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Initially we have designed a client server model with named pipes.
Where Server is capable of handling only one client.
We expanded the server to hold 4 client instances at a time.
After which application hangs frequently while connection is established between client and Server.
Added the code snippet below.
Please look at the snippet and suggest Is it a right method to handle multiple clients.
//Client.c
rhPipe = CreateFile("\\\\.\\Pipe\\Send", GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL);
if(rhPipe == INVALID_HANDLE_VALUE)
{
rhPipe = NULL;
return;
}
whPipe = CreateFile("\\\\.\\Pipe\\Recv", GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL);
if(whPipe == INVALID_HANDLE_VALUE)
{
whPipe = NULL;
return;
}
char message[512];
char buffer[1024];
BOOL writeStatus = FALSE;
BOOL bResult = FALSE;
DWORD cbBytes = 0;
COMMTIMEOUTS cto;
cto.ReadIntervalTimeout = 5;
cto.ReadTotalTimeoutConstant = 5*1000;
SetCommTimeouts(rhPipe, &cto);
while(1)
{
memset(message,0,sizeof(message));
strcpy(message,"Message From Client.... !!!");
writeStatus = FALSE;
cbBytes = 0;
writeStatus = WriteFile(whPipe, message, sizeof(message), &cbBytes, NULL);
if(writeStatus == FALSE || cbBytes != sizeof((message))
{
return;
}
memset(&buffer,0,sizeof(buffer));
bResult = ReadFile(rhPipe, &buffer, 1024, &cbBytes, NULL);
if(bResult == TRUE)
{
if(cbBytes == 0 )
printf("Receive from Pipe Timeout.... \n");
else
{
printf("Data Received From Server...: %s\n,buffer);
}
}
else
{
if(GetLastError() != 0)
{
CloseHandle(rhPipe);
CloseHandle(whPipe);
return;
}
}
}
//Server.c
typedef struct
{
OVERLAPPED oOverlap;
HANDLE hPipeInst;
CHAR chRequest[BUFFER_SIZE];
DWORD cbRead;
TCHAR chReply[BUFFER_SIZE];
DWORD cbToWrite;
DWORD dwState;
BOOL fPendingIO;
int processId;
} PIPEINST, *LPPIPEINST;
#define RECEIVING_PIPE 0
#define TRANSMITTING_PIPE 1
#define INSTANCES 4
PIPEINST Pipe[INSTANCES];
HANDLE hEvents[INSTANCES];
int CreateIPCPipe(int option)
{
char log_buf[512];
switch(option)
{
case RECEIVING_PIPE:
{
int i;
for (i = 0; i < INSTANCES; i++)
{
hEvents[i] = CreateEvent(NULL,TRUE,FALSE, NULL);
if (hEvents[i] == NULL)
{
return 0;
}
Pipe[i].oOverlap.hEvent = hEvents[i];
Pipe[i].hPipeInst = CreateNamedPipe("\\\\.\\Pipe\\Recv", PIPE_ACCESS_DUPLEX | FILE_FLAG_OVERLAPPED, PIPE_TYPE_MESSAGE | PIPE_READMODE_MESSAGE | PIPE_WAIT, INSTANCES, BUFFER_SIZE, BUFFER_SIZE, PIPE_TIMEOUT, NULL);
if (Pipe[i].hPipeInst == INVALID_HANDLE_VALUE)
{
return 1;
}
else
{
if( Pipe[i].hPipeInst == NULL )
return 2;
}
Pipe[i].fPendingIO = ConnectToNewClient( Pipe[i].hPipeInst, &Pipe[i].oOverlap);
Pipe[i].dwState = Pipe[i].fPendingIO ? CONNECTING_STATE : READING_STATE;
}
}
break;
case TRANSMITTING_PIPE:
{
HANDLE hThread = NULL;
DWORD dwThreadId;
hThread = CreateThread(NULL,0,responsePipeConnectionHandler,NULL,0,&dwThreadId);
if (hThread == NULL)
{
memset(log_buf,0,sizeof(log_buf));
sprintf(log_buf,"Response server creation failed with %d.", GetLastError());
debug_log(log_buf,DEBUG_LOG);
return 1;
}
}
break;
default:
break;
}
return 0;
}
BOOL ConnectToNewClient(HANDLE hPipe, LPOVERLAPPED lpo)
{
char log_buf[512];
BOOL fConnected, fPendingIO = FALSE;
lpo->Offset = 0;
lpo->OffsetHigh = 0;
fConnected = ConnectNamedPipe(hPipe, lpo);
if (fConnected)
{
memset(log_buf,0,sizeof(log_buf));
sprintf(log_buf,"ConnectNamedPipe failed with %d.", GetLastError());
debug_log(log_buf,DEBUG_LOG);
return 0;
}
switch (GetLastError())
{
// The overlapped connection in progress.
