From 7ef51e89d5a1d7d75cb0b8d3832327beb46319dd Mon Sep 17 00:00:00 2001
From: Paul Selkirk <paul@psgd.org>
Date: Wed, 3 May 2017 16:38:09 -0400
Subject: Add some task metrics.

---
 task.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)

(limited to 'task.c')

diff --git a/task.c b/task.c
index 2e2ddec..e156940 100644
--- a/task.c
+++ b/task.c
@@ -81,6 +81,14 @@ static tcb_t *cur_task = NULL;
 
 #define STACK_GUARD_WORD 0x55AA5A5A
 
+#ifdef TASK_METRICS
+static uint32_t tick_start = 0;
+static uint32_t tick_prev  = 0;
+static uint32_t tick_idle  = 0;
+static uint32_t tick_max   = 0;
+static uint32_t nyield     = 0;
+#endif
+
 /* Add a task.
  */
 tcb_t *task_add(char *name, funcp_t func, void *cookie, void *stack, size_t stack_len)
@@ -180,6 +188,10 @@ void task_yield(void)
     if (tail == NULL)
 	return;
 
+#ifdef TASK_METRICS
+    uint32_t tick0 = HAL_GetTick();
+#endif
+
     /* Find the next runnable task. Loop if every task is waiting. */
     while (1) {
         next = next_task();
@@ -197,6 +209,20 @@ void task_yield(void)
      * } while (next == NULL);
      */
 
+#ifdef TASK_METRICS
+    uint32_t tick = HAL_GetTick();
+    tick_idle += (tick - tick0);
+    if (tick_start == 0)
+        tick_start = tick;
+    if (tick_prev != 0) {
+        uint32_t duration = tick0 - tick_prev;
+        if (duration > tick_max)
+            tick_max = duration;
+    }
+    tick_prev = tick;
+    ++nyield;
+#endif
+
     /* If there are no other runnable tasks (and cur_task is runnable),
      * we don't need to context-switch.
      */
@@ -354,3 +380,25 @@ void task_mutex_unlock(task_mutex_t *mutex)
     if (mutex != NULL)
 	mutex->locked = 0;
 }
+
+#ifdef TASK_METRICS
+void task_get_metrics(struct task_metrics *tm)
+{
+    if (tm != NULL) {
+        tm->avg.tv_sec  = 0;
+        tm->avg.tv_usec = (HAL_GetTick() - tick_start - tick_idle) * 1000 / nyield;
+        if (tm->avg.tv_usec > 1000000) {
+            tm->avg.tv_sec  = tm->avg.tv_usec / 1000000;
+            tm->avg.tv_usec = tm->avg.tv_usec % 1000000;
+        }
+        tm->max.tv_sec  = tick_max / 1000;
+        tm->max.tv_usec = (tick_max % 1000) * 1000;
+    }
+}
+
+void task_reset_metrics(void)
+{
+    tick_start = HAL_GetTick();
+    tick_prev = tick_idle = tick_max = nyield = 0;
+}
+#endif
-- 
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