MAX
#endif
)
{
PANIC();
}
else
{
FAR struct tcb_s *rtcb = this_task();
bool switch_needed;
sinfo("TCB=%p PRI=%d\n", tcb, priority);
/* Remove the tcb task from the ready-to-run list.
* sched_removereadytorun will return true if we just
* remove the head of the ready to run list.
*/
switch_needed = sched_removereadytorun(tcb);
/* Setup up the new task priority */
tcb->sched_priority = (uint8_t)priority;
/* Return the task to the specified blocked task list.
* sched_addreadytorun will return true if the task was
* added to the new list. We will need to perform a context
* switch only if the EXCLUSIVE or of the two calls is non-zero
* (i.e., one and only one the calls changes the head of the
* ready-to-run list).
*/
switch_needed ^= sched_addreadytorun(tcb);
/* Now, perform the context switch if one is needed */
if (switch_needed)
{
/* If we are going to do a context switch, then now is the right
* time to add any pending tasks back into the ready-to-run list.
* task list now
*/
if (g_pendingtasks.head)
{
sched_mergepending();
}
/* Update scheduler parameters */
sched_suspend_scheduler(rtcb);
/* Copy the exception context into the TCB at the (old) head of the
* ready-to-run Task list. if up_setjmp returns a non-zero
* value, then this is really the previously running task restarting!
*/
if (!up_setjmp(rtcb->xcp.regs))
{
/* Restore the exception context of the rtcb at the (new) head
* of the ready-to-run task list.
*/
rtcb = this_task();
sinfo("New Active Task TCB=%p\n", rtcb);
/* The way that we handle signals in the simulation is kind of
* a kludge. This would be unsafe in a truly multi-threaded, interrupt
* driven environment.
*/
if (rtcb->xcp.sigdeliver)
{
sinfo("Delivering signals TCB=%p\n", rtcb);
((sig_deliver_t)rtcb->xcp.sigdeliver)(rtcb);
rtcb->xcp.sigdeliver = NULL;
}
/* Update scheduler parameters */
sched_resume_scheduler(rtcb);
/* Then switch contexts */
up_longjmp(rtcb->xcp.regs, 1);
}
}
}
}
void up_reprioritize_rtr(struct tcb_s *tcb, uint8_t priority)
{
/* Verify that the caller is sane */
if (tcb->task_state < FIRST_READY_TO_RUN_STATE ||
tcb->task_state > LAST_READY_TO_RUN_STATE
#if SCHED_PRIORITY_MIN > 0
|| priority < SCHED_PRIORITY_MIN
#endif
#if SCHED_PRIORITY_MAX < UINT8_MAX
|| priority > SCHED_PRIORITY_MAX
#endif
)
{
PANIC(OSERR_BADREPRIORITIZESTATE);
}
else
{
struct tcb_s *rtcb = (struct tcb_s*)g_readytorun.head;
bool switch_needed;
slldbg("TCB=%p PRI=%d\n", tcb, priority);
/* Remove the tcb task from the ready-to-run list.
* sched_removereadytorun will return true if we just
* remove the head of the ready to run list.
*/
switch_needed = sched_removereadytorun(tcb);
/* Setup up the new task priority */
tcb->sched_priority = (uint8_t)priority;
/* Return the task to the specified blocked task list.
* sched_addreadytorun will return true if the task was
* added to the new list. We will need to perform a context
* switch only if the EXCLUSIVE or of the two calls is non-zero
* (i.e., one and only one the calls changes the head of the
* ready-to-run list).
*/
switch_needed ^= sched_addreadytorun(tcb);
/* Now, perform the context switch if one is needed */
if (switch_needed)
{
/* If we are going to do a context switch, then now is the right
* time to add any pending tasks back into the ready-to-run list.
* task list now
*/
if (g_pendingtasks.head)
{
sched_mergepending();
}
/* Are we in an interrupt handler? */
if (current_regs)
{
/* Yes, then we have to do things differently.
* Just copy the current_regs into the OLD rtcb.
*/
up_savestate(rtcb->xcp.regs);
/* Restore the exception context of the rtcb at the (new) head
* of the g_readytorun task list.
