From 448df55335c7a68c6e409c7abe94fcf8bdbc3ca6 Mon Sep 17 00:00:00 2001
From: Karsten Fleischer <karsten.fleischer@hrs.de>
Date: Sat, 26 Oct 2024 18:09:58 +0200
Subject: [PATCH] Protect ISRs, getter and setters with mutex

---
 src/ESP32RotaryEncoder.cpp | 27 ++++++++++++++++++++++++++-
 src/ESP32RotaryEncoder.h   |  1 +
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/src/ESP32RotaryEncoder.cpp b/src/ESP32RotaryEncoder.cpp
index 013ab91..f6b403f 100644
--- a/src/ESP32RotaryEncoder.cpp
+++ b/src/ESP32RotaryEncoder.cpp
@@ -48,43 +48,53 @@ void RotaryEncoder::setEncoderType( EncoderType type )
 
 void RotaryEncoder::setBoundaries( long minValue, long maxValue, bool circleValues )
 {
+  portENTER_CRITICAL(&mux);
   if( minValue > maxValue )
     ESP_LOGW( LOG_TAG, "Minimum value (%ld) is greater than maximum value (%ld); behavior is undefined.", minValue, maxValue );
 
   setMinValue( minValue );
   setMaxValue( maxValue );
   setCircular( circleValues );
+  portEXIT_CRITICAL(&mux);
 }
 
 void RotaryEncoder::setMinValue( long minValue )
 {
+  portENTER_CRITICAL(&mux);
   ESP_LOGD( LOG_TAG, "minValue = %ld", minValue );
 
   this->minEncoderValue = minValue;
+  portEXIT_CRITICAL(&mux);
 }
 
 void RotaryEncoder::setMaxValue( long maxValue )
 {
+  portENTER_CRITICAL(&mux);
   ESP_LOGD( LOG_TAG, "maxValue = %ld", maxValue );
 
   this->maxEncoderValue = maxValue;
+  portEXIT_CRITICAL(&mux);
 }
 
 void RotaryEncoder::setCircular( bool circleValues )
 {
+  portENTER_CRITICAL(&mux);
   ESP_LOGD( LOG_TAG, "Boundaries %s circular", ( circleValues ? "are" : "are not" ) );
 
   this->circleValues = circleValues;
+  portEXIT_CRITICAL(&mux);
 }
 
 void RotaryEncoder::setStepValue( long stepValue )
 {
+  portENTER_CRITICAL(&mux);
   ESP_LOGD( LOG_TAG, "stepValue = %ld", stepValue );
 
   if( stepValue > maxEncoderValue || stepValue < minEncoderValue )
     ESP_LOGW( LOG_TAG, "Step value (%ld) is outside the bounds (%ld...%ld); behavior is undefined.", stepValue, minEncoderValue, maxEncoderValue );
 
   this->stepValue = stepValue;
+  portEXIT_CRITICAL(&mux);
 }
 
 void RotaryEncoder::onTurned( EncoderCallback f )
@@ -216,6 +226,7 @@ void RotaryEncoder::disable()
 
 bool RotaryEncoder::buttonPressed()
 {
+  portENTER_CRITICAL(&mux);
   if( !_isEnabled )
     return false;
 
@@ -225,12 +236,14 @@ bool RotaryEncoder::buttonPressed()
   bool wasPressed = buttonPressedFlag;
 
   buttonPressedFlag = false;
+  portEXIT_CRITICAL(&mux);
 
   return wasPressed;
 }
 
 bool RotaryEncoder::encoderChanged()
 {
+  portENTER_CRITICAL(&mux);
   if( !_isEnabled )
     return false;
 
@@ -240,15 +253,21 @@ bool RotaryEncoder::encoderChanged()
   bool hasChanged = encoderChangedFlag;
 
   encoderChangedFlag = false;
+  portEXIT_CRITICAL(&mux);
 
   return hasChanged;
 }
 
 long RotaryEncoder::getEncoderValue()
 {
+  portENTER_CRITICAL(&mux);
   constrainValue();
 
-  return currentValue;
+  long value = currentValue;
+
+  portEXIT_CRITICAL(&mux);
+
+  return value;
 }
 
 void RotaryEncoder::constrainValue()
@@ -267,12 +286,14 @@ void RotaryEncoder::constrainValue()
 
 void RotaryEncoder::setEncoderValue( long newValue )
 {
+  portENTER_CRITICAL(&mux);
   if( newValue != currentValue )
     ESP_LOGD( LOG_TAG, "Overriding encoder value from '%ld' to '%ld'", currentValue, newValue );
 
   currentValue = newValue;
 
   constrainValue();
+  portEXIT_CRITICAL(&mux);
 }
 
 void ARDUINO_ISR_ATTR RotaryEncoder::loop()
@@ -286,6 +307,7 @@ void ARDUINO_ISR_ATTR RotaryEncoder::loop()
 
 void ARDUINO_ISR_ATTR RotaryEncoder::_button_ISR()
 {
+  portENTER_CRITICAL_ISR(&mux);
   static unsigned long _lastInterruptTime = 0;
 
   // Simple software de-bounce
@@ -312,10 +334,12 @@ void ARDUINO_ISR_ATTR RotaryEncoder::_button_ISR()
   }
 
   _lastInterruptTime = millis();
+  portEXIT_CRITICAL_ISR(&mux);
 }
 
 void ARDUINO_ISR_ATTR RotaryEncoder::_encoder_ISR()
 {
+  portENTER_CRITICAL_ISR(&mux);
   /**
    * Almost all of this came from a blog post by Garry on GarrysBlog.com:
    * https://garrysblog.com/2021/03/20/reliably-debouncing-rotary-encoders-with-arduino-and-esp32/
@@ -386,4 +410,5 @@ void ARDUINO_ISR_ATTR RotaryEncoder::_encoder_ISR()
     // Remember current time so we can calculate speed
     _lastInterruptTime = millis();
   }
+  portEXIT_CRITICAL_ISR(&mux);
 }
diff --git a/src/ESP32RotaryEncoder.h b/src/ESP32RotaryEncoder.h
index 7c538ba..d964997 100644
--- a/src/ESP32RotaryEncoder.h
+++ b/src/ESP32RotaryEncoder.h
@@ -49,6 +49,7 @@ typedef enum {
 class RotaryEncoder {
 
   protected:
+    mutable portMUX_TYPE mux = portMUX_INITIALIZER_UNLOCKED;
 
     #if defined( ESP32 )
       typedef std::function<void(long)> EncoderCallback;