Example of object pool in shiva. Two tables are created, 1 to store the objects, 1 to store boolean values representing whether the object is in-use. Each object that is part of the pool stores his own table index.

droneControl_Function_allocateDrone.lua

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function droneControl.allocateDrone ( )
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   for i = 0, this.nDronePoolSize ( ) - 1
   do
        --if the entry is false the pool item is free
        if( table.getAt ( this.tDroneFree ( ), i ) == false)
        then
            --allocate the entry
            table.setAt ( this.tDroneFree ( ), i, true )
            
            --enable the drone object
            local hDrone = table.getAt ( this.tDronePool ( ), i )
            object.sendEvent ( hDrone, "uberDroneAI", "onEnable" )
            return hDrone
        end
    end
	
    return nil
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end
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droneControl_Function_createShip.lua

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function droneControl.createShip ( )
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  local hDrone = this.allocateDrone ( )
  if(hDrone == nil) then return nil end
  
  --do stuff with ship
  
  return hDrone
	
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end
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droneControl_Function_freeDrone.lua

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function droneControl.freeDrone ( hDrone )
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	--set the drone to free
    local index = object.getAIVariable ( hDrone, "uberDroneAI", "nTableIndex" )
    table.setAt ( this.tDroneFree ( ), index, false )
    
    --disable the drone object
    object.sendEvent ( hDrone, "uberDroneAI", "onDisable" )
	
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end
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droneControl_Handler_onInit.lua

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function droneControl.onInit (  )
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    --initialize drone pool
    local hScene = application.getCurrentUserScene ( )
    
    --For each table, if the table is empty then initialize new objects.
    --If the table is not empty, disable all objects
    
    --Drones
    if(table.getSize ( this.tDronePool ( ) ) == 0)
    then
        for i = 0, this.nDronePoolSize ( ) - 1
        do
            local hDrone = scene.createRuntimeObject ( hScene, "Swarm_Ship_4_verts" )
            if(hDrone)
            then
                table.add ( this.tDronePool ( ), hDrone  )
                table.add ( this.tDroneFree ( ), false )
                
                object.setAIVariable ( hDrone, "uberDroneAI", "nTableIndex", i )
                object.setVisible ( hDrone, false )
            end
        end
    else
        --just set all entries to un-used
        for i = 0, this.nDronePoolSize ( ) - 1
        do
            table.setAt( this.tDroneFree ( ), i, false )
        end
    end
    
    scene.sendEventToAllObjects ( hScene, "uberDroneAI", "onDisable" )
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end
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