C / C++ / MFC

30-Jun-03 17:52

The doc's for AcceptEx() state that :

On _WindowsXP_ or later, once the AcceptEx function completes and the SO_UPDATE_ACCEPT_CONTEXT option is set on the accepted socket, the local address associated with the accepted socket can also be retrieved using the getsockname function. Likewise, the remote address associated with the accepted socket can be retrieved using the getpeername function.

Great, but what do i do on Win2K ?
After setting SO_UPDATE_ACCEPT_CONTEXT getsockname() works but getpeername() doesn't - in fact it doesn't even give an error, just acts as a no-op.
I don't want to save the remote address from GetAcceptExSockaddrs() as state if i can get/set it in the socket.

I would like to be able to do one of the following :

1. Be able to set the peer address in the accepted socket to the remote address obtained from GetAcceptExSockaddrs() - is there a low-level way to do this ?

2. Use a function(s) other than getpeername() that will also give me the peer address.

3. Give up programming and find a remote tropical island where the most advanced piece of technology i have to deal with is the ice-cooler that's keeping my beer cold.

Any suggestions ?

...cmk

Ryan Binns30-Jun-03 18:52

30-Jun-03 18:52

cmk wrote:
3. Give up programming and find a remote tropical island where the most advanced piece of technology i have to deal with is the ice-cooler that's keeping my beer cold.

That sounds like the best one Big Grin | :-D

Seriously, getpeername() should work, unless there's some obscure reason why it doesn't. Does it work if you don't set SO_UPDATE_ACCEPT_CONTEXT? It only mentions this flag for WinXP, so perhaps it's not necessary for pre-WinXP machines. Certainly, I've used getpeername() successfully on pre-WinXP machines, although I've generally used accept(), not AcceptEx()

Ryan

Being little and getting pushed around by big guys all my life I guess I compensate by pushing electrons and holes around. What a bully I am, but I do enjoy making subatomic particles hop at my bidding - Roger Wright (2^nd April 2003, The Lounge)

Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late - John Nichol "Point Of Impact"

cmk30-Jun-03 21:06

30-Jun-03 21:06

>>Does it work if you don't set SO_UPDATE_ACCEPT_CONTEXT?

No, if i don't set SO_UPDATE_ACCEPT_CONTEXT then even getsockname() won't work.
I think they mention XP because they finally got around to fixing it there. Smile | :)

The problem is only with AcceptEx(), not accept() or WSAAccept().

Part of the problem is that accept() and WSAAccept() are sync calls that block until a connection is available and then they create the socket and establish the connection in one shot.

AcceptEx() is async and requires the socket to be created, then an AcceptEx() request posted. When a connection is available the winsock lib (?) attaches the connection to the pre-created socket but does not set any other state information. Setting SO_UPDATE_ACCEPT_CONTEXT copies the state info from the listening socket to the accepted socket (or is supposed to anyways).

It looks like it doesn't do a complete job in Win2K, so i was hoping to find a low-level way of setting it myself, or find another way of obtaining the peer address from the handle (there has to be a way as netstat shows both sides of the connection).

...cmk

Ryan Binns30-Jun-03 22:14

30-Jun-03 22:14

Is there any particular reason why you don't want to save the remote address returned by AcceptEx() (using GetAcceptExSockaddrs() as you mentioned before)? It sounds to me like there's not much choice.

If you can find out how netstat does it, then that would be the way to go, but I'm not sure how it does it, so you'll have to a bit more investigation Smile | :)

Ryan

Being little and getting pushed around by big guys all my life I guess I compensate by pushing electrons and holes around. What a bully I am, but I do enjoy making subatomic particles hop at my bidding - Roger Wright (2^nd April 2003, The Lounge)

Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late - John Nichol "Point Of Impact"

cmk1-Jul-03 8:41

1-Jul-03 8:41

>> Is there any particular reason why you don't want to save the remote address returned by AcceptEx() (using GetAcceptExSockaddrs() as you mentioned before)?

