VS/VC++ Struct Member Alignment (set to 4)?

I would like to ask why Struct Member Alignement is set to 4 instead to Default (or 8 on x64)?
(in Visual Studio 2008 - Project properties ( -> Configuration properties) -> C/C++ -> Code Generation -> Struct Member Alignment)
There were runtime problems after linking with an external library (default alignment); so it might be better to change the skeleton template in SDK.
For example in After Effects CS5 SDK for windows in:
after_effects_cs5_sdk_win\Adobe After Effects CS5 Win SDK\Examples\template\Skeleton\win\Skeleton.vcproj
look for:
StructMemberAlignment="3"
and set it to 0 (default) or at least to 4 (64bit alignment)
StructMemberAlignment="0"
or
StructMemberAlignment="4"
greets
m

Hi Mike,
I believe you're correct, thanks for pointing that out. These projects had been brought forward from the CS4 versions, which were 32-bit, and used 4-byte alignment at the time. Fortunately, the standard headers include PreConfig.h, which sets 8-byte alignment for the AE API structure definitions. But it makes sense to no longer set 4-byte alignment in the vcprojs.
Cheers,
Zac

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Dll struct member alignment

I need information about the struct member alignment setting when compiling DLLs for use with LabVIEW. In my DLL, I also make function calls to a rendering library, VTK, that was compiled with 8 byte alignment. My DLL will only work if compiled with 8 byte alignment. If I compile it with 1 byte, I get obvious bad struct alignment issues and functions that perform deep copies to struct members cause fatal memory errors, which makes sense. But I'm confused since the LabVIEW documentation says that the struct member alignment should be set to 1 byte for all projects.
So why does it work with 8 byte?
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Lou 83 wrote:
I need information about the struct member alignment setting when compiling DLLs for use with LabVIEW. In my DLL, I also make function calls to a rendering library, VTK, that was compiled with 8 byte alignment. My DLL will only work if compiled with 8 byte alignment. If I compile it with 1 byte, I get obvious bad struct alignment issues and functions that perform deep copies to struct members cause fatal memory errors, which makes sense. But I'm confused since the LabVIEW documentation says that the struct member alignment should be set to 1 byte for all projects.
So why does it work with 8 byte?
Am I taking a risk by using 8 byte?
If I only make calls to the 8 byte compiled library then is it even an issue?
Should I compile the rendering library with 1 byte so that I can compile my DLL with 1 byte as well?
Are LabVIEW CIN functions compiled with 1 byte; is that the reason?
I guess I just need to know why DLLs for LabVIEW should be compiled with 1 byte alignment and if this rule can be bent.
Any information is greatly appreciated.
thank you,
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Rolf Kalbermatter
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a division of Test & Measurement Solutions

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Hello,
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Hello Millie1177,
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SS9 CC5.6 compiler bug - algorithm count confused with struct member

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CC: Sun C++ 5.6 2004/07/15
#include <algorithm>
using namespace std;
struct A {
int count;
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This bug has been fixed in the C++ 5.6 compiler. I'm not sure if the fix is in the first patch which is about to be released. If not, the fix definitely will be in the next patch.
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Avoiding struct member padding in C

Hello,
The following is a very simple structure, the hand calculated size of which is 6.
On solaris we know that members are padded to word, byte boundaries for better performance.
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struct phone
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Any compilation facility would be very helpful.
Any pointers that you feel relevant can make a big difference.
Thanking in advance for the help

A couple of things. Unless your structures are unique enough so that different packing is required for each structure, you can use the pack pragma since it holds for the entire file. In other words, a single pack pragma at the beginning of a file effects all the structures from that point on. So, you don't necessarily have to put a different pragma on each structure definition.
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Paper alignment set up

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Hi @JKLP ,
I see that you are experiencing issues with the paper feed when trying to do the alignment on the new printer. You are getting a message to 'load plain paper'. I would like to help you resolve this issue.
Make sure the printer is connected directly to a wall outlet. (don't use a power hub or a surge protector) This ensures the printer is receiving full power and may help this situation.
Please take a look at this document to see if it will help.
An 'Out of Paper' Message Displays on the Control Panel and the Printer Does Not Pick Up Paper.
If you need further assistance, just let me know.
Have a great day!
Thank You.
Please click “Accept as Solution ” if you feel my post solved your issue, it will help others find the solution.
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64 bit Illustrator CS6 plug-in - CSXSEvent bad pointers

