C / C++ / MFC Discussion Boards

vikas amin1-Dec-05 23:27

1-Dec-05 23:27

I am having a problem with winsock ?

I have a connected a embedded device with its own TCP/IP stack
which is use to communcate to my application,
in the vc++ i have used the winsock objects .

due to some or the other reasion there are erors like
TCP DUMP or TCP ACK LOST or TCP KEPT ALIVE ,
my application gives some assertions which i cannot track back.
Is there any way to hand this erros by my appliacation

I want individual thread for a socket waiting for connection ,
have done it by CThread call .

Is there any way to know that is my socket alive or not .

What is the force full way to close a socket
Shutdown(socket ,0) or Close(socket)

thak you

Vikas Amin
Embin Technology
Bombay
vikas.amin@embin.com

Re: WinSock.h problem in TCP/IP

sunit52-Dec-05 0:03

sunit5

2-Dec-05 0:03

Shutdown doesnot closes the Socket,resources attached to this
Socket are not freed.For this u have to use the Close,It is
to disable sends and/or receives on the socket.

Close-: it releases the socket descriptor, so that further references to it will fail with the error WSAENOTSOCK

-- modified at 6:04 Friday 2nd December, 2005

Re: WinSock.h problem in TCP/IP

sunit52-Dec-05 0:28

sunit5

2-Dec-05 0:28

u can use a utility called Error Lookup which gives tge text description of an error

Re: WinSock.h problem in TCP/IP

vikas amin2-Dec-05 2:35

vikas amin

2-Dec-05 2:35

thank you
will try for it

Vikas Amin
Embin Technology
Bombay
vikas.amin@embin.com

Re: WinSock.h problem in TCP/IP

Eytukan2-Dec-05 2:10

Eytukan

2-Dec-05 2:10

to check if the thread is alive or not :

DWORD dwExitcode;
::GetExitCodeThread(cwt->m_hThread,&dwExitcode);
if(dwExitcode==STILL_ACTIVE)
{
bla..bla..
}

"But your mind is very complex, very tricky. It makes simple things complicated. -- that's its work. And for centuries it has been trained for only one thing: to make things so complicated that your life becomes impossible."- Osho

<marquee scrollamount="1" scrolldelay="1" direction="up" height="10" step="1">
--[V]--

Re: WinSock.h problem in TCP/IP

Eytukan2-Dec-05 2:11

Eytukan

2-Dec-05 2:11

cwt is CWinThread.

<marquee scrollamount="1" scrolldelay="1" direction="up" height="10" step="1">
--[V]--

Re: WinSock.h problem in TCP/IP

vikas amin2-Dec-05 2:50

vikas amin

2-Dec-05 2:50

tHANK YOU

bUT I HAVE USED THE
SOCKET client_socket ;
for object declaration

So is there any function in the winsock.h which will help
me to know is the socket connected or not .
And is there any fuctino that lets me know that what is the
exact error in the communication (low level/ TCP stact level)

Vikas Amin
Embin Technology
Bombay
vikas.amin@embin.com

Re: WinSock.h problem in TCP/IP

Eytukan6-Dec-05 2:02

Eytukan

6-Dec-05 2:02

vikas amin wrote:
And is there any fuctino that lets me know that what is the
exact error in the communication (low level/ TCP stact level)

what about WSAGetLastError? Unsure | :~

<marquee scrollamount="1" scrolldelay="1" direction="up" height="10" step="1">
--[V]--

Cwnd Close or destroy

Boder Coder1-Dec-05 23:01

Boder Coder

1-Dec-05 23:01

Hi, I want to put check message AfxMessageBox() immediately before Cwnd is closed. When I use 'OnClose() method', it shows AfxMessageBox and closed. However the application.exe is running in the windows. ir can be seen from Ctr+Alt+Del. When I use 'OnDestroy() method' it doesn't show AfxMEssageBox, because the window is already closed. However The Application is killed, it dosen't appear in the task manager. I want to learn How can I do these two things together. I want to check the some variable and show message before window closing and providing application.exe doesn't appear in the task manager.

Re: Cwnd Close or destroy

Russell^'2-Dec-05 0:18

Russell^'

2-Dec-05 0:18

If you want to show a box to stop (or not) a closing a window you can use PreTranslateMessage and look for the message WM_CLOSE.
So you can STOP this message (after the responce of the messagebox)

Matteo

Re: Cwnd Close or destroy

ThatsAlok2-Dec-05 0:58

ThatsAlok

2-Dec-05 0:58

Matteo_78 wrote:
If you want to show a box to stop (or not) a closing a window you can use PreTranslateMessage and look for the message WM_CLOSE.
So you can STOP this message (after the responce of the messagebox)

A little Correction, When a application close from the taskmgr, Windows doesn't send WM_CLOSE/WM_QUIT to the Application.. its simply kill it.

