Re: Using HDC thats NULL - C / C++ / MFC Discussion Boards

«_Superman_»3-Dec-09 8:19

3-Dec-09 8:19

Not sure if this is what you want but you could use high resolution timer functions like QueryPerformanceCounter/QueryPerformanceFrequency before and after a piece of executing code and compare their values.

«_Superman_»
I love work. It gives me something to do between weekends.

Microsoft MVP (Visual C++)

Re: How to measure program speed?

Grimes3-Dec-09 9:47

Grimes

3-Dec-09 9:47

Hi
How would one use this?

QueryFrequencyCounter(Begin)
...CODE...
QueryFrequencyCounter(END)
TIME = END - BEGIN;

What is the unit of the counter? milliseconds or microseconds or clock cycles?

I will give it a try, thank you!

KOM UIT DAAAAA!!!

Re: How to measure program speed?

David Crow3-Dec-09 9:55

David Crow

3-Dec-09 9:55

Grimes wrote:
What is the unit of the counter? milliseconds or microseconds or clock cycles?

See here and 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

Re: How to measure program speed?

«_Superman_»3-Dec-09 9:59

«_Superman_»

3-Dec-09 9:59

Here is an interesting blog - QueryPerformanceCounter counts elapsed time, not CPU cycles[^]

«_Superman_»
I love work. It gives me something to do between weekends.

Microsoft MVP (Visual C++)

Re: How to measure program speed?

Member 41945933-Dec-09 15:12

Member 4194593

3-Dec-09 15:12

Check the Masm32 forum. In the Laboratory there is a huge amount of information about timing, a Macro to set up the timing, and what it takes to get accurate results.

Re: How to measure program speed?

Grimes3-Dec-09 21:37

Grimes

3-Dec-09 21:37

Thanks!!!

That counter macro seems to be counting the CPU cycles for a block of code. That does seem like the best way of determining the efficiency of a block of code, unlike time, that can vary greatly on different machines.

thanks for the help!

KOM UIT DAAAAA!!!

Using HDC thats NULL

dipuks3-Dec-09 6:06

dipuks

3-Dec-09 6:06

Hey

Can anyone tell what will happen if i use a HDC thats NULL?

For eg,

HDC hDc = {0};

DrawTextEx(hDc, ........);

I found that it will not throw an exception or something.

So is it OK to use like this?

Is there any MSDN documentation that talks about null HDC?

Thanks in advance

Re: Using HDC thats NULL

«_Superman_»3-Dec-09 6:15

«_Superman_»

3-Dec-09 6:15

That depends on the function you are using it in.
For example, the CreateCompatibleDC function says that if HDC is NULL it uses the current screen as the reference.

So if there is nothing mentioned about the behavior when HDC is NULL, if sure the behavior is undefined and you should not do that.

«_Superman_»
I love work. It gives me something to do between weekends.

Microsoft MVP (Visual C++)

Re: Using HDC thats NULL

dipuks3-Dec-09 7:17

dipuks

3-Dec-09 7:17

I am using HDC to write to a PDF printer. But the code is so entagled that, there's pieces of a text file writing code is also between that.

So when there's a case that only a text file need to be written and no PDF, then i pass the HDC for PDF as NULL.

So far in my testing i have seen that this works perfect.

Is there any other function that will return me a valid HDC, but will not mess up any text file writing?

Can i use CreateCompatibleDC to pass an HDC that will not mess up any other part of the application? But at the same time there will be a valid HDC rather than a NULL one.

Thanks

Re: Using HDC thats NULL

«_Superman_»3-Dec-09 7:55

«_Superman_»

3-Dec-09 7:55

I think I have too little understanding to give a reliable answer.
You will need to break up your question and isolate it from your domain if I need to understand.

«_Superman_»
I love work. It gives me something to do between weekends.

Microsoft MVP (Visual C++)

Problem in running an application(developed in VC++ 2005) from windows service ..

jain_MS3-Dec-09 5:27

jain_MS

3-Dec-09 5:27

Hi ,
While running an exe from service window , its throwing like

"The exception Unknown software exception (0x40000015) occurred in the application at location 0x781346b4."

Error 1067: the process terminated unexceptedly.

And in the Event viewer ...it is showing the message as ..

Faulting application mtserver.exe, version 6.2.86.0, faulting module msvcr80.dll, version 8.0.50727.4053, fault address 0x000046b4.

Note: its working fine in debug mode.

Please let me know ur valuable comments.

Ur help much appreciated

Regds
Jain

Re: Problem in running an application(developed in VC++ 2005) from windows service ..

«_Superman_»3-Dec-09 5:55

«_Superman_»

3-Dec-09 5:55

Does it fail even if the EXE is executed by double clicking from user mode?
If so try attaching a debugger to the process.
You could try running the EXE in debug mode, but without attaching the debugger (Ctrl + F5).

