Reworked entity callback dispatcher

Fixed crash when callback was deleted in middle callback dispatcher

reapi/src/amx_hook.h

@@ -29,29 +29,3 @@ private:
 	fwdstate m_state;
 	AMX *m_amx;
 };
-
-template <typename T>
-class CAmxxHookUnique: public CAmxxHookBase
-{
-public:
-	~CAmxxHookUnique()
-	{
-		if (m_uniqueData)
-		{
-			delete m_uniqueData;
-			m_uniqueData = nullptr;
-		}
-	}
-
-	CAmxxHookUnique(AMX *amx, const char *funcname, int index, T *data = nullptr) :
-		CAmxxHookBase(amx, funcname, index, -1),
-		m_uniqueData(data)
-	{
-
-	}
-
-	T *GetUnique() const { return m_uniqueData; }
-
-private:
-	T *m_uniqueData;
-};

reapi/src/entity_callback.cpp

@@ -1,179 +0,0 @@
-#include "precompiled.h"
-
-CEntityCallback g_entCallback;
-
-void CEntityCallback::PurgeCallbacks(CBaseEntity *pEntity, CallbackType_e type)
-{
-	auto it = m_callbacks.begin();
-	while (it != m_callbacks.end())
-	{
-		eCallback_t *pUnique = (*it)->GetUnique();
-
-		// this callback was already sets, need to unregister the current forward
-		if (pUnique->m_callbackType == type && pUnique->m_entity == pEntity) {
-			delete (*it);
-			it = m_callbacks.erase(it);
-		} else {
-			it++;
-		}
-	}
-}
-
-void CEntityCallback::Clear(CBaseEntity *pEntity)
-{
-	if (pEntity)
-	{
-		auto it = m_callbacks.begin();
-		while (it != m_callbacks.end())
-		{
-			eCallback_t *pUnique = (*it)->GetUnique();
-			if (pUnique->m_entity == pEntity) {
-				delete (*it);
-				it = m_callbacks.erase(it);
-			} else {
-				it++;
-			}
-		}
-	}
-	else
-	{
-		for (auto h : m_callbacks) {
-			delete h;
-		}
-
-		m_callbacks.clear();
-	}
-}
-
-bool CEntityCallback::SetThink(AMX *amx, CBaseEntity *pEntity, const char *pszCallback, const cell *pParams, size_t iParamsLen)
-{
-	PurgeCallbacks(pEntity, CType_Think);
-
-	int fwdid;
-	if (iParamsLen > 0) {
-		fwdid = g_amxxapi.RegisterSPForwardByName(amx, pszCallback, FP_CELL, FP_ARRAY, FP_DONE);
-	} else {
-		fwdid = g_amxxapi.RegisterSPForwardByName(amx, pszCallback, FP_CELL, FP_DONE);
-	}
-
-	if (fwdid == -1) {
-		AMXX_LogError(amx, AMX_ERR_NATIVE, "%s: failed to register forward.", __FUNCTION__);
-		return false;
-	}
-
-	m_callbacks.push_back(new CAmxxHookUnique<eCallback_t>(amx, pszCallback, fwdid, new eCallback_t(pEntity, pParams, iParamsLen, CType_Think)));
-	pEntity->SetThink(&CBaseEntity::SUB_Think);
-	return true;
-}
-
-bool CEntityCallback::SetTouch(AMX *amx, CBaseEntity *pEntity, const char *pszCallback, const cell *pParams, size_t iParamsLen)
-{
-	PurgeCallbacks(pEntity, CType_Touch);
-
-	int fwdid;
-	if (iParamsLen > 0) {
-		fwdid = g_amxxapi.RegisterSPForwardByName(amx, pszCallback, FP_CELL, FP_CELL, FP_ARRAY, FP_DONE);
-	} else {
-		fwdid = g_amxxapi.RegisterSPForwardByName(amx, pszCallback, FP_CELL, FP_CELL, FP_DONE);
-	}
-
-	if (fwdid == -1) {
-		AMXX_LogError(amx, AMX_ERR_NATIVE, "%s: failed to register forward.", __FUNCTION__);
-		return false;
-	}
-
-	m_callbacks.push_back(new CAmxxHookUnique<eCallback_t>(amx, pszCallback, fwdid, new eCallback_t(pEntity, pParams, iParamsLen, CType_Touch)));
-	pEntity->SetTouch(&CBaseEntity::SUB_Touch);
-	return true;
-}
-
-bool CEntityCallback::SetUse(AMX *amx, CBaseEntity *pEntity, const char *pszCallback, const cell *pParams, size_t iParamsLen)
