C / C++ / MFC Discussion Boards

Rajesh R Subramanian8-Dec-10 0:02

8-Dec-10 0:02

You could read these couple of very good essays:

Inside memory allocation[^]
Memory damage primer[^]

They aren't particularly explaining how the OS reclaims the resources after a process exits, but nevertheless they make a great read.

It was ever thus, the Neophiles will always rush out and get 'The Latest Thing' at a high price and with all the inherent faults - Dalek Dave.

Re: Process exit memory released?

vipin_nvk8-Dec-10 0:34

vipin_nvk

8-Dec-10 0:34

Thanx Rajesh

Re: Process exit memory released?

Rajesh R Subramanian8-Dec-10 0:36

Rajesh R Subramanian

8-Dec-10 0:36

vipin_nvk wrote:
Thanx Rajesh

Ah, how very refreshing to see a polite member. Have a 5 vote from me. Smile | :)

It was ever thus, the Neophiles will always rush out and get 'The Latest Thing' at a high price and with all the inherent faults - Dalek Dave.

Re: Process exit memory released?

Rajesh R Subramanian7-Dec-10 23:32

Rajesh R Subramanian

7-Dec-10 23:32

Bleedingfingers gave you the correct answer.

vipin_nvk wrote:
My application is a C++ application.

The language used to build your program is irrelevant. The OS will ALWAYS take it back after your program is done!

It was ever thus, the Neophiles will always rush out and get 'The Latest Thing' at a high price and with all the inherent faults - Dalek Dave.

Re: Process exit memory released?

Cedric Moonen8-Dec-10 0:16

Cedric Moonen

8-Dec-10 0:16

In addition to other answer, I just wantewd to say that it is very good practice to always release the memory you are using. This will reduce the risk of memory leaks you will have when the application is running (see another answer about memory leaks).

Cédric Moonen
Software developer

Charting control [v3.0]
OpenGL game tutorial in C++

Re: Process exit memory released?

Maximilien8-Dec-10 1:42

Maximilien

8-Dec-10 1:42

Even if the OS will reclaim the memory, it's no excuse not to clean up yourself.

M.

Watched code never compiles.

Re: Process exit memory released?

Niklas L8-Dec-10 21:58

Niklas L

8-Dec-10 21:58

Always clean up your allocated memory. Even though the OS will reclaim the allocated memory, deleting objects (C++) might have important side effects, such as releasing resources in other processes the instance has allocated on construction. This might lead to 'leaks' in other running processes. Also, if you don't properly delete allocated resources, your code will not be reusable in other applications. Cleaning up your own mess is an important part of C++. Clean up.

home

How can identify why AfxBeginThread return value is NULL?

Le@rner7-Dec-10 18:08

Le@rner

7-Dec-10 18:08

Hi all,

in my application i have generate so many threads but some time AfxBeginThread return NULL please tell me how can i identify why its return NULL.

here i m also try GetLastError() but its return "The Operation Completed Successfully"

please help me for this.

thanks in advance.

Re: How can identify why AfxBeginThread return value is NULL?

Rajesh R Subramanian7-Dec-10 19:44

Rajesh R Subramanian

7-Dec-10 19:44

I'd recommend that you set a conditional breakpoint, and try to look at the call stack to see what caused the failure.

I hope you know that MFC comes with source code.

It was ever thus, the Neophiles will always rush out and get 'The Latest Thing' at a high price and with all the inherent faults - Dalek Dave.

Re: How can identify why AfxBeginThread return value is NULL?

bleedingfingers7-Dec-10 20:00

bleedingfingers

7-Dec-10 20:00

Le@rner wrote:
n my application i have generate so many threads but some time AfxBeginThread return NULL please tell me how can i identify why its return NULL.

It appears to me that you are generating threads "as required" in your program. Am I wrong? If not, on what conditions do you attempt to create the threads?

Also, please post the relevant portions of the code. The way you are creating the threads, I mean the way you are calling the AfxBeginthread(...), could hold a clue.

...byte till it megahertz...

my donation to web rubbish

Re: How can identify why AfxBeginThread return value is NULL?

Le@rner7-Dec-10 20:29

Le@rner

7-Dec-10 20:29

//here CTest_Thread is class that is derived from CWinThread

int in_num=0;
std::map<int, CTest_Thread*>  assocs_th;

assocs_th[in_num] = (CTest_Thread*) AfxBeginThread( RUNTIME_CLASS(CTest_Thread), THREAD_PRIORITY_NORMAL, NULL,CREATE_SUSPENDED, NULL);

if (NULL != assocs_th[in_num])
{
	//assign values to thread class variables
	//assocs_th[in_num]->file_path = path;
	assocs_th[in_num]->ResumeThread();
     
     in_num++;
}
else
{				
	AfxMessageBox("Error");
}

Re: How can identify why AfxBeginThread return value is NULL?

Rajesh R Subramanian7-Dec-10 20:48

Rajesh R Subramanian

7-Dec-10 20:48

1, How many such threads are you actually creating?

2, Are you in need of UI threads or worker threads?

3, Are you aware that you are actually creating UI threads?

4, Have you setup a breakpoint and stepped into the code while it fails as I pointed out earlier?

Also, what's the point of having an int in_num and incrementing it, because neither is it declared static, nor is it running within a loop where the incrementing happens. Confused | :confused:

It was ever thus, the Neophiles will always rush out and get 'The Latest Thing' at a high price and with all the inherent faults - Dalek Dave.

