sched/hrtimer: use uint8_t for hrtimer state

Use uint8_t to represent the hrtimer state to improve performance.

Signed-off-by: Chengdong Wang <wangchengdong@lixiang.com>

Author: wangchdo

include/nuttx/hrtimer.h

@@ -57,13 +57,10 @@ enum hrtimer_mode_e
  * Callers must not modify the state directly.
  */
 
-enum hrtimer_state_e
-{
-  HRTIMER_STATE_INACTIVE = 0, /* Timer is inactive and not queued */
-  HRTIMER_STATE_ARMED,        /* Timer is armed and waiting for expiry */
-  HRTIMER_STATE_RUNNING,      /* Timer callback is currently executing */
-  HRTIMER_STATE_CANCELED      /* Timer canceled (callback may be running) */
-};
+#define HRTIMER_STATE_INACTIVE       0  /* Timer is inactive and not queued */
+#define HRTIMER_STATE_ARMED          1  /* Timer is armed and waiting for expiry */
+#define HRTIMER_STATE_RUNNING        2  /* Timer callback is currently executing */
+#define HRTIMER_STATE_CANCELED       3  /* Timer canceled (callback may be running) */
 
 /* Forward declarations */
 
@@ -97,12 +94,12 @@ struct hrtimer_node_s
 
 struct hrtimer_s
 {
-  hrtimer_node_t  node;        /* RB-tree node for sorted insertion */
-  enum hrtimer_state_e state;  /* Current timer state */
-  hrtimer_cb func;             /* Expiration callback function */
-  FAR void *arg;               /* Argument passed to callback */
-  uint64_t expired;            /* Absolute expiration time (ns) */
-  uint8_t cpus;                /* Number of cpus that are running the timer */
+  hrtimer_node_t node;   /* RB-tree node for sorted insertion */
+  hrtimer_cb func;       /* Expiration callback function */
+  FAR void *arg;         /* Argument passed to callback */
+  uint64_t expired;      /* Absolute expiration time (ns) */
+  uint8_t state;         /* Current timer state */
+  uint8_t cpus;          /* Number of cpus that are running the timer */
 };
 
 /****************************************************************************

sched/hrtimer/hrtimer.h

@@ -32,6 +32,7 @@
 #include <nuttx/clock.h>
 #include <nuttx/hrtimer.h>
 
+#ifdef CONFIG_HRTIMER
 /****************************************************************************
  * Public Data
  ****************************************************************************/
@@ -154,7 +155,7 @@ int hrtimer_starttimer(uint64_t ns)
 
 static inline_function
 int hrtimer_compare(FAR const hrtimer_node_t *a,
-                FAR const hrtimer_node_t *b)
+                    FAR const hrtimer_node_t *b)
 {
   FAR const hrtimer_t *atimer = (FAR const hrtimer_t *)a;
   FAR const hrtimer_t *btimer = (FAR const hrtimer_t *)b;
@@ -173,4 +174,6 @@ int hrtimer_compare(FAR const hrtimer_node_t *a,
 
 RB_PROTOTYPE(hrtimer_tree_s, hrtimer_node_s, entry, hrtimer_compare);
 
+#endif /* CONFIG_HRTIMER */
+
 #endif /* __SCHED_HRTIMER_HRTIMER_H */

sched/hrtimer/hrtimer_cancel.c

@@ -27,10 +27,10 @@
 #include <nuttx/config.h>
 #include <nuttx/arch.h>
 #include <nuttx/clock.h>
-#include "sched/sched.h"
 
 #include <errno.h>
 
+#include "sched/sched.h"
 #include "hrtimer/hrtimer.h"
 
 /****************************************************************************
@@ -41,9 +41,6 @@
 
 #define HRTIMER_CANCEL_SYNC_DELAY_MS  5
 
-#define hrtimer_is_free(hrtimer) (((hrtimer)->state == HRTIMER_STATE_INACTIVE) && \
-                                  ((hrtimer)->cpus == 0))
-
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -107,7 +104,15 @@ int hrtimer_cancel(FAR hrtimer_t *hrtimer)
           /* Remove the timer from the active tree */
 
           RB_REMOVE(hrtimer_tree_s, &g_hrtimer_tree, &hrtimer->node);
-          hrtimer->state = HRTIMER_STATE_INACTIVE;
+
+          if (hrtimer->cpus == 0)
+            {
+              hrtimer->state = HRTIMER_STATE_INACTIVE;
+            }
+          else
+            {
+              hrtimer->state = HRTIMER_STATE_CANCELED;
+            }
           break;
         }
 
@@ -200,7 +205,7 @@ int hrtimer_cancel_sync(FAR hrtimer_t *hrtimer)
    * and the state becomes inactive.
    */
 
-  while (!hrtimer_is_free(hrtimer))
+  while (hrtimer->state != HRTIMER_STATE_INACTIVE)
     {
       if (cansleep)
         {

sched/hrtimer/hrtimer_process.c

@@ -70,6 +70,8 @@ void hrtimer_process(uint64_t now)
 {
   FAR hrtimer_t *hrtimer;
   uint32_t period = 0;
+  uint64_t expired;
+  hrtimer_cb func;
   irqstate_t flags;
 
   /* Lock the hrtimer RB-tree to protect access */
@@ -84,7 +86,10 @@ void hrtimer_process(uint64_t now)
     {
       /* Check if the timer has expired */
 
-      if (!clock_compare(hrtimer->expired, now))
+      expired = hrtimer->expired;
+      func = hrtimer->func;
+
+      if (!clock_compare(expired, now))
         {
           break;
         }
@@ -110,7 +115,10 @@ void hrtimer_process(uint64_t now)
 
       /* Execute the timer callback */
 
-      period = hrtimer->func(hrtimer);
+      if (func == hrtimer->func)
+        {
+          period = func(hrtimer);
+        }
 
       /* Re-enter critical section to update timer state */
 
@@ -124,7 +132,7 @@ void hrtimer_process(uint64_t now)
             {
               /* Timer callback completed normally */
 
-              if (period > 0)
+              if ((period > 0) && (hrtimer->expired == expired))
                 {
                   /* Periodic timer: re-arm with the next expiration */