PolledTimeout Class for wrapping millis() loops

esp8266 · devyte · Nov 26, 2018 · Oct 2, 2018 · Oct 2, 2018 · Oct 18, 2018
commit f43c43c321c587d5117ef68fac41a7f6a44759d2
diff --git a/cores/esp8266/PolledTimeout.h b/cores/esp8266/PolledTimeout.h
@@ -0,0 +1,68 @@
+#ifndef __POLLEDTIMING_H__
+#define __POLLEDTIMING_H__
+
+namespace esp8266
+{
+
+template<bool PeriodicT>  
+class polledTimeout
+{
+public:
+  using timeType = unsigned int;
+
+  polledTimeout(timeType timeout) 
+    : _timeout(timeout), _start(millis())  
+  {} 
+
+  bool expired()
+  {
+    if(PeriodicT)
+      return expiredRetrigger();
+    return expiredOneShot();
+  }
+
+  operator bool()
+  {
+    return expired(); 
+  }
+
+  bool reset()
+  {
+    _start = millis();  
+  }
+
+protected:
+  bool checkExpired(timeType t) const
+  {
+    return (t - _start) >=  _timeout;
+  }
+
+  bool expiredRetrigger()
+  {
+    timeType current = millis();
+    if(checkExpired(current))
+    {
+      unsigned int n = (current - _start) / _timeout; //how many _timeouts periods have elapsed, will usually be 1 (current - _start >= _timeout)
+      _start += n  * _timeout;
+      return true;
+    }
+    return false;
+  }
+
+  bool expiredOneShot() const
+  {
+    return checkExpired(millis());
+  }
+
+  timeType _timeout;
+  timeType _start;
+};
+
+
+using polledTimeoutOneShot = polledTimeout<false>;
+using polledTimeoutPeriodic = polledTimeout<true>;
+
+
+}//esp8266
+
+#endif