-{
-	PurgeCallbacks(pEntity, CType_Use);
-
-	int fwdid;
-	if (iParamsLen > 0) {
-		fwdid = g_amxxapi.RegisterSPForwardByName(amx, pszCallback, FP_CELL, FP_CELL, FP_CELL, FP_CELL, FP_FLOAT, FP_ARRAY, FP_DONE);
-	} else {
-		fwdid = g_amxxapi.RegisterSPForwardByName(amx, pszCallback, FP_CELL, FP_CELL, FP_CELL, FP_CELL, FP_FLOAT, FP_DONE);
-	}
-
-	if (fwdid == -1) {
-		AMXX_LogError(amx, AMX_ERR_NATIVE, "%s: failed to register forward.", __FUNCTION__);
-		return false;
-	}
-
-	m_callbacks.push_back(new CAmxxHookUnique<eCallback_t>(amx, pszCallback, fwdid, new eCallback_t(pEntity, pParams, iParamsLen, CType_Use)));
-	pEntity->SetUse(&CBaseEntity::SUB_Use);
-	return true;
-}
-
-bool CEntityCallback::SetBlocked(AMX *amx, CBaseEntity *pEntity, const char *pszCallback, const cell *pParams, size_t iParamsLen)
-{
-	PurgeCallbacks(pEntity, CType_Blocked);
-
-	int fwdid;
-	if (iParamsLen > 0) {
-		fwdid = g_amxxapi.RegisterSPForwardByName(amx, pszCallback, FP_CELL, FP_CELL, FP_ARRAY, FP_DONE);
-	} else {
-		fwdid = g_amxxapi.RegisterSPForwardByName(amx, pszCallback, FP_CELL, FP_CELL, FP_DONE);
-	}
-
-	if (fwdid == -1) {
-		AMXX_LogError(amx, AMX_ERR_NATIVE, "%s: failed to register forward.", __FUNCTION__);
-		return false;
-	}
-
-	m_callbacks.push_back(new CAmxxHookUnique<eCallback_t>(amx, pszCallback, fwdid, new eCallback_t(pEntity, pParams, iParamsLen, CType_Blocked)));
-	pEntity->SetBlocked(&CBaseEntity::SUB_Blocked);
-	return true;
-}
-
-bool CEntityCallback::SetMoveDone(AMX *amx, CBaseEntity *pEntity, const char *pszCallback, const cell *pParams, size_t iParamsLen)
-{
-	PurgeCallbacks(pEntity, CType_MoveDone);
-
-	int fwdid;
-	if (iParamsLen > 0) {
-		fwdid = g_amxxapi.RegisterSPForwardByName(amx, pszCallback, FP_CELL, FP_ARRAY, FP_DONE);
-	} else {
-		fwdid = g_amxxapi.RegisterSPForwardByName(amx, pszCallback, FP_CELL, FP_DONE);
-	}
-
-	if (fwdid == -1) {
-		AMXX_LogError(amx, AMX_ERR_NATIVE, "%s: failed to register forward.", __FUNCTION__);
-		return false;
-	}
-
-	m_callbacks.push_back(new CAmxxHookUnique<eCallback_t>(amx, pszCallback, fwdid, new eCallback_t(pEntity, pParams, iParamsLen, CType_MoveDone)));
-
-	// TODO: Make sure that the entity actually inherited from CBaseToggle
-	((CBaseToggle *)pEntity)->SetMoveDone(&CBaseToggle::SUB_MoveDone);
-	return true;
-}
-
-// Fundamental callbacks
-void CBaseEntity::SUB_Think()
-{
-	g_entCallback.FireCallbacks(this, CEntityCallback::CType_Think, indexOfEdict(pev));
-}
-
-void CBaseEntity::SUB_Touch(CBaseEntity *pOther)
-{
-	g_entCallback.FireCallbacks(this, CEntityCallback::CType_Touch, indexOfEdict(pev), indexOfEdict(pOther->pev));
-}
-
-void CBaseEntity::SUB_Use(CBaseEntity *pActivator, CBaseEntity *pCaller, USE_TYPE useType, float value)
-{
-	g_entCallback.FireCallbacks(this, CEntityCallback::CType_Use, indexOfEdict(pev), indexOfEdict(pActivator->pev), indexOfEdict(pCaller->pev), useType, value);
-}
-
-void CBaseEntity::SUB_Blocked(CBaseEntity *pOther)
-{
-	g_entCallback.FireCallbacks(this, CEntityCallback::CType_Blocked, indexOfEdict(pev), indexOfEdict(pOther->pev));
-}
-
-void CBaseToggle::SUB_MoveDone()
-{
-	g_entCallback.FireCallbacks(this, CEntityCallback::CType_MoveDone, indexOfEdict(pev));
-}

