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Hi there,
does anyone have a sample code for using buffer transfer mode with TWAIN instead of native mode?
Thanks,
Dudi
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Ladies and Gents,
Wrote a Win 32 app, which ran nicely thankyou, within it I had aggregate structures containing up to 800K instances of a Point class. All was well.
When I ported it to run in under an MFC app, the delete of the top level container was taking > 5 seconds, where previously it was near instantaneous.
It uses STL containers, all the usual speed up tricks, but simply moving the classes into an MFC app causes it to run very very slow.... when deleting.
Anyone come across this?? Any idea's??
Cheers
Laurence
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Are you compiling with debug enabled? MFC has a special new/delete for debug builds, that does a lot of memory leak checking. Great for debugging, but it slows it down a lot.
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Thanks for the reply.
Tried it under Debug and Release, with the same Nett result.
Omitted the DEBUG_NEW macro from the classes in question anyway.
Cheers
Laurence
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I have:
typedef std::basic_string<TCHAR> String;
The i use
void whatever()<br />
{<br />
String myString = "anton";<br />
}<br />
The question is, would my string be destroyed, or i had just eatent a memory leak.
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Your string will be destroyed correctly once the function ends, as the variable is local to the function.
If you had done:
void whatever()<br />
{<br />
String *myString = new String ("anton");<br />
}
Then you would have had a leak
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I've got a question that I would love some feedback on.
I've written a C++ CGI application running on Win2k that generates thumbnail pictures. The generation process works fine but if I have too many thumbnails to generate, my web server kills the process after 6 or 7 minutes.
What I would like to do is to have my CGI program start a seperate process that does the conversion, sends a "working" page to the brouser, and then quit. The seperate process would continue to work on the thumbnails. It would update a text file to show it's progress.
I want to avoid having more then one executable but I can't just call my CGI program again using an execl() because my program does not have an .EXE extension. It has a .CGI extension. Is there a way to start a new thread (is fork the correct wording?) from a function or in creating a new object?
Thanks for any help you can give.
- Dave S
====
Dave S
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Dave_Schneider wrote:
my web server kills the process after 6 or 7 minutes.
yes it will, the webserver does not want to keep a connection open for any longer.
MSN Messenger.
prakashnadar@msn.com
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First off, the CreateProcess() api doesn't require any special extensions (exe/com/dll/etc....) to load and exec a process.
Secondly, what could you be doing that would require a 6-7 minute response time???? Generating thumbnails should be a pretty quick operation (on the order of 100-300ms), not 7 minutes.
onwards and upwards...
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Thanks for the responses. I'm new to the whole multi-process/multi-thread thing.
So I can start another instances of my program by calling CreateProcess(), and then quit the original process without affecting my new process?
The reason it takes longer then 6-7 minutes to get a response is I am generating more then one thumbnail. My program takes a directory of pictures and looks to see if there are thumbnails for each one. If no thumbnails are found, it generates them. My problem comes when a new directory has several hundred pictures.
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Are you creating a bitmap for each thumbnail or simply copying the thumbnails onto one large image? Also, what method are you using to generate the thumbnails?
If you call CreateProcess and do not specify an owning process, then that process is independent.
FYI: CGI programs are typically not very scalable. You should use ISAPI or a C++ app server like this one [^].
onwards and upwards...
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I'm taking JPEG's of sizes ranging from 200kb-400kb (1280x960) and doing a down-sample on them to 2kb-4kb (200x150) JPEG's. I'm using the DevIL image library to do the work.
Because I want to get as much detail as I can in these thumbnails, I an using a slower down-sampler.
I'm interested in looking more at your suggestion of using a ISAPI or a C++ app server, but your link did not seem to work.
Thanks.
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Sorry, here is the right one: ^]
onwards and upwards...
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Hello, I've encountered the following error:
Warning: calling DestroyWindow in CDialog::~CDialog --
OnDestroy or PostNcDestroy in derived class will not be called.
This happens, when I unload a DLL file from my program. If I override PostNcDestroy or DestroyWindow (I should free memory there) the 2 functions never get called. The dll has a dialog interface in it, and I should clean-up the memory since the dialog is no-modal, and there is dynamically allocated memory also for strings which I display in ListView. All should work fine, but PostNcDestroy and/or Destroy Window never get called. All I get is the above metioned warning in debug mode. And because of not getting these messages, I'cant free the memory and I get memory leaks. Anyone had the same problem?
Thanks in advance,
D.
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make sure your functions are declared as virtual!
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Yes, they are declared as virtual 
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[Edited]
When your modeless dialog closes, it should do this:
DestroyWindow();
delete this;
/ravi
My new year's resolution: 2048 x 1536
Home | Articles | Freeware | Music
ravib@ravib.com
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Thanks for the comment Ravi,
I know that I have to call DestroyWindow() and delete this in my modeless dialog, but the problem is that I don'get notified about it, I get the warning, and my handlers are not called, the modeless dialog is contained within a DLL file, and when it's unloaded, the warning is displayed in the debugger, the handlers are not called, and I get the memory leaks.
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Ah. Perhaps you could destruct the dialog (in an orderly manner by calling a public method that cleans up properly) when your DLL unloads? Your DLL will get notified when it's about to be unloaded.
/ravi
My new year's resolution: 2048 x 1536
Home | Articles | Freeware | Music
ravib@ravib.com
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Over ride the OnCancel, OnOk event and call destroywindow and dont call the baseclass implementation.
If you calling EndDialog any where remove them and replace it with destroywindow.
MSN Messenger.
prakashnadar@msn.com
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Thank you all for the help, I'm going to try these methods, and if they don't fix that bug, I will post again 
Thanks for your attention and time
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Dear All,
I would like to create some public variables reading from my data base records. How can I do that? it's mean that there are some string stored in database. When the application initalisation. some (datatype) variables should be created as public use.
Regards,
Anson Tong
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I dont think that is possible under c/c++ i.e dynamically creating public variables...
Well you can have a list and add all the values to the list... each index humm, can be called as the dynamically created variable but its not. The variable type of each index will be same.
MSN Messenger.
prakashnadar@msn.com
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