*/
rtcb = (struct tcb_s*)g_readytorun.head;
slldbg("New Active Task TCB=%p\n", rtcb);
/* Then switch contexts */
up_restorestate(rtcb->xcp.regs);
}
/* Copy the exception context into the TCB at the (old) head of the
* g_readytorun Task list. if up_saveusercontext returns a non-zero
* value, then this is really the previously running task restarting!
*/
else if (!up_saveusercontext(rtcb->xcp.regs))
{
/* Restore the exception context of the rtcb at the (new) head
* of the g_readytorun task list.
*/
rtcb = (struct tcb_s*)g_readytorun.head;
slldbg("New Active Task TCB=%p\n", rtcb);
/* Then switch contexts */
up_fullcontextrestore(rtcb->xcp.regs);
}
}
}
}
void up_reprioritize_rtr(struct tcb_s *tcb, uint8_t priority)
{
/* Verify that the caller is sane */
if (tcb->task_state < FIRST_READY_TO_RUN_STATE ||
tcb->task_state > LAST_READY_TO_RUN_STATE
#if SCHED_PRIORITY_MIN > 0
|| priority < SCHED_PRIORITY_MIN
#endif
#if SCHED_PRIORITY_MAX < UINT8_MAX
|| priority > SCHED_PRIORITY_MAX
#endif
)
{
PANIC();
}
else
{
struct tcb_s *rtcb = (struct tcb_s*)g_readytorun.head;
bool switch_needed;
slldbg("TCB=%p PRI=%d\n", tcb, priority);
/* Remove the tcb task from the ready-to-run list.
* sched_removereadytorun will return true if we just
* remove the head of the ready to run list.
*/
switch_needed = sched_removereadytorun(tcb);
/* Setup up the new task priority */
tcb->sched_priority = (uint8_t)priority;
/* Return the task to the specified blocked task list.
* sched_addreadytorun will return true if the task was
* added to the new list. We will need to perform a context
* switch only if the EXCLUSIVE or of the two calls is non-zero
* (i.e., one and only one the calls changes the head of the
* ready-to-run list).
*/
switch_needed ^= sched_addreadytorun(tcb);
/* Now, perform the context switch if one is needed */
if (switch_needed)
{
/* If we are going to do a context switch, then now is the right
* time to add any pending tasks back into the ready-to-run list.
* task list now
*/
if (g_pendingtasks.head)
{
sched_mergepending();
}
/* Update scheduler parameters */
sched_suspend_scheduler(rtcb);
/* Are we in an interrupt handler? */
if (current_regs)
{
/* Yes, then we have to do things differently.
* Just copy the current_regs into the OLD rtcb.
*/
up_savestate(rtcb->xcp.regs);
/* Restore the exception context of the rtcb at the (new) head
* of the g_readytorun task list.
*/
rtcb = (struct tcb_s*)g_readytorun.head;
/* Update scheduler parameters */
sched_resume_scheduler(rtcb);
/* Then switch contexts. Any necessary address environment
* changes will be made when the interrupt returns.
*/
up_restorestate(rtcb->xcp.regs);
}
/* Copy the exception context into the TCB at the (old) head of the
* g_readytorun Task list. if up_saveusercontext returns a non-zero
* value, then this is really the previously running task restarting!
*/
else if (!up_saveusercontext(rtcb->xcp.regs))
{
/* Restore the exception context of the rtcb at the (new) head
* of the g_readytorun task list.
*/
rtcb = (struct tcb_s*)g_readytorun.head;
#ifdef CONFIG_ARCH_ADDRENV
/* Make sure that the address environment for the previously
* running task is closed down gracefully (data caches dump,
* MMU flushed) and set up the address environment for the new
* thread at the head of the ready-to-run list.
*/
(void)group_addrenv(rtcb);
#endif
/* Update scheduler parameters */
sched_resume_scheduler(rtcb);
/* Then switch contexts */
up_fullcontextrestore(rtcb->xcp.regs);
}
}
}
}
void up_block_task(struct tcb_s *tcb, tstate_t task_state)
{
struct tcb_s *rtcb = this_task();
bool switch_needed;
/* Verify that the context switch can be performed */
ASSERT((tcb->task_state >= FIRST_READY_TO_RUN_STATE) &&
(tcb->task_state <= LAST_READY_TO_RUN_STATE));
/* Remove the tcb task from the ready-to-run list. If we
* are blocking the task at the head of the task list (the
* most likely case), then a context switch to the next
* ready-to-run task is needed. In this case, it should
* also be true that rtcb == tcb.
