void rt_schedule(void)
{
rt_base_t level;
struct rt_thread *to_thread;
struct rt_thread *from_thread;
/* disable interrupt */
level = rt_hw_interrupt_disable();
/* check the scheduler is enabled or not */
if (rt_scheduler_lock_nest == 0)
{
rt_ubase_t highest_ready_priority;
if (rt_thread_ready_priority_group != 0)
{
/* need_insert_from_thread: need to insert from_thread to ready queue */
int need_insert_from_thread = 0;
to_thread = _get_highest_priority_thread(&highest_ready_priority);
if ((rt_current_thread->stat & RT_THREAD_STAT_MASK) == RT_THREAD_RUNNING)
{
if (rt_current_thread->current_priority < highest_ready_priority)
{
to_thread = rt_current_thread;
}
else if (rt_current_thread->current_priority == highest_ready_priority && (rt_current_thread->stat & RT_THREAD_STAT_YIELD_MASK) == 0)
{
to_thread = rt_current_thread;
}
else
{
need_insert_from_thread = 1;
}
rt_current_thread->stat &= ~RT_THREAD_STAT_YIELD_MASK;
}
if (to_thread != rt_current_thread)
{
/* if the destination thread is not the same as current thread */
rt_current_priority = (rt_uint8_t)highest_ready_priority;
from_thread = rt_current_thread;
rt_current_thread = to_thread;
RT_OBJECT_HOOK_CALL(rt_scheduler_hook, (from_thread, to_thread));
if (need_insert_from_thread)
{
rt_schedule_insert_thread(from_thread);
}
rt_schedule_remove_thread(to_thread);
to_thread->stat = RT_THREAD_RUNNING | (to_thread->stat & ~RT_THREAD_STAT_MASK);
/* switch to new thread */
RT_DEBUG_LOG(RT_DEBUG_SCHEDULER,
("[%d]switch to priority#%d "
"thread:%.*s(sp:0x%08x), "
"from thread:%.*s(sp: 0x%08x)\n",
rt_interrupt_nest, highest_ready_priority,
RT_NAME_MAX, to_thread->name, to_thread->sp,
RT_NAME_MAX, from_thread->name, from_thread->sp));
#ifdef RT_USING_OVERFLOW_CHECK
_rt_scheduler_stack_check(to_thread);
#endif
if (rt_interrupt_nest == 0)
{
extern void rt_thread_handle_sig(rt_bool_t clean_state);
rt_hw_context_switch((rt_ubase_t)&from_thread->sp,
(rt_ubase_t)&to_thread->sp);
/* enable interrupt */
rt_hw_interrupt_enable(level);
#ifdef RT_USING_SIGNALS
/* check stat of thread for signal */
level = rt_hw_interrupt_disable();
if (rt_current_thread->stat & RT_THREAD_STAT_SIGNAL_PENDING)
{
extern void rt_thread_handle_sig(rt_bool_t clean_state);
rt_current_thread->stat &= ~RT_THREAD_STAT_SIGNAL_PENDING;
rt_hw_interrupt_enable(level);
/* check signal status */
rt_thread_handle_sig(RT_TRUE);
}
else
{
rt_hw_interrupt_enable(level);
}
#endif
goto __exit;
}
else
{
RT_DEBUG_LOG(RT_DEBUG_SCHEDULER, ("switch in interrupt\n"));
rt_hw_context_switch_interrupt((rt_ubase_t)&from_thread->sp,
(rt_ubase_t)&to_thread->sp);
}
}
else
{
rt_schedule_remove_thread(rt_current_thread);
rt_current_thread->stat = RT_THREAD_RUNNING | (rt_current_thread->stat & ~RT_THREAD_STAT_MASK);
}
}
}
/* enable interrupt */
rt_hw_interrupt_enable(level);
__exit:
return;
}
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2014-03-24