Hi
I am having difficulty with a x64 bit compile of our plug-in with regards to PlugPlug events dispatched from Flash panels. Under 32bit operation, all seems to be fine. XML is dispatched from Flash and it received without problem in the C++ plug-in. However under 64bit architecture, the CSXSEvent is received with invalid pointers. Here's the data received:
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I'm not doing anything special from Flash, this works fine under CS6 x32:
 protected function btnLogin_clickHandler(event:MouseEvent):void
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Any help appreciated, or pointers of where I should look or have gone wrong.
Thanks

Hi
I have managed to resolve the issue. Here's what I found if it is of any interest to anyone else. I noticed that the event.data bytes were reversed (big/little endian order?). I managed to hack it by reversing the bytes by shifting the bits left and right (event.data << 32 | event.data >> 32). That actually displayed the XML from the Flash panel!
However the dispatch still did not work.
I looked deeper into the CS6 sample FreeGrid and noticed that the "Struct Member Alignment" on the project was set to 8 bytes (/Zp8). The settings on my project was actually set to 4 bytes (/Zp4). On changing that to 8 byte alignment, suddenly all functionality returned back to normal. I'm not sure how PlugPlug was sending the data through, but seemed it was coming into the CSXSEvent structure incorrectly.
Not sure if this was a silly mistake on my part, but the 32 bit version has been happily working for quite a while now.
I've been using Visual Studio 2008 btw.
Thanks

For Experts: Why does LabView cause System reboot while accessing hardware with driver?

Hello NI Developers!
I use LabView 7.1 under Windows XP
I have a programm console application which accesses through Jungo Windriver PCI-E board.
This program works fine - and performs DMA data transfer between PC and Board's memory.
In order to implement this console application work together with LabView I did following:
1) Added this function inside the source:
_declspec(dllexport) void LVMainFunction(uInt32 *IntValue);
_declspec(dllexport) void LVMainFunction(uInt32 *IntValue)
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                                    // so we are able to see "printf" outputs
   freopen("CONIN$","a+",stdin);    //redirec standard input stream to current window so
                                    // so we are able pass inputs from keyboard
   main();                          //Call applications main function which does all the work
2) Compiled this new source as DLL library
3) Call LVMainFunction(...) function from LabView using Call Library Node
In the result: Executing VI - opens new console window, shows debug outputs and receives keyboard inputs.
It works fine till the last function, which perform DMA data transfer - and reboots PC.
1) Why does this happen?
2) I understand that opening console from Call Library Node, attaches together this console window and running VI. So If I close one of them - both windows closes.
   So does LabView have somekind of restrictions of accessing Hardware's functions?
I can read Board's resource information and view size of memory on board, interrupt functions and other information about device, but when I try to reach
DMA my system reboots. And I understand that this should be some kind of LabView problem, cause I tried different implementations, even without use of
console window - and the result is the same.
3) Should I split the program in to two separate processes and perform data exchange using Sockets or Pipes techology?
Thank you in advance!
ACiDUser
Message Edited by ACiDuser on 11-13-2008 09:37 AM

Hello!
At LAST!!!
I solved this problem!
From the beginning I was following National Instruments manual on how to build DLL with external IDE:
http://zone.ni.com/reference/en-XX/help/371361A-01/lvhowto/building_library_project/
Set the Struct member alignment control to 1 Byte.
Now this option caused my PC to reboot!
So could someone explain why this happened? and If it is a bad tip, so it's better to remove from manual. Then other people will not have such problems as I did
- wasting 2 monthes of time determining the problem.
I changed it to Set the Struct member alignment control to DEFAULT.
and now everything works fine.
Regards
Message Edited by ACiDuser on 11-13-2008 11:14 AM

Stack corrupted around CNiPointers

Hi,
I'm trying to convert a Measurement Studio project from 6.0 to 8.1.1 for Visual Studio 2005. It's a LabView callable DLL which uses UI components. When I run it in debug mode I get numerous Run-Time Check Failures saying that the stack is corrupted around local CNiPointers objects. I also get corruption of locals on the stack near calls to CNiGraph::GetAxes() and GetPlots(). One common thing among all the problem areas is the use of .Item() on objects of type CNiPointers, CNiAxes, and CNiPlots. In release mode I have also seen evidence of stack corruption in those areas.
Is there a problem with those NI classes or do I have some project setting wrong?
Thanks.
Claus