*/
switch_needed = sched_removereadytorun(tcb);
/* Add the task to the specified blocked task list */
sched_addblocked(tcb, (tstate_t)task_state);
/* If there are any pending tasks, then add them to the ready-to-run
* task list now
*/
if (g_pendingtasks.head)
{
switch_needed |= sched_mergepending();
}
/* Now, perform the context switch if one is needed */
if (switch_needed)
{
/* Update scheduler parameters */
sched_suspend_scheduler(rtcb);
/* Are we in an interrupt handler? */
if (current_regs)
{
/* Yes, then we have to do things differently.
* Just copy the current_regs into the OLD rtcb.
*/
up_savestate(rtcb->xcp.regs);
/* Restore the exception context of the rtcb at the (new) head
* of the ready-to-run task list.
*/
rtcb = this_task();
/* Reset scheduler parameters */
sched_resume_scheduler(rtcb);
/* Then switch contexts. Any new address environment needed by
* the new thread will be instantiated before the return from
* interrupt.
*/
up_restorestate(rtcb->xcp.regs);
}
/* No, then we will need to perform the user context switch */
else
{
/* Get the context of the task at the head of the ready to
* run list.
*/
struct tcb_s *nexttcb = this_task();
#ifdef CONFIG_ARCH_ADDRENV
/* Make sure that the address environment for the previously
* running task is closed down gracefully (data caches dump,
* MMU flushed) and set up the address environment for the new
* thread at the head of the ready-to-run list.
*/
(void)group_addrenv(nexttcb);
#endif
/* Reset scheduler parameters */
sched_resume_scheduler(nexttcb);
/* Then switch contexts */
up_switchcontext(rtcb->xcp.regs, nexttcb->xcp.regs);
/* up_switchcontext forces a context switch to the task at the
* head of the ready-to-run list. It does not 'return' in the
* normal sense. When it does return, it is because the blocked
* task is again ready to run and has execution priority.
*/
}
}
}
void up_reprioritize_rtr(FAR struct tcb_s *tcb, uint8_t priority)
{
/* Verify that the caller is sane */
if (tcb->task_state < FIRST_READY_TO_RUN_STATE ||
tcb->task_state > LAST_READY_TO_RUN_STATE
#if SCHED_PRIORITY_MIN > 0
|| priority < SCHED_PRIORITY_MIN
#endif
#if SCHED_PRIORITY_MAX < UINT8_MAX
|| priority > SCHED_PRIORITY_MAX
#endif
)
{
PANIC();
}
else
{
FAR struct tcb_s *rtcb = this_task();
bool switch_needed;
slldbg("TCB=%p PRI=%d\n", tcb, priority);
/* Remove the tcb task from the ready-to-run list.
* sched_removereadytorun will return true if we just
* remove the head of the ready to run list.
*/
switch_needed = sched_removereadytorun(tcb);
/* Setup up the new task priority */
tcb->sched_priority = (uint8_t)priority;
/* Return the task to the specified blocked task list.
* sched_addreadytorun will return true if the task was
* added to the new list. We will need to perform a context
* switch only if the EXCLUSIVE or of the two calls is non-zero
* (i.e., one and only one the calls changes the head of the
* ready-to-run list).
*/
switch_needed ^= sched_addreadytorun(tcb);
/* Now, perform the context switch if one is needed */
if (switch_needed)
{
/* If we are going to do a context switch, then now is the right
* time to add any pending tasks back into the ready-to-run list.
* task list now
*/
if (g_pendingtasks.head)
{
sched_mergepending();
}
/* Update scheduler parameters */
sched_suspend_scheduler(rtcb);
/* Are we in an interrupt handler? */
if (IN_INTERRUPT)
{
/* Yes, then we have to do things differently.
* Just copy the current context into the OLD rtcb.
*/
SAVE_IRQCONTEXT(rtcb);
/* Restore the exception context of the rtcb at the (new) head
* of the ready-to-run task list.
*/
rtcb = this_task();
/* Update scheduler parameters */
sched_resume_scheduler(rtcb);
/* Then setup so that the context will be performed on exit
* from the interrupt.
