memory leak

Developer Tools
1

Hi all,

I have a major problem with my Flexpendant program (version 5.07)

My program has a timer_tick event of every 1 sec. Every 1 sec it is calling a subroutine that makes connection with the controller, get/write some data, dispose it etc. I’ve also read the disposing on the user forum and i dispose the rapid data before the controller.

My problem is that every minute the memory of the FP is dropping about 100KB. The available memory is about 23MB, so after a while the FP restarts itself. There’s no memory leaking problem message showing. The code is as follows.

Dim AController As Controller 'connect with robot controller

Dim ARapid As Rapid 'connect with rapiddata

Dim rbt_rdPickpoint As RapidData ’ Temp data

Dim rbt_rdtPickpoint As RapidDataType ’ Temp data Type

Dim rbt_udPickpoint(1) As UserDefined ’ Userdefined structure

Dim rbt_rdPattern As RapidData ’ Temp data

Dim rbt_rdtPattern As RapidDataType ’ Temp data Type

Dim rbt_udPattern(1) As UserDefined ’ Userdefined structure

AController = New Controller ’ assign new class controller

ARapid = AController.Rapid ’ assign new class rapid data

’ – read data,

rbt_rdPickpoint = ARapid.GetRapidData(“MAINTASK”, “GLOBAL”, “Pickpoint”) ’ Get data

rbt_rdtPickpoint = ARapid.GetRapidDataType(“MAINTASK”, “GLOBAL”, “tPickpoint”) ’ Get data structure

rbt_Pickpoint(1) = New tPickpoint(rbt_rdtPickpoint) 'define new tmp structure, 1ste pp

rbt_Pickpoint(1).FillFromString((DirectCast(rbt_rdPickpoint.ReadItem(1), UserDefined)).ToString()) ’ set data in the right var

rbt_udPickpoint(1) = DirectCast(rbt_rdPickpoint.ReadItem(1), UserDefined)

rbt_rdPattern = ARapid.GetRapidData(“MAINTASK”, “GLOBAL”, “Pattern”) ’ Get data

rbt_rdtPattern = ARapid.GetRapidDataType(“MAINTASK”, “GLOBAL”, “tPattern”) ’ Get data structure

rbt_Pattern(1) = New tPattern(rbt_rdtPattern) 'define new tmp structure

rbt_udPattern(1) = DirectCast(rbt_rdPattern.ReadItem(1), UserDefined)

rbt_Pattern(1).FillFromString((DirectCast(rbt_rdPattern.ReadItem(1), UserDefined)).ToString()) ’ set data in the right var

’ Pickpoint

If Not rbt_rdPickpoint Is Nothing Then

rbt_rdPickpoint.Dispose()

rbt_rdPickpoint = Nothing

End If

If Not rbt_rdtPickpoint Is Nothing Then

rbt_rdtPickpoint.Dispose()

rbt_rdtPickpoint = Nothing

End If

’ Pattern

If Not rbt_rdPattern Is Nothing Then

rbt_rdPattern.Dispose()

rbt_rdPattern = Nothing

End If

If Not rbt_rdtPattern Is Nothing Then

rbt_rdtPattern.Dispose()

rbt_rdtPattern = Nothing

End If

If Not ARapid Is Nothing Then

ARapid.Dispose()

ARapid = Nothing

End If

’ dispose variables

If Not AController Is Nothing Then

AController.Dispose()

AController = Nothing

End If

Is there something wrong with my code or with RAB5.07. Can anyone help me?

2

I’m not sure why your application is leaking memory as you describe, how much memory does it consume before it restarts?I’ve never used UserDefined structure; you might try disabling that part of your code to see if there is a problem with that particular item.

Addditionally, you might try some of the following changes to see if they improve the behavior of your application:

  1. Create a controller reference when your app is instantiated and use that same reference throughout its lifecycle, instead of creating and destroying it in each tick event.

  2. Create “variable subscriptions” to the the data you need to read when your app is instantiated and add event handlers for the ValueChanged events for each value. This will simplify or maybe eliminate the need for the the timer, which itself can be quite burdensome to the platform. You can then dispose these resources at the end of the app lifecycle.

For instance, you might try do something like:

'initialization code

'assumes a controller reference, “ctrl”, is already created

Dim RapidDataSub as RapidDomain.RapidData

RapidDataSub = ctrl.Rapid.GetRapidData(“myNumVar”)

AddHandler RapidDataSub.ValueChanged, AddressOf InvokeRapidDataSubChanged

'now when the value changes, the event handler will be called

Private Sub InvokeRapidDataSubChanged(ByVal sender As Object, ByVal e As RapidDomain.DataValueChangedEventArgs)

'this code is not executing on the main thread, so we must invoke it back to the main thread if

'we need to use it to update the UI

Me.Invoke(New EventHandler(AddressOf UpdateUI), sender, e)

End Sub

Private Sub UpdateUI(ByVal sender As Object, ByVal e As System.EventArgs)

'do something useful with the fact that the value changed; the MessageBox

'here is simply used to demonstrate the principle

GTPUMessageBox.Show(Me, Nothing, _

“The variable value changed.”, _

“Value Changed!”, _

System.Windows.Forms.MessageBoxIcon.Hand, _

System.Windows.Forms.MessageBoxButtons.OK)

End Sub

3

Hi Russ,

Thank you for your help. I try to relocate the controller reference after the program is initialized, but that doesn’t help. You have to move the rapid reference also. I also implement the second option, as an event, but i have seen that if the data change every 2 s, the event handler cannot follow the changement. Therefore it is showing a queue error for that event after a while, so i think i still have to use the timer tick to update my UI.

i have another question. I have seen, if you open and close a screen on the flexpendant, it doens’t matter what kind of screen (for eg, the IO, Jogging) is use some memory. It you do this a lot it lose a lot a memory. When will the use memory be available again, even if the program is close?

Regards,

Huynh

4

It is my understanding that launching the ABB menu is supposed to force the garbage collector to run, which should reclaim unreferenced memory.