int up_cpu_paused(int cpu)
{
FAR struct tcb_s *otcb = this_task();
FAR struct tcb_s *ntcb;
/* Update scheduler parameters */
sched_suspend_scheduler(otcb);
#ifdef CONFIG_SCHED_INSTRUMENTATION
/* Notify that we are paused */
sched_note_cpu_paused(otcb);
#endif
/* Copy the CURRENT_REGS into the OLD TCB (otcb). The co-processor state
* will be saved as part of the return from xtensa_irq_dispatch().
*/
xtensa_savestate(otcb->xcp.regs);
/* Wait for the spinlock to be released */
spin_unlock(&g_cpu_paused[cpu]);
spin_lock(&g_cpu_wait[cpu]);
/* Upon return, we will restore the exception context of the new TCB
* (ntcb) at the head of the ready-to-run task list.
*/
ntcb = this_task();
#ifdef CONFIG_SCHED_INSTRUMENTATION
/* Notify that we have resumed */
sched_note_cpu_resumed(ntcb);
#endif
/* Reset scheduler parameters */
sched_resume_scheduler(ntcb);
/* Did the task at the head of the list change? */
if (otcb != ntcb)
{
/* Set CURRENT_REGS to the context save are of the new TCB to start.
* This will inform the return-from-interrupt logic that a context
* switch must be performed.
*/
xtensa_restorestate(ntcb->xcp.regs);
}
spin_unlock(&g_cpu_wait[cpu]);
return OK;
}
void up_release_pending(void)
{
struct tcb_s *rtcb = (struct tcb_s*)g_readytorun.head;
sdbg("From TCB=%p\n", rtcb);
/* Merge the g_pendingtasks list into the g_readytorun task list */
/* sched_lock(); */
if (sched_mergepending())
{
/* The currently active task has changed! We will need to switch
* contexts.
*
* Update scheduler parameters.
*/
sched_suspend_scheduler(rtcb);
/* Copy the exception context into the TCB of the task that was
* currently active. 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;
}
/* Update scheduler parameters */
sched_resume_scheduler(rtcb);
/* Then switch contexts */
up_longjmp(rtcb->xcp.regs, 1);
}
}
}
void up_unblock_task(struct tcb_s *tcb)
{
/* Verify that the context switch can be performed */
if ((tcb->task_state < FIRST_BLOCKED_STATE) ||
(tcb->task_state > LAST_BLOCKED_STATE))
{
warn("%s: task sched error\n", __func__);
return;
}
else
{
struct tcb_s *rtcb = current_task;
/* Remove the task from the blocked task list */
sched_removeblocked(tcb);
/* Add the task in the correct location in the prioritized
* ready-to-run task list.
*/
if (sched_addreadytorun(tcb) && !up_interrupt_context())
{
/* The currently active task has changed! */
/* Update scheduler parameters */
sched_suspend_scheduler(rtcb);
/* Are we in an interrupt handler? */
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
/* Update scheduler parameters */
sched_resume_scheduler(nexttcb);
/* context switch */
up_switchcontext(rtcb, nexttcb);
}
}
}
void up_release_pending(void)
{
struct tcb_s *rtcb = current_task;
/* Merge the g_pendingtasks list into the ready-to-run task list */
if (sched_mergepending())
{
struct tcb_s *nexttcb = this_task();
/* The currently active task has changed! We will need to switch
* contexts.
*
* Update scheduler parameters.
*/
sched_suspend_scheduler(rtcb);
#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);
}
}
void up_unblock_task(struct tcb_s *tcb)
{
struct tcb_s *rtcb = this_task();
/* Verify that the context switch can be performed */
DEBUGASSERT((tcb->task_state >= FIRST_BLOCKED_STATE) &&
(tcb->task_state <= LAST_BLOCKED_STATE));
/* Remove the task from the blocked task list */
sched_removeblocked(tcb);
/* Add the task in the correct location in the prioritized
* ready-to-run task list
*/
if (sched_addreadytorun(tcb))
{
/* The currently active task has changed! We need to do
* a context switch to the new task.
*/
/* 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();
/* Update scheduler parameters */
sched_resume_scheduler(rtcb);
/* Then switch contexts */
up_restorestate(rtcb->xcp.regs);
}
/* No, then we will need to perform the user context switch */
else
{
struct tcb_s *nexttcb = this_task();
/* Update scheduler parameters */
sched_resume_scheduler(nexttcb);
/* Switch context to the context of the task at the head of the
* ready to run list.
