StackOverflowException in Thread

[=?Utf-8?B?QnViYmE=?=]

I've written code that uses a thread to read a 70K line CSV file one line at
a time, however, after about 9 to 10 thousand lines into the file I get a
StackOverflowEx ception while the thread tries to update a counter.

I'm sure I'm doing this correctly but if anyone can tell me different I'd
appreciate it.

ssStrip is a StatusStrip on the main form.

Private WithEvents m_tHistorical As BackgroundWorke r = New BackgroundWorke r()

Private Sub cmdRun_Click(By Val sender As System.Object, ByVal e As
System.EventArg s) Handles cmdRun.Click
Me.ssStrip.Item s(1).Visible = True
Me.ssStrip.Item s(2).Visible = True
m_tHistorical.R unWorkerAsync(N ew
StreamReader("S SG_Historical-29-03-2007.csv", False))
End Sub

Private Sub m_tHistorical_D oWork(ByVal sender As Object, ByVal e As
System.Componen tModel.DoWorkEv entArgs) Handles m_tHistorical.D oWork
e.Result = ReadHistoricalC SV(CType(sender , BackgroundWorke r), e)
End Sub

Private Function ReadHistoricalC SV(ByVal W As BackgroundWorke r, ByVal e
As DoWorkEventArgs ) As Boolean
Dim S As StreamReader = CType(e.Argumen t(), StreamReader), Result As
Boolean = False
Static Rows As Integer = 0
If (W.Cancellation Pending()) Then
e.Cancel = True
Else
Result = S.EndOfStream()
If (Result) Then
S.Close()
Else
S.ReadLine()
Rows += 1
UpdateHCSVRows( Rows) ' <-- This is the line with the
StackOverFlow
Result = ReadHistoricalC SV(W, e)
End If
End If
Return Result
End Function

Private Sub UpdateHCSVRows( ByVal R As Integer)
If (Me.ssStrip.Inv okeRequired()) Then
Me.Invoke(New CSVHRowsCallbac k(AddressOf UpdateHCSVRows) , New
Object() {R})
Else
Me.ssStrip.Item s(1).Text = FormatNumber(R, 0,
TriState.UseDef ault, TriState.UseDef ault, TriState.True)
End If
End Sub

--
Regards,

Bubba

[Chris Dunaway]

Re: StackOverflowEx ception in Thread

On Mar 30, 8:22 am, Bubba <B...@discussio ns.microsoft.co mwrote:

I've written code that uses a thread to read a 70K line CSV file one line at
a time, however, after about 9 to 10 thousand lines into the file I get a
StackOverflowEx ception while the thread tries to update a counter.
>

<snip>

Private Sub UpdateHCSVRows( ByVal R As Integer)
If (Me.ssStrip.Inv okeRequired()) Then
Me.Invoke(New CSVHRowsCallbac k(AddressOf UpdateHCSVRows) , New
Object() {R})
Else
Me.ssStrip.Item s(1).Text = FormatNumber(R, 0,
TriState.UseDef ault, TriState.UseDef ault, TriState.True)
End If
End Sub
>

Your Sub above is calling itself recursively! That's why you are
getting the StackOverflowEx ception. Try moving the InvokeRequired
check *outside* the Sub.

Chris

[=?Utf-8?B?QnViYmE=?=]

Re: StackOverflowEx ception in Thread

"Chris Dunaway" wrote:

On Mar 30, 8:22 am, Bubba <B...@discussio ns.microsoft.co mwrote:

I've written code that uses a thread to read a 70K line CSV file one line at
a time, however, after about 9 to 10 thousand lines into the file I get a
StackOverflowEx ception while the thread tries to update a counter.

>
<snip>
>

<snip/>

Your Sub above is calling itself recursively! That's why you are
getting the StackOverflowEx ception. Try moving the InvokeRequired
check *outside* the Sub.
>

Not to sure what you mean here as this is required when updating the UI from
a different thread.

What I did try was to comment out all of the lines apart from
Me.ssStrip.Item s... one and it ran updating the row count until it got to the
10K mark and again failed with the same error.

--
Regards,

Bubba

[Smokey Grindle]

Re: StackOverflowEx ception in Thread

Me.Invoke(New CSVHRowsCallbac k(AddressOf UpdateHCSVRows) , New
Object() {R})

your code there is callign itself, which puts a new stack frame onto the
stack, eventually it will overflow the stack because you got it stuck in a
never ending loop


"Bubba" <Bubba@discussi ons.microsoft.c omwrote in message
news:FAC07EBC-765D-4901-BB25-021B28BC6716@mi crosoft.com...

