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I am writting an application that needs to create a thread, I have no problem if I only want to pass a handle, however I need to pass several parameters to the thread. I tried creating a structure to no avail, I also tried passing the address of the variable structure with the same results.
Can I create handle to a structure, or what options do I have?
I also wonder if the values in the parameters the thread uses will change if my application changes them.
This  newbie, thanks you in advance for your help.
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Passing a pointer to a structure/class object should work fine.
You need to make sure that pointer and the object it points to
stays in scope. The struct/class object can be on the heap, or
it can be a global object, or a member of another struct/class
object that stays in scope.
Mark
Mark Salsbery
Microsoft MVP - Visual C++
![Java | [Coffee]](https://codeproject.global.ssl.fastly.net/script/Forums/Images/coffee.gif)
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Thanks for prompt reply!
You are absolutely correct, and I am having difficulty doing this. I am declaring the structure outside of WinMain and I am setting the values in my message loop. I thought that would take care of the scoping issue. What am I missing?
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Can you show the code (or equivalent)?
Here's a simple example - it's a silly example since the thread proc has
direct access to the global struct object, but hopefully it
shows you a way to pass a pointer to the thread proc...
#include <process.h>
struct MyThreadParams
{
int a;
int b;
int c;
};
MyThreadParams GlobalThreadParams;
unsigned __stdcall WorkerThreadProc(void *lpParameter)
{
MyThreadParams *pThreadParams = (MyThreadParams *)lpParameter;
return 0;
}
int SomeFunc()
{
GlobalThreadParams.a = 0;
GlobalThreadParams.b = 1;
GlobalThreadParams.c = 2;
HANDLE hThread = (HANDLE)_beginthreadex(NULL, 0, WorkerThreadProc, &GlobalThreadParams, 0, NULL);
if (hThread)
{
::CloseHandle(hThread);
}
...
Mark Salsbery
Microsoft MVP - Visual C++
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Errr, just a stupid question: what's the point of passing a pointer to a global structure ? Your thread can access it directly 
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I try a stupid answer: the thread hasn't to know it is working on global scope. I mean, you may have two or three of such structs and the thread is designed to work always on a single one, then you select the proper one on thread call (i.e. something similar to a master/slave approach to threading).
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
[my articles]
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If you look closely, I stated:
"...it's a silly example since the thread proc has
direct access to the global struct object, but hopefully it
shows you a way to pass a pointer to the thread proc..."
So, basically, it's because I was too lazy to type a more
robust example 
Mark
Mark Salsbery
Microsoft MVP - Visual C++
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Mark Salsbery wrote: If you look closely
Ha ! That was the problem, I knew it
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Cedric Moonen wrote: I knew it
I knew it too, because I now have my CPMRU
Mark Salsbery
Microsoft MVP - Visual C++
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Thanks you very much, it works, you 'da man.
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Ok since this seemed to set off a side discussion. My ultimate plan is to have the thread function in an include file, does this change the equation?
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I'm working on a small embedded web server for my app Surfulater and wonder if anyone knows the steps involved in a XMLHttpRequest POST.
It appears that the server gets the Headers first, then sends back a 200 OK response and then receives the BODY for the POST.
This isn't my understanding of how it should work from reading the HTTP 1.1 RFC etc. Which indicates the POST Headers and Body are sent as one. My testing so far has been from IE6 only.
I'm trying to work out if my code is wrong or my understanding of the HTTP spec or the Browser implementation varies.
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Neville Franks wrote: It appears
Appears?
led mike
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led mike wrote: Appears
Verb: appear:
1. Give a certain impression or have a certain outward aspect "This appears to be a very difficult problem"; "They appeared like people who had not eaten or slept for a long time"
2...
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Verb: appear:
also "It appears you still have not explained how you determined this is happening" 
led mike
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led mike wrote: also "It appears you still have not explained how you determined this is happening"
By looking at what WSARecv received. The problem was the HTTP POST data was being received in multiple TCP packets, whereas I incorrectly assumed the Header & Body would come as one.
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Neville Franks wrote: By looking at what WSARecv received. The problem was the HTTP POST data was being received in multiple TCP packets, whereas I incorrectly assumed the Header & Body would come as one.
Yes, that is an artifact of TCP not HTTP. However your original post said:
Neville Franks wrote: It appears that the server gets the Headers first, then sends back a 200 OK response and then receives the BODY for the POST.
How do you know that? What do you mean "the server"? If it's your server, the one you are developing then you are doing it wrong. Of course the client doesn't know that because by the time it gets your 200 reply it has already sent it's entire message so it has no way of knowing that didn't read it all before you sent your reply.
led mike
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You are right, the code in my server was wrong. Up until now it only had code to handle a GET and this incorrectly handled POST. It got a packet with the "complete" headers which for a GET is the end of the story. For a POST there maybe a BODY still to come. It was simply a matter of updating the logic to correctly determine the end of the POST request.
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I am developing a COM based exe that needs some already available functionality ( which exists in the form a static library using MFC ( MFC statically linked ) ). The API's exposed by the static library use primitive data types such as int , unsigned char etc .
However when I include the static library in the COM project, it gives me a linker error about some CString's used .
This is how the code is organized
static library header file mystatic.h
int LibFunc1( int in, char *out) ;
static library source file mystatic.cpp
int LibFunc1( int in, char *out) <br />
{<br />
<br />
.. <br />
CString s = "Hello"; <br />
}
Com Component using static library
#include "mystatic.h"<br />
<br />
<br />
..<br />
..<br />
LibFunc1(x, y)
I am wondering if there is a better way of re-using this as I dont want to rewrite the static library logic .
Help is appreciated.
Engineering is the effort !
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What version of MFC is the library linked with?
If CString is the only class you use, it's no longer part of MFC,
and can be used without MFC.
Mark
Mark Salsbery
Microsoft MVP - Visual C++
![Java | [Coffee]](https://www.codeproject.com/script/Forums/Images/coffee.gif)
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MFC 4
Engineering is the effort !
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I have stated CString as an eg however the static library uses other classes such as CStringArray , CArray etc
Engineering is the effort !
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Cool.
What are the exact linker errors?
From the code you've shown, the COM module shouldn't know
anything about a CString in the library code.
Mark
Mark Salsbery
Microsoft MVP - Visual C++
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Hi,
Suppose two processes are communication through Namedpipes and one of them gets killed.
Then how will the first process come to know that second process got killed.
Any kind of help would be welcome.
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A read or write on the pipe will fail.
I would guess the error will be ERROR_BROKEN_PIPE...test it
Mark
Mark Salsbery
Microsoft MVP - Visual C++
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