C / C++ / MFC

Where Does the Extra Thread Come From?

5-Dec-06 0:16

treeview seems good.

but explaining this in English (no SMS) is better so that everybody can understand your post Wink | ;)

thanks

You don't know where to start ? ask a good friend

[VisualCalc 3.0][Flags Beginner's Guide]

Cliff Hatch4-Dec-06 23:42

4-Dec-06 23:42

I'm working on an application that launches a separate thread for some processor intensive activities.

I used Spy to look at the running application, expecting to see two threads - but there were three! I can make out the main thread and the one that I launched. Both these clock up CPU time as expected. The third thread doesn't appear to do anything - CPU time etc. stays at zero.

The application works fine - I'm just curious to know where the extra thread comes from. I assume the system creates it automatically for some purpose. Does anyone know what it might be for?

Best Regards

Cliff Hatch

Naveen5-Dec-06 0:09

Naveen

5-Dec-06 0:09

what type of application did u create?

nave

Cliff Hatch5-Dec-06 0:23

5-Dec-06 0:23

.NET 2002, MFC Application, MDI.

Roger Stoltz5-Dec-06 0:26

Roger Stoltz

5-Dec-06 0:26

Debug your application and halt it after your second thread is created and it has ran for a while.
Switch the context of the unknown thread and have a look at the bottom of the call stack.
Does it say something with 'RPC'?

"It's supposed to be hard, otherwise anybody could do it!" - selfquote

"No one remembers a coward!" - Jan Elfström 1998
"...but everyone remembers an idiot!" - my lawyer 2005 when heard of Jan's saying above

Cliff Hatch5-Dec-06 1:31

5-Dec-06 1:31

Thanks for the suggestion Roger, but I'm having difficulty following your instructions.

All the threads close down cleanly when I halt - I assume you mean "pause"?

How should I switch the context of the unknown thread? The number of switches increments when I refresh the Spy properties window - is this what you mean?

I don't see how the call stack or anything else will be affected when the application is paused.

Apologies for this - I think I must be completely mis-interpreting your suggestion - could you provide some clarification?

Best Regards

Cliff

Re: Where Does the Extra Thread Come From? [modified]

Roger Stoltz5-Dec-06 3:16

Roger Stoltz

5-Dec-06 3:16

Cliff Hatch wrote:
All the threads close down cleanly when I halt - I assume you mean "pause"?

:-> Ummm, terminology stuff... Yes, I meant "pause", otherwise the rest of my suggestions would not be of any use. Smile | :)

Find the menu option 'Threads...', in VC6 it's under the 'Debug' menu.
Inside the small thread window you can choose which thread you'd like to see the context for. As I understood it there will be three whereas you'll recognize the top of the call stack for two of them since it most likely will be your own code. The third is the unknown and it would help a lot if you can provide information about the call stack for that thread.

Cliff Hatch wrote:
I don't see how the call stack or anything else will be affected when the application is paused.

Of course the call stack won't change during the application pause, but the contents of the call stack are important: what's at the bottom and what's at the top of the call stack.

Cliff Hatch wrote:
Apologies for this - I think I must be completely mis-interpreting your suggestion

No worries!

--
Roger

Cliff Hatch5-Dec-06 5:46

5-Dec-06 5:46

Many thanks for this Roger.

I didn't know the "Threads" window existed. I found it under "Debug", "Windows", "Threads" in .NET 2002, and suddenly your original post makes perfect sense. Smile | :)

The unknown thread has the generic sounding title "Win32 Thread", and the call stack contains just two entries:

ntdll.dll!7c90eb94()
kernel32.dll!7c80b683()

I'm still curious about what it does, but it is clearly a system thing (see also reply from David Crow below). I'm happy to accept that - and even happier to have discovered a new Visual Studio feature along the way. Big Grin | :-D

Best Regards

Cliff

-- modified at 12:11 Tuesday 5th December, 2006

David Crow5-Dec-06 3:30

David Crow

5-Dec-06 3:30

The other thread could come from code other than yours. For example, use Task Manager to watch Visual Studio's thread count. Now open a file, and watch the thread count increase by several.

