C / C++ / MFC

Malcolm McMahon28-Aug-01 3:04

28-Aug-01 3:04

Yes, the WSAAyncSelect maintains a single state for a socket, each call overrides the previous and the flags are indeed a bit map you can or. Always call your recv until you get a WOULDBLOCK error, then wait for the message.

Kuniva28-Aug-01 23:11

Kuniva

28-Aug-01 23:11

um sorry i dont get that.

how can i see if the message WSAAsyncselect() sends is triggered by FD_READ or FD_CLOSE ???

i also need to know how i can see if there's an incoming connection request and how to accept it because i just added FD_ACCEPT to WSAAsyncselect() and i made the socket listen but it just accepted the connection without i used the accept() function... i think its weird... (i saw the connection was accepted because i ran netstat and it said under connection status "ESTABLISHED")

Kuniva

Kuniva28-Aug-01 23:14

Kuniva

28-Aug-01 23:14

i will make this more practical to imagine by telling u what program it is.
It is supposed to be a multithreaded echo server, i mean, its supposed to accept any incoming connection request AND (the special bit) when 1 client sends something to the server, the server needs to send this back exactly as it came to ALL (i repeat ALL) connected clients.

hope this helps?

Thanks for the help

Kuniva

Malcolm McMahon29-Aug-01 0:04

29-Aug-01 0:04

The top half of the long value in the window message (from memory) contains the
FD_ flags for the event(s) that trigger the message.

In general, however, I use AsyncSelect like this:

I make a winsock call.
If the call returns the WOULDBLOCK result I wait for AsyncSelect to send a message.
I make the same call again. This time I should get a real result (should I get a WOULDBLOCK I'll wait again).

When I get these messages I generally just look for an error code , or a FD_CLOSE. Otherwise I check the status by making the winsock calls.

So, for example, you do a listen. You call accept and it will normally give you a WOULDBLOCK (if it doesn't it means a call is already waiting and you can take it).

Then you wait for a message from asynselect to tell you there's a connection waiting.

Then you make that accept call again and it gives you the new socket.

The only exception to this pattern is the connect call which you only make once. In the case of the connect call once your FD_CONNECT comes back you're connected. You don't make the connect call again (an annoying inconsistency to my mind).

Tooltips and Trees

Malcolm McMahon28-Aug-01 2:50

28-Aug-01 2:50

I've been trying to get tooltip hints working as the mouse passes over a TreeCtrl. I've created an OnToolTip handler, which does indeed get called when you settle the mouse on a tree item.

What I can't figure is how to translate what's passed to the handler into a HTREEITEM or similar so I can find the co-responding tree item and, hence, build suitable text. Confused | :confused:

I've got control IDs and a window handle available but I can't see how to translate either.

I've been using a CMapPtrToPtr to map the HTREEITEM to the relevant data object though, on further study, it probably makes more sense to point the item data field at the object.

Tomasz Sowinski28-Aug-01 3:24

Tomasz Sowinski

28-Aug-01 3:24

Do you handle TVN_GETINFOTIP?

Tomasz Sowinski -- http://www.shooltz.com

Malcolm McMahon28-Aug-01 5:20

28-Aug-01 5:20

I think that's the message I handle (don't have the code with me here). Certainly the routine I put in get's called when I'd expect it to, I just don't know how to make sense of the parameters.

Tomasz Sowinski28-Aug-01 5:25

Tomasz Sowinski

28-Aug-01 5:25

You should have pointer to NMTVGETINFOTIP structure, which is full of relevant information.

Tomasz Sowinski -- http://www.shooltz.com

Malcolm McMahon28-Aug-01 5:28

28-Aug-01 5:28

Yup, I think that's the structure (this would be a lot easier if I had the code here). The structure I get contains a window handle and a what is probably a controll id. But what I need to access the data and supply the text is the HTREEITEM handle, which just doesn't seem to be arround. Nor can I find anything in CTreeCtrl that seems intended to look it up.