reapi/src/entity_callback.h

@@ -1,78 +0,0 @@
-#pragma once
-
-#include "amx_hook.h"
-
-class CEntityCallback
-{
-public:
-	void Clear(CBaseEntity *pEntity = nullptr);
-
-	bool SetThink   (AMX *amx, CBaseEntity *pEntity, const char *pszCallback, const cell *pParams, size_t iParamsLen);
-	bool SetTouch   (AMX *amx, CBaseEntity *pEntity, const char *pszCallback, const cell *pParams, size_t iParamsLen);
-	bool SetUse     (AMX *amx, CBaseEntity *pEntity, const char *pszCallback, const cell *pParams, size_t iParamsLen);
-	bool SetBlocked (AMX *amx, CBaseEntity *pEntity, const char *pszCallback, const cell *pParams, size_t iParamsLen);
-	bool SetMoveDone(AMX *amx, CBaseEntity *pEntity, const char *pszCallback, const cell *pParams, size_t iParamsLen);
-
-	enum CallbackType_e
-	{
-		CType_Think,
-		CType_Touch,
-		CType_Use,
-		CType_Blocked,
-		CType_MoveDone,
-	};
-
-	template <typename ...f_args>
-	void FireCallbacks(CBaseEntity *pEntity, CallbackType_e type, volatile f_args... args)
-	{
-		for (auto fwd : m_callbacks) {
-			auto data = fwd->GetUnique();
-			if (data->m_entity == pEntity && data->m_callbackType == type)
-			{
-				if (data->m_iParamLen > 0) {
-					g_amxxapi.ExecuteForward(fwd->GetFwdIndex(), args..., g_amxxapi.PrepareCellArrayA(data->m_pParams, data->m_iParamLen, true));
-				} else {
-					g_amxxapi.ExecuteForward(fwd->GetFwdIndex(), args...);
-				}
-			}
-		}
-	}
-
-private:
-	void PurgeCallbacks(CBaseEntity *pEntity, CallbackType_e type);
-	struct eCallback_t
-	{
-		eCallback_t(CBaseEntity *pEntity, const cell *pParams, size_t iParamsLen, CallbackType_e type) :
-			m_entity(pEntity), m_callbackType(type)
-		{
-			if (iParamsLen > 0) {
-				m_iParamLen = iParamsLen + 1;
-				m_pParams = new cell[m_iParamLen];
-				Q_memcpy(m_pParams, pParams, sizeof(cell) * iParamsLen);
-				m_pParams[iParamsLen] = 0;
-			} else {
-				m_iParamLen = 0;
-				m_pParams = nullptr;
-			}
-		};
-
-		~eCallback_t()
-		{
-			if (m_pParams) {
-				delete[] m_pParams;
-				m_pParams = nullptr;
-			}
-
-			m_iParamLen = 0;
-		}
-
-		CBaseEntity *m_entity;
-		CallbackType_e m_callbackType;
-		cell *m_pParams;
-		size_t m_iParamLen;
-	};
-
-	std::vector<CAmxxHookUnique<eCallback_t> *> m_callbacks;
-};
-
-extern CEntityCallback g_entCallback;