"Chris Dunaway" wrote:
>

>On Mar 30, 8:22 am, Bubba <B...@discussio ns.microsoft.co mwrote:

I've written code that uses a thread to read a 70K line CSV file one
line at
a time, however, after about 9 to 10 thousand lines into the file I get
a
StackOverflowEx ception while the thread tries to update a counter.
>

>>
><snip>
>>

<snip/>

>

>Your Sub above is calling itself recursively! That's why you are
>getting the StackOverflowEx ception. Try moving the InvokeRequired
>check *outside* the Sub.
>>

>
Not to sure what you mean here as this is required when updating the UI
from
a different thread.
>
What I did try was to comment out all of the lines apart from
Me.ssStrip.Item s... one and it ran updating the row count until it got to
the
10K mark and again failed with the same error.
>
--
Regards,
>
Bubba
>
>

[=?Utf-8?B?QnViYmE=?=]

Re: StackOverflowEx ception in Thread

"Smokey Grindle" wrote:

Me.Invoke(New CSVHRowsCallbac k(AddressOf UpdateHCSVRows) , New
Object() {R})
>
your code there is callign itself, which puts a new stack frame onto the
stack, eventually it will overflow the stack because you got it stuck in a
never ending loop

Fair enough I can see this and understand, but I was only following what I
saw on the MSDN. Does anyone know how I should re-write this to fix it?


--
Regards,

Bubba

[=?Utf-8?B?QnViYmE=?=]

Re: StackOverflowEx ception in Thread

"Bubba" wrote:

"Smokey Grindle" wrote:
>

Me.Invoke(New CSVHRowsCallbac k(AddressOf UpdateHCSVRows) , New
Object() {R})

your code there is callign itself, which puts a new stack frame onto the
stack, eventually it will overflow the stack because you got it stuck in a
never ending loop

>
Fair enough I can see this and understand, but I was only following what I
saw on the MSDN. Does anyone know how I should re-write this to fix it?
>

Ok with that said I've changed the code to the following:

Private Function ReadHistoricalC SV(ByVal W As BackgroundWorke r, ByVal e
As DoWorkEventArgs ) As Boolean
Dim S As StreamReader = CType(e.Argumen t(), StreamReader), Result As
Boolean = False
Static Rows As Integer = 0
If (W.Cancellation Pending()) Then
e.Cancel = True
Else
Result = S.EndOfStream()
If (Result) Then
S.Close()
Else
S.ReadLine()
Rows += 1
Me.ssStrip.Item s(1).Text = FormatNumber(Ro ws, 0,
TriState.UseDef ault, TriState.UseDef ault, TriState.True)
Result = ReadHistoricalC SV(W, e)
End If
End If
Return Result
End Function

And I still get an error, again this procedure is calling itself, as is
shown in the MSDN so I'm assuming that this is the correct way, as it is the
only way I can see that allows you to cancel the thread's execution.

I'm at a loss with this one but I really need to get this resolved as I have
another 2 files just as large that need proccessing. I'm using threads so
that the processing of all three files can be done simultaneously to speed up
the process and make use of the quad processor based machine it runs on.

Can anyone help me out here?
--
Regards,

Bubba

[Stephany Young]

Re: StackOverflowEx ception in Thread

Well, the point is that you're still calling 'yourself' recursively thus
causing the stack to blow out.

You need to work on the 'keep it simple' principle and not turn a simple
task into a complicated one.

Try:

Private Sub ReadHistoricalC SV(ByVal W As BackgroundWorke r, ByVal e As
DoWorkEventArgs )

Dim Rows As Integer = 0

Dim S As StreamReader = CType(e.Argumen t, StreamReader)

While Not S.EndOfStream AndAlso Not W.CancellationP ending
S.ReadLine()
Rows += 1
Me.ssStrip.Item s(1).Text = FormatNumber(Ro ws, 0, TriState.UseDef ault,
TriState.UseDef ault, TriState.True)
Loop

If W.CancellationP ending Then
e.Cancel
Else
S.Close()
End If

End Sub

Note that the method it is now a Sub rather than a Function because it does
not need a return value.

The method loops until EndOfStream is true on the StreamReader object or
CancellationPen ding is set on the BackgroundWorke r object, whichever occurs
first.


"Bubba" <Bubba@discussi ons.microsoft.c omwrote in message
news:BC0B8A50-3111-4475-957D-B1E1C6B711CD@mi crosoft.com...

