Re: Windows XP Memory allocation questions - C / C++ / MFC Discussion Boards

David Crow13-Sep-07 17:24

13-Sep-07 17:24

Then you've obviously done something else wrong, as Michael's suggestion is correct. How are you verifying that it does not work?

"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

Re: Convert DWORD_PTR back to my object

carrivick13-Sep-07 19:29

carrivick

13-Sep-07 19:29

I'm guessing you are getting cannot convert DWORD_PTR to Instrument *.

Oh and allways try and use eplicit casting i.e. static_cast rather than C-Style casts.

Try this

Instrument *instObject = static_cast<Instrument *>((static_cast<void *>(treeCtrl->GetItemData(hItem))));

or if not

Instrument *instObject = dynamic_cast<Instrument *>((dynamic_cast<void *>(treeCtrl->GetItemData(hItem))));

Could you copy the exact compiler error into the thread.

Re: Convert DWORD_PTR back to my object

Michael Dunn13-Sep-07 22:13

Michael Dunn

13-Sep-07 22:13

reinterpret_cast is the right one for this situation, since you're converting between a pointer and a non-pointer type.

--Mike--
Visual C++ MVP Cool | :cool:

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Re: Convert DWORD_PTR back to my object

paresh_joe13-Sep-07 19:41

paresh_joe

13-Sep-07 19:41

oh sorry its working now ... it was my mistake ...

Thanks a lot ... Big Grin | :-D

Windows XP Memory allocation questions

Budric B.13-Sep-07 5:34

Budric B.

13-Sep-07 5:34

Hi,
in the process of running my program is allocating a lot of memory (gigabytes). After it reaches a certain size strange things start to happen so I'm trying to debug it. I have some questions.

1. To my surprise new operator does not return NULL on error. It seems to throw an exception. When did this happen? What's the exception object? I'm using VS 8.

2. Is new a thread safe operator? What if I'm using some libraries that most likely use malloc. Is memory allocation still thread safe? I'm using dynamic link run time for my program and hopefully all the libraries. If some library is using a different run-time but I don't free its memory is that fine?

3. What is the memory allocation limit for a process in Windows XP? Is it 2 GB? Or RAM + swap space?

4. Any free GUI profilers out there?

Thanks for your help.

Re: Windows XP Memory allocation questions

Mark Salsbery13-Sep-07 6:01

Mark Salsbery

13-Sep-07 6:01

Budric B. wrote:
To my surprise new operator does not return NULL on error. It seems to throw an exception. When did this happen?

I thought it was a lot longer ago, but according to the docs:

"In Visual C++ .NET 2002, the new function in the Standard C++ Library will support
the behavior specified in the C++ standard, which is to throw a std::bad_alloc exception
if the memory allocation fails.

In Visual C++ 2005, the C Runtime Library's new function will also throw a std::bad_alloc
exception if the memory allocation fails.

If you still want the non-throwing version of new for the C Runtime Library, link your program
with nothrownew.obj. However, when you link with nothrownew.obj, new in the Standard C++
Library will no longer function."

Budric B. wrote:
2. Is new a thread safe operator?

In the Multithread CRT, Yes. Any third-party library, well...

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Re: Windows XP Memory allocation questions

Waldermort13-Sep-07 6:16

Waldermort

13-Sep-07 6:16

Sounds to me like you have some serious memory leakage. Make sure you call delete on every time you allocate using new.

Try this[^] utility, it's excellent for finding leaks.

As for your questions:
1. use try catch blocks.
2. yes.
3. Usually RAM, but not too sure...
4. www.google.com

Waldermort

Re: Windows XP Memory allocation questions

Nemanja Trifunovic13-Sep-07 6:34

Nemanja Trifunovic

13-Sep-07 6:34

Budric B. wrote:
1. To my surprise new operator does not return NULL on error. It seems to throw an exception. When did this happen? What's the exception object? I'm using VS 8.

That's the way it is supposed to work - it throws bad_alloc. If you want to get a NULL instead, use nothrow[^]

Budric B. wrote:
2. Is new a thread safe operator? What if I'm using some libraries that most likely use malloc. Is memory allocation still thread safe? I'm using dynamic link run time for my program and hopefully all the libraries. If some library is using a different run-time but I don't free its memory is that fine?

Yes. Yes. Yes.

Budric B. wrote:
3. What is the memory allocation limit for a process in Windows XP? Is it 2 GB? Or RAM + swap space?

In practice, less then 2GB[^] (BTW, who would vote down that text and why Confused | :confused:

)

Budric B. wrote:
4. Any free GUI profilers out there?

Try GlowCode.

Programming Blog
utf8-cpp

Re: Windows XP Memory allocation questions

Budric B.13-Sep-07 7:41

Budric B.