It bothers me at a very fundamental level to store state that i can get from a cheap function call. Smile | :)

>> It sounds to me like there's not much choice.

<sigh> at this point i expect you're right (was up until 2:30am looking for other workarounds - no joy).

I'll either derive a new socket class for accepted connections, add a peer address field and then overload my GetPeerAddr() method ... what a senseless waste, or go back to sync WSAAccept() (looking like the 'cleaner' solution).

...cmk

Ryan Binns1-Jul-03 15:39

1-Jul-03 15:39

cmk wrote:
It bothers me at a very fundamental level to store state that i can get from a cheap function call.

What's the difference between you storing the address returned by AcceptEx() and referencing it at any time, and the sockets implementation storing the address returned by AcceptEx() and you calling a function to retrieve it. It sounds pretty similar to me, except that the first one is more efficient than the second.

Ryan

Being little and getting pushed around by big guys all my life I guess I compensate by pushing electrons and holes around. What a bully I am, but I do enjoy making subatomic particles hop at my bidding - Roger Wright (2^nd April 2003, The Lounge)

Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late - John Nichol "Point Of Impact"

cmk1-Jul-03 17:08

how to get the current window system language name?

1-Jul-03 17:08

Ryan Binns wrote:
What's the difference between you storing the address returned by AcceptEx() and referencing it at any time, and the sockets implementation storing the address returned by AcceptEx() and you calling a function to retrieve it.

When i store the address i am duplicating what is already in memory somewhere, that is i am using twice as much memory to store the peer address as i should have to (once in the winsock lib, once in my code).

So when we talk about efficiency it is faster for me to access the address if i store it, but it is less memory if i can use the address that the winsock lib has. As we are talking about connections, if you have a server that deals with 1,000's of simultaneous connections this can add up (ok, not much, but enough that it bothers me Smile | :)

).

Anyways, i've already coded my work around.
Added an #ifdef CKNET_USE_ACCEPTEX that if enabled uses AcceptEx and adds a peer address field to my connection class, #ifndef then tie up one (or more) of the IOCP threads to sit in a loop waiting on accept(). I find both acceptable workarounds for now.

...cmk

benben30-Jun-03 17:35

benben

30-Jun-03 17:35

Hi:
how to get the current windows system language name? I want to know if it is English or the other languages(such as chinese, japanese)

Re: how to get the current window system language name?

Toni7830-Jun-03 18:14

Re: how to get the current window system language name?

30-Jun-03 18:14

Check out the PRIMARYLANGID macro. I hope that helps you.

// Afterall, I realized that even my comment lines have bugs

When one cannot invent, one must at least improve (in bed).-My latest fortune cookie

Ryan Binns30-Jun-03 18:58

Re: how to get the current window system language name?

30-Jun-03 18:58

Look at the GetLocaleInfo() function, specifying either LOCALE_SYSTEM_DEFAULT or LOCALE_USER_DEFAULT for the first parameter.

Ryan

Being little and getting pushed around by big guys all my life I guess I compensate by pushing electrons and holes around. What a bully I am, but I do enjoy making subatomic particles hop at my bidding - Roger Wright (2^nd April 2003, The Lounge)

Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late - John Nichol "Point Of Impact"

Toni7830-Jun-03 19:12

Re: how to get the current window system language name?

30-Jun-03 19:12

Man, I wish I had heard about that function a year ago. Good job Ryan! Your replies never cease to amaze me. I truly learn a lot from your posts.

// Afterall, I realized that even my comment lines have bugs

When one cannot invent, one must at least improve (in bed).-My latest fortune cookie

Rage30-Jun-03 20:51

Rage

30-Jun-03 20:51

Toni78 wrote:
Your replies never cease to amaze me. I truly learn a lot from your posts.

so true.

