!322 add schedule hook for cpu usage statistics

Merge pull request !322 from songchao/rt-smart

src/scheduler.c

@@ -49,6 +49,7 @@ rt_uint8_t rt_current_priority;
 
 #ifdef RT_USING_HOOK
 static void (*rt_scheduler_hook)(struct rt_thread *from, struct rt_thread *to);
+static void (*rt_scheduler_switch_hook)(struct rt_thread *tid);
 
 /**
  * @addtogroup Hook
@@ -68,6 +69,11 @@ rt_scheduler_sethook(void (*hook)(struct rt_thread *from, struct rt_thread *to))
     rt_scheduler_hook = hook;
 }
 
+void
+rt_scheduler_switch_sethook(void (*hook)(struct rt_thread *tid))
+{
+    rt_scheduler_switch_hook = hook;
+}
 /**@}*/
 #endif
 
@@ -372,7 +378,7 @@ void rt_schedule(void)
 #ifdef RT_USING_OVERFLOW_CHECK
                 _rt_scheduler_stack_check(to_thread);
 #endif
-
+                RT_OBJECT_HOOK_CALL(rt_scheduler_switch_hook, (current_thread));
                 rt_hw_context_switch((rt_ubase_t)&current_thread->sp,
                         (rt_ubase_t)&to_thread->sp, to_thread);
             }
@@ -478,6 +484,7 @@ void rt_schedule(void)
                 _rt_scheduler_stack_check(to_thread);
 #endif
 
+                RT_OBJECT_HOOK_CALL(rt_scheduler_switch_hook, (from_thread));
                 if (rt_interrupt_nest == 0)
                 {
                     extern void rt_thread_handle_sig(rt_bool_t clean_state);