Merge branch 'mc/func-return-value-interp' into next

* mc/func-return-value-interp:
  src/timer: more unique include guard
  src/timer: clean up tick loop
  src/timer: consistent use of const
  arduino-timer: handler return value interpretation

Closes: contrem#1
Signed-off-by: Michael Contreras <[email protected]>

Author: contrem

README.md

@@ -27,7 +27,7 @@ void loop() {
 Make a function to call when the *Timer* expires
 ```cpp
 bool function_to_call(void *argument /* optional argument given to in/at/every */) {
-    return false; // to keep the timer active - true removes it (for timer.every())
+    return true; // to repeat the action - false to stop
 }
 ```
 
@@ -104,7 +104,7 @@ auto timer = timer_create_default(); // create a timer with default settings
 
 bool toggle_led(void *) {
   digitalWrite(LED_BUILTIN, !digitalRead(LED_BUILTIN)); // toggle the LED
-  return false; // stop repeating? false
+  return true; // keep timer active? true
 }
 
 void setup() {

examples/blink/blink.ino

@@ -11,7 +11,7 @@ auto timer = timer_create_default(); // create a timer with default settings
 
 bool toggle_led(void *) {
   digitalWrite(LED_BUILTIN, !digitalRead(LED_BUILTIN)); // toggle the LED
-  return false; // stop repeating? false
+  return true; // repeat? true
 }
 
 void setup() {

examples/blink_micros/blink_micros.ino

@@ -11,7 +11,7 @@ Timer<1, micros> timer; // create a timer with 1 task and microsecond resolution
 
 bool toggle_led(void *) {
   digitalWrite(LED_BUILTIN, !digitalRead(LED_BUILTIN)); // toggle the LED
-  return false; // stop repeating? false
+  return true; // repeat? true
 }
 
 void setup() {

examples/blink_print/blink_print.ino

@@ -12,13 +12,13 @@ auto timer = timer_create_default(); // create a timer with default settings
 
 bool toggle_led(void *) {
   digitalWrite(LED_BUILTIN, !digitalRead(LED_BUILTIN)); // toggle the LED
-  return false; // stop repeating? false
+  return true; // repeat? true
 }
 
 bool print_message(void *) {
   Serial.print("print_message: Called at: ");
   Serial.println(millis());
-  return false; // stop repeating? false
+  return true; // repeat? true
 }
 
 void setup() {

examples/full/full.ino

@@ -19,14 +19,14 @@ Timer<1, micros> u_timer;
 
 bool toggle_led(void *) {
   digitalWrite(LED_BUILTIN, !digitalRead(LED_BUILTIN)); // toggle the LED
-  return false; // stop repeating? false
+  return true; // repeat? true
 }
 
 bool print_message(void *msg) {
   const char *m = (const char *)msg;
   Serial.print("print_message: ");
   Serial.println(m);
-  return false; // stop repeating? false
+  return true; // repeat? true
 }
 
 size_t repeat_count = 1;
@@ -38,7 +38,7 @@ bool repeat_x_times(void *opaque) {
   Serial.print("/");
   Serial.println(limit);
 
-  return ++repeat_count > limit; // remove this task after limit reached
+  return ++repeat_count <= limit; // remove this task after limit reached
 }
 
 void setup() {

extras/tests/rollover-generic/rollover-generic.ino

@@ -23,13 +23,13 @@ void setup() {
     pinMode(LED_BUILTIN, OUTPUT);
     _timer.every(1, [](void *) -> bool {
         ++_millis; // increase _millis every millisecond
-        return false;
+        return true;
     });
 
     // should blink the led every second, regardless of wrapping
     timer.every(1000, [](void *) -> bool {
         digitalWrite(LED_BUILTIN, !digitalRead(LED_BUILTIN));
-        return false;
+        return true;
     });
 }
 

extras/tests/rollover/rollover.ino

@@ -20,7 +20,7 @@ void setup() {
     pinMode(LED_BUILTIN, OUTPUT);
     timer.every(1000, [](void *) -> bool {
         digitalWrite(LED_BUILTIN, !digitalRead(LED_BUILTIN));
-        return false;
+        return true;
     });
 }
 

src/timer.h

@@ -32,8 +32,8 @@
    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
-#ifndef _TIMER_H__
-#define _TIMER_H__
+#ifndef _CM_ARDUINO_TIMER_H__
+#define _CM_ARDUINO_TIMER_H__
 
 #if defined(ARDUINO) && ARDUINO >= 100
 #include <Arduino.h>
@@ -89,19 +89,14 @@ class Timer {
     tick(unsigned long t)
     {
         for (size_t i = 0; i < max_tasks; ++i) {
-            struct task *task = &tasks[i];
-            const handler_t handler = task->handler;
-            void *opaque = task->opaque;
-            const unsigned long start = task->start,
-                                expires = task->expires;
-            const unsigned long duration = t - start;
+            struct task * const task = &tasks[i];
+            const unsigned long duration = t - task->start;
 
-            if (handler && duration >= expires) {
+            if (task->handler && duration >= task->expires) {
+                task->repeat = task->handler(task->opaque) && task->repeat;
 
-                if (!task->repeat) remove(task);
-                else task->start = t;
-
-                if (handler(opaque)) remove(task);
+                if (task->repeat) task->start = t;
+                else remove(task);
             }
         }
     }
@@ -132,7 +127,7 @@ class Timer {
     next_task_slot()
     {
         for (size_t i = 0; i < max_tasks; ++i) {
-            struct task *slot = &tasks[i];
+            struct task * const slot = &tasks[i];
             if (slot->handler == NULL) return slot;
         }
 
@@ -144,7 +139,7 @@ class Timer {
     add_task(unsigned long start, unsigned long expires,
              handler_t h, void *opaque, bool repeat = 0)
     {
-        struct task *slot = next_task_slot();
+        struct task * const slot = next_task_slot();
 
         if (!slot) return NULL;