*/
SET_IRQCONTEXT(rtcb);
}
/* Copy the exception context into the TCB at the (old) head of the
* ready-to-run Task list. if SAVE_USERCONTEXT returns a non-zero
* value, then this is really the previously running task restarting!
*/
else if (!SAVE_USERCONTEXT(rtcb))
{
/* Restore the exception context of the rtcb at the (new) head
* of the ready-to-run task list.
*/
rtcb = this_task();
/* Update scheduler parameters */
sched_resume_scheduler(rtcb);
/* Then switch contexts */
RESTORE_USERCONTEXT(rtcb);
}
}
}
}
void up_block_task(_TCB *tcb, tstate_t task_state)
{
/* Verify that the context switch can be performed */
if ((tcb->task_state < FIRST_READY_TO_RUN_STATE) ||
(tcb->task_state > LAST_READY_TO_RUN_STATE))
{
PANIC(OSERR_BADBLOCKSTATE);
}
else
{
_TCB *rtcb = (_TCB*)g_readytorun.head;
bool switch_needed;
/* Remove the tcb task from the ready-to-run list. If we
* are blocking the task at the head of the task list (the
* most likely case), then a context switch to the next
* ready-to-run task is needed. In this case, it should
* also be true that rtcb == tcb.
*/
switch_needed = sched_removereadytorun(tcb);
/* Add the task to the specified blocked task list */
sched_addblocked(tcb, (tstate_t)task_state);
/* If there are any pending tasks, then add them to the g_readytorun
* task list now
*/
if (g_pendingtasks.head)
{
switch_needed |= sched_mergepending();
}
/* Now, perform the context switch if one is needed */
if (switch_needed)
{
/* Are we in an interrupt handler? */
if (current_regs)
{
/* Yes, then we have to do things differently.
* Just copy the current_regs into the OLD rtcb.
*/
up_savestate(rtcb->xcp.regs);
/* Restore the exception context of the rtcb at the (new) head
* of the g_readytorun task list.
*/
rtcb = (_TCB*)g_readytorun.head;
/* Then switch contexts */
up_restorestate(rtcb->xcp.regs);
}
/* Copy the user C context into the TCB at the (old) head of the
* g_readytorun Task list. if up_saveusercontext returns a non-zero
* value, then this is really the previously running task restarting!
*/
else if (!up_saveusercontext(rtcb->xcp.regs))
{
/* Restore the exception context of the rtcb at the (new) head
* of the g_readytorun task list.
*/
rtcb = (_TCB*)g_readytorun.head;
/* Then switch contexts */
up_fullcontextrestore(rtcb->xcp.regs);
}
}
}
}
void up_reprioritize_rtr(struct tcb_s *tcb, uint8_t priority)
{
/* Verify that the caller is sane */
if (tcb->task_state < FIRST_READY_TO_RUN_STATE ||
tcb->task_state > LAST_READY_TO_RUN_STATE
#if SCHED_PRIORITY_MIN > UINT8_MIN
|| priority < SCHED_PRIORITY_MIN
#endif
#if SCHED_PRIORITY_MAX < UINT8_MAX
|| priority > SCHED_PRIORITY_MAX
#endif
)
{
warn("%s: task sched error\n", __func__);
return;
}
else
{
struct tcb_s *rtcb = current_task;
bool switch_needed;
/* Remove the tcb task from the ready-to-run list.
* sched_removereadytorun will return true if we just
* remove the head of the ready to run list.
*/
switch_needed = sched_removereadytorun(tcb);
/* Setup up the new task priority */
tcb->sched_priority = (uint8_t)priority;
/* Return the task to the specified blocked task list.
* sched_addreadytorun will return true if the task was
* added to the new list. We will need to perform a context
* switch only if the EXCLUSIVE or of the two calls is non-zero
* (i.e., one and only one the calls changes the head of the
* ready-to-run list).
*/
switch_needed ^= sched_addreadytorun(tcb);
/* Now, perform the context switch if one is needed */
if (switch_needed && !up_interrupt_context())
{
struct tcb_s *nexttcb;
/* If there are any pending tasks, then add them to the ready-to-run
* task list now. It should be the up_realease_pending() called from
* sched_unlock() to do this for disable preemption. But it block
* itself, so it's OK.