13-Sep-07 7:41

thanks for the heads up on the flag, I'll try it with my code.

Database Embedding

perrin486913-Sep-07 5:12

perrin4869

13-Sep-07 5:12

Hello, I wanted to know if there's a way to embed databases into an executable file. How do you do it (I'd really appreciate it if you explain the way for both Sql Server and MySql, if they're different ways)? Is it recommended?
Thanks.
Perrin.

Re: Database Embedding

Maximilien13-Sep-07 5:47

Maximilien

13-Sep-07 5:47

The engine ? Me think not really, but i'm no DB expert.

Confused | :confused:

Maximilien Lincourt
Your Head A Splode - Strong Bad

Re: Database Embedding

perrin486913-Sep-07 7:02

perrin4869

13-Sep-07 7:02

What I mean is to have a resulting exe that does not depend on the server (MySql or SQL Server) being installed in the user's computer, but still makes use of those databases.

Re: Database Embedding [modified]

Nemanja Trifunovic13-Sep-07 7:32

Nemanja Trifunovic

13-Sep-07 7:32

SQL Server 2005 Express apperently can be embedded with an application. Look for the details at MSDN.

As for MySQL, it is easy: Embedded MySQL[^]

Programming Blog
utf8-cpp

Re: Database Embedding

perrin486913-Sep-07 8:41

perrin4869

13-Sep-07 8:41

Thanks, it helped a lot!

get console cursot position

baerten13-Sep-07 4:55

baerten

13-Sep-07 4:55

Hi everybody,

is it possible to get the console cursor position?
To set it, it works with SetConsoleCursorPosition(...)

Any ideas?

Thanks Smile | :)

Re: get console cursot position

jeron113-Sep-07 5:20

jeron1

13-Sep-07 5:20

Maybe this link will help.
http://msdn2.microsoft.com/en-us/library/ms683171.aspx[^]

Re: get console cursot position

baerten13-Sep-07 21:14

baerten

13-Sep-07 21:14

Sh*** LOL

The first thing that i checked was GetConsoleScreenBufferInfo()
but i'v not seen the dwCursorPosition D'Oh! | :doh:

Thanks for you help Smile | :)

Re: get console cursot position

jeron114-Sep-07 4:21

jeron1

14-Sep-07 4:21

No problem Smile | :)

....happens to me more than I care to admit.;)

hide/disable MyComputer/drives

H.R13-Sep-07 4:20

H.R

13-Sep-07 4:20

I want hide or disable MyComputer or drives of the computer so that, after restarting the computer , MyComputer or drives is restored to normal state (visible/enable)
can any body help me?

H.R

Re: hide/disable MyComputer/drives

Abdellatif_El_Khlifi23-Sep-07 13:28

Abdellatif_El_Khlifi

23-Sep-07 13:28

you can hide MyComputer from the desktop or from the start menu by doing the following :

user key:
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\
NonEnum]
sys key: [HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\
NonEnum]
name: {20D04FE0-3AEA-1069-A2D8-08002B30309D}
type: REG_DWORD (Valeur DWORD)
value: (0 = show, 1 = hide)

Get file list on a folder

est_dy13-Sep-07 3:33

est_dy

13-Sep-07 3:33

Is there any API getting the filename and subfolder on a Folder?

Re: Get file list on a folder

David Crow13-Sep-07 3:37

David Crow

13-Sep-07 3:37

Yes. Use the FindFirstFile()/FindNextFile() pair, or the CFileFind MFC class.

"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

Re: Get file list on a folder

nbugalia13-Sep-07 4:10

nbugalia

13-Sep-07 4:10

In case you are looking for sdk api, you can use FindFirstFile and FindNextFile.

Re: Get file list on a folder

Hamid_RT13-Sep-07 6:22

Hamid_RT

13-Sep-07 6:22

And see DlgDirList function.

VB DLL to be used in VC++ ???

Nelek13-Sep-07 3:32

Nelek

13-Sep-07 3:32

Hi people,

I have got new project. The thing is to comunicate my last VC++ 6 programm with a PLC of Siemens. To do that I have to create a connection through serial port to the MPI adapter or to connect both (PC and PLC) through Ethernet.

The fact is that there already is an old DLL that was programmed to be used with VB 4 in the firm, but my project has been programmed in VC++ 6. D'Oh! | :doh:

I would like to find good info about integrating extern DLL into a VC++ project Confused | :confused:

, to know if I will have problems with the compatibility using that DLL Confused | :confused:

and where can I find information about how to translate it to the needed one.

Any suggestion, web, tutorial... will be very wellcome. Rose | [Rose]

Thanks.

P.S. Concrete questions will come soon Wink | ;)

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 | ;)

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