Tomasz Sowinski28-Aug-01 5:34

Tomasz Sowinski

28-Aug-01 5:34

Yup, I think that's the structure (this would be a lot easier if I had the code here). The structure I get contains a window handle and a what is probably a controll id.

You're probably talking about NMHDR - it contains a handle and an id. You can cast the pointer to *NMTVGETINFOTIP to get more info - assuming that you're really handling TVN_GETINFOTIP.

Tomasz Sowinski -- http://www.shooltz.com

Malcolm McMahon28-Aug-01 5:41

28-Aug-01 5:41

Thanks, that's probably it. I may well be looking at too generic a message too. I'll give it a go tonight.

Memory leak

Noman Nadeem28-Aug-01 2:16

Noman Nadeem

28-Aug-01 2:16

Hi,
I have come accross a memory leak in my project ...

could anyone suggest any memmory leak testing utility which will help me pinpoint the source of the leak

regards

Re: Memory leak

Anders Molin28-Aug-01 2:23

Anders Molin

28-Aug-01 2:23

BoundsChecker from Numega is great. You can get a 15-days evaluation copy their website...

- Anders

Money talks, but all mine ever says is "Goodbye!"

Re: Memory leak

billb211228-Aug-01 6:15

billb2112

28-Aug-01 6:15

BoundsChecker does work wonders, but the object dump should do a pretty good job of telling you where your leak might be. Sometimes, if you're lucky, if you click on the object name or the memory address the debugger spits out right below "Detected memory leaks -->" it will put you in the right area of the source. If it doesn't, then you'll have to do a little fishing on your own or consider NuMega products.

Bill

http://www.ratebeer.com

Re: Memory leak

Derek Waters28-Aug-01 14:08

Derek Waters

28-Aug-01 14:08

Actually, if you really want to track down these memory leaks without forking out for BoundsChecker, there is a really good debugging trick described in Knowledge Base Article Q151585 which described the _crtBreakAlloc variable (You can search for Q151585 or "Use _crtBreakAlloc to Debug a Memory Allocation" in MSDN)

Basically, when you get an object dump with numbers next to it, you start your program in the debugger, set _crtBreakAlloc to that number, then run your program. The debugger will break when the memory is allocated that you have forgotten to free. Very very handy.

------------------------
Derek Waters
derek@lj-oz.com

Two simple questions ...

Hadi Rezaee28-Aug-01 1:12

Hadi Rezaee

28-Aug-01 1:12

Hi all,

Q1.
I can convert LPSTR to LPWSTR:

USES_CONVERSION;
LPWSTR lp1 = A2W(szString);

Is any other way to convert LPSTR to LPWSTR ???

Q2.
What is difference between E_FAIL and S_FALSE ???

Thanks for helps ...

My month article: Game programming by DirectX by Lan Mader.
Please visit in: www.geocities.com/hadi_rezaie/index.html

Hadi Rezaie

Anders Molin28-Aug-01 2:20

Anders Molin

28-Aug-01 2:20

something like:

wchar_t* AmA2W(const char *s)
{
  int clen = strlen(s);
  wchar_t *w = (wchar_t*)calloc(clen + 1, sizeof(wchar_t));
  MultiByteToWideChar(CP_ACP, 0, s, clen, w, clen);
  return w;
}

Just remember to manually free the returned string.

- Anders

Money talks, but all mine ever says is "Goodbye!"

Hadi Rezaee28-Aug-01 19:12

Hadi Rezaee

28-Aug-01 19:12

Hi Molin,
About, fifth parameter in MultiByteToWideChar ...
If i put -1 instead w, then what will happen ?

My month article: Game programming by DirectX by Lan Mader.
Please visit in: www.geocities.com/hadi_rezaie/index.html

Hadi Rezaie

Anders Molin28-Aug-01 22:09

Anders Molin

28-Aug-01 22:09

I guess the function will fail. The fifth parameter is a wide-character buffer...

- Anders

Money talks, but all mine ever says is "Goodbye!"