reapi/src/entity_callback_dispatcher.cpp

@@ -0,0 +1,234 @@
+#include "precompiled.h"
+
+// Deletes all registered callbacks for the specified entity, or all entities if pEntity is nullptr
+void CEntityCallbackDispatcher::DeleteExistingCallbacks(CBaseEntity *pEntity, CallbackType type)
+{
+	for (std::list<EntityCallback *>::const_iterator it = m_callbacks.begin();
+		it != m_callbacks.end(); )
+	{
+		EntityCallback *callback = (*it);
+
+		// This callback was already sets, need to unregister the current forward
+		if (!pEntity || (callback->m_pEntity == pEntity && (callback->m_callbackType == type || None == type)))
+		{
+			// Are we in the middle of processing callbacks?
+			if (IsProcessingCallbacks())
+			{
+				// Sets the mark for the object to be deleted later
+				const std::list<EntityCallback *>::const_iterator callbackIt =
+					std::find(m_callbacksMarkForDeletion.begin(), m_callbacksMarkForDeletion.end(), callback);
+
+				if (callbackIt == m_callbacksMarkForDeletion.end())
+					m_callbacksMarkForDeletion.push_back(callback);
+
+				it++;
+			}
+			else
+			{
+				it = m_callbacks.erase(it);
+				delete callback;
+			}
+		}
+		else
+		{
+			it++;
+		}
+	}
+
+	if (!pEntity && !IsProcessingCallbacks())
+		m_callbacks.clear();
+}
+
+// Deletes all registered callbacks
+void CEntityCallbackDispatcher::DeleteAllCallbacks()
+{
+	DeleteExistingCallbacks(nullptr);
+}
+
+bool CEntityCallbackDispatcher::SetThink(AMX *amx, CBaseEntity *pEntity, const char *pszCallback, const cell *pParams, size_t iParamsLen)
+{
+	DeleteExistingCallbacks(pEntity, Think);
+
+	int fwdid;
+	if (iParamsLen > 0)
+		fwdid = g_amxxapi.RegisterSPForwardByName(amx, pszCallback, FP_CELL, FP_ARRAY, FP_DONE);
+	else
+		fwdid = g_amxxapi.RegisterSPForwardByName(amx, pszCallback, FP_CELL, FP_DONE);
+
+	if (fwdid == -1)
+	{
+		AMXX_LogError(amx, AMX_ERR_NATIVE, "%s: failed to register forward.", __FUNCTION__);
+		return false;
+	}
+
+	m_callbacks.push_back(new EntityCallback(amx, pszCallback, fwdid, pEntity, pParams, iParamsLen, Think));
+	pEntity->SetThink(&CBaseEntity::SUB_Think);
+	return true;
+}
+
+bool CEntityCallbackDispatcher::SetTouch(AMX *amx, CBaseEntity *pEntity, const char *pszCallback, const cell *pParams, size_t iParamsLen)
+{
+	DeleteExistingCallbacks(pEntity, Touch);
+
+	int fwdid;
+	if (iParamsLen > 0)
+		fwdid = g_amxxapi.RegisterSPForwardByName(amx, pszCallback, FP_CELL, FP_CELL, FP_ARRAY, FP_DONE);
+	else
+		fwdid = g_amxxapi.RegisterSPForwardByName(amx, pszCallback, FP_CELL, FP_CELL, FP_DONE);
+
+	if (fwdid == -1)
+	{
+		AMXX_LogError(amx, AMX_ERR_NATIVE, "%s: failed to register forward.", __FUNCTION__);
+		return false;
+	}
+
+	m_callbacks.push_back(new EntityCallback(amx, pszCallback, fwdid, pEntity, pParams, iParamsLen, Touch));
+	pEntity->SetTouch(&CBaseEntity::SUB_Touch);
+	return true;
+}
+
+bool CEntityCallbackDispatcher::SetUse(AMX *amx, CBaseEntity *pEntity, const char *pszCallback, const cell *pParams, size_t iParamsLen)
+{
+	DeleteExistingCallbacks(pEntity, Use);
+
+	int fwdid;
+	if (iParamsLen > 0)
+		fwdid = g_amxxapi.RegisterSPForwardByName(amx, pszCallback, FP_CELL, FP_CELL, FP_CELL, FP_CELL, FP_FLOAT, FP_ARRAY, FP_DONE);
+	else
+		fwdid = g_amxxapi.RegisterSPForwardByName(amx, pszCallback, FP_CELL, FP_CELL, FP_CELL, FP_CELL, FP_FLOAT, FP_DONE);
+
+	if (fwdid == -1)
+	{
+		AMXX_LogError(amx, AMX_ERR_NATIVE, "%s: failed to register forward.", __FUNCTION__);
+		return false;
+	}
+
+	m_callbacks.push_back(new EntityCallback(amx, pszCallback, fwdid, pEntity, pParams, iParamsLen, Use));
+	pEntity->SetUse(&CBaseEntity::SUB_Use);
+	return true;
+}
+
+bool CEntityCallbackDispatcher::SetBlocked(AMX *amx, CBaseEntity *pEntity, const char *pszCallback, const cell *pParams, size_t iParamsLen)
+{
+	DeleteExistingCallbacks(pEntity, Blocked);
+
+	int fwdid;
+	if (iParamsLen > 0)
+		fwdid = g_amxxapi.RegisterSPForwardByName(amx, pszCallback, FP_CELL, FP_CELL, FP_ARRAY, FP_DONE);
+	else