Re: How can identify why AfxBeginThread return value is NULL?

bleedingfingers7-Dec-10 23:30

bleedingfingers

7-Dec-10 23:30

OK but you didn't answer the first part of my post. My questions are basically same as Rajesh's. Without knowing about those, it would be very hard for anyone to help.

...byte till it megahertz...

my donation to web rubbish

Re: How can identify why AfxBeginThread return value is NULL?

Le@rner7-Dec-10 23:35

Le@rner

7-Dec-10 23:35

you ask:"It appears to me that you are generating threads "as required" in your program."

yes i do

Re: How can identify why AfxBeginThread return value is NULL?

Rajesh R Subramanian7-Dec-10 23:57

Rajesh R Subramanian

7-Dec-10 23:57

You seem to ignore the questions that are actually important to solve this thread. Instead, you keep on giving useless information.

If you don't provide all the details that you were asked, chances of you getting help here is bleak.

It was ever thus, the Neophiles will always rush out and get 'The Latest Thing' at a high price and with all the inherent faults - Dalek Dave.

Re: How can identify why AfxBeginThread return value is NULL?

trotwa7-Dec-10 22:18

trotwa

7-Dec-10 22:18

First check, that you use the multithreaded c-runtime. Compiler option: /MT
Wink | ;)

Re: How can identify why AfxBeginThread return value is NULL?

Le@rner7-Dec-10 22:20

Le@rner

7-Dec-10 22:20

yes i use this

Re: How can identify why AfxBeginThread return value is NULL?

Rajesh R Subramanian7-Dec-10 22:57

Rajesh R Subramanian

7-Dec-10 22:57

That doesn't make any sense.

Without linking to the multi-threaded version of the CRT, you cannot make a call to AfxBeginThread(). The compiler will complain, because AfxBeginThread()internally uses _beginthreadex() to spawn a thread, which can be called only if you link to the multi-threaded version of CRT.

It was ever thus, the Neophiles will always rush out and get 'The Latest Thing' at a high price and with all the inherent faults - Dalek Dave.

CToolBar Button Flickers. [modified]

janaswamy uday7-Dec-10 17:54

janaswamy uday

7-Dec-10 17:54

Hi All,

I am getting flicker when Disable the CToolBar Buttons when ON_UPDATE_COMMAND_UI message with
CmdUI->Enable(FALSE) twice depending on some condition.
But everytime I move my mouse the grayed-out button flickers.
Un-grayed buttons do not flicker. Any Prolem whith this.

Code
-------

void CMainFrame::OnUpdateFileDeleteplans(CCmdUI* pCmdUI)
{
bool bExecuteSQLWin = false;

if(bExecuteSQLWin)
pCmdUI->Enable(FALSE);
else
pCmdUI->Enable();

pCmdUI->Enable(CheckOpenPlans()); --> Here i added with a Function CheckOpenPlans().......>==========//

}

bool CMainFrame::CheckOpenPlans()
{
CMDIChildWnd* MyWnd = NULL;
MyWnd = MDIGetActive();
CView* pView = NULL;

if(MyWnd != NULL)
{
pView = (CView*) MyWnd->GetActiveView();
if((pView->IsKindOf(RUNTIME_CLASS(CSelectQueryView)) || pView->IsKindOf(RUNTIME_CLASS(OpenPlansTreeView))))
{
MyWnd = NULL;
pView = NULL;
return false;
}
else
{
MyWnd = NULL;
pView = NULL;
return true;
}
}

return true;
}

modified on Monday, December 20, 2010 12:29 AM

Is there any DB2 driver for VC

cy163@hotmail.com7-Dec-10 13:40

cy163@hotmail.com

7-Dec-10 13:40

Hi All,

I am using VC++ 6.0. I am using ODBC to connect to DB2 database. I wonder if there is any driver(connector) dedicated for VC6.0.

Thanks

Felix

VC FLEX

cy163@hotmail.com7-Dec-10 13:38

cy163@hotmail.com

7-Dec-10 13:38

Hi ALL,

I am using Visual C++ 6.0 studio. I want to render processing result data graphically by showing a flash to the user with FLEX technology. I wonder if this is possible.

Thanks

Felix

Re: VC FLEX

KingsGambit7-Dec-10 21:43

KingsGambit

7-Dec-10 21:43

Yes it is possible. You can use Adobe Flash Player ActiveX control in ypur VC++ project. You can make use of events and methods provided by Adobe Flash Player control to communicate between C++ and the Flash file (Which is the result of compiling your Flex project).

Re: VC FLEX

Cool_Dev8-Dec-10 21:17

Cool_Dev

8-Dec-10 21:17

in addition to what is said above, don't wonder to hear that you can call functions in your swf flash movie from C++, and events dispatched from swf can be handled in c++, using the interfaces provided by flash player activex.

890916 - CTabbedPane

ilostmyid27-Dec-10 2:32

ilostmyid2

7-Dec-10 2:32

hi i need to know what is this class for and how can i use it. i need a simple sample plz.
thx

Re: 890916 - CTabbedPane

David Crow7-Dec-10 3:25

David Crow

7-Dec-10 3:25

See here.

"One man's wage rise is another man's price increase." - Harold Wilson

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

"Man who follows car will be exhausted." - Confucius

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