Fixed listener queue memory overflow (#24)

matthewturner · Jun 17, 2024 · 9ce85d8 · 9ce85d8
1 parent 7a48bcc
commit 9ce85d8
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Showing 5 changed files with 14 additions and 7 deletions.
diff --git a/src/EvtContext.cpp b/src/EvtContext.cpp
@@ -44,21 +44,27 @@ void EvtContext::reset()
     _listenerCount = 0;
 }
 
-void EvtContext::addListener(IEvtListener *lstn)
+bool EvtContext::addListener(IEvtListener *lstn)
 {
     for (byte i = 0; i < _listenerCount; i++)
     {
         if (_listeners[i] == 0)
         {
             lstn->reset();
             _listeners[i] = lstn;
-            return;
+            return true;
         }
     }
 
+    if (_listenerCount == EVENTUALLY_MAX_LISTENERS) {
+        // do not add listener if there is no space left in _listeners
+        return false;
+    }
+
     lstn->reset();
     _listeners[_listenerCount] = lstn;
     _listenerCount++;
+    return true;
 }
 
 void EvtContext::removeListener(IEvtListener *lstn)

diff --git a/src/EvtContext.h b/src/EvtContext.h
@@ -24,7 +24,7 @@ class EvtContext : public IEvtContext
   EvtContext(bool manageListeners = false);
   virtual void reset() override;
   virtual void loopIteration() override;
-  virtual void addListener(IEvtListener *lstn) override;
+  virtual bool addListener(IEvtListener *lstn) override;
   virtual void removeListener(IEvtListener *lstn) override;
   virtual void manageListeners(bool manage) override;
   virtual byte listenerCount() override;

diff --git a/src/EvtContextManager.cpp b/src/EvtContextManager.cpp
@@ -5,9 +5,9 @@ EvtContextManager::EvtContextManager()
     pushContext(&_defaultContext);
 }
 
-void EvtContextManager::addListener(IEvtListener *lstn)
+bool EvtContextManager::addListener(IEvtListener *lstn)
 {
-    currentContext()->addListener(lstn);
+    return currentContext()->addListener(lstn);
 }
 
 void EvtContextManager::removeListener(IEvtListener *lstn)

diff --git a/src/EvtContextManager.h b/src/EvtContextManager.h
@@ -22,7 +22,7 @@ class EvtContextManager : public IEvtContext
 
   virtual void reset() override;
   virtual void loopIteration() override;
-  virtual void addListener(IEvtListener *lstn) override;
+  virtual bool addListener(IEvtListener *lstn) override;
   virtual void removeListener(IEvtListener *lstn) override;
   virtual void manageListeners(bool manage) override;
   virtual byte listenerCount() override;

diff --git a/src/IEvtContext.h b/src/IEvtContext.h
@@ -19,7 +19,8 @@ class IEvtContext
 
   /// @brief Adds a listener to the list of listeners.
   /// @param lstn
-  virtual void addListener(IEvtListener *lstn) = 0;
+  /// @return true: successful, false: failed, no space left in listerner queue
+  virtual bool addListener(IEvtListener *lstn) = 0;
 
   /// @brief Removes the listener and frees memory (using delete).
   /// Potentially introduces fragmentation of the heap so use sparingly.