kernel/sched: Mark sleeping threads suspended

On SMP, there was a bug where the logic that re-adds _current to the
run queue at swap time would accidentally reschedule threads that had
just gone to sleep, because the is_thread_prevented_from_running()
predicate only tests for threads that are "suspended" or "pending" and
not sleeping.

Overload _THREAD_SUSPENDED to indicate "sleeping" also.  Simple fix
for an immediate bug, though long term we really want to unify all the
blocked conditions to prevent this kind of state bug.

Signed-off-by: Andy Ross <[email protected]>

Author: Andy Ross

kernel/sched.c

@@ -423,6 +423,7 @@ void z_thread_timeout(struct _timeout *to)
 		z_unpend_thread_no_timeout(th);
 	}
 	z_mark_thread_as_started(th);
+	z_mark_thread_as_not_suspended(th);
 	z_ready_thread(th);
 }
 #endif
@@ -944,9 +945,12 @@ s32_t z_impl_k_sleep(s32_t duration)
 #endif
 	z_remove_thread_from_ready_q(_current);
 	z_add_thread_timeout(_current, ticks);
+	z_mark_thread_as_suspended(_current);
 
 	(void)z_swap(&local_lock, key);
 
+	__ASSERT(!z_is_thread_state_set(_current, _THREAD_SUSPENDED), "");
+
 	ticks = expected_wakeup_time - z_tick_get_32();
 	if (ticks > 0) {
 		return __ticks_to_ms(ticks);
@@ -979,6 +983,7 @@ void z_impl_k_wakeup(k_tid_t thread)
 		return;
 	}
 
+	z_mark_thread_as_not_suspended(thread);
 	z_ready_thread(thread);
 
 	if (!z_is_in_isr()) {