C / C++ / MFC

25% loss on fiber optic "T1"

1-Jun-04 7:29

Something to begin with

Here[^]

WinPcap: the Free Packet Capture Architecture for Windows
[^]

Papa

while (TRUE)
Papa.WillLove ( Bebe ) ;

joegood1-Jun-04 7:03

joegood

1-Jun-04 7:03

First some details:
Our application receives a data feed over a fiber optic T1. We develop both the client and server applications that send and receive the data. Both applications are written in ANSII C++ for portability. We use Winsock when running on a Windows platform.

The problem:
Sometimes the T1 line experiences 25% loss according to the ping tool. During these times we often see our connection from client to server disconnect with an error 10054 (An existing connection was forcibly closed by the remote host.). Is there anything we can do, programatically, to avoid connection loss or to quickly recover from the connection loss?

Thanks in advance

Sharing a variable with no synchronization

Hesham Amin1-Jun-04 6:42

1-Jun-04 6:42

Hi is it dangerous to have many threads read one shared variable/object without using any synchronization mechanisms?
(read only)
this variable can be a static or a regular member of a class...

jmkhael1-Jun-04 6:46

1-Jun-04 6:46

You are not changing anywhere this variable?

Papa

while (TRUE)
Papa.WillLove ( Bebe ) ;

Hesham Amin1-Jun-04 6:51

1-Jun-04 6:51

no just a global variable that i set before i begin any threads..
after threads begin..they just need to read the variable/object.

jmkhael1-Jun-04 6:53

1-Jun-04 6:53

And in the object, are they changing any data concurently?
Or its just read read situation?

Papa

while (TRUE)
Papa.WillLove ( Bebe ) ;

Hesham Amin1-Jun-04 6:56

1-Jun-04 6:56

a read read situation..
just in case that i change any data .. i use make synchronization inside the function that make the change.

jmkhael1-Jun-04 7:00

1-Jun-04 7:00

Shouldn't have a problem.

Papa

while (TRUE)
Papa.WillLove ( Bebe ) ;

Hesham Amin1-Jun-04 7:05

1-Jun-04 7:05

thanks..
just wanted to make sure Smile | :)

Blake Miller1-Jun-04 13:09

Blake Miller

1-Jun-04 13:09

If there is any chance that some threads might be READING the data while others are changing it EVER, then you will have trouble unless you synchorize the readers ALONG with the writers.
If the data is only written before any of your reader threads start up, you are safe.

Grid control

richiebabes1-Jun-04 6:09

richiebabes

1-Jun-04 6:09

I can't get Chris Maunder's grid control to work. Get this:

Linking...
GridCtrl.obj : error LNK2019: unresolved external symbol "public: virtual __thiscall CTitleTip::~CTitleTip(void)" (??1CTitleTip@@UAE@XZ) referenced in function __unwindfunclet$??0CGridCtrl@@QAE@HHHH@Z$0
GridCtrl.obj : error LNK2019: unresolved external symbol "public: __thiscall CTitleTip::CTitleTip(void)" (??0CTitleTip@@QAE@XZ) referenced in function "public: __thiscall CGridCtrl::CGridCtrl(int,int,int,int)" (??0CGridCtrl@@QAE@HHHH@Z)
GridCtrl.obj : error LNK2019: unresolved external symbol "public: void __thiscall CTitleTip::Hide(void)" (?Hide@CTitleTip@@QAEXXZ) referenced in function "protected: void __thiscall CGridCtrl::OnHScroll(unsigned int,unsigned int,class CScrollBar *)" (?OnHScroll@CGridCtrl@@IAEXIIPAVCScrollBar@@@Z)
GridCtrl.obj : error LNK2019: unresolved external symbol "public: void __thiscall CTitleTip::Show(class CRect,char const *,int,struct tagRECT *,struct tagLOGFONTA const *,unsigned long,unsigned long)" (?Show@CTitleTip@@QAEXVCRect@@PBDHPAUtagRECT@@PBUtagLOGFONTA@@KK@Z) referenced in function "protected: void __thiscall CGridCtrl::OnMouseMove(unsigned int,class CPoint)" (?OnMouseMove@CGridCtrl@@IAEXIVCPoint@@@Z)
Debug/gc.exe : fatal error LNK1120: 4 unresolved externals

Help!!!!!!!!!1

Re: Grid control

jmkhael1-Jun-04 6:13

AfxBeginThread problem (with member function)

1-Jun-04 6:13

Seems like a file is missing from the project

Papa

while (TRUE)
Papa.WillLove ( Bebe ) ;

BlackDice1-Jun-04 5:46

1-Jun-04 5:46

I've used the AfxbeginThread function before with a global function, but is there a way I can use it with a member function of the object it's operating in? When I try to use it here, I get the following error message:

error C2665: 'AfxBeginThread' : none of the 2 overloads can convert parameter 1 from type 'UINT (LPVOID)'

and here is the function declaration:

UINT Parse( LPVOID pParam );

If it's broken, I probably did it

bdiamond

jmkhael1-Jun-04 5:48

1-Jun-04 5:48

declare it as a static function
A member function has a thiscall convention, so it has an additional this parameter passed.
When you declare it static this wont be passed anymore, thus fixing your problem

Papa

while (TRUE)
Papa.WillLove ( Bebe ) ;

BlackDice1-Jun-04 5:51

1-Jun-04 5:51

thanks!! just what I needed!

If it's broken, I probably did it

bdiamond

BlackDice1-Jun-04 5:54

1-Jun-04 5:54

that was what I needed, but now I get errors because I tried to call a non-static member function within the procedure,(BeginWaitCursor), but there's also other ones.

If it's broken, I probably did it

bdiamond

jmkhael1-Jun-04 5:59

1-Jun-04 5:59

Several options:

1. Pass this into the parameter to the thread and call the functions
2. Send a message to the original window and handle them

Papa

while (TRUE)
Papa.WillLove ( Bebe ) ;

BlackDice1-Jun-04 6:06

1-Jun-04 6:06

I got it!! What I did was pass the 'this' pointer as the LPVOID argument and cast it to a pointer of the type of my dialog class, then use that pointer to reference the controls and member variables. Thanks!!

If it's broken, I probably did it

bdiamond

vector problem

BlackDice1-Jun-04 5:19