From 4cfe60a9cbfc294b0f6aac15f77e90c69582ae77 Mon Sep 17 00:00:00 2001
From: SheldonDai <sheldondai@tencent.com>
Date: Mon, 23 Sep 2019 20:40:31 +0800
Subject: [PATCH] fix a tick list add bug

fix a tick list add bug: if a lower priority task has the same tick_expires with a higher priority task in the tick list, the lower should be added behind the higher one.
---
 kernel/core/include/tos_task.h | 2 +-
 kernel/core/tos_task.c         | 2 +-
 kernel/core/tos_tick.c         | 4 ++++
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/kernel/core/include/tos_task.h b/kernel/core/include/tos_task.h
index 49e11ad1..4dd73644 100644
--- a/kernel/core/include/tos_task.h
+++ b/kernel/core/include/tos_task.h
@@ -48,7 +48,7 @@ typedef void (*k_task_entry_t)(void *arg);
  * task control block
  */
 typedef struct k_task_st {
-    k_stack_t          *sp;                 /**< task stack pointer. This lady always comes first, we use her in port_s.S for context switch. */
+    k_stack_t          *sp;                 /**< task stack pointer. This lady always comes first, we count on her in port_s.S for context switch. */
 
 #if TOS_CFG_OBJECT_VERIFY_EN > 0u
     knl_obj_t           knl_obj;            /**< just for verification, test whether current object is really a task. */
diff --git a/kernel/core/tos_task.c b/kernel/core/tos_task.c
index ff3ec11a..4481a5be 100644
--- a/kernel/core/tos_task.c
+++ b/kernel/core/tos_task.c
@@ -11,7 +11,7 @@ __STATIC_INLINE__ void task_reset(k_task_t *task)
 
 #if TOS_CFG_MUTEX_EN > 0u
     tos_list_init(&task->mutex_own_list);
-    task->prio_pending = K_TASK_PRIO_INVALID;
+    task->prio_pending  = K_TASK_PRIO_INVALID;
 #endif
 
     task->pend_state    = PEND_STATE_NONE;
diff --git a/kernel/core/tos_tick.c b/kernel/core/tos_tick.c
index 0d764426..5b732d8b 100644
--- a/kernel/core/tos_tick.c
+++ b/kernel/core/tos_tick.c
@@ -18,6 +18,10 @@ __STATIC__ void tick_task_place(k_task_t *task, k_tick_t timeout)
         if (task->tick_expires < curr_expires) {
             break;
         }
+        if (task->tick_expires == curr_expires &&
+            task->prio < curr_task->prio) {
+            break;
+        }
         prev_expires = curr_expires;
     }
     task->tick_expires -= prev_expires;