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"Judge not by the eye but by the heart." - Native American Proverb

Cliff Hatch5-Dec-06 6:07

How to load stirng in resource..

5-Dec-06 6:07

Thanks David

Yes, I see the thread count changing. There seem to be a number of short-lived threads in addition to the persistent one I noticed.

Best Regards

Cliff

Shah Satish4-Dec-06 23:24

Shah Satish

4-Dec-06 23:24

Hi!!
How i can load my srting in resource file..

ie in my method, i have created one messagebox like

Messagebox(NULL,_T("There is no selected text" + pmy + "in my section "),_T("Error message"),MB_OK);

now i want this string in my resource file.. ie in resource file i have created IDS_ABOUTBOX.

Can any body help me??

Thanking you..

Shah Satish

toxcct4-Dec-06 23:27

4-Dec-06 23:27

use

CString::LoadString(IDS_MY_STRING);

for instance, or

CString::Format(IDS_MY_STRING, _T("optional parameter if required"), 3);

You don't know where to start ? ask a good friend

[VisualCalc 3.0][Flags Beginner's Guide]

Shah Satish4-Dec-06 23:31

Shah Satish

4-Dec-06 23:31

But in my method...ie where declred my message box, there is no class...

but in Tools.cpp there is one function called..GetString but first of all i have to load.

shah satish

toxcct4-Dec-06 23:43

4-Dec-06 23:43

first of all, i'll ask you to make an effort because i don't really understand your english. i only guess what you're trying to do.
as i already explicited the methods to use, here is an illustration :

CString strMessage, strTitle;
strTitle.LoadString(IDS_ERROR_MESSAGE);
strMessage.Format(IDS_NO_SELECTED_TEXT, pmy);
 
Messagebox(NULL, strMessage, strTitle, MB_OK);

with the following asserts :
IDS_NO_SELECTED_TEXT : "There is no selected text %s in my section"
change the %s consequently if your parameter is not a string

IDS_ERROR_MESSAGE : "Error message"

You don't know where to start ? ask a good friend

[VisualCalc 3.0][Flags Beginner's Guide]

Some can explain when i need to use 'Select' function in TCP/IP ?

Shah Satish5-Dec-06 0:05

Shah Satish

5-Dec-06 0:05

Hello sir,
Sorry for my English language...but this is the exactly what i want to do..

Thank you very much for your help..

Shah

Yanshof4-Dec-06 23:05

Yanshof

4-Dec-06 23:05

Hi All,

I don't understand when i need\can use the function select in TCP\IP develop
( winsock use) i understand how to use it - but when to do it i don't know.

If there is some example - i will happy to have the link.

Thanks for any help.

Re: Some can explain when i need to use 'Select' function in TCP/IP ?

KarstenK4-Dec-06 23:22

KarstenK

4-Dec-06 23:22

AFAIK you need the select "to pump" the TCP/IP traffic. So you got to call select in a timed loop. You should do the winsock stuff in a separate thread.

Thats the most I know about this. Unsure | :~

Greetings from Germany

difference between windows shutdown and restart in VC++ code

seemadavid4-Dec-06 23:00

seemadavid

4-Dec-06 23:00

I need to distinguish between the windows shutdown and restart commands given by the user ,using VC++ code. Can anyone help me with that? To identify which event is taking place.

Thanks for ur help and time !!!

Re: difference between windows shutdown and restart in VC++ code

KarstenK4-Dec-06 23:28

KarstenK

4-Dec-06 23:28

I think the WM_ENDSESSION message will help you. Another interesting WM ist WM_POWERBROADCAST for power events.

Greetings from Germany

regarding access to its contents

p.geetha4-Dec-06 22:17

p.geetha

4-Dec-06 22:17

sir,
we are not able to access part-ii and part-iii.
we didt get any link to access above mentioned.
please suggests to do the necessary

Geetha.P

Re: regarding access to its contents

toxcct4-Dec-06 22:23