*/
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_release_pending(void)
{
struct tcb_s *rtcb = this_task();
sinfo("From TCB=%p\n", rtcb);
/* Merge the g_pendingtasks list into the ready-to-run task list */
/* sched_lock(); */
if (sched_mergepending())
{
/* The currently active task has changed! We will need to switch
* contexts.
*
* Update scheduler parameters.
*/
sched_suspend_scheduler(rtcb);
/* Are we operating in interrupt context? */
if (g_current_regs)
{
/* Yes, then we have to do things differently.
* Just copy the g_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();
/* 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);
}
/* 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 = 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);
/* Then switch contexs */
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_unblock_task(struct tcb_s *tcb)
{
struct tcb_s *rtcb = this_task();
/* Verify that the context switch can be performed */
ASSERT((tcb->task_state >= FIRST_BLOCKED_STATE) &&
(tcb->task_state <= LAST_BLOCKED_STATE));
/* Remove the task from the blocked task list */
sched_removeblocked(tcb);
/* Add the task in the correct location in the prioritized
* ready-to-run task list
*/
if (sched_addreadytorun(tcb))
{
/* The currently active task has changed! We need to do
* a context switch to the new task.
*/
/* 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_copystate(rtcb->xcp.regs, current_regs);
/* 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. Any necessary address environment
* changes will be made when the interrupt returns.
*/
current_regs = rtcb->xcp.regs;
}
/* We are not in an interrupt handler. Copy the user C context
* into the TCB of the task that was previously active. 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 new task that is ready to
* run (probably tcb). This is the new rtcb at the 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
/* Update 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
{
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_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)
{
/* 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 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;
/* Reset 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 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;
/* Reset scheduler parameters */
sched_resume_scheduler(rtcb);
/* Then switch contexts */
RESTORE_USERCONTEXT(rtcb);
}
}
}
/****************************************************************************
* 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_unblock_task(FAR struct tcb_s *tcb)
{
FAR struct tcb_s *rtcb = this_task();
/* Verify that the context switch can be performed */
ASSERT((tcb->task_state >= FIRST_BLOCKED_STATE) &&
(tcb->task_state <= LAST_BLOCKED_STATE));
sdbg("Unblocking TCB=%p\n", tcb);
/* Remove the task from the blocked task list */
sched_removeblocked(tcb);
/* Reset scheduler parameters */
sched_resume_scheduler(tcb);
/* Add the task in the correct location in the prioritized
* ready-to-run task list
*/
if (sched_addreadytorun(tcb))
{
/* The currently active task has changed! */
/* Update scheduler parameters */
sched_suspend_scheduler(rtcb);
/* Copy the exception context into the TCB of the task that was
* previously active. 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 new task that is ready to
* run (probably tcb). This is the new rtcb at the head of the
* ready-to-run task list.
*/
rtcb = this_task();
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;
}
/* Update scheduler parameters */
sched_resume_scheduler(rtcb);
/* Then switch contexts */
up_longjmp(rtcb->xcp.regs, 1);
}
}
}
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_release_pending(void)
{
struct tcb_s *rtcb = this_task();
sinfo("From TCB=%p\n", rtcb);
/* Merge the g_pendingtasks list into the ready-to-run task list */
/* sched_lock(); */
if (sched_mergepending())
{
/* The currently active task has changed! We will need to
* switch contexts.
*/
/* Update scheduler parameters */
sched_suspend_scheduler(rtcb);
/* Are we operating in interrupt context? */
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();
/* 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 of the task that
* was currently active. 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();
/* Update scheduler parameters */
sched_resume_scheduler(rtcb);
/* Then switch contexts */
up_fullcontextrestore(rtcb->xcp.regs);
}
}
}
void up_release_pending(void)
{
struct tcb_s *rtcb = this_task();
sinfo("From TCB=%p\n", rtcb);
/* Merge the g_pendingtasks list into the ready-to-run task list */
/* sched_lock(); */
if (sched_mergepending())
{
/* The currently active task has changed! We will need to switch
* contexts.
*/
/* Update scheduler parameters */
sched_suspend_scheduler(rtcb);
/* Are we operating in interrupt context? */
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();
/* Update scheduler parameters */
sched_resume_scheduler(rtcb);
/* Then switch contexts */
up_restorestate(rtcb->xcp.regs);
}
/* No, then we will need to perform the user context switch */
else
{
struct tcb_s *nexttcb = this_task();
/* Update scheduler parameters */
sched_resume_scheduler(nexttcb);
/* Switch context to the context of the task at the head of the
* ready to run list.
