Do nested connections get reused?

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#1

I have a gun client script that listens for when the gun is equipped and when the gun is unequipped.

Tool.Equipped:Connect(function(mouse)
mouse.Button1Down:Connect(function()
		if ExpectingInput == false or buttonCool >= 1 or reloading then
			return
		end
		buttonCool = buttonCool + 1
		mouseHold = true
		repeat
			if CanFire and ammo > 0 then
				fire()		
			end
			wait()
		until mouseHold == false or reloading == true
		wait()
		buttonCool = 0	
		ExpectingInput = true		
	end)
	mouse.Button1Up:Connect(stopFire)
    end)
end)

Unequipped:

Tool.Unequipped:Connect(function()
	ExpectingInput = false
	UpdateMouseIcon()
	GUI.Parent = Tool
	equipAnim:stop()
	afterEquipAnim:stop()
end)

If I unequip and then re-equip would the connections inside Tool.Equipped:Connect be reused , or would it be a memory leak and a new connection is made each time it is equipped?

#2

No, it would create a new connection. Connect() will always link a handler function to the event listener provided even despite previous connections. This lets multiple scripts have the same listeners for a certain event.

You can use the Disconnect() function in Tool.Unequipped if you set a global variable to disconnect the pre-existing connection. But overall it might just be easier to use the Activated event.

#3

So how come when I equip and reequip, and make it print something when the mouse is clicked, it doesn’t print the something twice even though there is a new connection and the previous connections still exists?
Or is that what you meant by your second sentence where it will link the handler function to the event listener?

#4

Oh wow thats crazy.
Connections are disconnected either when the Disconnect() function is called, or the object it’s listening to is destroyed. Although the mouse object is never destroyed, it’s probably using a pointer variable and the connection is only connected to that. This seems to be because you’re passing in the mouse object as an argument.

You’ll notice however if the mouse object is not a parameter it will repeatedly connect the function.

Example Code 
 local set_mouse=game:GetService('Players').LocalPlayer:GetMouse()
 script.Parent.Equipped:Connect(function(mouse)
      mouse.Button1Down:Connect(function ()
           print('Mouse Param Connection')
      end)
      set_mouse.Button1Down:Connect(function()
          print('Mouse Set Connection')
      end)
 end)
 script.Parent.Unequipped:Connect(function ()
     print('\n')
 end)

Anyway, this means that connections still do not get reused. The connection you have is connected to a pointer object which only exists while the tool is equipped, and will be destroyed when it isn’t equipped because the variable is no longer relevant.

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