Re: How Thread Run Parallely - C / C++ / MFC Discussion Boards

PJ Arends28-Feb-06 11:00

28-Feb-06 11:00

void CMainFrame::Scroll()
{
CDC *pDC = this->GetActiveView()->GetDC();

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I may be crazy
But it just may be a lunatic you’re looking for
-- Billy Joel --

Within you lies the power for good - Use it!

How Thread Run Parallely

zahid_ash28-Feb-06 6:52

zahid_ash

28-Feb-06 6:52

I have created my own class CThread inherited from CWinThread,
I am Starting Threads using

for loop begin
AfxBeginThread(RUNTIME_CLASS(CThread));
for loop ends

I have created 15 thread in a loop, will they run parallely or with the time slice scheduling, Actualy I want that they should run parralelly , so that i can write in 15 different file simaltinoiusly.

I want to work fast on these threads.

Regards.

Re: How Thread Run Parallely

David Crow28-Feb-06 7:13

David Crow

28-Feb-06 7:13

zahid_ash wrote:
...I have created 15 thread in a loop, will they run parallely or with the time slice scheduling...

They will never run in parallel on a uniprocessor machine.

"Let us be thankful for the fools. But for them the rest of us could not succeed." - Mark Twain

"There is no death, only a change of worlds." - Native American Proverb

Re: How Thread Run Parallely

zahid_ash28-Feb-06 7:42

zahid_ash

28-Feb-06 7:42

Is there any technique to write in the in the different file parallely or read from them .

i want to shorten the read write time

Regards.

Re: How Thread Run Parallely

Maximilien28-Feb-06 7:46

Maximilien

28-Feb-06 7:46

not with a single CPU computer.

Maximilien Lincourt
Your Head A Splode - Strong Bad

Re: How Thread Run Parallely

David Crow28-Feb-06 7:50

David Crow

28-Feb-06 7:50

I think so, as long as the read and write operations are not happening at the exact spot in the file. See LockFile() for more.

zahid_ash wrote:
i want to shorten the read write time

Well, creating a bunch of threads on a uniprocessor machine is one way to not "shorten the read write time." The overhead of context-switching between all of the threads will be your demise.

"Let us be thankful for the fools. But for them the rest of us could not succeed." - Mark Twain

"There is no death, only a change of worlds." - Native American Proverb

Re: How Thread Run Parallely

zahid_ash28-Feb-06 7:58

zahid_ash

28-Feb-06 7:58

Will they run parallely on multi processor machine.

How can i demise the context switching of thread,

Regards.

Re: How Thread Run Parallely

David Crow28-Feb-06 8:10

David Crow

28-Feb-06 8:10

zahid_ash wrote:
Will they run parallely on multi processor machine.

Yes, but I've no experience with this. I think SetThreadIdealProcessor() will be required.

zahid_ash wrote:
How can i demise the context switching of thread,

I'm not sure exactly what it is that you are asking here, but I think the answer is, "When more than one thread is involved, the processosr will need to periodically switch between them so that at any given monent, only one thread is actually active." This obviously incurs overhead that cannot be avoided.

"Let us be thankful for the fools. But for them the rest of us could not succeed." - Mark Twain

"There is no death, only a change of worlds." - Native American Proverb

Open and write in XML-Document

hanno2528-Feb-06 5:16

hanno25

28-Feb-06 5:16

Hi!

DOes anybody know, what I have to do, if I want either to create an new .XML-File or open an existing .XML-File to write at the beginning of this file?
I thought, that I can handle this like a normal text-file but that has been a mistake.
So, if anybody knows something about this, please let me know!

Thanks, Hanno

Re: Open and write in XML-Document

David Crow28-Feb-06 5:29

David Crow

28-Feb-06 5:29

Use IXMLDocument or DOMDocument.

"Let us be thankful for the fools. But for them the rest of us could not succeed." - Mark Twain

"There is no death, only a change of worlds." - Native American Proverb

Re: Open and write in XML-Document

hanno2528-Feb-06 5:43

hanno25

28-Feb-06 5:43

Thanks for your help. Could you send a small piece of code, explaning this a little bit?
With best regards, Hanno

Re: Open and write in XML-Document

David Crow28-Feb-06 5:46

David Crow

28-Feb-06 5:46

Why not just Google for those two interfaces? Also try CodeProject articles, and MSDN.

"Let us be thankful for the fools. But for them the rest of us could not succeed." - Mark Twain

"There is no death, only a change of worlds." - Native American Proverb

Re: Open and write in XML-Document

Dominik Reichl28-Feb-06 6:21

Dominik Reichl

28-Feb-06 6:21

If you want a light-weight XML library (i.e. not MSXML), have a look at http://tinyxml.sourceforge.net/[^].