«_Superman_»
I love work. It gives me something to do between weekends.

Microsoft MVP (Visual C++)

Memory allocation in multi-threaded application

baerten3-Dec-09 5:08

baerten

3-Dec-09 5:08

Hi everybody,

I like to find out where a function or maybe an entire library allocates a huge amount of memory.
In the task-manager I see that the application really uses 25MB of the memory and allocates a total of 166MB.

I tested already GlowCode, but it displays only the memory which is really in use.
Is there another tool or programming technique to find the call of the function?

Big thanks for any help Smile | :)

Re: Memory allocation in multi-threaded application

David Crow3-Dec-09 5:42

David Crow

3-Dec-09 5:42

baerten wrote:
Is there another tool or programming technique to find the call of the function?

Re: Memory allocation in multi-threaded application

crewchill3-Dec-09 12:18

crewchill

3-Dec-09 12:18

I think he meant which code calls the heap allocator?

Try IBM Rational Purify. They have 30-day license I believe. It should keep track of allocations and deallocations, leaks, etc, complete with the stack of the callers.

i'm foolish, so you can help me very easy

nenfa3-Dec-09 3:38

nenfa

3-Dec-09 3:38

i'm so foolish, who can help me?

i got one message identification, for example, it's 0x10b3, how can i get the described information about it?

as above is just one instance, if many message identification arise, i'll jump into whirlpool

Re: i'm foolish, so you can help me very easy

loyal ginger3-Dec-09 3:47

loyal ginger

3-Dec-09 3:47

Windows Message ID constants[^]

Re: i'm foolish, so you can help me very easy

David Crow3-Dec-09 3:48

David Crow

3-Dec-09 3:48

sunen wrote:
...how can i get the described information about it?

Given that you've simply shown a base-16 number, how are we to know? Confused | :confused:

Re: i'm foolish, so you can help me very easy

Iain Clarke, Warrior Programmer5-Dec-09 3:20

Iain Clarke, Warrior Programmer

5-Dec-09 3:20

A fool is someone who fails to learn.

So, asking this question once is not foolish. Asking the same question again, will be.

So, to your actual question. Read the following blog article. I'll wait.

The Old New Thing: Which message numbers belong to whom?[^]
.
.
.
.

Back already? Wow!

So, 0x10b3 lies solidly in the class defined message category. So, without knowing what kind of window you have (or more importantly: what kind of window other code thinks you have), it's impossible at answer your question.

Without knowing a lot more, we can't help, sorry.

I wish you luck, and cleverness,

Iain.

I have now moved to Sweden for love (awwww).
If you're in Scandinavia and want an MVP on the payroll (or happy with a remote worker), or need contract work done, give me a job! http://cv.imcsoft.co.uk/[^]

Re: i'm foolish, so you can help me very easy

nenfa5-Dec-09 5:46

nenfa

5-Dec-09 5:46

you're a good man, thank you very much

Why GlobalLock failed?

transoft3-Dec-09 3:11

transoft

3-Dec-09 3:11

Hi,

I tried to use "GlobalLock" to get HBITMAP data. But it returns NULL.

void myfunc(HBITMAP hMen)
{
....
lpVoid = (UCHAR *)GlobalLock(hMem);
....
}

lpVoid is NULL

What else function I can use to get Bitmap data from HBITMAP?

Thanks,

Re: Why GlobalLock failed?

Rajesh R Subramanian3-Dec-09 3:16

Rajesh R Subramanian

3-Dec-09 3:16

transoft wrote: Why GlobalLock failed?

I found this little detail in the documentation[^] page:

If the function fails, the return value is NULL. To get extended error information, call GetLastError()[^].

“Follow your bliss.” – Joseph Campbell

Re: Why GlobalLock failed?

C^hris L^osinger3-Dec-09 4:23

C^hris L^osinger

3-Dec-09 4:23

transoft wrote:
What else function I can use to get Bitmap data from HBITMAP?

GetDIBits

an HBITMAP is not an HGLOBAL.

image processing toolkits | batch image processing

How can i STOP this

Hwewet3-Dec-09 1:58

Hwewet

3-Dec-09 1:58

Hello,

when i came with the debugger to a function like this my
debugger will step into an little part of assembler.
i think it is the constructor.

how can i deactivate this sh*t!

i use MFC 2003 Version 7.1

void test(CString compress)
{

}

test("HALLO");

Thanks

Re: How can i STOP this

Richard MacCutchan3-Dec-09 2:47

Richard MacCutchan

3-Dec-09 2:47

Hwewet wrote:
how can i deactivate this sh*t!

This type of language should be reserved for the back room.

However if you do not want to see the assembler then use "Step Over" rather than "Step Into".

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.