PolledTimeout Class for wrapping millis() loops (WIP) (#5198)

* PolledTimeout Class for wrapping millis() loops

* Add yield policies, improve reset, add host tests

* Fix copyright, comments

* adjust host tests for better time precision

* add fuzzyness to timing tests for CI jitter

* add blink example with polledTimeout

* improve namespace and type naming, add copyright, comments

* fix astyle

libraries/esp8266/examples/BlinkPolledTimeout/BlinkPolledTimeout.ino

@@ -0,0 +1,78 @@
+/*
+  ESP8266 Blink with polledTimeout by Daniel Salazar
+
+  Copyright (c) 2018 Daniel Salazar. All rights reserved.
+  This file is part of the esp8266 core for Arduino environment.
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+
+  Note that this sketch uses LED_BUILTIN to find the pin with the internal LED
+*/
+
+
+#include <PolledTimeout.h>
+
+void ledOn() {
+  digitalWrite(LED_BUILTIN, LOW);   // Turn the LED on (Note that LOW is the voltage level
+}
+
+void ledOff() {
+  digitalWrite(LED_BUILTIN, HIGH);  // Turn the LED off by making the voltage HIGH
+}
+
+void ledToggle() {
+  digitalWrite(LED_BUILTIN, !digitalRead(LED_BUILTIN));  // Change the state of the LED
+}
+
+
+
+esp8266::polledTimeout::periodic halfPeriod(500); //use fully qualified type and avoid importing all ::esp8266 namespace to the global namespace
+
+// the setup function runs only once at start
+void setup() {
+  pinMode(LED_BUILTIN, OUTPUT);     // Initialize the LED_BUILTIN pin as an output
+
+  using esp8266::polledTimeout::oneShot; //import the type to the local namespace
+
+  //STEP1; turn the led ON
+  ledOn();
+
+  //STEP2: wait for ON timeout
+  oneShot timeoutOn(2000);
+  while (!timeoutOn) {
+    yield();
+  }
+
+  //STEP3: turn the led OFF
+  ledOff();
+
+  //STEP4: wait for OFF timeout to assure the led is kept off for this time before exiting setup
+  oneShot timeoutOff(2000);
+  while (!timeoutOff) {
+    yield();
+  }
+
+  //Done with STEPs, do other stuff
+  halfPeriod.reset(); //halfPeriod is global, so it gets inited on sketch start. Clear it here to make it ready for loop, where it's actually used.
+}
+
+
+// the loop function runs over and over again forever
+void loop() {
+  if (halfPeriod) {
+    ledToggle();
+  }
+}