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Hi all,
I have 2 forms (Form1 and Form2) in my app. Form1 has 2 buttons (Button1 and Button2). The Load event of Form2 has this code:
Private Sub Form2_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load<br />
Dim obj(,,) As Object<br />
ReDim obj(50, 24000, 100)<br />
End Sub<br />
When you click Button1 on Form1 this code is executed:
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click<br />
Dim obj(,,) As Object<br />
ReDim obj(50, 25000, 100)<br />
End Sub<br />
The ReDim statement gives an OutOfMemoryException. When I change the statement to
ReDim obj(50, 24000, 100)
the exception isn't thrown anymore.
When Button2 is clicked, this code is executed:
Private Sub Button2_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button2.Click<br />
For tel As Integer = 1 To 10<br />
Dim f As New Form2<br />
f.Show()<br />
Next<br />
End Sub<br />
This works just fine.
After searching the web for answers, I think it may have to do with the heap size, but I'm not sure at all.
My questions:
Why is the Button1 code giving an exception and why is this not happening when clicking Button2?
What should I do to make the Button1 code work without throwing an exception?
Skippy II
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I've got a better question. Why are you creating such MASSIVE arrays of objects?? 120,000,000+??
Just creating that many Objects, that don't do anything, in a single one of your arrays takes over a 1GB of RAM?? And you're creating at least 10 of these?? What on earth for??
BTW: I can't tell how much memory your code will use, because it ran my machine out of RAM. But I can make an educated guess that it's probably going to be around a 40 gigabytes if all of those arrays are filled with objects.
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Thanks for your reaction.
I know it doesn't make much sense to create such big arrays. At least not 10 of them. But I would like to use the idea in a grid control. The array would contain columnnumbers, rownumbers and cell properties.
Now the code provided is just an example and is not the whole project of course. It is only a simple way to explain the problem.
In fact, what I wanted to show, is that when allocating memory for 125,000,000 objects an error is thrown. But when allocating memory for 10 times 120,000,000 objects, no error is thrown at all.
I hope your "better" question is answered. 
Any idea about my questions?
Skippy II
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Skippy II wrote: In fact, what I wanted to show, is that when allocating memory for 125,000,000 objects an error is thrown. But when allocating memory for 10 times 120,000,000 objects, no error is thrown at all.
All you did was declare an array that MIGHT hold that many objects. In this case, it'll allocate pointers to Nothing, which, on a 32-bit machine, is a 4 byte value containing all 0's. So, 120,000,000 * 4 = 480,000,000 bytes will be allocated to hold 120,000,000 address that point to nowhere.
So, when you allocate one of those empty arrays, you're actually reserving 480MB of memory to hold pointers to nowhere, and when you create 10 of them, 4.8GB of RAM. Since the standard user mode address space can only handle 2GB per process and 2GB for the kernel space, BOOM - OutOfMemory. You can change the boot config of Windows so the split is 3GB for user space and 1GB for kernel, but you still won't get enough to do what you want.
AND you still haven't created the objects that these arrays will point to!
Try it:
Dim arr(50,25000,100) As Object
For a As Integer = 0 to 49
For b As Integer = 0 to 24999
For c As Integer = 0 to 99
arr(a, b, c) = New Object()
Next
Next
Next
You'll reach 1GB of RAM before you get half way through the outside loop.
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I cannot deny what you write. You're absolutely right. The idea may not be the best. But you still do not answer the questions.
Why is an error thrown when declaring an array that might hold 125,000,000 objects, but not when declaring 10 times an array of 120,000,000 items?
Skippy II
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Hi,
the array you allocate in Form2_Load() is no longer alive when Form2_Load terminates,
hence the garbage collector can reclaim it when it feels a need, such as when your next
form instance runs its Form2_Load().
Therefore your app probably never holds more than one of those huge arrays.
Luc Pattyn [Forum Guidelines] [My Articles]
this months tips:
- use PRE tags to preserve formatting when showing multi-line code snippets
- before you ask a question here, search CodeProject, then Google
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Thanks for replying, Luc. That is indeed very true. I completely overlooked this .
Do you know if there is a way to increase the available memory allocation?
Skippy II
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Hi,
Skippy II wrote: a way to increase the available memory allocation?
