C / C++ / MFC

Matthew Faithfull19-Sep-07 1:03

Matthew Faithfull

19-Sep-07 1:03

OK. _aligned_malloc is a memory allocation function in the Visual C Runtime, MSVCRT*.dll.
It isn't usually called directly although I think it is exported. _aligned_free is the matching memory deallocation function. You need to check your project settings for which CLibrary/CRuntime you're using and look at the code to see whether it's using new or malloc or calloc or calling _aligned_malloc directly. Then you may need to add a #include or two. It's difficult to give you more details without knowing which Visual Studio version you're using and closely examining the sample.

Nothing is exactly what it seems but everything with seems can be unpicked.

bosfan19-Sep-07 1:08

bosfan

19-Sep-07 1:08

Hello,
thanks for assertion, i use VS6 and my sample is from msdn, link to the site is in my first post!

regards!
termal

Matthew Faithfull19-Sep-07 1:31

Matthew Faithfull

19-Sep-07 1:31

Hmm I'm confused now, The message that turned up in my email is not the message you posted here?!?

Hi,
i change the original line with _aligned_malloc:
pListHead = (PSLIST_HEADER)_aligned_malloc(sizeof(SLIST_HEADER), MEMORY_ALLOCATION_ALIGNMENT);
to:
pListHead = (PSLIST_HEADER)malloc(MEMORY_ALLOCATION_ALIGNMENT);

and i dont have errors! [confused]

regards
termal

Anyway you'll need to change that to
pListHead = (PSLIST_HEADER)malloc( sizeof(SLIST_HEADER) );
or you certainly will get errors when you run it. The original problem may be that _aligned_malloc is no longer exported from the Visual C Runtime, or it might require you to add an addtional include over and above memory.h e.g. #include <dbg.h> from the C Library source. Either way I wouldn't recommend calling _aligned_malloc directly from your code as it's intended to be an internal function. It will get called from malloc anyway, at least in debug mode, several levels down. If you installed the C Library source code along with VC++ 6 you can step into the malloc call in the debugger and marvel at the amount of stuff that happens just to get you a few bytes of memory to play with. Enjoy.

Nothing is exactly what it seems but everything with seems can be unpicked.

bosfan19-Sep-07 3:06

bosfan

19-Sep-07 3:06

Hello,
yes you have right, i delete my previous message because is wrong, i change it like you said!

regards
termal

Randor 19-Sep-07 1:39

Randor

19-Sep-07 1:39

To use _aligned_malloc() with Visual Studio 6 you will need to download and install the Microsoft Platform SDK.

http://www.microsoft.com/downloads/details.aspx?familyid=0BAF2B35-C656-4969-ACE8-E4C0C0716ADB[^]

Side Note: The aligned memory allocation functions are generally used for optimizing memory for MMX/SSE/SSE2 instruction usage. Although the standard size of a register is 32 bits (on 32 bit processors), not all registers are 32 bit sized. MMX registers are 64 bits wide and SSE registers are 128 bits wide. When moving, modifying or copying memory the operations are much faster when the data in memory is aligned on these boundries. Hope this helps.

Best Wishes,

-Randor (David Delaune)

Tab Control Related problem

bosfan19-Sep-07 3:09

bosfan

19-Sep-07 3:09

Hello Randor,
yes that help's me, i dont know that before!!!

With best regards
Termal

Y_Kaushik18-Sep-07 23:55

Y_Kaushik

18-Sep-07 23:55

Hi In my Modal dialog besed page. I am making a Tab control three page
but when i compile and build this application four button at the buttom of the each page display ( named Ok,Cancel,Apply,Help) . Now According to my
program requirment i need to defined action for each page .

How can i remove all four button. OR

Is it possible the there would be only two button named save and cancel and
Save button behave differently for each page.

The coding for that three page is below.