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

Re: Cwnd Close or destroy

ThatsAlok2-Dec-05 0:38

ThatsAlok

2-Dec-05 0:38

MuratMetu wrote:
I want to check the some variable and show message before window closing and providing application.exe doesn't appear in the task manager.

Is there anyway to handle the forced exit of an application by task manager?[^]

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

Internal Error

Cool Ju1-Dec-05 22:53

Cool Ju

1-Dec-05 22:53

Hi,

Does anybody know why this error occur and also please provide some solution.

Internal Error

Unhandled Exception in Debugger::HandleIPCEvent
Event id= 0x20c
Exception code=0xc000005, Eip=0x7927230b
Process id = 0x840(2112), Thread id=0x934(2612)

Thanks,
Cool Ju Cool | :cool:

Dream Ur Destiny

Re: Internal Error

ThatsAlok2-Dec-05 1:16

ThatsAlok

2-Dec-05 1:16

Cool Ju wrote:
Process id = 0x840(2112), Thread id=0x934(2612)

Now could you tell me At the time of crash/Exception.. ProcessID 0x840 belong to which task...

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

From TaskManager - Do not want anyone end task an App./Pross

PanB1-Dec-05 22:03

PanB

1-Dec-05 22:03

Hi There.

Is there any way, I can stop a user to end task an application/Process running, from Task Manager.

Lets say I have a simple application, i.e., HelloWorld. I do not want any user to end task that application from Task manager.

Another Query:
Is it possible to hide an application/process from Task Manager?

Thanks and Regards.
PanB Smile | :)

-- modified at 4:09 Friday 2nd December, 2005

Re: From TaskManager - Do not want anyone end task an App./Pross

ThatsAlok1-Dec-05 23:24

ThatsAlok

1-Dec-05 23:24

PanB wrote:
Is there any way, I can stop a user to end task an application/Process running, from Task Manager.

Lets say I have a simple application, i.e., HelloWorld. I do not want any user to end task that application from Task manager.

Upto Window OS 2000, you can make service to stop user from killing it from Taskmgr.. but Xp and Upward any thing can be closed from taskmgr

PanB wrote:
Is it possible to hide an application/process from Task Manager?

Yes.. Hook the NT dll..

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

Re: From TaskManager - Do not want anyone end task an App./Pross

PanB1-Dec-05 23:27

PanB

1-Dec-05 23:27

Hi Alok.

Thanks for the reply and time.
Actually, I am working on WinXP.

Let me explain my problem in detail.

Lets say I have 2 executables.... a.exe and b.exe.
From a.exe, I am launching my another application b.exe.
i.e., wxExecute(modulePath, wxEXEC_ASYNC, NULL);
In modulePath, I am providing the string to launch b.exe.

Now, both of these applications are running as a stand alone process. But a.exe is a parent and b.exe a child process.

Now at this stage, if a user Kills a.exe from Task Manager, b.exe still run as a stand alone application.

My Requirement.

1. User should not be able to end task a.exe
----1st approach - I may hide it.
----2ns approach - User should not have previledge to kill it.

2. Id user end task a.exe, then b.exe should also be killed automatically.

If you can help, with any of the above appraoches, it will be great.

Thanks for your time and support.
Regards
PanB

Re: From TaskManager - Do not want anyone end task an App./Pross

ThatsAlok2-Dec-05 0:55

ThatsAlok

2-Dec-05 0:55

PanB wrote:
1. User should not be able to end task a.exe
----1st approach - I may hide it.
----2ns approach - User should not have previledge to kill it.

IMHO 1 St Approach will be better, here is link for hiding process from taskmgr,
http://www.codeproject.com/system/Paladin.asp[^]

PanB wrote:
2. Id user end task a.exe, then b.exe should also be killed automatically.

b.exe should check that a.exe is running or not at regular interval (use WM_TIMER and FindWindow), if b.exe don't find a.exe in process list (for this Check out EnumProcess api that will enumerate current system process list for you), it should stop itself or exit...I have used this approach in app monitoring program and its work fine for me till now. (you can make a seprate thread for monitoring in the b.exe).

if you have any suggestion apart from that.. please do share Smile | :)

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

Re: From TaskManager - Do not want anyone end task an App./Pross

PanB2-Dec-05 1:01

PanB

2-Dec-05 1:01

Alok.

Actually you are right.
I was also in touch with other developers in relation to the same.

Other option I was planning to implement was API hooking but that "virusy" way to do things.