+		fwdid = g_amxxapi.RegisterSPForwardByName(amx, pszCallback, FP_CELL, FP_CELL, FP_DONE);
+
+	if (fwdid == -1)
+	{
+		AMXX_LogError(amx, AMX_ERR_NATIVE, "%s: failed to register forward.", __FUNCTION__);
+		return false;
+	}
+
+	m_callbacks.push_back(new EntityCallback(amx, pszCallback, fwdid, pEntity, pParams, iParamsLen, Blocked));
+	pEntity->SetBlocked(&CBaseEntity::SUB_Blocked);
+	return true;
+}
+
+bool CEntityCallbackDispatcher::SetMoveDone(AMX *amx, CBaseEntity *pEntity, const char *pszCallback, const cell *pParams, size_t iParamsLen)
+{
+	DeleteExistingCallbacks(pEntity, MoveDone);
+
+	int fwdid;
+	if (iParamsLen > 0)
+		fwdid = g_amxxapi.RegisterSPForwardByName(amx, pszCallback, FP_CELL, FP_ARRAY, FP_DONE);
+	else
+		fwdid = g_amxxapi.RegisterSPForwardByName(amx, pszCallback, FP_CELL, FP_DONE);
+
+	if (fwdid == -1)
+	{
+		AMXX_LogError(amx, AMX_ERR_NATIVE, "%s: failed to register forward.", __FUNCTION__);
+		return false;
+	}
+
+	m_callbacks.push_back(new EntityCallback(amx, pszCallback, fwdid, pEntity, pParams, iParamsLen, MoveDone));
+
+	// Make sure that the entity actually inherited from CBaseToggle
+	CBaseToggle *pEntityToggle = dynamic_cast<CBaseToggle *>(pEntity);
+	if (!pEntityToggle)
+	{
+		AMXX_LogError(amx, AMX_ERR_NATIVE, "%s: '%s' has no refs to the base class of an entity 'CBaseToggle'", __FUNCTION__, STRING(pEntity->pev->classname));
+		return false;
+	}
+
+	// TODO: Make sure that the entity actually inherited from CBaseToggle
+	pEntityToggle->SetMoveDone(&CBaseToggle::SUB_MoveDone);
+	return true;
+}
+
+void CEntityCallbackDispatcher::UnsetThink(AMX *amx, CBaseEntity *pEntity)
+{
+	pEntity->SetThink(nullptr);
+	DeleteExistingCallbacks(pEntity, Think);
+}
+
+void CEntityCallbackDispatcher::UnsetTouch(AMX *amx, CBaseEntity *pEntity)
+{
+	pEntity->SetTouch(nullptr);
+	DeleteExistingCallbacks(pEntity, Touch);
+}
+
+void CEntityCallbackDispatcher::UnsetUse(AMX *amx, CBaseEntity *pEntity)
+{
+	pEntity->SetUse(nullptr);
+	DeleteExistingCallbacks(pEntity, Use);
+}
+
+void CEntityCallbackDispatcher::UnsetBlocked(AMX *amx, CBaseEntity *pEntity)
+{
+	pEntity->SetBlocked(nullptr);
+	DeleteExistingCallbacks(pEntity, Blocked);
+}
+
+void CEntityCallbackDispatcher::UnsetMoveDone(AMX *amx, CBaseEntity *pEntity)
+{
+	// Make sure that the entity actually inherited from CBaseToggle
+	CBaseToggle *pEntityToggle = dynamic_cast<CBaseToggle *>(pEntity);
+	if (!pEntityToggle)
+	{
+		AMXX_LogError(amx, AMX_ERR_NATIVE, "%s: '%s' has no refs to the base class of an entity 'CBaseToggle'", __FUNCTION__, STRING(pEntity->pev->classname));
+		return;
+	}
+
+	pEntityToggle->SetMoveDone(nullptr);
+	DeleteExistingCallbacks(pEntity, MoveDone);
+}
+
+// Fundamental callbacks
+void CBaseEntity::SUB_Think()
+{
+	EntityCallbackDispatcher().DispatchCallbacks(this, CEntityCallbackDispatcher::Think, indexOfEdict(pev));
+}
+
+void CBaseEntity::SUB_Touch(CBaseEntity *pOther)
+{
+	EntityCallbackDispatcher().DispatchCallbacks(this, CEntityCallbackDispatcher::Touch, indexOfEdict(pev), indexOfEdict(pOther->pev));
+}
+
+void CBaseEntity::SUB_Use(CBaseEntity *pActivator, CBaseEntity *pCaller, USE_TYPE useType, float value)
+{
+	EntityCallbackDispatcher().DispatchCallbacks(this, CEntityCallbackDispatcher::Use, indexOfEdict(pev), indexOfEdict(pActivator->pev), indexOfEdict(pCaller->pev), useType, value);
+}
+
+void CBaseEntity::SUB_Blocked(CBaseEntity *pOther)
+{
+	EntityCallbackDispatcher().DispatchCallbacks(this, CEntityCallbackDispatcher::Blocked, indexOfEdict(pev), indexOfEdict(pOther->pev));
+}
+
+void CBaseToggle::SUB_MoveDone()
+{
+	EntityCallbackDispatcher().DispatchCallbacks(this, CEntityCallbackDispatcher::MoveDone, indexOfEdict(pev));
+}
+
+// Instance of the callback dispatcher
+static CEntityCallbackDispatcher s_EntityCallbackDispatcher = {};
+
+// Returns the instance of the callback dispatcher
+CEntityCallbackDispatcher &EntityCallbackDispatcher()
+{
+	return s_EntityCallbackDispatcher;
+}