CPropertySheet property(" New Student...");

CStudentGeneral st_gen;
CStudentFee st_fee;
CStudentAdditional st_add;

property.AddPage(&st_gen);
property.AddPage(&st_add);
property.AddPage(&st_fee);

if(property.DoModal() == IDOK)
{

}

Regard's
Kaushik

nbugalia19-Sep-07 0:20

nbugalia

19-Sep-07 0:20

Following code should help -
property.AddPage(&st_fee); //Your code.
property.m_psh.dwFlags |= PSH_NOAPPLYNOW | PSH_NOCONTEXTHELP;//To remove Apply and help button.
property.SetFinishText("Save");

Y_Kaushik19-Sep-07 0:47

Y_Kaushik

19-Sep-07 0:47

Thanks for reply

Sir ji if i apply your code an error occur

error C2065: 'PSH_NOCONTEXTHELP' : undeclared identifier

I want to remove all button from here.

Regard's
Kaushik

nbugalia19-Sep-07 1:01

nbugalia

19-Sep-07 1:01

I am sorry, it was for version 5.80.

To remove all buttons, use SetWizardButtons(0);
and it should work. Good Luck Smile | :)

Y_Kaushik19-Sep-07 1:07

Y_Kaushik

19-Sep-07 1:07

Thanks sir

Regard's
Kaushik

David Crow19-Sep-07 2:50

19-Sep-07 2:50

Is your sheet a wizard (i.e., have you called SetWizardMode())?

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Nelek19-Sep-07 2:41

19-Sep-07 2:41

You can set a parameter that says which page is opened. Then switch the funcionality of your button according to the sheet.

Or

you can make more buttons (one per sheet), put specifical code in every button, and make them visible/invisible according to the actual sheet.

Greetings.

--------
M.D.V.

If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?

Help me to understand what I'm saying, and I'll explain it better to you

Wink | ;)

David Crow19-Sep-07 2:57

don't understand MSDN explanations. Can someone explain this?

19-Sep-07 2:57

In the sheet's OnInitDialog() method, you can move and hide any of the four buttons. For example:

CWnd *pWnd = GetDlgItem(ID_APPLY_NOW);
ASSERT(NULL != pWnd);
pWnd->ShowWindow(SW_HIDE);

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Nelek18-Sep-07 23:23

Re: don't understand MSDN explanations. Can someone explain this?

18-Sep-07 23:23

Hi all,

As I mentioned in another message, I have to connect my program with a PLC of Siemens. I have found a quite good DLL to do that. Now I'm reading the documentation and the examples that come with the DLL, but there are somethings that I don't understand very well and the help/tutorial is supposing a high level in plain C (that I don't reach Frown | :(

My programm is made in VC++ 6.0, I would like to have some explanations about the following things and to know if in VC++ 6.0 are needed these commands/prerrogatives.

In the header file
1)
#if defined( _MSC_VER ) && _MSC_VER > 600
#pragma pack( push, 1 )
#else
#pragma pack( 1 )
#endif

2)
#if defined( _MSC_VER ) && _MSC_VER > 600
#pragma pack( pop )
#else
#pragma pack()
#endif

These 2 blocks mean that depending on the version the parameters of those functions are different. I have taken a look in the help but I have not understood it well.

MSDN says:
push (optional)
Puts a specified packing alignment value, n, on the internal compiler stack, and sets the current packing alignment value to n. If n is not specified, the current packing alignment value is pushed.
pop (optional)
Removes the record from the top of the internal compiler stack. If n is not specified with pop, then the packing value associated with the resulting record on the top of the stack is the new packing alignment value. If n is specified, for example, #pragma pack(pop, 16), n becomes the new packing alignment value. If you pop with identifier, for example, #pragma pack(pop, r1), then all records on the stack are popped until the record with identifier is found, and that record is popped and the packing value associated with the resulting record on the top of is the stack the new packing alignment value. If you pop with an identifier that is not found in any record on the stack, then the pop is ignored.

But... wtf does it mean? D'Oh! | :doh:

In the *.cpp
1) #define WIN32_LEAN_AND_MEAN // we don’t need all specifications Confused | :confused:

2) __cdecl

A decent explanation will be very wellcome.

Thanks

toxcct18-Sep-07 23:35

toxcct

18-Sep-07 23:35

this 2 block will delimit every 1-Byte-aligned structs/classes/unions between the pack and the pop.

the subtlty is in the syntax understood by the compiler.