Thanks for your support and time.

Questions:
Do you have any sample code to implement the solution. Or just explain the steps I need to follow to implement the same.

Thanks and Best Regards.
PanB

Re: From TaskManager - Do not want anyone end task an App./Pross

ThatsAlok2-Dec-05 1:12

ThatsAlok

2-Dec-05 1:12

PanB wrote:
Do you have any sample code to implement the solution. Or just explain the steps I need to follow to implement the same.

for which Problem... i.e. Problem One :- i have already giving you link that will hook TaskMgr to Hide your Application and problem Second :- I have already given you hint.. if problem is still there then tell me ..

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

Re: From TaskManager - Do not want anyone end task an App./Pross

Blake Miller2-Dec-05 6:18

Blake Miller

2-Dec-05 6:18

How about this.

Duplicate your A.EXE process handle and give the copy 'inheritable' permissions before starting the child process. Pass the handle's value to the child process. Then the child can check the duplicated parent process handle to see if it is signaled to detect that the parent process has exited.

Else, have the child just 'open' the parent process to see if it is running, and use that opened handle to watch for it being signaled.

I can't believe you recommended FindWindow, you should know better than that WTF | :WTF:

Re: From TaskManager - Do not want anyone end task an App./Pross

ThatsAlok4-Dec-05 17:55

ThatsAlok

4-Dec-05 17:55

Blake Miller wrote:
I can't believe you recommended FindWindow

Why Not!, May be I am not clear in expressing my thought.. but i believe this code will express me well..

HWND g_hParentWnd=NULL;

g_hParentWnd=FindWindow(...,...); // Find the Window...

Now make a thread or on WM_TIMER

If(!::IsWindow(g_hParentWnd)) // if the Parent Window Is not Present
 {
  // Exit Process
 }

Blake Miller wrote:
you should know better than that

Any Particular Region for That Sir!

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

Re: From TaskManager - Do not want anyone end task an App./Pross

Blake Miller5-Dec-05 6:01

Blake Miller

5-Dec-05 6:01

I knew what your intention was, you just should not use FindWindow, and I thought you already knew that.

It is well-documented in the literature that FindWindow sends a WM_GETTEXT to all the windows it searches. If you encounter a window that has a stalled message loop, then your application will hang as well. And then if ANOTHER progrma does FindWindow, then guess what, it stalls when it gets to your application, and so on, and so on. Microsoft no longer recommends using that functon UNLESS you are only searching by the window's class name, which does not use the WM_GETTEXT method call.

These articles discuss the problem:

http://www.codeproject.com/dialog/messagemgmt.asp[^]

This one especially:

http://www.developerfusion.co.uk/show/1716/5/[^]

Another:

http://blogs.msdn.com/oldnewthing/archive/2003/8/21.aspx[^]

Re: From TaskManager - Do not want anyone end task an App./Pross

ThatsAlok5-Dec-05 17:34

ThatsAlok

5-Dec-05 17:34

Blake Miller wrote:
is well-documented in the literature that FindWindow sends a WM_GETTEXT to all the windows it searches.

I forget thats Frown | :(

.. Thanks for great Information!

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

Re: From TaskManager - Do not want anyone end task an App./Pross

ThatsAlok5-Dec-05 21:11

ThatsAlok

5-Dec-05 21:11

Blake Miller wrote:
It is well-documented in the literature that FindWindow sends a WM_GETTEXT to all the windows it searches. If you encounter a window that has a stalled message loop, then your application will hang as well. And then if ANOTHER program does FindWindow()

Sorry to Trouble you again Sir!. I am just clearing my doubt.

Here is entry of author of Blogs OldNewthing :-
"
If you are trying to GetWindowText() from a window in another process, then GetWindowText() will use the string from the "special place" and not send a message.
"

What MSDN states: -
In Remark Section of FindWindow :-
"
FindWindow calls the GetWindowText function to retrieve the window name for comparison. For a description of a potential problem that can arise, see the Remarks for GetWindowText.
"

Yes, Sir you 100% right that GetWindowText internally call WM_GETTEXT (i.e. FindWindow api call WM_GETTEXT), but with little exception, here what the remark section tells about that: -

"
If the target window is owned by another process and has a caption, GetWindowText retrieves the window caption text. If the window does not have a caption, the return value is a null string. This behavior is by design. It allows applications to call GetWindowText without hanging if the process that owns the target window is hung
"

But Sir, As Usual, you are Right, it will no good to use the FindWindow method in the scenario where we searching for the window which is hung, then GetWindowText will return NULL String( as written in Documentation), that can make Monitoring application Quit... When the Monitored application is still running. I will Take care of this in future!

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

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