*/
if (g_pendingtasks.head)
{
warn("Disable preemption failed for reprioritize task\n");
sched_mergepending();
}
/* Update scheduler parameters */
sched_suspend_scheduler(rtcb);
/* Get the TCB of the new task to run */
nexttcb = this_task();
#ifdef CONFIG_ARCH_ADDRENV
/* Make sure that the address environment for the previously
* running task is closed down gracefully (data caches dump,
* MMU flushed) and set up the address environment for the new
* thread at the head of the ready-to-run list.
*/
(void)group_addrenv(nexttcb);
#endif
/* Update scheduler parameters */
sched_resume_scheduler(nexttcb);
/* context switch */
up_switchcontext(rtcb, nexttcb);
}
}
}
/****************************************************************************
* Name: up_block_task
*
* Description:
* The currently executing task at the head of
* the ready to run list must be stopped. Save its context
* and move it to the inactive list specified by task_state.
*
* This function is called only from the NuttX scheduling
* logic. Interrupts will always be disabled when this
* function is called.
*
* Inputs:
* tcb: Refers to a task in the ready-to-run list (normally
* the task at the head of the list). It most be
* stopped, its context saved and moved into one of the
* waiting task lists. It it was the task at the head
* of the ready-to-run list, then a context to the new
* ready to run task must be performed.
* task_state: Specifies which waiting task list should be
* hold the blocked task TCB.
*
****************************************************************************/
void up_block_task(struct tcb_s *tcb, tstate_t task_state)
{
/* Verify that the context switch can be performed */
if ((tcb->task_state < FIRST_READY_TO_RUN_STATE) ||
(tcb->task_state > LAST_READY_TO_RUN_STATE))
{
warn("%s: task sched error\n", __func__);
return;
}
else
{
struct tcb_s *rtcb = current_task;
bool switch_needed;
/* Remove the tcb task from the ready-to-run list. If we
* are blocking the task at the head of the task list (the
* most likely case), then a context switch to the next
* ready-to-run task is needed. In this case, it should
* also be true that rtcb == tcb.
*/
switch_needed = sched_removereadytorun(tcb);
/* Add the task to the specified blocked task list */
sched_addblocked(tcb, (tstate_t)task_state);
/* Now, perform the context switch if one is needed */
if (switch_needed)
{
struct tcb_s *nexttcb;
/* Update scheduler parameters */
sched_suspend_scheduler(rtcb);
/* this part should not be executed in interrupt context */
if (up_interrupt_context())
{
panic("%s: %d\n", __func__, __LINE__);
}
/* If there are any pending tasks, then add them to the ready-to-run
* task list now. It should be the up_realease_pending() called from
* sched_unlock() to do this for disable preemption. But it block
* itself, so it's OK.
*/
if (g_pendingtasks.head)
{
warn("Disable preemption failed for task block itself\n");
sched_mergepending();
}
nexttcb = this_task();
#ifdef CONFIG_ARCH_ADDRENV
/* Make sure that the address environment for the previously
* running task is closed down gracefully (data caches dump,
* MMU flushed) and set up the address environment for the new
* thread at the head of the ready-to-run list.
*/
(void)group_addrenv(nexttcb);
#endif
/* Reset scheduler parameters */
sched_resume_scheduler(nexttcb);
/* context switch */
up_switchcontext(rtcb, nexttcb);
}
}
}
void up_block_task(struct tcb_s *tcb, tstate_t task_state)
{
struct tcb_s *rtcb = (struct tcb_s*)g_readytorun.head;
bool switch_needed;
/* Verify that the context switch can be performed */
ASSERT((tcb->task_state >= FIRST_READY_TO_RUN_STATE) &&
(tcb->task_state <= LAST_READY_TO_RUN_STATE));
sdbg("Blocking TCB=%p\n", tcb);
/* Remove the tcb task from the ready-to-run list. If we
* are blocking the task at the head of the task list (the
* most likely case), then a context switch to the next
* ready-to-run task is needed. In this case, it should
* also be true that rtcb == tcb.