*/
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_unblock_task(struct tcb_s *tcb)
{
struct tcb_s *rtcb = this_task();
/* Verify that the context switch can be performed */
ASSERT((tcb->task_state >= FIRST_BLOCKED_STATE) &&
(tcb->task_state <= LAST_BLOCKED_STATE));
/* Remove the task from the blocked task list */
sched_removeblocked(tcb);
/* Add the task in the correct location in the prioritized
* ready-to-run task list
*/
if (sched_addreadytorun(tcb))
{
/* The currently active task has changed! We need to do
* a context switch to the new task.
*/
/* 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_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();
/* 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);
}
/* No, then we will need to perform the user context switch */
else
{
/* Restore the exception context of the new task that is ready to
* run (probably tcb). This is the new rtcb at the head of the
* ready-to-run task 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
/* Update 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_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);
}
}
}
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 = 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 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();
}
/* 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();
/* Update scheduler parameters */
sched_resume_scheduler(rtcb);
/* Then switch contexts */
up_restorestate(rtcb->xcp.regs);
}
/* No, then we will need to perform the user context switch */
else
{
struct tcb_s *nexttcb = this_task();
/* Update scheduler parameters */
sched_resume_scheduler(nexttcb);
/* Switch context to the context of the task at the head of the
* ready to run list.
*/
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 */
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. */
up_restorestate(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();
/* Reset scheduler parameters */
sched_resume_scheduler(rtcb);
/* Then switch contexts */
up_fullcontextrestore(rtcb->xcp.regs);
}
}
}
void up_release_pending(void)
{
struct tcb_s *rtcb = (struct tcb_s*)g_readytorun.head;
slldbg("From TCB=%p\n", rtcb);
/* Merge the g_pendingtasks list into the g_readytorun task list */
/* sched_lock(); */
if (sched_mergepending())
{
/* The currently active task has changed! We will need to switch
* contexts.
*
* Update scheduler parameters.
*/
sched_suspend_scheduler(rtcb);
/* Are we operating in interrupt context? */
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 of the task that
* was currently active. 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_release_pending(void)
{
FAR struct tcb_s *rtcb = this_task();
slldbg("From TCB=%p\n", rtcb);
/* Merge the g_pendingtasks list into the ready-to-run task list */
/* sched_lock(); */
if (sched_mergepending())
{
/* The currently active task has changed! We will need to switch
* contexts.
*
* Update scheduler parameters.
*/
sched_suspend_scheduler(rtcb);
/* Are we operating in interrupt context? */
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. Any necessary address environment
* changes will be made when the interrupt returns.
*/
SET_IRQCONTEXT(rtcb);
}
/* Copy the exception context into the TCB of the task that
* was currently active. 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();
#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 */
RESTORE_USERCONTEXT(rtcb);
}
}
}
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_release_pending(void)
{
FAR struct tcb_s *rtcb = (FAR struct tcb_s*)g_readytorun.head;
slldbg("From TCB=%p\n", rtcb);
/* Merge the g_pendingtasks list into the g_readytorun task list */
/* sched_lock(); */
if (sched_mergepending())
{
/* The currently active task has changed! We will need to switch
* contexts.
*
* Update scheduler parameters.
*/
sched_suspend_scheduler(rtcb);
/* Are we operating in interrupt context? */
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 g_readytorun task list.
*/
rtcb = (FAR struct tcb_s*)g_readytorun.head;
/* 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 of the task that
* was currently active. 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;
/* Update scheduler parameters */
sched_resume_scheduler(rtcb);
/* Then switch contexts */
RESTORE_USERCONTEXT(rtcb);
}
}
}
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_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));
/* 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);
/* 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;
/* Reset scheduler parameters */
sched_resume_scheduler(rtcb);
/* Then switch contexts */
up_restorestate(rtcb->xcp.regs);
}
/* No, then we will need to perform the user context switch */
else
{
struct tcb_s *nexttcb = (struct tcb_s*)g_readytorun.head;
/* Reset scheduler parameters */
sched_resume_scheduler(nexttcb);
/* Switch context to the context of the task at the head of the
* ready to run list.
*/
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.
*/
}
}
}