reapi/src/entity_callback_dispatcher.h

@@ -0,0 +1,172 @@
+#pragma once
+
+#include "amx_hook.h"
+
+// Manages entity member functions such as (m_pfnThink, m_pfnTouch, m_pfnUse) and dispatches callbacks to AMXX plugins
+class CEntityCallbackDispatcher
+{
+public:
+	bool SetThink     (AMX *amx, CBaseEntity *pEntity, const char *pszCallback, const cell *pParams, size_t iParamsLen);
+	bool SetTouch     (AMX *amx, CBaseEntity *pEntity, const char *pszCallback, const cell *pParams, size_t iParamsLen);
+	bool SetUse       (AMX *amx, CBaseEntity *pEntity, const char *pszCallback, const cell *pParams, size_t iParamsLen);
+	bool SetBlocked   (AMX *amx, CBaseEntity *pEntity, const char *pszCallback, const cell *pParams, size_t iParamsLen);
+	bool SetMoveDone  (AMX *amx, CBaseEntity *pEntity, const char *pszCallback, const cell *pParams, size_t iParamsLen);
+
+	void UnsetThink   (AMX *amx, CBaseEntity *pEntity);
+	void UnsetTouch   (AMX *amx, CBaseEntity *pEntity);
+	void UnsetUse     (AMX *amx, CBaseEntity *pEntity);
+	void UnsetBlocked (AMX *amx, CBaseEntity *pEntity);
+	void UnsetMoveDone(AMX *amx, CBaseEntity *pEntity);
+
+	// Enumeration of possible callback types for entity events
+	enum CallbackType
+	{
+		None,		// No specific callback type, means unset
+		Think,
+		Touch,
+		Use,
+		Blocked,
+		MoveDone,
+	};
+
+	//
+	// @brief Deletes all registered callbacks
+	void DeleteAllCallbacks();
+
+	//
+	// @brief Deletes existing callbacks of the specified type associated with the given entity
+	//
+	// @param pEntity Pointer to the entity for which callbacks should be deleted.
+	// @param type    Type of callback to delete (default:None to delete all types)
+	//
+	void DeleteExistingCallbacks(CBaseEntity *pEntity, CallbackType type = None);
+
+	// Are we in the middle of processing callbacks?
+	bool IsProcessingCallbacks() const { return m_bIsProcessingCallbacks; }
+
+	//
+	// @brief Dispatches callbacks associated with the specified entity and callback type
+	//
+	// This function iterates through registered callbacks and executes them for the
+	// given entity and callback type
+	//
+	//
+	// @param pEntity Pointer to the entity for which callbacks should be dispatched
+	// @param type    Type of callback to dispatch
+	// @param args    Arguments to pass to the callbacks
+	//
+	template <typename ...f_args>
+	void DispatchCallbacks(CBaseEntity *pEntity, CallbackType type, volatile f_args... args)
+	{
+		// Flag to indicate that callback processing is currently active.
+		// This flag is set to true while callback processing to prevent immediate deletion
+		// of registered callbacks that may be involved in caused AMXX plugin callbacks
+		// Callbacks marked for deletion are prune after callback processing is complete
+		m_bIsProcessingCallbacks = true;
+
+		// Iterate through the list of registered callbacks
+		for (std::list<EntityCallback *>::const_iterator it = m_callbacks.begin();
+				it != m_callbacks.end(); it++)
+		{
+			const EntityCallback *callback = (*it);
+
+			// Check if the callback is associated with the specified entity and callback type
+			if (callback->m_pEntity == pEntity && callback->m_callbackType == type)
+			{
+				// Check if user parameters provided for this callback
+				if (callback->m_nUserParamBlockSize > 0)
+				{
+					// Execute the callback with the provided arguments and user parameters
+					g_amxxapi.ExecuteForward(callback->GetFwdIndex(), args..., g_amxxapi.PrepareCellArrayA(callback->m_pUserParams, callback->m_nUserParamBlockSize, true));
+				}
+				else
+				{
+					// Execute the callback with the provided arguments
+					g_amxxapi.ExecuteForward(callback->GetFwdIndex(), args...);
+				}
+			}
+		}
+
+		// Reset the flag to indicate that callback processing has concluded
+		// From this point onward, entity callbacks will be immediately deleted on the spot as it is,
+		// without any deferred removals or processing
+		m_bIsProcessingCallbacks = false;
+
+		// Is there at least one candidate marked for deletion?
+		if (!m_callbacksMarkForDeletion.empty())
+		{
+			for (std::list<EntityCallback *>::const_iterator it = m_callbacksMarkForDeletion.begin();
+				it != m_callbacksMarkForDeletion.end(); it++)
+			{
+				const EntityCallback *toDelete = (*it);
+
+				const std::list<EntityCallback *>::const_iterator callbackIt =
+					std::find(m_callbacks.begin(), m_callbacks.end(), toDelete);
+
+				// Check if the marked for deletion callback
+				// was found in the list of registered callbacks
+				if (callbackIt != m_callbacks.end())
+				{
+					m_callbacks.erase(callbackIt);
+					delete toDelete;
+				}
+			}
+
+			m_callbacksMarkForDeletion.clear();
+		}
+	}
+
+private:
+	// EntityCallback - a class representing a registered callback for an entity
+	class EntityCallback: public CAmxxHookBase
+	{
+	public:
+		EntityCallback(AMX *amx, const char *funcname, int index,
+			CBaseEntity *pEntity, const cell *pParams, size_t iParamsLen, CallbackType type
+			) :
+				CAmxxHookBase(amx, funcname, index, -1),
+				m_pEntity(pEntity), m_callbackType(type)
+		{
+			if (iParamsLen > 0) {
+				m_nUserParamBlockSize = iParamsLen + 1;
+				m_pUserParams = new cell[m_nUserParamBlockSize];
+				Q_memcpy(m_pUserParams, pParams, sizeof(cell) * iParamsLen);
+				m_pUserParams[iParamsLen] = 0;
+			} else {
+				m_nUserParamBlockSize = 0;
+				m_pUserParams = nullptr;
+			}
+		}
+
+		~EntityCallback()
+		{
+			if (m_pUserParams)
+				delete[] m_pUserParams;
+			m_pUserParams = nullptr;
+			m_nUserParamBlockSize = 0;
+		}
+
+		// Pointer to the entity for which the callback is registered
+		CBaseEntity *m_pEntity;
+
+		// Type of the callback (e.g., Think, Touch, Use, and so on)
+		CallbackType m_callbackType;
+
+		// User-provided data to be passed to their callback function
+		cell *m_pUserParams;
+
+		// The length of user-provided parameters to be passed to their callback function
+		size_t m_nUserParamBlockSize;
+	};
+
+	// Flag indicating that callback processing is currently in progress
+	bool m_bIsProcessingCallbacks;
+
+	// List of registered callbacks
+	std::list<EntityCallback *> m_callbacks;
+
+	// List of callbacks marked for deletion after dispatching callbacks is complete
+	std::list<EntityCallback *> m_callbacksMarkForDeletion;
+};
+
+CEntityCallbackDispatcher &EntityCallbackDispatcher();

