3 files changed, 121 insertions, 4 deletions

diff --git a/src/Bindings/ManualBindings.cpp b/src/Bindings/ManualBindings.cpp
index a9368f613..b12fa5f03 100644
--- a/src/Bindings/ManualBindings.cpp
+++ b/src/Bindings/ManualBindings.cpp
@@ -941,10 +941,6 @@ protected:
 	}
 } ;
 
-
-
-
-
 static int tolua_cWorld_QueueTask(lua_State * tolua_S)
 {
 	// Binding for cWorld::QueueTask
@@ -980,7 +976,65 @@ static int tolua_cWorld_QueueTask(lua_State * tolua_S)
 	return 0;
 }
 
+class cLuaScheduledWorldTask :
+	public cWorld::cScheduledTask
+{
+public:
+	cLuaScheduledWorldTask(cPluginLua & a_Plugin, int a_FnRef, int a_Ticks) :
+		cScheduledTask(a_Ticks),
+		m_Plugin(a_Plugin),
+		m_FnRef(a_FnRef)
+	{
+	}
+
+protected:
+	cPluginLua & m_Plugin;
+	int m_FnRef;
+	
+	// cWorld::cTask overrides:
+	virtual void Run(cWorld & a_World) override
+	{
+		m_Plugin.Call(m_FnRef, &a_World);
+	}
+};
+
+
+static int tolua_cWorld_ScheduleTask(lua_State * tolua_S)
+{
+	// Binding for cWorld::ScheduleTask
+	// Params: function, Ticks
+	
+	// Retrieve the cPlugin from the LuaState:
+	cPluginLua * Plugin = GetLuaPlugin(tolua_S);
+	if (Plugin == NULL)
+	{
+		// An error message has been already printed in GetLuaPlugin()
+		return 0;
+	}
+
+	// Retrieve the args:
+	cWorld * self = (cWorld *)tolua_tousertype(tolua_S, 1, 0);
+	if (self == NULL)
+	{
+		return lua_do_error(tolua_S, "Error in function call '#funcname#': Not called on an object instance");
+	}
+	if (!lua_isfunction(tolua_S, 2))
+	{
+		return lua_do_error(tolua_S, "Error in function call '#funcname#': Expected a function for parameter #1");
+	}
+
+	// Create a reference to the function:
+	int FnRef = luaL_ref(tolua_S, LUA_REGISTRYINDEX);
+	if (FnRef == LUA_REFNIL)
+	{
+		return lua_do_error(tolua_S, "Error in function call '#funcname#': Could not get function reference of parameter #1");
+	}
+	
+	int Ticks = (int) tolua_tonumber (tolua_S, 3, 0);
 
+	self->ScheduleTask(new cLuaScheduledWorldTask(*Plugin, FnRef,Ticks));
+	return 0;
+}
 
 
 
diff --git a/src/World.cpp b/src/World.cpp
index 1cf82d641..2b85e4b58 100644
--- a/src/World.cpp
+++ b/src/World.cpp
@@ -690,6 +690,7 @@ void cWorld::Tick(float a_Dt, int a_LastTickDurationMSec)
 	TickClients(a_Dt);
 	TickQueuedBlocks();
 	TickQueuedTasks();
+	TickScheduledTasks();
 	
 	GetSimulatorManager()->Simulate(a_Dt);
 
@@ -861,6 +862,31 @@ void cWorld::TickQueuedTasks(void)
 	}  // for itr - m_Tasks[]
 }
 
+void cWorld::TickScheduledTasks()
+{
+	ScheduledTaskList Tasks;
+	// Make a copy of the tasks to avoid deadlocks on accessing m_Tasks
+	{
+		cCSLock Lock(m_CSScheduledTasks);
+		ScheduledTaskList::iterator itr = m_ScheduledTasks.begin();
+		while (itr != m_ScheduledTasks.end() && (*itr)->Ticks > 0)
+		{
+			Tasks.push_back(m_ScheduledTasks.front());
+			m_ScheduledTasks.pop_front();
+		}
+		for(;itr != m_ScheduledTasks.end(); itr++)
+		{
+			(*itr)->Ticks--;
+		}
+	}
+
+	// Execute and delete each task:
+	for (ScheduledTaskList::iterator itr = Tasks.begin(), end = Tasks.end(); itr != end; ++itr)
+	{
+		(*itr)->Run(*this);
+		delete *itr;
+	}  // for itr - m_Tasks[]
+}
 
 
 
@@ -2571,6 +2597,19 @@ void cWorld::QueueTask(cTask * a_Task)
 	m_Tasks.push_back(a_Task);
 }
 
+void cWorld::ScheduleTask(cScheduledTask * a_Task)
+{
+	cCSLock Lock(m_CSScheduledTasks);
+	for(ScheduledTaskList::iterator itr = m_ScheduledTasks.begin(); itr != m_ScheduledTasks.end(); itr++) 
+	{
+		if((*itr)->Ticks >= a_Task->Ticks) 
+		{
+			m_ScheduledTasks.insert(itr, a_Task);
+			return;
+		}
+	}
+	m_ScheduledTasks.push_back(a_Task);
+}
 
 
 
diff --git a/src/World.h b/src/World.h
index b61708d03..6ddb3ec86 100644
--- a/src/World.h
+++ b/src/World.h
@@ -82,7 +82,18 @@ public:
 		virtual void Run(cWorld & a_World) = 0;
 	} ;
 	
+	/// A common ancestor for all scheduled tasks queued onto the tick thread
+	class cScheduledTask
+	{
+	public:
+		cScheduledTask(const int a_Ticks) : Ticks(a_Ticks) {};
+		virtual ~cScheduledTask() {};
+		virtual void Run(cWorld & a_World) = 0;
+		int Ticks;
+	};
+	
 	typedef std::vector<cTask *> cTasks;
+	typedef std::list<cScheduledTask *> ScheduledTaskList;
 	
 	class cTaskSaveAllChunks :
 		public cTask
@@ -533,6 +544,9 @@ public:
 	
 	/// Queues a task onto the tick thread. The task object will be deleted once the task is finished
 	void QueueTask(cTask * a_Task);  // Exported in ManualBindings.cpp
+	
+	// Queues a task onto the tick thread. The task object will be deleted once the task is finished
+	void ScheduleTask(cScheduledTask * a_Task);
 
 	/// Returns the number of chunks loaded	
 	int GetNumChunks() const;  // tolua_export
@@ -745,9 +759,16 @@ private:
 	/// Guards the m_Tasks
 	cCriticalSection m_CSTasks;
 	
+	/// Guards the m_ScheduledTasks
+	cCriticalSection m_CSScheduledTasks;
+	
 	/// Tasks that have been queued onto the tick thread; guarded by m_CSTasks
 	cTasks m_Tasks;
 	
+	/// Tasks that have been queued to be executed on the tick thread at some number of ticks in
+	/// the future; guarded by m_CSScheduledTasks
+	ScheduledTaskList m_ScheduledTasks;
+	
 	/// Guards m_Clients
 	cCriticalSection  m_CSClients;
 	
@@ -775,6 +796,9 @@ private:
 	/// Executes all tasks queued onto the tick thread
 	void TickQueuedTasks(void);
 	
+	/// Executes all tasks queued onto the tick thread
+	void TickScheduledTasks(void);
+	
 	/// Ticks all clients that are in this world
 	void TickClients(float a_Dt);