*/
switch_needed = sched_removereadytorun(tcb);
/* Add the task to the specified blocked task list */
sched_addblocked(tcb, (tstate_t)task_state);
/* If there are any pending tasks, then add them to the g_readytorun
* task list now
*/
if (g_pendingtasks.head)
{
switch_needed |= sched_mergepending();
}
/* Now, perform the context switch if one is needed */
if (switch_needed)
{
/* Update scheduler parameters */
sched_suspend_scheduler(rtcb);
/* Copy the exception context into the TCB at the (old) head of the
* g_readytorun Task list. if up_setjmp returns a non-zero
* value, then this is really the previously running task restarting!
*/
if (!up_setjmp(rtcb->xcp.regs))
{
/* Restore the exception context of the rtcb at the (new) head
* of the g_readytorun task list.
*/
rtcb = (struct tcb_s*)g_readytorun.head;
sdbg("New Active Task TCB=%p\n", rtcb);
/* The way that we handle signals in the simulation is kind of
* a kludge. This would be unsafe in a truly multi-threaded, interrupt
* driven environment.
*/
if (rtcb->xcp.sigdeliver)
{
sdbg("Delivering signals TCB=%p\n", rtcb);
((sig_deliver_t)rtcb->xcp.sigdeliver)(rtcb);
rtcb->xcp.sigdeliver = NULL;
}
/* Reset scheduler parameters */
sched_resume_scheduler(rtcb);
/* Then switch contexts */
up_longjmp(rtcb->xcp.regs, 1);
}
}
}
void up_block_task(FAR struct tcb_s *tcb, tstate_t task_state)
{
FAR struct tcb_s *rtcb = (FAR struct tcb_s*)g_readytorun.head;
bool switch_needed;
/* Verify that the context switch can be performed */
ASSERT((tcb->task_state >= FIRST_READY_TO_RUN_STATE) &&
(tcb->task_state <= LAST_READY_TO_RUN_STATE));
/* dbg("Blocking TCB=%p\n", tcb); */
/* Remove the tcb task from the ready-to-run list. If we
* are blocking the task at the head of the task list (the
* most likely case), then a context switch to the next
* ready-to-run task is needed. In this case, it should
* also be true that rtcb == tcb.
*/
switch_needed = sched_removereadytorun(tcb);
/* Add the task to the specified blocked task list */
sched_addblocked(tcb, (tstate_t)task_state);
/* If there are any pending tasks, then add them to the g_readytorun
* task list now
*/
if (g_pendingtasks.head)
{
switch_needed |= sched_mergepending();
}
/* Now, perform the context switch if one is needed */
if (switch_needed)
{
/* Are we in an interrupt handler? */
if (IN_INTERRUPT())
{
/* Yes, then we have to do things differently.
* Just copy the current registers into the OLD rtcb.
*/
SAVE_IRQCONTEXT(rtcb);
/* Restore the exception context of the rtcb at the (new) head
* of the g_readytorun task list.
*/
rtcb = (FAR struct tcb_s*)g_readytorun.head;
/* dbg("New Active Task TCB=%p\n", rtcb); */
/* Then setup so that the context will be performed on exit
* from the interrupt.
*/
SET_IRQCONTEXT(rtcb);
}
/* Copy the user C context into the TCB at the (old) head of the
* g_readytorun Task list. if SAVE_USERCONTEXT returns a non-zero
* value, then this is really the previously running task restarting!
*/
else if (!SAVE_USERCONTEXT(rtcb))
{
/* Restore the exception context of the rtcb at the (new) head
* of the g_readytorun task list.
*/
rtcb = (FAR struct tcb_s*)g_readytorun.head;
/* dbg("New Active Task TCB=%p\n", rtcb); */
/* Then switch contexts */
RESTORE_USERCONTEXT(rtcb);
}
}
}
int sched_setpriority(FAR struct tcb_s *tcb, int sched_priority)
{
FAR struct tcb_s *rtcb = (FAR struct tcb_s*)g_readytorun.head;
tstate_t task_state;
irqstate_t saved_state;
/* Verify that the requested priority is in the valid range */
if (sched_priority < SCHED_PRIORITY_MIN ||
sched_priority > SCHED_PRIORITY_MAX)
{
set_errno(EINVAL);
return ERROR;
}
/* We need to assure that there there is no interrupt activity while
* performing the following.
*/
saved_state = irqsave();
/* There are four cases that must be considered: */
task_state = tcb->task_state;
switch (task_state)
{
/* CASE 1. The task is running or ready-to-run and a context switch
* may be caused by the re-prioritization
*/
case TSTATE_TASK_RUNNING:
/* A context switch will occur if the new priority of the running
* task becomes less than OR EQUAL TO the next highest priority
* ready to run task.