Hi, Jonathon,
Thanks for the quick response. I am happy to give you more info, including tests I've done already, and to try your suggestions. Here are anwers to your points:
- Yes, everything worked fine in 6.0. When it came time to upgrade, I first tried to build it under Visual Studio 2005 with the original Meas. Studio 6.0 headers and libs but it wanted to link the old MFC libs and could not find them. So I installed Meas. Studio 8.1.1 (I was afraid to install 8.1.2 from the December CD set because of "risk of bodily injury") and deleted the old headers and libs from the project. It recompiled and linked just fine.
- Yes, the stack corruption breakpoints happened the first time I ran in debug mode. When I turned off the stack checker, I got some bogus failures warning of using uninitialized variables. I say "bogus" because when I step through the code, the variables are clearly initialized. I suspect that the unchecked stack corruption is confusing the variable checker. When I turned that off as well, the debug code worked correctly. However, the release build still failed. I added some tracing dumps to the release build and saw that a local variable called "bRet" was being clobbered by this unrelated line of code:
m_graph.GetAxes().Item(1).SetMinMax(m_dXAxisMin, m_dXAxisMax);
but only in release mode - the debug build did not change the value of bRet! I took that as more evidence of stack corruption.
- Yes, the stack check breakpoints always occur in the three places I mentioned in the first post and the release mode failure always occurs as above (given the same app test conditions). Another interesting test result is that, if I turn on speed optimization, then the release build does not fail as above. Rather, it causes the LabView app to abruptly exit completely without any dialog or warning!
- I will try to build and run a similar NI example. If that works fine, I'll try to strip down my project and demonstrate the failure.
- The error says "Run-Time Check Failure #2 - Stack around the variable 'pointers' was corrupted." The local variable declaration is:
CNiPointers pointers = m_sliderWnd.GetPointers();
If I stick a "return;" just after that line, I get the same message but if I put "return;" just before that line, I get no error there!
- I am calling the debug DLL from LabView. And the debug DLL is calling release builds of the Meas. Studio libraries. Is there any way to link in debug versions of these libs? It would be great to step through some of the NI code (at least the top, non-proprietary layers) like you can with MFC libraries.
So I hope you can see why I suspect true stack corruption within the calls into those NI classes. Maybe I have some build setting wrong. This project was automatically converted by Visual Studio 2005 from the old one. I also tried creating a new Meas. Studio project and compared its settings with mine. I then changed some of my settings to match but to no avail. The only one I did not change was the "Struct Member Alignment". The new project used "8 Bytes" but mine requires "1 Byte" because it must parse LabView arrays and clusters.
Thank you for your attention.
Claus

Vertical alignment is middle regardless of setting

Running LiveCycle Designer ES 8.2 and Adobe Acrobat Pro 9 on Windows 7.
I'm designing a form with many text fields. Most of them work great. However, I several text fields--some standalone, some table cells--where the vertical alignment of the user-entered value always shows as middle.
For example, this text field has the vertical alignment set to bottom, using the paragraph pallette:
This is the same field with the alignment set to top:
And this is the same field again, with the alignment set to middle:
You will notice that they all look the same--always middle. I'm able to set the caption alignment fine, and I'm aware of the way to distinguish between adjusting the caption and value properties in the paragraph pallette.
I can't determine any pattern as to why some of my text fields align fine according to the settings I specify, and some of them are always, always middle-aligned.
Are there any other settings or conditions which may be overriding my alignment settings for these specific fields?
It first started happening with table cells, so I assumed some table setting was causing the problem (although I never found it). Once standalone text fields started doing it too, though, I was extra stumped.
I am able to adjust all the horitzonal alignment settings fine. I have tried deleting the offending cells and starting from scratch, but it hasn't helped.
Any suggestions or help would be appreciated!
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Setting Vertical alignment

I know how to set vertical alignment in a Microsoft Word document.
I have been unable to find out how to do the same thing in Pages '08.
I know it has to be there because if I open a document in Pages that was created with Microsoft Word that has vertical alignment set to center it is recognized by Pages.
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I do not think it is available through the UI. The way to add vertical alignment to a page is to copy a page from a converted Word document and paste it to your Pages document.
It does not seem like Pages XML is currently fully documented, even though it has been claimed to be. I thought it would be here but that is not for the current version, and it is incomplete.
I would guess it is this kind of information:
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Custom Table Cell Renderer Unable To Set Horizontal Alignment

