Add Schedule and Functional/Scheduled Ticker

Author: hreintke

cores/esp32/Schedule.cpp

@@ -0,0 +1,78 @@
+#include "Schedule.h"
+
+struct scheduled_fn_t
+{
+    scheduled_fn_t* mNext;
+    std::function<void(void)> mFunc;
+};
+
+static scheduled_fn_t* sFirst = 0;
+static scheduled_fn_t* sLast = 0;
+
+static scheduled_fn_t* sFirstUnused = 0;
+static scheduled_fn_t* sLastUnused = 0;
+
+static int sCount = 0;
+
+static scheduled_fn_t* get_fn() {
+    scheduled_fn_t* result = NULL;
+    // try to get an item from unused items list
+    if (sFirstUnused) {
+        result = sFirstUnused;
+        sFirstUnused = result->mNext;
+        if (sFirstUnused == NULL) {
+            sLastUnused = NULL;
+        }
+    }
+    // if no unused items, and count not too high, allocate a new one
+    else if (sCount != SCHEDULED_FN_MAX_COUNT) {
+        result = new scheduled_fn_t;
+        result->mNext = NULL;
+        ++sCount;
+    }
+    return result;
+}
+
+static void recycle_fn(scheduled_fn_t* fn)
+{
+    if (!sLastUnused) {
+        sFirstUnused = fn;
+    }
+    else {
+        sLastUnused->mNext = fn;
+    }
+    fn->mNext = NULL;
+    sLastUnused = fn;
+}
+
+bool schedule_function(std::function<void(void)> fn)
+{
+    scheduled_fn_t* item = get_fn();
+    if (!item) {
+        return false;
+    }
+    item->mFunc = fn;
+    item->mNext = NULL;
+    if (!sFirst) {
+        sFirst = item;
+    }
+    else {
+        sLast->mNext = item;
+    }
+    sLast = item;
+    return true;
+}
+
+void run_scheduled_functions()
+{
+	scheduled_fn_t* rFirst = sFirst;
+	sFirst = NULL;
+	sLast  = NULL;
+    while (rFirst) {
+        scheduled_fn_t* item = rFirst;
+        rFirst = item->mNext;
+        item->mFunc();
+        item->mFunc = std::function<void(void)>();
+        recycle_fn(item);
+    }
+}

cores/esp32/Schedule.h

@@ -0,0 +1,27 @@
+#ifndef ESP_SCHEDULE_H
+#define ESP_SCHEDULE_H
+
+#include <functional>
+
+#define SCHEDULED_FN_MAX_COUNT 32
+#define SCHEDULED_FN_INITIAL_COUNT 4
+
+// Warning 
+// This API is not considered stable. 
+// Function signatures will change.
+// You have been warned.
+
+// Run given function next time `loop` function returns, 
+// or `run_scheduled_functions` is called.
+// Use std::bind to pass arguments to a function, or call a class member function.
+// Note: there is no mechanism for cancelling scheduled functions.
+// Keep that in mind when binding functions to objects which may have short lifetime.
+// Returns false if the number of scheduled functions exceeds SCHEDULED_FN_MAX_COUNT.
+bool schedule_function(std::function<void(void)> fn);
+
+// Run all scheduled functions. 
+// Use this function if your are not using `loop`, or `loop` does not return
+// on a regular basis.
+void run_scheduled_functions();
+
+#endif //ESP_SCHEDULE_H

cores/esp32/main.cpp

@@ -1,6 +1,7 @@
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
 #include "Arduino.h"
+#include "Schedule.h"
 
 #if CONFIG_AUTOSTART_ARDUINO
 
@@ -16,6 +17,7 @@ void loopTask(void *pvParameters)
     for(;;) {
         micros(); //update overflow
         loop();
+        run_scheduled_functions();
     }
 }
 

libraries/Ticker/src/Ticker.cpp

@@ -54,5 +54,18 @@ void Ticker::detach() {
     esp_timer_stop(_timer);
     esp_timer_delete(_timer);
     _timer = nullptr;
+	_callback_function = nullptr;
   }
 }
+
+void Ticker::_static_callback(void* arg){
+	Ticker* _this = (Ticker*)arg;
+	if (_this == nullptr)
+	{
+		return;
+	}
+	if (_this->_callback_function)
+	{
+		_this->_callback_function();
+	}
+}

libraries/Ticker/src/Ticker.h

@@ -25,6 +25,9 @@
 #ifndef TICKER_H
 #define TICKER_H
 
+#include <functional>
+#include "Schedule.h"
+
 extern "C" {
   #include "esp_timer.h"
 }
@@ -36,15 +39,28 @@ class Ticker
   ~Ticker();
   typedef void (*callback_t)(void);
   typedef void (*callback_with_arg_t)(void*);
+  typedef std::function<void(void)> callback_function_t;
+
+  void attach_scheduled(float seconds, callback_function_t callback)
+  {
+	attach(seconds,std::bind(schedule_function, callback));
+  }
+
+  void attach(float seconds, callback_function_t callback)
+  {
+	_callback_function = callback;
+	attach(seconds, _static_callback, (void*)this);
+  }
 
-  void attach(float seconds, callback_t callback)
+  void attach_ms_scheduled(uint32_t milliseconds, callback_function_t callback)
   {
-    _attach_ms(seconds * 1000, true, reinterpret_cast<callback_with_arg_t>(callback), 0);
+	attach_ms(milliseconds, std::bind(schedule_function, callback));
   }
 
-  void attach_ms(uint32_t milliseconds, callback_t callback)
+  void attach_ms(uint32_t milliseconds, callback_function_t callback)
   {
-    _attach_ms(milliseconds, true, reinterpret_cast<callback_with_arg_t>(callback), 0);
+	_callback_function = callback;
+	attach_ms(milliseconds, _static_callback, (void*)this);
   }
 
   template<typename TArg>
@@ -66,14 +82,26 @@ class Ticker
     _attach_ms(milliseconds, true, reinterpret_cast<callback_with_arg_t>(callback), arg32);
   }
 
-  void once(float seconds, callback_t callback)
+  void once_scheduled(float seconds, callback_function_t callback)
   {
-    _attach_ms(seconds * 1000, false, reinterpret_cast<callback_with_arg_t>(callback), 0);
+	once(seconds, std::bind(schedule_function, callback));
   }
 
-  void once_ms(uint32_t milliseconds, callback_t callback)
+  void once(float seconds, callback_function_t callback)
   {
-    _attach_ms(milliseconds, false, reinterpret_cast<callback_with_arg_t>(callback), 0);	
+	_callback_function = callback;
+	once(seconds, _static_callback, (void*)this);
+  }
+
+  void once_ms_scheduled(uint32_t milliseconds, callback_function_t callback)
+  {
+	once_ms(milliseconds, std::bind(schedule_function, callback));
+  }
+
+  void once_ms(uint32_t milliseconds, callback_function_t callback)
+  {
+	_callback_function = callback;
+	once_ms(milliseconds, _static_callback, (void*)this);
   }
 
   template<typename TArg>
@@ -97,10 +125,11 @@ class Ticker
 
 protected:	
   void _attach_ms(uint32_t milliseconds, bool repeat, callback_with_arg_t callback, uint32_t arg);
-
+  static void _static_callback (void* arg);
 
 protected:
   esp_timer_handle_t _timer;
+  callback_function_t _callback_function = nullptr;
 };