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From: MM on 26 May 2010 07:35
I've just realised that the reason my app keeps crashing out of VB IDE
is because the duration I'm setting is zero!

I'm now testing whether the delta time = 0 and if so, setting it
arbitrarily to 5. But why the crash?

MM
From: Karl E. Peterson on 26 May 2010 12:53
MM wrote:
> I've just realised that the reason my app keeps crashing out of VB IDE
> is because the duration I'm setting is zero!
>
> I'm now testing whether the delta time = 0 and if so, setting it
> arbitrarily to 5. But why the crash?

No idea. First time I've heard that, and of course it's been over 10
years since I was inside that project so details aren't as vivid as
they once were.

Can you create a simple repro case for me to look at?

--
..NET: It's About Trust! http://vfred.mvps.org
Customer Hatred Knows No Bounds at MSFT
ClassicVB Users Regroup! comp.lang.basic.visual.misc
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From: MM on 27 May 2010 02:09
On Wed, 26 May 2010 09:53:37 -0700, Karl E. Peterson <karl(a)exmvps.org>
wrote:

>
>MM wrote:
>> I've just realised that the reason my app keeps crashing out of VB IDE
>> is because the duration I'm setting is zero!
>>
>> I'm now testing whether the delta time = 0 and if so, setting it
>> arbitrarily to 5. But why the crash?
>
>No idea. First time I've heard that, and of course it's been over 10
>years since I was inside that project so details aren't as vivid as
>they once were.
>
>Can you create a simple repro case for me to look at?

Create a new VB6 project and include Reference to CCRP High
Performance Timer. Add a label, Label1, to Form1.

Code:

Option Explicit

Implements ICcrpCountdownNotify
Private cntNotify As ccrpCountdown
Private TimeLeft As Long

Private Sub Form_Load()
TimeLeft = 3000
Set cntNotify = New ccrpCountdown
cntNotify.Interval = 100
Set cntNotify.Notify = Me
cntNotify.Duration = TimeLeft
cntNotify.Enabled = True
End Sub

Private Sub ICcrpCountdownNotify_Timer()
cntNotify.Enabled = False
DoSomething
End Sub

Sub DoSomething()
Label1 = TimeLeft
TimeLeft = TimeLeft - 1000
cntNotify.Duration = TimeLeft
cntNotify.Enabled = True
End Sub

It crashes when the Duration is set to 0.
("VB6 caused an exception 10H in module MSVBVM60.DLL")

This is running SP6.

MM
From: Karl E. Peterson on 27 May 2010 12:59
MM wrote:
> On Wed, 26 May 2010 09:53:37 -0700, Karl E. Peterson <karl(a)exmvps.org>
> wrote:
>
>>
>> MM wrote:
>>> I've just realised that the reason my app keeps crashing out of VB IDE
>>> is because the duration I'm setting is zero!
>>>
>>> I'm now testing whether the delta time = 0 and if so, setting it
>>> arbitrarily to 5. But why the crash?
>>
>> No idea. First time I've heard that, and of course it's been over 10
>> years since I was inside that project so details aren't as vivid as
>> they once were.
>>
>> Can you create a simple repro case for me to look at?
>
> Create a new VB6 project and include Reference to CCRP High
> Performance Timer. Add a label, Label1, to Form1.
>
> Code:
>
> Option Explicit
>
> Implements ICcrpCountdownNotify
> Private cntNotify As ccrpCountdown
> Private TimeLeft As Long
>
> Private Sub Form_Load()
> TimeLeft = 3000
> Set cntNotify = New ccrpCountdown
> cntNotify.Interval = 100
> Set cntNotify.Notify = Me
> cntNotify.Duration = TimeLeft
> cntNotify.Enabled = True
> End Sub
>
> Private Sub ICcrpCountdownNotify_Timer()
> cntNotify.Enabled = False
> DoSomething
> End Sub
>
> Sub DoSomething()
> Label1 = TimeLeft
> TimeLeft = TimeLeft - 1000
> cntNotify.Duration = TimeLeft
> cntNotify.Enabled = True
> End Sub
>
> It crashes when the Duration is set to 0.
> ("VB6 caused an exception 10H in module MSVBVM60.DLL")
>
> This is running SP6.