Hello,
I have a problem that I'm at my wit's end with, and I was hoping for some help.
I need to render the cells in my table differently (alignment, colors, etc) depending on the row AND the column, not just the column. I've got this working just fine, except for changing the cell's horizontal alignment won't work.
I have a CustomCellRenderer that extends DefaultTableCellRenderer and overrides the getTableCellRendererComponent() method, setting the foreground/background colors and horizontal alignment of the cell based on the cell's value.
I have a CustomTable that extends JTable and overrides the getCellRenderer(int row, int column) method to return a private instance of this CustomCellRenderer.
This works fine for foreground/background colors, but my calls to setHorizontalAlignment() in the getTableCellRendererComponent() seem to have no effect, every cell is always displayed LEFT aligned! It's almost like the cell's alignment is determined by something else than the table.getCellRenderer(row,column).getTableCellRendererComponent() method.
I've also tried setting the renderer for every existing TableColumn in the TableModel to this custom renderer, as well as overriding the table's getDefaultColumn() method to return this custom renderer as well for any Class parameter, with no success.
No matter what I've tried, I can customize the cell however I want, EXCEPT for the horizontal alignment!!!
Any ideas???
Here's the core custom classes that I'm using:
class CustomTable extends JTable {
private CustomRenderer customRenderer = new CustomRenderer();
public CustomTable() {
super();
public TableCellRenderer getCellRenderer(int row, int column) {
return customRenderer;
} // end class CustomTable
class CustomRenderer extends DefaultTableCellRenderer {
public CustomRenderer() {
super();
public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
super.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column);
if (row % 2 == 0) {
setForeground(Color.red);
setHorizontalAlignment(RIGHT);
} else {
setForeground(Color.blue);
setHorizontalAlignment(LEFT);
return this;
} // end class CustomRenderer
Even worse, I've gotten this to work fine in a trivial example I made to try and re-create the problem. But for some reason, this same thing is just not working for horizontal alignment in my actual project?!?
Anyone have any ideas how the cell's horizontal alignment set in the getTableCellRendererComponent() method is being ignored or overwritten before the cell is being displayed???
Thanks, any help is appreciated,
-Alex Blume

Ok, so I've looked into their source and I think I know where and what the trouble is. The JTable.java has a method called:
3658> public TableCellRenderer getCellRenderer(int row, int column) {
3659> TableColumn tableColumn = getColumnModel().getColumn(column);
3660> TableCellRenderer renderer = tableColumn.getCellRenderer();
3661> if (renderer == null) {
3662> renderer = getDefaultRenderer(getColumnClass(column));
3663> }
3664> return renderer;
3665> }
starting at line 3658 of their source code. It retrieves the TableCellRenderer on line 3660 by calling the tableColumn's getCellRenderer method. This is found in the TableColumn.java class:
421> public TableCellRenderer getCellRenderer() {
422> return cellRenderer;
423> }
See the problem? Only ONE cell Renderer. It's referring to a variable found at line 140 which is of type TableCellRenderer ... well actually it's created as a DefaultTableCellRenderer at some point since TableCellRenderer is an interface.
Basically the fix is this:
In the TableColumn.java file, a collection (Vector, LinkedList, whatever) needs to keep track of each cell's renderer. This will solve the solution. Of course this will be something that you or I can make.
What's funny is the contradiction in documentation between JTable's and TableColumn's getCellRenderer() method. First, if we look at TableColumn's documentation it states:
"Returns the TableCellRenderer used by the JTable to draw values for this column."
Based on that first statement, the getCellRenderer() method in TableColumn is doing its job exactly. No lies, no contradictions in what it does.
However, that method is called up inside of the JTable's getCellRenderer() method which says a completely different thing which is:
"Returns an appropriate renderer for the cell specified by this row and column."
Now we have a problem. For the cell specified. It appears that the rush to push this out blinded some developer who either:
1) mis-interpreted what the JTable getCellRenderer() method was supposed to do and inadvertently added a feature or;
2) was in a 2 a.m. blitz, wired on Pepsi and adrenalin and wrote the bug in.
Either way, I'm really hoping that they'll fix this because it will take care of at least 2 bugs. Btw, anyone interested in posting a subclass to solve this problem (subclass of TableColumn) is more than welcome. I've spent much too much time on this and my project is already behind so I can't really afford any more time on this.
later,
a.