reapi/src/main.cpp

@@ -69,7 +69,7 @@ void ServerDeactivate_Post()
 	api_cfg.ServerDeactivate();
 	g_hookManager.Clear();
 	g_queryFileManager.Clear();
-	g_entCallback.Clear();
+	EntityCallbackDispatcher().DeleteAllCallbacks();
 
 	g_pFunctionTable->pfnSpawn = DispatchSpawn;
 	g_pFunctionTable->pfnKeyValue = KeyValue;
@@ -140,6 +140,6 @@ void OnFreeEntPrivateData(edict_t *pEdict)
 		return;
 	}
 
-	g_entCallback.Clear(pEntity);
+	EntityCallbackDispatcher().DeleteExistingCallbacks(pEntity);
 	SET_META_RESULT(MRES_IGNORED);
 }

reapi/src/natives/natives_common.cpp

@@ -287,7 +287,7 @@ cell AMX_NATIVE_CALL amx_SetThink(AMX *amx, cell *params)
 	char namebuf[256];
 	const char *funcname = getAmxString(amx, params[arg_handler], namebuf);
 	if (unlikely(funcname == nullptr || funcname[0] == '\0')) {
-		pEntity->SetThink(nullptr);
+		EntityCallbackDispatcher().UnsetThink(amx, pEntity);
 		return TRUE;
 	}
 
@@ -298,7 +298,7 @@ cell AMX_NATIVE_CALL amx_SetThink(AMX *amx, cell *params)
 	}
 
 	cell *pParams = (PARAMS_COUNT >= 3) ? getAmxAddr(amx, params[arg_params]) : nullptr;
-	return (cell)g_entCallback.SetThink(amx, pEntity, funcname, pParams, params[arg_len]);
+	return (cell)EntityCallbackDispatcher().SetThink(amx, pEntity, funcname, pParams, params[arg_len]);
 }
 