Huh. Weird. Easy enough to repro, thanks.

So help me understand the goal, here. You want to have a series of
events, occuring at a decreasing interval?

I'm having trouble understanding why you're setting a duration of zero.

Odds are, this one is going to have the answer, "Don't do that." There
always were "issues" with resetting those properties during an event
callback. That was one of the prime reasons I've considered opening
the source up to public scrutiny, and seeing if a better implementation
might occur to anyone.

--
..NET: It's About Trust! http://vfred.mvps.org
Customer Hatred Knows No Bounds at MSFT
ClassicVB Users Regroup! comp.lang.basic.visual.misc
Free usenet access at http://www.eternal-september.org


From: MM on 27 May 2010 15:08
On Thu, 27 May 2010 09:59:56 -0700, Karl E. Peterson <karl(a)exmvps.org>
wrote:

>MM wrote:
>> On Wed, 26 May 2010 09:53:37 -0700, Karl E. Peterson <karl(a)exmvps.org>
>> wrote:
>>
>>>
>>> MM wrote:
>>>> I've just realised that the reason my app keeps crashing out of VB IDE
>>>> is because the duration I'm setting is zero!
>>>>
>>>> I'm now testing whether the delta time = 0 and if so, setting it
>>>> arbitrarily to 5. But why the crash?
>>>
>>> No idea. First time I've heard that, and of course it's been over 10
>>> years since I was inside that project so details aren't as vivid as
>>> they once were.
>>>
>>> Can you create a simple repro case for me to look at?
>>
>> Create a new VB6 project and include Reference to CCRP High
>> Performance Timer. Add a label, Label1, to Form1.
>>
>> Code:
>>
>> Option Explicit
>>
>> Implements ICcrpCountdownNotify
>> Private cntNotify As ccrpCountdown
>> Private TimeLeft As Long
>>
>> Private Sub Form_Load()
>> TimeLeft = 3000
>> Set cntNotify = New ccrpCountdown
>> cntNotify.Interval = 100
>> Set cntNotify.Notify = Me
>> cntNotify.Duration = TimeLeft
>> cntNotify.Enabled = True
>> End Sub
>>
>> Private Sub ICcrpCountdownNotify_Timer()
>> cntNotify.Enabled = False
>> DoSomething
>> End Sub
>>
>> Sub DoSomething()
>> Label1 = TimeLeft
>> TimeLeft = TimeLeft - 1000
>> cntNotify.Duration = TimeLeft
>> cntNotify.Enabled = True
>> End Sub
>>
>> It crashes when the Duration is set to 0.
>> ("VB6 caused an exception 10H in module MSVBVM60.DLL")
>>
>> This is running SP6.
>
>Huh. Weird. Easy enough to repro, thanks.
>
>So help me understand the goal, here. You want to have a series of
>events, occuring at a decreasing interval?
>
>I'm having trouble understanding why you're setting a duration of zero.

This happened during development of an app. I'd expect the Duration
(if set to 0 or minus) to throw a runtime error, but not crash the
IDE.

>Odds are, this one is going to have the answer, "Don't do that." There
>always were "issues" with resetting those properties during an event
>callback. That was one of the prime reasons I've considered opening
>the source up to public scrutiny, and seeing if a better implementation
>might occur to anyone.

What I'm doing is to take a subtitle file and calculate the delta
times between subtitles. My current workround is to test each delta
time and, if zero, set it to 5 (milliseconds). These are the deltas
between display of subtitles for a movie. (Not every subtitle file was
created pristine by its originator!) I've also added a function to
check the integrity and watch for this kind of error (where subtitles
overlap [which they shouldn't]). So it's not a deal-breaker.

However, I'd expect the CCRP part to throw a trappable error, not barf
uncontrollably... ;)

Thanks for your feedback.

MM
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