How to pass a struct to a DLL function and accessing it in another VI

Hi friends,
                   I am new to labview. I need to create a demo program in labview ,for displaying image from our own image capturing system. We have a DLL ( build in VC++) containing functions for capturing image from our system. Now I need to create a VI library for some of functions in DLL and Create a Demo program using those created subvi library . I used "Call Function node" and created some of subvi's.
Some of our DLL functions need to pass struct pointers. Our function prototype will be similar to the following function.
__declspec(dllexport) int __stdcall Initialize( unsigned char *imagebuffer,struct config *Configuration);
The passed struct is similar to
struct config
double                val1[3];
unsigned short   val2;
bool                    val3;
bool                    val4[3];
unsigned char    val5;
unsigned char   val6[3];
bool                    val7[26];
For passing "unsigned char *imagebuffer" I initialized array with "Numeric constant " and set the size of the array and send to the function.
The problem here is, I used this array in one of the subvi.
How can I use the returned imagebuffer array in my main demo program. How to connect the image array to subvi "Connecter Pane"
And which control can I use to display the image. The image data I get is form of 1-D Array .
The second problem is,
   For passing the structure, I used "Bundle " and filled the bundle with all the datatypes as in my struct and passed to the function. Is it correct ? How to access this bundle after returned from function in another Vi. ie.) How to connect this bundle to the connter pane ?
Thanks for your valuable suggestions.
aajjf.
Message Edited by aajjf on 04-19-2007 05:34 AM

aajjf wrote:
Hi friends,
                   I am new to labview. I need to create a demo program in labview ,for displaying image from our own image capturing system. We have a DLL ( build in VC++) containing functions for capturing image from our system. Now I need to create a VI library for some of functions in DLL and Create a Demo program using those created subvi library . I used "Call Function node" and created some of subvi's.
Some of our DLL functions need to pass struct pointers. Our function prototype will be similar to the following function.
__declspec(dllexport) int __stdcall Initialize( unsigned char *imagebuffer,struct config *Configuration);
The passed struct is similar to
struct config
double                val1[3];
unsigned short   val2;
bool                    val3;
bool                    val4[3];
unsigned char    val5;
unsigned char   val6[3];
bool                    val7[26];
For passing "unsigned char *imagebuffer" I initialized array with "Numeric constant " and set the size of the array and send to the function.
The problem here is, I used this array in one of the subvi.
How can I use the returned imagebuffer array in my main demo program. How to connect the image array to subvi "Connecter Pane"
And which control can I use to display the image. The image data I get is form of 1-D Array .
The second problem is,
   For passing the structure, I used "Bundle " and filled the bundle with all the datatypes as in my struct and passed to the function. Is it correct ? How to access this bundle after returned from function in another Vi. ie.) How to connect this bundle to the connter pane ?
Thanks for your valuable suggestions.
aajjf.
Message Edited by aajjf on 04-19-2007 05:34 AM
You say nothing about how your cluster looks but I'm afraid you did the standard error here and placed arrays in it. That is not what the C structure is representing for several reasons.
First fixed size arrays in C are inlined inside a structure, so are not a pointer but for the case of your val1 element three doubles.
Second although not relevant here because of above point: LabVIEW arrays are not the same as C arrays. LabVIEW uses a pointer to a pointer and has the size of the array in elements prepended to the array data. C simply uses a pointer and all the rest is the programmers sorrow. The Call Library Node does convert the top level element of variables you pass according to the type configuration of that parameter but does no conversion of internal elements at all. So passing clusters with anything like arrays or strings is always wrong unless the DLL is aware of the specific datatypes LabVIEW uses.
Last but not least you can end up with alignment issues. Elements in structures are aligned by every C compiler to a certain value. This value can be defined by the programmer in the project settings or for Visual C through #pragma pack() statements in the C code. The alignment rule says that an variable is aligned to the smaller of the two values that are either a multiple of the variable element size or the alignment setting. Most 32bit code nowadays uses 8 bit default alignment but LabVIEW always uses 1 byte. In your case there is nothing to observe since the large variables are at the beginning. Otherwise you might have had to insert filler elements in the LabVIEW cluster.
One last thing bool is a C++ type only. Its size is 1 byte and incidentially this is the same LabVIEW uses for Booleans.
Rolf Kalbermatter
Rolf Kalbermatter
CIT Engineering Netherlands
a division of Test & Measurement Solutions

VS/VC++ Struct Member Alignment (set to 4)?

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