C / C++ / MFC Discussion Boards

Re: Interprocess Comunication Using Events

Sarath C5-Oct-08 17:24

Sarath C

5-Oct-08 17:24

Are you sure your event has been created before opening in the child process? Please ensure using WinObj.

-Sarath.
"Great hopes make everything great possible" - Benjamin Franklin

My blog - Sharing My Thoughts, An Article - Understanding Statepattern

Re: Interprocess Comunication Using Events

ForNow5-Oct-08 17:35

ForNow

5-Oct-08 17:35

I Checked the handle return from CreateEvent

it had a valid Value

I added code to Create Security DisCriptor TO the Create Event

I am going to try that out

The Only thing I am not 100% certin is Whether Readfile And Write

Share/Inherit the same OverLapped.hEvent

Logically it would seem they would

Re: Interprocess Comunication Using Events

Sarath C5-Oct-08 17:41

Sarath C

5-Oct-08 17:41

Did you check the error using GetLastError()? What's the error code/message you're getting?

-Sarath.
"Great hopes make everything great possible" - Benjamin Franklin

My blog - Sharing My Thoughts, An Article - Understanding Statepattern

Re: Interprocess Comunication Using Events

ForNow5-Oct-08 17:45

ForNow

5-Oct-08 17:45

Yes it was 0x002 FILE_NOT_FOUND

Does really make sense ???

Re: Interprocess Comunication Using Events

Sarath C5-Oct-08 17:56

Sarath C

5-Oct-08 17:56

ForNow wrote:
Yes it was 0x002 FILE_NOT_FOUND

Does really make sense ???

It should make sense. I strongly believe the event doesn't exist in the system when you tried to open it. So please check the source where the even being created and also check if the application calling "CloseHandle" before spawning the child process.

Debug your client program and just before you open the event, verify whether it exists or not using tools like WinObj.

-Sarath.
"Great hopes make everything great possible" - Benjamin Franklin

My blog - Sharing My Thoughts, An Article - Understanding Statepattern

Re: Interprocess Comunication Using Events

ForNow5-Oct-08 19:20

ForNow

5-Oct-08 19:20

thankx

Re: Interprocess Comunication Using Events

ForNow6-Oct-08 14:34

ForNow

6-Oct-08 14:34

I couldn't get anywhere with WinOBJ However I did notice the Handles Column in Task Manager go up by one
When after I executed the CreateEvent

Re: Interprocess Comunication Using Events

Sarath C6-Oct-08 17:22

Sarath C

6-Oct-08 17:22

Hope you've created a named object. The objects with exclamation mark represents events. The tool lacks a "Find" option. Sort it and find it out yourself. Kernel objects will be appeared under "BaseNamedObjects" in the tree

-Sarath.
"Great hopes make everything great possible" - Benjamin Franklin

My blog - Sharing My Thoughts, An Article - Understanding Statepattern

Re: Interprocess Comunication Using Events

ForNow6-Oct-08 19:44

ForNow

6-Oct-08 19:44

The Event I have Created is named While stepping thru the Code with the Visual Studio Debugger after CreateEvent seems like a Handle is Returned

However when I go to WinOBj under --> KenerelObjects Tab there are only two named events HighMemoryCondition and LowmemoryCondition

Re: Interprocess Comunication Using Events

ForNow9-Oct-08 20:29

ForNow

9-Oct-08 20:29

I wrapped the event name inside the TEXT macro for Create and Open Event

and it worked

Re: Interprocess Comunication Using Events

Sarath C13-Oct-08 1:00

Sarath C

13-Oct-08 1:00

How you'd able to compile the source code?

OpenEvent() is Unicode ANSI compatible. if your project settings is to use Unicode character set, then you will have to pass Unicode string.

-Sarath.
"Great hopes make everything great possible" - Benjamin Franklin

My blog - Sharing My Thoughts, An Article - Understanding Statepattern

Re: Interprocess Comunication Using Events

ForNow13-Oct-08 4:09

ForNow

13-Oct-08 4:09

I changed that in the Build to non unicode I seem to be

making progress

[Message Deleted]

flustarter5-Oct-08 11:45

flustarter

5-Oct-08 11:45

[Message Deleted]

Re: Please help!!!! with 2 Dimensional array setup!!!!

Garth J Lancaster5-Oct-08 12:45

Garth J Lancaster

5-Oct-08 12:45

you havnt been around here for long, so you probably missed the bit that goes "we dont do people's homework/assignments/yada yada", even if we do feel a little sorry for them ...

If you post any attempt at code you've got we can use that as a starting point...

I'd suggest (since you say you're using c++) you look at :-

'string' : to hold the filename and a copy of each line in the file - you should only need two string instances to start with

ifstream : to access a data 'stream'/file for input

getline : to get one line of input from the stream/file into a string

while :(loop construct) to loop for all lines in the file until eof (end-of-file) is detected.

for starters.. you'll need to include appropriate headers - I'd suggest fstream, iostream and string ... once you can loop through a file and print its output to 'cout' or such, then think about how each line in the file needs to be split up/parsed to go into your array

'g'

LL_KEYBOARD hook problem

hxhl955-Oct-08 8:24

hxhl95

5-Oct-08 8:24

Hey everyone,

I've been getting some rather interesting results from my LL_KEYBOARD hook recently. Here is my code:

LRESULT CALLBACK LowLevelKeyboardProc (INT nCode, WPARAM wParam, LPARAM lParam)
{
	if (nCode < 0 || nCode != HC_ACTION)
		return CallNextHookEx( hKeyboardHook, nCode, wParam, lParam);

	KBDLLHOOKSTRUCT* p = (KBDLLHOOKSTRUCT*)lParam;
	char logchar=(char)p->vkCode;

It was working fine for a week, but I was adding KEYUP detection for the Ctrl, Alt, and Shift keys when it started giving me unexpected results.

