kernel/sched: Remove remaining irq_lock use
The k_sleep() locking was actually to protect the _current state from
preemption before the context switch, so document that and replace
with a spinlock. Should probably unify this with the rather cleaner
logic in pend_curr(), but right now "sleeping" and "pended" are
needlessly distinct states.
And we can remove the locking entirely from k_wakeup(). There's no
reason for any of that to need to be synchronized. Even if we're
racing with other thread modifiations, the state on exit will be a
runnable thread without a timeout, or whatever timeout/pend state the
other side was requesting (i.e. it's a bug, but not one solved by
synhronization).
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
diff --git a/kernel/sched.c b/kernel/sched.c
index 31ccc56..f0663c8 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -871,7 +871,6 @@
#ifdef CONFIG_MULTITHREADING
u32_t expected_wakeup_time;
s32_t ticks;
- unsigned int key;
__ASSERT(!_is_in_isr(), "");
__ASSERT(duration != K_FOREVER, "");
@@ -886,12 +885,18 @@
ticks = _TICK_ALIGN + _ms_to_ticks(duration);
expected_wakeup_time = ticks + z_tick_get_32();
- key = irq_lock();
+
+ /* Spinlock purely for local interrupt locking to prevent us
+ * from being interrupted while _current is in an intermediate
+ * state. Should unify this implementation with pend().
+ */
+ struct k_spinlock local_lock = {};
+ k_spinlock_key_t key = k_spin_lock(&local_lock);
_remove_thread_from_ready_q(_current);
_add_thread_timeout(_current, ticks);
- (void)_Swap_irqlock(key);
+ (void)_Swap(&local_lock, key);
ticks = expected_wakeup_time - z_tick_get_32();
if (ticks > 0) {
@@ -917,25 +922,18 @@
void _impl_k_wakeup(k_tid_t thread)
{
- unsigned int key = irq_lock();
-
- /* verify first if thread is not waiting on an object */
if (_is_thread_pending(thread)) {
- irq_unlock(key);
return;
}
if (_abort_thread_timeout(thread) < 0) {
- irq_unlock(key);
return;
}
_ready_thread(thread);
- if (_is_in_isr()) {
- irq_unlock(key);
- } else {
- _reschedule_irqlock(key);
+ if (!_is_in_isr()) {
+ _reschedule_unlocked();
}
}
