kernel: Add _unpend_all convenience wrapper to scheduler API

Refactoring.  Mempool wants to unpend all threads at once.  It's
cleaner to do this in the scheduler instead of the IPC code.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>

kernel/include/ksched.h

@@ -43,6 +43,7 @@ void _pend_thread(struct k_thread *thread, _wait_q_t *wait_q, s32_t timeout);
 int _reschedule(int key);
 struct k_thread *_unpend_first_thread(_wait_q_t *wait_q);
 void _unpend_thread(struct k_thread *thread);
+void _unpend_all(_wait_q_t *wait_q);
 void _thread_priority_set(struct k_thread *thread, int prio);
 void *_get_next_switch_handle(void *interrupted);
 struct k_thread *_find_first_thread_to_unpend(_wait_q_t *wait_q,

kernel/mempool.c

@@ -99,13 +99,7 @@ void k_mem_pool_free_id(struct k_mem_block_id *id)
 	 */
 	key = irq_lock();
 
-	while (!sys_dlist_is_empty(&p->wait_q)) {
+	_unpend_all(&p->wait_q);
-		struct k_thread *th = (void *)sys_dlist_peek_head(&p->wait_q);
-
-		_unpend_thread(th);
-		_ready_thread(th);
-		need_sched = 1;
-	}
 
 	if (need_sched && !_is_in_isr()) {
 		_reschedule(key);

kernel/sched.c

@@ -337,6 +337,18 @@ struct k_thread *_unpend_first_thread(_wait_q_t *wait_q)
 	return t;
 }
 
+void _unpend_all(_wait_q_t *waitq)
+{
+	while (!sys_dlist_is_empty(waitq)) {
+		struct k_thread *th = (void *)sys_dlist_peek_head(waitq);
+
+		_unpend_thread(th);
+		_ready_thread(th);
+		need_sched = 1;
+	}
+}
+
+
 /* Block the current thread and swap to the next.  Releases the
  * irq_lock, does a _Swap and returns the return value set at wakeup
  * time