"Bubba" wrote:
>

>"Smokey Grindle" wrote:
>>

Me.Invoke(New CSVHRowsCallbac k(AddressOf UpdateHCSVRows) , New
Object() {R})
>
your code there is callign itself, which puts a new stack frame onto
the
stack, eventually it will overflow the stack because you got it stuck
in a
never ending loop

>>
>Fair enough I can see this and understand, but I was only following what
>I
>saw on the MSDN. Does anyone know how I should re-write this to fix it?
>>

>
Ok with that said I've changed the code to the following:
>
Private Function ReadHistoricalC SV(ByVal W As BackgroundWorke r, ByVal e
As DoWorkEventArgs ) As Boolean
Dim S As StreamReader = CType(e.Argumen t(), StreamReader), Result
As
Boolean = False
Static Rows As Integer = 0
If (W.Cancellation Pending()) Then
e.Cancel = True
Else
Result = S.EndOfStream()
If (Result) Then
S.Close()
Else
S.ReadLine()
Rows += 1
Me.ssStrip.Item s(1).Text = FormatNumber(Ro ws, 0,
TriState.UseDef ault, TriState.UseDef ault, TriState.True)
Result = ReadHistoricalC SV(W, e)
End If
End If
Return Result
End Function
>
And I still get an error, again this procedure is calling itself, as is
shown in the MSDN so I'm assuming that this is the correct way, as it is
the
only way I can see that allows you to cancel the thread's execution.
>
I'm at a loss with this one but I really need to get this resolved as I
have
another 2 files just as large that need proccessing. I'm using threads so
that the processing of all three files can be done simultaneously to speed
up
the process and make use of the quad processor based machine it runs on.
>
Can anyone help me out here?
--
Regards,
>
Bubba
>

[=?Utf-8?B?QnViYmE=?=]

Re: StackOverflowEx ception in Thread

"Stephany Young" wrote:

Well, the point is that you're still calling 'yourself' recursively thus
causing the stack to blow out.
>
You need to work on the 'keep it simple' principle and not turn a simple
task into a complicated one.
>
Try:
>
Private Sub ReadHistoricalC SV(ByVal W As BackgroundWorke r, ByVal e As
DoWorkEventArgs )
>
Dim Rows As Integer = 0
>
Dim S As StreamReader = CType(e.Argumen t, StreamReader)
>
While Not S.EndOfStream AndAlso Not W.CancellationP ending
S.ReadLine()
Rows += 1
Me.ssStrip.Item s(1).Text = FormatNumber(Ro ws, 0, TriState.UseDef ault,
TriState.UseDef ault, TriState.True)
Loop
>
If W.CancellationP ending Then
e.Cancel
Else
S.Close()
End If
>
End Sub
>
Note that the method it is now a Sub rather than a Function because it does
not need a return value.
>
The method loops until EndOfStream is true on the StreamReader object or
CancellationPen ding is set on the BackgroundWorke r object, whichever occurs
first.

Thanks Stephany,

I see the logic of this approach and with a bit of tweaking it works,
however I'm not to sure as to why the MSDN examples the use of re-entrant
threads. I guess there must be a reason for it, but one that escapes me for
now.

[Michel Posseth [MCP]]

Re: StackOverflowEx ception in Thread


When i write multithreaded proggy`s i use seperate methods for UI updating
now in these methods you can use invokerequired without anny problems
of reentering your worker method


regards

Michel [MCP]






"Bubba" <Bubba@discussi ons.microsoft.c omschreef in bericht
news:D7AF4CFD-985E-4CBE-873A-29B13F0C8698@mi crosoft.com...

"Stephany Young" wrote:
>

>Well, the point is that you're still calling 'yourself' recursively thus
>causing the stack to blow out.
>>
>You need to work on the 'keep it simple' principle and not turn a simple
>task into a complicated one.
>>
>Try:
>>
> Private Sub ReadHistoricalC SV(ByVal W As BackgroundWorke r, ByVal e As
>DoWorkEventArg s)
>>
> Dim Rows As Integer = 0
>>
> Dim S As StreamReader = CType(e.Argumen t, StreamReader)
>>
> While Not S.EndOfStream AndAlso Not W.CancellationP ending
> S.ReadLine()
> Rows += 1
> Me.ssStrip.Item s(1).Text = FormatNumber(Ro ws, 0,
>TriState.UseDe fault,
>TriState.UseDe fault, TriState.True)
> Loop
>>
> If W.CancellationP ending Then
> e.Cancel
> Else
> S.Close()
> End If
>>
> End Sub
>>
>Note that the method it is now a Sub rather than a Function because it
>does
>not need a return value.
>>
>The method loops until EndOfStream is true on the StreamReader object or
>CancellationPe nding is set on the BackgroundWorke r object, whichever
>occurs
>first.

>
Thanks Stephany,
>
I see the logic of this approach and with a bit of tweaking it works,
however I'm not to sure as to why the MSDN examples the use of re-entrant
threads. I guess there must be a reason for it, but one that escapes me
for
now.
>