*/
if (sched_priority <= tcb->flink->sched_priority)
{
/* A context switch will occur. */
up_reprioritize_rtr(tcb, (uint8_t)sched_priority);
}
/* Otherwise, we can just change priority since it has no effect */
else
{
/* Change the task priority */
tcb->sched_priority = (uint8_t)sched_priority;
}
break;
/* CASE 2. The task is running or ready-to-run and a context switch
* may be caused by the re-prioritization
*/
case TSTATE_TASK_READYTORUN:
/* A context switch will occur if the new priority of the ready-to
* run task is (strictly) greater than the current running task
*/
if (sched_priority > rtcb->sched_priority)
{
/* A context switch will occur. */
up_reprioritize_rtr(tcb, (uint8_t)sched_priority);
}
/* Otherwise, we can just change priority and re-schedule (since it
* have no other effect).
*/
else
{
/* Remove the TCB from the ready-to-run task list */
ASSERT(!sched_removereadytorun(tcb));
/* Change the task priority */
tcb->sched_priority = (uint8_t)sched_priority;
/* Put it back into the ready-to-run task list */
ASSERT(!sched_addreadytorun(tcb));
}
break;
/* CASE 3. The task is not in the ready to run list. Changing its
* Priority cannot effect the currently executing task.
*/
default:
/* CASE 3a. The task resides in a prioritized list. */
if (g_tasklisttable[task_state].prioritized)
{
/* Remove the TCB from the prioritized task list */
dq_rem((FAR dq_entry_t*)tcb, (FAR dq_queue_t*)g_tasklisttable[task_state].list);
/* Change the task priority */
tcb->sched_priority = (uint8_t)sched_priority;
/* Put it back into the prioritized list at the correct
* position
*/
sched_addprioritized(tcb, (FAR dq_queue_t*)g_tasklisttable[task_state].list);
}
/* CASE 3b. The task resides in a non-prioritized list. */
else
{
/* Just change the task's priority */
tcb->sched_priority = (uint8_t)sched_priority;
}
break;
}
irqrestore(saved_state);
return OK;
}
void up_block_task(_TCB *tcb, tstate_t task_state)
{
/* Verify that the context switch can be performed */
if ((tcb->task_state < FIRST_READY_TO_RUN_STATE) ||
(tcb->task_state > LAST_READY_TO_RUN_STATE))
{
PANIC(OSERR_BADBLOCKSTATE);
}
else
{
_TCB *rtcb = (_TCB*)g_readytorun.head;
bool switch_needed;
/* Remove the tcb task from the ready-to-run list. If we
* are blocking the task at the head of the task list (the
* most likely case), then a context switch to the next
* ready-to-run task is needed. In this case, it should
* also be true that rtcb == tcb.
*/
switch_needed = sched_removereadytorun(tcb);
/* Add the task to the specified blocked task list */
sched_addblocked(tcb, (tstate_t)task_state);
/* If there are any pending tasks, then add them to the g_readytorun
* task list now
*/
if (g_pendingtasks.head)
{
switch_needed |= sched_mergepending();
}
/* Now, perform the context switch if one is needed */
if (switch_needed)
{
/* Are we in an interrupt handler? */
if (current_regs)
{
/* Yes, then we have to do things differently.
* Just copy the current_regs into the OLD rtcb.
*/
up_savestate(rtcb->xcp.regs);
/* Restore the exception context of the rtcb at the (new) head
* of the g_readytorun task list.
*/
rtcb = (_TCB*)g_readytorun.head;
/* Then switch contexts */
up_restorestate(rtcb->xcp.regs);
}
/* No, then we will need to perform the user context switch */
else
{
/* Switch context to the context of the task at the head of the
* ready to run list.
*/
_TCB *nexttcb = (_TCB*)g_readytorun.head;
up_switchcontext(rtcb->xcp.regs, nexttcb->xcp.regs);
/* up_switchcontext forces a context switch to the task at the
* head of the ready-to-run list. It does not 'return' in the
* normal sense. When it does return, it is because the blocked
* task is again ready to run and has execution priority.
*/
}
}
}
}