~RaGE();

Re: how to get the current window system language name?

Ryan Binns30-Jun-03 22:03

30-Jun-03 22:03

Thanks

benben30-Jun-03 20:39

benben

30-Jun-03 20:39

Thanks a lot
benben

Re: Thanks

Ryan Binns30-Jun-03 22:04

CListCtrl can we get a handle to the icon associated to the text

30-Jun-03 22:04

You're welcome Smile | :)

FASTian30-Jun-03 17:30

FASTian

30-Jun-03 17:30

Can we get a handle or icon id of an item which has been inserted in to a ListCtrl?

Example: if we have two icons in our image list and we inserted 100 items in the list can we find out if item 30 has icon #1 displayed with it or icon #2 displayed with it

P.S we are assuming that a image list has been associated to the control.

Re: CListCtrl can we get a handle to the icon associated to the text

Ryan Binns30-Jun-03 19:07

How to disable the "Esc" key

30-Jun-03 19:07

If you're using MFC, do this:

LVITEM lvi;
lvi.mask = LVIF_IMAGE;
lvi.iItem = nItemIndex;  // The index of the item to get the image of
m_listCtrl.GetItem(&lvi);
// lvi.iImage will be the index of the image, starting from 0

If you're not using MFC, do it this way:

LVITEM lvi;
lvi.mask = LVIF_IMAGE;
lvi.iItem = nItemIndex;  // The index of the item to get the image of
SendMessage(hwndListCtrl, LVM_GETITEM, 0, (LPARAM)&lvi);
// lvi.iImage will be the index of the image, starting from 0

Hope this helps,

Ryan

Being little and getting pushed around by big guys all my life I guess I compensate by pushing electrons and holes around. What a bully I am, but I do enjoy making subatomic particles hop at my bidding - Roger Wright (2^nd April 2003, The Lounge)

Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late - John Nichol "Point Of Impact"

FlyingDancer30-Jun-03 17:15

FlyingDancer

30-Jun-03 17:15

I create a dialog.
And it is not expected to be closed when pressing the "Esc" key.
How to solve this problem?
Thank you in advance

Toni7830-Jun-03 17:23

30-Jun-03 17:23

Try to override CDialog::OnCancel().
Something like
void CMyDialog::OnCancel() { return;}

// Afterall, I realized that even my comment lines have bugs

When one cannot invent, one must at least improve (in bed).-My latest fortune cookie

FlyingDancer30-Jun-03 18:15

FlyingDancer

30-Jun-03 18:15

It works well after I do as your directions.
Rose | [Rose]

Toni7830-Jun-03 18:50

30-Jun-03 18:50

I am glad that it works well. I would also consider kmaz's directions as well even though I have never tried (or for that matter of fact heard that approach [then again, I have a lot to learn]). But it sounds very interesting and probably is worth to try it.

// Afterall, I realized that even my comment lines have bugs

When one cannot invent, one must at least improve (in bed).-My latest fortune cookie

FlyingDancer30-Jun-03 19:37

FlyingDancer

30-Jun-03 19:37

It seems very difficult
If by overriding the function, I want to do like below:
bool m_bEsc;
void CAbc::OnCancel()
{
if( !m_bEsc)
return;
else
CDialog::OnCancel();
}
bool A()//Some operations to keybord's actions
{
....
}

Do you think that can work well?

Toni7830-Jun-03 19:53

30-Jun-03 19:53

Aleon666 wrote:
bool m_bEsc;
void CAbc::OnCancel()
{
if( !m_bEsc)
return;
else
CDialog::OnCancel();
}
bool A()//Some operations to keybord's actions
{
....
}

I don't see a reason why that would not work. Somebody else correct me please if I am wrong. But you have to try it yourself.

// Afterall, I realized that even my comment lines have bugs

When one cannot invent, one must at least improve (in bed).-My latest fortune cookie

Ryan Binns30-Jun-03 22:06