MicroProfiler is running out of labels, showing incorrect stack traces and nulls

Bug Reports Engine Bugs
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#1

The MicroProfiler for our game is no longer useful because it is “corrupted”. We don’t use any custom labels as of recent, and this is still a problem. Impossible stack traces are showing up and also Script_null’s.

A private message is associated with this bug report

2 Likes
#2

I looked at the MP dump that you posted but I couldn’t see any script_nulls. I’ve also tried taking a few in-experience but no issues show up.
Is there a good way to reproduce this? I would love to be able to do that.

#3

Sharing some of Joey’s screenshots here:

image
image1055×66 18.3 KB

image

“no Raycasting is performed under ClientMagicOrbs”
“even in any functions that it calls as well”
“i’ve noticed this happens frequently to things that are bound to RenderStepped”

RunService:BindToRenderStep("MagicOrbs", Enum.RenderPriority.Last.Value, function(dt)
    for player, instance in pairs(playerInstances) do
        if instance:IsDestroyed() then
            playerInstances[player] = nil
            continue
        end
        instance:RenderStepped(dt)
        if instance:IsDestroyed() then
            playerInstances[player] = nil
        end
    end
end)

Added another dump to the Jira issue that has Script_null tags.

#4

I can see some script_nulls so we are running out of label space. I can see that the oldest frames have all scripts with “_null” but none of them after that have this problem. In other words we have space for labels in the most recent frames and shorter captures would be fine.

I played this experience in the debugger and It seems that the instance:RenderStepped(dt) is leading to raycasts from various scripts including:

  1. Parallel Pet Controller - performPlayerRaycast and performStandardRaycast
  2. Breakables Frontend - property update → getMousePart
  3. CameraModule.ZoomController.Popper - queryPoint()
#5

Following up on this – if we remove the usage of BindToRenderStep and instead use RenderStepped:Connect, the mislabeling issue is resolved.

We’re now using this (hilarious) wrapper for BindToRenderStep that allows us to take accurate microprofiler dumps:

--!strict

local RunService = game:GetService("RunService")

local whitelist = { 
	[1210210] = true,
	[2882755487] = true,
}

local TESTING = false
if game.GameId == 5349377275 then
	if RunService:IsClient() and whitelist[game.Players.LocalPlayer.UserId] then
		TESTING = true
	end
end

if TESTING then
	return function(name: string, priority: number, callback: (dt: number) -> ()): (() -> ())
		local connection = RunService.RenderStepped:Connect(callback)
		return function()
			connection:Disconnect()
		end
	end
end

return function(name: string, priority: number, callback: (dt: number) -> ()): (() -> ())
	RunService:BindToRenderStep(name, priority, callback)
	return function()
		RunService:UnbindFromRenderStep(name)
	end
end