The problem is that when I press the Ctrl key, logchar is equal to -72. I'm surprised by that, since I'm pretty sure the vkCode for the control key is 0x11. Because of this, I'm not detecting the Ctrl keypress, and ToAscii outputs the value for the ctrl key incorrectly. (It's outputting something that looks like a cent sign. If someone could explain why ToAscii accepts -72 as a valid vkcode that would also be appreciated)

The same problem occurs with any non-character key (except for space).

If anyone has any ideas on this I would highly appreciate it.

Thanks in advance. Smile | :)

Re: LL_KEYBOARD hook problem

PJ Arends5-Oct-08 11:24

PJ Arends

5-Oct-08 11:24

the char type has the range of -127 to 128. you want to use an unsigned char which has the range of 0 to 256.

Re: LL_KEYBOARD hook problem

hxhl955-Oct-08 14:16

hxhl95

5-Oct-08 14:16

Ok. I changed it and now the ctrl key is giving a value of 162, which is still not equal to VK_CONTROL (0x11).

Re: LL_KEYBOARD hook problem

PJ Arends5-Oct-08 16:56

PJ Arends

5-Oct-08 16:56

It is however equal to VK_LCONTROL.

Re: LL_KEYBOARD hook problem

hxhl956-Oct-08 7:10

hxhl95

6-Oct-08 7:10

So every time I press the left control key I get a VK_LCONTROL value? Does that mean that the right control key is VK_RCONTROL?

If so, why did the vkcode equal VK_CONTROL a few days ago? I had a switch statement on logchar, and on case VK_CONTROL I would print out [CTRL]. It worked fine until two days ago.

Finally, are there any keyboard drivers that do not seperate VK_LCONTROL from VK_RCONTROL and instead just give a VK_CONTROL value?

Thanks for your help. Big Grin | :-D

Sockets - Roughly, how many clients can a server handle for gaming purposes

simon alec smith5-Oct-08 7:15

simon alec smith

5-Oct-08 7:15

I would like to know, the above mentioned,
for a car racing game,

would the server be able to handle say a thousand cars.

Can anybody suggest a means of testing such a venture?

I am working in MFC at the moment.

Thanks Simon.

Re: Sockets - Roughly, how many clients can a server handle for gaming purposes

cmk5-Oct-08 16:26

cmk

5-Oct-08 16:26

The limit isn't likely going to be based on the network limits.
It will be based on the game engine and the way data is exchanged with the clients.

See: 4.8 How many simultaneous sockets can I have open with Winsock?
http://tangentsoft.net/wskfaq/advanced.html[^]

Also read up on how to impliment IOCP.
e.g. http://msdn.microsoft.com/en-us/magazine/cc302334.aspx[^]
http://www.codeproject.com/info/search.aspx?artkw=iocp[^]

...cmk

The idea that I can be presented with a problem, set out to logically solve it with the tools at hand, and wind up with a program that could not be legally used because someone else followed the same logical steps some years ago and filed for a patent on it is horrifying.
- John Carmack

Re: Sockets - Roughly, how many clients can a server handle for gaming purposes

Moak6-Oct-08 23:18

Moak

6-Oct-08 23:18

One thousand sockets doesn't sounds like impossible. I guess you will hit limitations somewhere else, for example traffic limitation of your internet provider or performance bottlenecks in your server (who has to handle and distribute events to all clients).

Hope it helps.

My webchat in Europe Java | [Coffee]

CFormView looses title on losing focus

bxveer5-Oct-08 3:44

bxveer

5-Oct-08 3:44

I have an app that uses several CFormView objects. I set a default title to each of them when adding their frame windows to the document. I also set a new title in the OnUpdate function of these views based on the value of a member attribute. When the view is invoked it displays the title/caption in the title bar but, strangely, looses the title when loosing focus. The titles becomes ":1", ":2", etc. for these views if I switch from them to other views. To get back the title, I have to force an update so the OnUpdate gets called and the title is reset.

I am sure it's something very minor that's causing it but not sure what it is. Any feedback is very much appreciated.

CSplitterWnd

john56325-Oct-08 3:36

john5632

5-Oct-08 3:36

Hi,
I want to split my window in 2 row but the below code is giving exception.
What is wrong with this?

<br />
CFrameWnd::OnCreateClient(lpcs, pContext);<br />
	if (!m_wndSplitter.CreateStatic(this,2,1))<br />
		return FALSE;<br />
<br />
	m_wndSplitter.CreateView (0,0, RUNTIME_CLASS (CTreeFileRecovered),CSize (245,120), pContext);<br />
	m_wndSplitter.CreateView (1,0, RUNTIME_CLASS (CListFileRecovered),CSize (100,400), pContext);<br />
	<br />
	return TRUE;<br />

Re: CSplitterWnd

PJ Arends5-Oct-08 11:19

PJ Arends

5-Oct-08 11:19

Not enough info. What is the exception and what line of code is giving it?

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