 /*
@@ -331,7 +331,7 @@ cell AMX_NATIVE_CALL amx_SetTouch(AMX *amx, cell *params)
 	char namebuf[256];
 	const char *funcname = getAmxString(amx, params[arg_handler], namebuf);
 	if (unlikely(funcname == nullptr || funcname[0] == '\0')) {
-		pEntity->SetTouch(nullptr);
+		EntityCallbackDispatcher().UnsetTouch(amx, pEntity);
 		return TRUE;
 	}
 
@@ -342,7 +342,7 @@ cell AMX_NATIVE_CALL amx_SetTouch(AMX *amx, cell *params)
 	}
 
 	cell *pParams = (PARAMS_COUNT >= 3) ? getAmxAddr(amx, params[arg_params]) : nullptr;
-	return (cell)g_entCallback.SetTouch(amx, pEntity, funcname, pParams, params[arg_len]);
+	return (cell)EntityCallbackDispatcher().SetTouch(amx, pEntity, funcname, pParams, params[arg_len]);
 }
 
 /*
@@ -375,7 +375,7 @@ cell AMX_NATIVE_CALL amx_SetUse(AMX *amx, cell *params)
 	char namebuf[256];
 	const char *funcname = getAmxString(amx, params[arg_handler], namebuf);
 	if (unlikely(funcname == nullptr || funcname[0] == '\0')) {
-		pEntity->SetUse(nullptr);
+		EntityCallbackDispatcher().UnsetUse(amx, pEntity);
 		return TRUE;
 	}
 
@@ -386,7 +386,7 @@ cell AMX_NATIVE_CALL amx_SetUse(AMX *amx, cell *params)
 	}
 
 	cell *pParams = (PARAMS_COUNT >= 3) ? getAmxAddr(amx, params[arg_params]) : nullptr;
-	return (cell)g_entCallback.SetUse(amx, pEntity, funcname, pParams, params[arg_len]);
+	return (cell)EntityCallbackDispatcher().SetUse(amx, pEntity, funcname, pParams, params[arg_len]);
 }
 
 /*
@@ -419,7 +419,7 @@ cell AMX_NATIVE_CALL amx_SetBlocked(AMX *amx, cell *params)
 	char namebuf[256];
 	const char *funcname = getAmxString(amx, params[arg_handler], namebuf);
 	if (unlikely(funcname == nullptr || funcname[0] == '\0')) {
-		pEntity->SetBlocked(nullptr);
+		EntityCallbackDispatcher().UnsetBlocked(amx, pEntity);
 		return TRUE;
 	}
 
@@ -430,7 +430,7 @@ cell AMX_NATIVE_CALL amx_SetBlocked(AMX *amx, cell *params)
 	}
 
 	cell *pParams = (PARAMS_COUNT >= 3) ? getAmxAddr(amx, params[arg_params]) : nullptr;
-	return (cell)g_entCallback.SetBlocked(amx, pEntity, funcname, pParams, params[arg_len]);
+	return (cell)EntityCallbackDispatcher().SetBlocked(amx, pEntity, funcname, pParams, params[arg_len]);
 }
 
 /*
@@ -464,7 +464,7 @@ cell AMX_NATIVE_CALL amx_SetMoveDone(AMX *amx, cell *params)
 	char namebuf[256];
 	const char *funcname = getAmxString(amx, params[arg_handler], namebuf);
 	if (unlikely(funcname == nullptr || funcname[0] == '\0')) {
-		((CBaseToggle *)pEntity)->SetMoveDone(nullptr);
+		EntityCallbackDispatcher().UnsetMoveDone(amx, pEntity);
 		return TRUE;
 	}
 
@@ -475,7 +475,7 @@ cell AMX_NATIVE_CALL amx_SetMoveDone(AMX *amx, cell *params)
 	}
 
 	cell *pParams = (PARAMS_COUNT >= 3) ? getAmxAddr(amx, params[arg_params]) : nullptr;
-	return (cell)g_entCallback.SetMoveDone(amx, pEntity, funcname, pParams, params[arg_len]);
+	return (cell)EntityCallbackDispatcher().SetMoveDone(amx, pEntity, funcname, pParams, params[arg_len]);
 }
 
 AMX_NATIVE_INFO Natives_Common[] =

reapi/src/precompiled.h

@@ -9,6 +9,7 @@
 
 // C++
 #include <vector>				// std::vector
+#include <list>					// std::list
 
 // platform defs
 #include "platform.h"
@@ -60,7 +61,7 @@
 #include "api_config.h"
 #include "hook_manager.h"
 #include "hook_callback.h"
-#include "entity_callback.h"
+#include "entity_callback_dispatcher.h"
 #include "member_list.h"
 
 // natives