#if defined( _MSC_VER ) && _MSC_VER > 600 searches if the version of the compiler is higher that Visual C++ 6. if so, it tells to the compiler to user the 1 byte alignment with #pragma pack( push, 1 ). but it the compiler is more recent #pragma pack( 1 ) is sufficient. Same applies to the #pragma pop syntax.
you have to know that the compiler manages such alignments with a stack of integers. the current alignement is the integer at the top of the stack. but at any time, you can add a new value (push), or remove some (pop)...

[VisualCalc][Binary Guide][CommDialogs] | [Forums Guidelines]

Didn't explain myself good

Nelek19-Sep-07 0:35

Re: Didn't explain myself good

19-Sep-07 0:35

Hi toxcct,

First of all... Thanks for your answer.

But the problem was not with the version of compiler.

The things that I didn't understand are the pragma pack (...), the WIN32_LEAN_AND_MEAN and the __cdecl

Anyways thanks.

toxcct19-Sep-07 1:49

toxcct

19-Sep-07 1:49

as explained in the MSDN, "When WIN32_LEAN_AND_MEAN is defined, a large number of header files are deliberately excluded by windows.h". read here[^] for a short brief.

for the __cdecl, this is what we name a "calling convention".
a calling convention is for the compiler to which of the caller or the callee is to clean the call stack.
I explain myself. when you call a function, a call stack is implicitely created to push the parameters and some extra informations such as the execution pointer. but once the function called ended its process, the memory then allocated has to be freed. such a memory can me cleaned by either the caller or the callee, but the important point here is that BOTH must accort themselves to use the same convention (imagine the leak if none is freeing the memory, or the disaster if both are cleaning a one and only memory place).

that is, several calling convention exist such like __cdecl, __stdcall, __fastcall, __thiscall...
google/MSDN can help you more than me for sure.

[VisualCalc][Binary Guide][CommDialogs] | [Forums Guidelines]

Re: Didn't explain myself good

Nelek19-Sep-07 2:08

Re: don't understand MSDN explanations. Can someone explain this?

19-Sep-07 2:08

I already was tin MSDN and didn't understand it well. With your explanation I can now imagine some things. I will make my own try-errors to check if I have got it. Thanks

David Crow19-Sep-07 3:04

Re: don't understand MSDN explanations. Can someone explain this?

19-Sep-07 3:04

Are you not understanding stacks (e.g., pushing and popping), or byte alignments?

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Nelek19-Sep-07 20:28

Re: don't understand MSDN explanations. Can someone explain this?

19-Sep-07 20:28

Also...

In a simple mode with a comparison: The stack is a box with two doors, where the allocation of the memory are packets incoming through the "push" side, then the cpu use the info that is inside (like toxcct said, the pointer to an application that is running to have access or communication). Once the information is not needed anymore, then the box is discharged through the "pop" side to let the box containing new usefull things. If the box is overloaded, an error comes and the things doesn't work fine anymore.

about the bytes alignment... Maybe is a problem of language, but I can not relate the term with anything logical.

For me is like:

----Byte----
----Byte---- They are aligned

-Byte-------
------Byte-- They are not aligned

David Crow20-Sep-07 2:42

Re: don't understand MSDN explanations. Can someone explain this?

20-Sep-07 2:42

Using your analogy, a stack would only have one door, whereas a queue would have two doors. A stack gets items pushed and popped from the same end. A queue gets items pushed onto one end and popped from the other end.

"A good athlete is the result of a good and worthy opponent." - David Crow

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Nelek20-Sep-07 4:12

Re: don't understand MSDN explanations. Can someone explain this?

20-Sep-07 4:12

Ahmm, ok

then it can happen like in the step7. If one programmer opens/calls a lot of different functions/processes, without closing the previous ones... there must be a moment where the stack overflows and then the programm/cpu crashes.

What about the bytes alignment? Was I right?

What I still don't understand (sorry if I ask a lot) is what a relation has the alignment of the Bytes with the question of the stack.

If the Bytes of a stack are pushed and popped through the same entry... with what should to be aligned?

David Crow20-Sep-07 4:30