[GEN][ZH] Change reference counter implementation for StateMachine to avoid mismatch with Retail (#1078)

Author: xezon

Core/Libraries/Source/WWVegas/WWLib/refcount.h

@@ -103,6 +103,10 @@ struct ActiveRefStruct
 typedef DataNode<RefCountClass *>	RefCountNodeClass;
 typedef List<RefCountNodeClass *>	RefCountListClass;
 
+/*
+** Note that Add_Ref and Release_Ref are always const, because copying, destroying and reference
+** counting const objects is meant to work.
+*/
 class RefCountClass
 {
 public:
@@ -249,10 +253,71 @@ class RefCountClass
 	*/
 	static bool							Validate_Active_Ref(RefCountClass * obj);
 
-#endif
+#endif // NDEBUG
 
 };
 
 
+/*
+** This template class is meant to be used as a class member for compact reference counter placements.
+** A 1 byte reference counter can be alright if the counter is not reaching the value limits.
+* 
+** Note that Add_Ref and Release_Ref are always const, because copying, destroying and reference
+** counting const objects is meant to work.
+*/
+template <typename IntegerType>
+class RefCountValue
+{
+public:
 
-#endif
+	RefCountValue(void)
+		: NumRefs(1)
+	{
+	}
+
+	~RefCountValue(void)
+	{
+		WWASSERT(NumRefs == IntegerType(0));
+	}
+
+	/*
+	** Add_Ref, call this function if you are going to keep a pointer to this object.
+	*/
+	void Add_Ref(void) const
+	{
+		WWASSERT(NumRefs != ~IntegerType(0));
+		++NumRefs;
+	}
+
+	/*
+	** Release_Ref, call this function when you no longer need the pointer to this object.
+	** You can pass a static function of type void(*)(DeleteType*) or 'operator delete'.
+	**
+	** Note that this function takes a const ObjectType*, because this function is expected
+	** to be called from within a const function as well.
+	*/
+	template <typename DeleteFunction, typename ObjectType>
+	void Release_Ref(DeleteFunction deleteFunction, const ObjectType* objectToDelete) const
+	{
+		WWASSERT(NumRefs != IntegerType(0));
+		if (--NumRefs == IntegerType(0))
+		{
+			deleteFunction(const_cast<ObjectType*>(objectToDelete));
+		}
+	}
+
+	/*
+	** Check the number of references to this object.
+	*/
+	IntegerType Num_Refs(void) const
+	{
+		return NumRefs;
+	}
+
+private:
+
+	mutable IntegerType NumRefs;
+};
+
+
+#endif // REFCOUNT_H

Generals/Code/GameEngine/Include/Common/StateMachine.h

@@ -238,7 +238,7 @@ inline State::~State() { }
 /**
  * A finite state machine.
  */
-class StateMachine : public MemoryPoolObject, public Snapshot, public RefCountClass
+class StateMachine : public MemoryPoolObject, public Snapshot
 {
 	MEMORY_POOL_GLUE_WITH_USERLOOKUP_CREATE( StateMachine, "StateMachinePool" );
 
@@ -264,6 +264,10 @@ class StateMachine : public MemoryPoolObject, public Snapshot, public RefCountCl
 
 	virtual StateReturnType setState( StateID newStateID );			///< change the current state of the machine (which may cause further state changes, due to onEnter)
 
+	void Add_Ref() const { m_refCount.Add_Ref(); }
+	void Release_Ref() const { m_refCount.Release_Ref(MemoryPoolObject::deleteInstanceInternal, this); }
+	void Num_Refs() const { m_refCount.Num_Refs(); }
+
 	StateID getCurrentStateID() const { return m_currentState ? m_currentState->getID() : INVALID_STATE_ID; }	///< return the id of the current state of the machine
 	Bool isInIdleState() const { return m_currentState ? m_currentState->isIdle() : true; }	// stateless things are considered 'idle'
 	Bool isInAttackState() const { return m_currentState ? m_currentState->isAttack() : true; }	// stateless things are considered 'idle'
@@ -342,12 +346,6 @@ class StateMachine : public MemoryPoolObject, public Snapshot, public RefCountCl
 	virtual void xfer( Xfer *xfer );
 	virtual void loadPostProcess();	
 
-	// RefCountClass interface
-	virtual void Delete_This()
-	{
-		MemoryPoolObject::deleteInstanceInternal(this);
-	}
-
 protected:
 
 	/**
@@ -384,6 +382,8 @@ class StateMachine : public MemoryPoolObject, public Snapshot, public RefCountCl
 	Bool					m_locked;													///< whether this machine is locked or not
 	Bool					m_defaultStateInited;							///< if initDefaultState has been called
 
+	RefCountValue<UnsignedByte> m_refCount;
+
 #ifdef STATE_MACHINE_DEBUG
 	Bool					m_debugOutput;
 	AsciiString		m_name;													///< Human readable name of this state - for debugging.  jba.

GeneralsMD/Code/GameEngine/Include/Common/StateMachine.h

@@ -239,7 +239,7 @@ inline State::~State() { }
 /**
  * A finite state machine.
  */
-class StateMachine : public MemoryPoolObject, public Snapshot, public RefCountClass
+class StateMachine : public MemoryPoolObject, public Snapshot
 {
 	MEMORY_POOL_GLUE_WITH_USERLOOKUP_CREATE( StateMachine, "StateMachinePool" );
 
@@ -265,6 +265,10 @@ class StateMachine : public MemoryPoolObject, public Snapshot, public RefCountCl
 
 	virtual StateReturnType setState( StateID newStateID );			///< change the current state of the machine (which may cause further state changes, due to onEnter)
 
+	void Add_Ref() const { m_refCount.Add_Ref(); }
+	void Release_Ref() const { m_refCount.Release_Ref(MemoryPoolObject::deleteInstanceInternal, this); }
+	void Num_Refs() const { m_refCount.Num_Refs(); }
+
 	StateID getCurrentStateID() const { return m_currentState ? m_currentState->getID() : INVALID_STATE_ID; }	///< return the id of the current state of the machine
 	Bool isInIdleState() const { return m_currentState ? m_currentState->isIdle() : true; }	// stateless things are considered 'idle'
 	Bool isInAttackState() const { return m_currentState ? m_currentState->isAttack() : true; }	// stateless things are considered 'idle'
@@ -344,12 +348,6 @@ class StateMachine : public MemoryPoolObject, public Snapshot, public RefCountCl
 	virtual void xfer( Xfer *xfer );
 	virtual void loadPostProcess();	
 
-	// RefCountClass interface
-	virtual void Delete_This()
-	{
-		MemoryPoolObject::deleteInstanceInternal(this);
-	}
-
 protected:
 
 	/**
@@ -386,6 +384,8 @@ class StateMachine : public MemoryPoolObject, public Snapshot, public RefCountCl
 	Bool					m_locked;													///< whether this machine is locked or not
 	Bool					m_defaultStateInited;							///< if initDefaultState has been called
 
+	RefCountValue<UnsignedByte> m_refCount;
+
 #ifdef STATE_MACHINE_DEBUG
 	Bool					m_debugOutput;
 	AsciiString		m_name;													///< Human readable name of this state - for debugging.  jba.