Don't know, I never needed anything above normal size; to me a multi-
dimensional array, or a very big one/two-dimensional array, indicate a wrong
aproach; if it takes that much memory, how long will it take to initialize, compute,
and draw conclusions from it?
Maybe this could help.[^]
Luc Pattyn [Forum Guidelines] [My Articles]
this months tips:
- use PRE tags to preserve formatting when showing multi-line code snippets
- before you ask a question here, search CodeProject, then Google
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I understand your reaction. Perhaps it is indeed a wrong approach.
But the problem is much bigger than the provided code. Actually the whole project is about creating a very fast virtual grid (a bit comparable to a virtual listview, but even a lot faster). Accessing an object array (with property values at a specific location) is way faster than accessing the regular properties. The first coding steps led to a very fast, but extremely complex way of programming (a combination of virtual and real cells in the grid). One solution is to extend the object array so every cell can be virtual. But then this OutOfMemoryException came up...
Anyway, thanks for your contribution.
Skippy II
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You can only get your hands on a total of 3GB of memory, IF you put the /3GB[^] switch in the boot.ini for Windows. There is no way to get any more, and even this technique is NOT recommened.
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Given code is not workng properly tell me in depth how to run
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What is the solution u got when u executed this code.
Or you got some errors tell me so that i can Help u out
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Ya i cannot fetch mother board serialnumber
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Thank u for ur reply ill try to find out the problem so that even i can get the knowledge of that
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Hi
I know how to create a form at runtime also know how to create any control at runtime. What I want to do is, create a form (frmtest) at runtime and then create for example a text box(text1) inside frmtest.
How do i do this?
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You can easily create forms at runtime, eg
Dim frmTest as new form
Set any attributes on that form which you want to, width, height, etc and then you can create the controls
Dim question as new textbox
Set any attributes (width, height, position, anchors, etc) and then add it to the form
frmTest.controls.add(question)
And finally show the form
frmTest.show()
Hope that helps you out a bit
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yest it did help ... thanks a lot for this.
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i'm having a groupbox which has certain collection of controls in a WINDOWS FORM instead of printing the whole form i'm in need to print the data in that particular Groupbox alone... please give me u r suggestions.....
- Thanks & Regards
kumaresh
-- modified at 7:56 Monday 15th October, 2007
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Check the following link which will show you a reply related to the query about printing a complete Form. –
http://www.codeproject.com/script/comments/forums.asp?msg=2271313&forumid=1646#xx2271313xx
This reply uses PrintToBitmap function of Form to draw it on a bitmap file and then this bitmap is printed.
Please know that same PrintToBitmap function is available for GroupBox control also.
Use this function to draw it on a bitmap object and then print this bitmap, in the same way as it is explained in the above mentioned reply.
I hope this helps . However in case of any problem let me know.
-Dave.
Dave Traister,
ComponentOne LLC.
www.componentone.com
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Hi. I have a problem with my program. My program schedules songs to play to fill every second of the day for 24 hours. It schedules everything correctly according to the rules specified for the first 8 hours if I comment out the other 16 hours.. I think the problem is that I have 48 (2 for each hour)datasets running which in turn fill 48 datagridviews all on one form. This form and datagridviews are not going to be seen as they run as a background process. My program stops responding if I try to schedule anything more than 8 hours (aka 16 datasets worth of data). After every hour scheduled I call the clear method of the 2 datasets for the hour which has been scheduled to try free up some memory but that doesn't help. Is there anything else I can try. I am running out of time before my project hand in and this is a major problem. I tried calling the datagridview.rows.clear() method to clear the datagridview for the Hour already scheduled vb.net says it can't clear the collection.? really need help here. (I can't change my code design now but for some reason if i place break points in the code it runs fine for more than 8 hours why could that be... everything is still in memory?)
Mr Oizo
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48 DataGridView controls on a form?? Don't you think that's a little excessive?? Why do you need 48 DGV's??
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Thanks for the reply Mr Kreskowiak. I changed it to just 2 datagridviews and after each hour scheduled I save to the database and dispose of any data in the dataset and rebind the dataset tables to the datagridviews again for the next hour, I repeat until each hour is scheduled and now everything works perfectly.  Have a good day
Mr Oizo
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hello friends,
i am searching to find motherboard device id i am getting information from microsoft.com that use system.win32 class and u wil find the motherboard device id but i don't know how to find it does any one know the way to find the motherboard id so tell me.?????????????????????//
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