I used TinyXML in several projects, it works pretty well.

Best regards
Dominik

_outp(0x64, 0xAD);
and
__asm mov al, 0xAD __asm out 0x64, al
do the same... but what do they do??
(doesn't work on NT)

finishing writing symbol to stdin?

9ine28-Feb-06 4:51

9ine

28-Feb-06 4:51

Whats the symbol to put to stdin to finish its reading

//console app reading in a loop until that magic symbol
while(res)
res = fscanf(stdin,"%s",&str);

//while pressing in console
string1
string2
string3
??? how to quit it

9ine

Re: finishing writing symbol to stdin?

David Crow28-Feb-06 4:53

David Crow

28-Feb-06 4:53

Use F6 or Ctrl-Z.

"Let us be thankful for the fools. But for them the rest of us could not succeed." - Mark Twain

"There is no death, only a change of worlds." - Native American Proverb

Re: finishing writing symbol to stdin?

9ine28-Feb-06 5:11

9ine

28-Feb-06 5:11

whats the code for that combination ctrl-z? \r \n \t ... ?

9ine

Re: finishing writing symbol to stdin?

David Crow28-Feb-06 5:22

David Crow

28-Feb-06 5:22

If you are typing at a command prompt (which is what I inferred from your "while pressing in console" comment), \r \n \t are meaningless. What exactly are you trying to do?

"Let us be thankful for the fools. But for them the rest of us could not succeed." - Mark Twain

"There is no death, only a change of worlds." - Native American Proverb

Re: finishing writing symbol to stdin?

9ine28-Feb-06 5:34

9ine

28-Feb-06 5:34

I'm not going to type numbers and then pressing F6, I need to write to console application stdin so it will read it like fscanf(stdin, ... ) or whatever the method until that character F6 encountered

9ine

Re: finishing writing symbol to stdin?

David Crow28-Feb-06 5:48

David Crow

28-Feb-06 5:48

Ok, let me see if I can put the pieces together. You have a Windows application that is going to spawn a console application. Right so far? The console applicaton is going to be reading from stdin, so you need to populate that stream from within the Windows application. Correct?

"Let us be thankful for the fools. But for them the rest of us could not succeed." - Mark Twain

"There is no death, only a change of worlds." - Native American Proverb

Re: finishing writing symbol to stdin?

9ine28-Feb-06 5:56

9ine

28-Feb-06 5:56

Exactly! and send that stream of floating numbers prepared as char strings array of course to console input so it will be reading it until F6 encountered.

9ine

Re: finishing writing symbol to stdin?

David Crow28-Feb-06 6:08

David Crow

28-Feb-06 6:08

See these two articles:

http://support.microsoft.com/default.aspx?scid=kb;en-us;190351[^]

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dllproc/base/creating_a_child_process_with_redirected_input_and_output.asp[^]

"Let us be thankful for the fools. But for them the rest of us could not succeed." - Mark Twain

"There is no death, only a change of worlds." - Native American Proverb

Re: finishing writing symbol to stdin?

PJ Arends28-Feb-06 7:38

PJ Arends

28-Feb-06 7:38

CTRL Z is ASCII 26, you can enter it in your text literals using the octal notation \032

You may be right
I may be crazy
But it just may be a lunatic you’re looking for
-- Billy Joel --

Within you lies the power for good - Use it!

onSize of CDialog

ns28-Feb-06 4:48

28-Feb-06 4:48

Isn't the onSize() event supposed to fire when you resize a CDialog?

void CDlgMap0::OnSize(UINT nType, int cx, int cy) 
{
	MakePE();
	CDialog::OnSize(nType, cx, cy);
}

In my case the execution never steps into the function.

I have in the .h file, where I added it by hand

protected:

	// Generated message map functions
	//{{AFX_MSG(CDlgMap0)
		// NOTE: the ClassWizard will add member functions here
		afx_msg void OnSize(UINT nType, int cx, int cy);

	//}}AFX_MSG
	DECLARE_MESSAGE_MAP()

thanks,
sb

Re: onSize of CDialog

David Crow28-Feb-06 4:52

David Crow

28-Feb-06 4:52

ns wrote:

In my case the execution never steps into the function.

How do you know?

What does CDlgMap0's BEGIN_MESSAGE_MAP() method look like?

"Let us be thankful for the fools. But for them the rest of us could not succeed." - Mark Twain

"There is no death, only a change of worlds." - Native American Proverb

Re: onSize of CDialog

ns28-Feb-06 5:01

28-Feb-06 5:01

The begin_mesage_map was empty. I've been away from MFC for 2 years (been using QT) . I see now I needed ON_WM_SIZE() in there. Thanks so much for the hint. It works now.
sb

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