case ERROR_IO_PENDING:
fPendingIO = TRUE;
break;
case ERROR_PIPE_CONNECTED:
if (SetEvent(lpo->hEvent))
break;
default:
{
memset(log_buf,0,sizeof(log_buf));
sprintf(log_buf,"ConnectNamedPipe failed with %d.", GetLastError());
debug_log(log_buf,DEBUG_LOG);
return 0;
}
}
return fPendingIO;
}
VOID DisconnectAndReconnect(DWORD i)
{
char log_buf[512];
debug_log("Disconnect and reconnect called",DEBUG_LOG);
if (! DisconnectNamedPipe(Pipe[i].hPipeInst) )
{
memset(log_buf,0,sizeof(log_buf));
sprintf(log_buf,"DisconnectNamedPipe failed with %d.", GetLastError());
debug_log(log_buf,DEBUG_LOG);
}
Pipe[i].fPendingIO = ConnectToNewClient(Pipe[i].hPipeInst, &Pipe[i].oOverlap);
Pipe[i].dwState = Pipe[i].fPendingIO ? CONNECTING_STATE : READING_STATE;
}
HANDLE GetResponseInstance()
{
//Returns Writing Instance
}
int RecvAndProcessPipeMsg()
{
char log_buf[512];
int i = 0;
BOOL wr_status = FALSE;
char message[512};
while (1)
{
BOOL isNewConnetion = FALSE, fSuccess = FALSE,dwWait = FALSE;
int cbRet = 0,dwErr = 0;
dwWait = WaitForMultipleObjects(INSTANCES, hEvents, FALSE, INFINITE);
i = dwWait - WAIT_OBJECT_0; // determines which pipe
if (i < 0 || i > (INSTANCES - 1))
{
printf("Index out of range: %d\n",i);
continue;
}
// Get the result if the operation was pending.
if (Pipe[i].fPendingIO)
{
fSuccess = GetOverlappedResult(Pipe[i].hPipeInst, &Pipe[i].oOverlap, &cbRet, FALSE);
memset(log_buf,0,sizeof(log_buf));
sprintf(log_buf,"Current state system is in : %d ",Pipe[i].dwState);
debug_log(log_buf,DEBUG_LOG);
switch (Pipe[i].dwState)
{
case CONNECTING_STATE:
if (! fSuccess)
{
memset(log_buf,0,sizeof(log_buf));
sprintf(log_buf,"Error %d.", GetLastError());
debug_log(log_buf,DEBUG_LOG);
return 0;
}
else
{
Pipe[i].dwState = READING_STATE;
int clientSessionId = 0;
GetNamedPipeClientProcessId(Pipe[i].hPipeInst,&Pipe[i].processId);
GetNamedPipeClientSessionId(Pipe[i].hPipeInst,&clientSessionId);
memset(log_buf,0,sizeof(log_buf));
sprintf(log_buf,"APP THREAD Process id: %d with sessionID : %d ",Pipe[i].processId,clientSessionId);
debug_log(log_buf,DEBUG_LOG);
memset(log_buf,0,sizeof(log_buf));
sprintf(log_buf,"Connected Client process id: %d",Pipe[i].processId);
debug_log(log_buf,DEBUG_LOG);
}
break;
case READING_STATE:
if (! fSuccess || cbRet == 0)
{
DisconnectAndReconnect(i);
continue;
}
Pipe[i].cbRead = cbRet;
Pipe[i].dwState = WRITING_STATE;
break;
case WRITING_STATE:
if (! fSuccess || cbRet != Pipe[i].cbToWrite)
{
DisconnectAndReconnect(i);
continue;
}
Pipe[i].dwState = READING_STATE;
break;
default:
{
debug_log("Invalid pipe state.",DEBUG_LOG);
return 0;
}
break;
}
}
// The pipe state determines which operation to do next.
switch (Pipe[i].dwState)
{
case READING_STATE:
debug_log("Now in read mode ",DEBUG_LOG);
fSuccess = ReadFile(Pipe[i].hPipeInst,Pipe[i].chRequest,BUFFER_SIZE,&Pipe[i].cbRead,&Pipe[i].oOverlap);
if (fSuccess && Pipe[i].cbRead != 0)
{
Pipe[i].fPendingIO = FALSE;
Pipe[i].dwState = WRITING_STATE;
continue;
}
dwErr = GetLastError();
if (! fSuccess && (dwErr == ERROR_IO_PENDING))
{
Pipe[i].fPendingIO = TRUE;
continue;
}
DisconnectAndReconnect(i);
break;
case WRITING_STATE:
debug_log("Now in WRITE STATE mode ",DEBUG_LOG);
if(isNewConnetion)
{
debug_log("AUTH NEGO ON PROGRESS ",DEBUG_LOG);
Pipe[i].fPendingIO = FALSE;
Pipe[i].dwState = READING_STATE;
isNewConnetion=FALSE;
continue;
}
else
{
Pipe[i].fPendingIO = FALSE;
Pipe[i].dwState = READING_STATE;
HANDLE responsePipe = GetPipeInfoFromTable(Pipe[i].processId);
if (responsePipe != NULL)
{
debug_log("Request has been obtained",DEBUG_LOG);
memset(&message,0,sizeof(message));
memcpy(&message,&Pipe[i].chRequest,sizeof(message));
printf("Received a new Request: %s\n",message);
HANDLE whPipe = GetResponseInstance();
wr_status = WriteFile(whPipe,"Server Received your Request", size,&cbBytes,NULL);
}
else
{
debug_log("Client response pipe not connected",DEBUG_LOG);
}
continue;
}
dwErr = GetLastError();
if (! fSuccess && (dwErr == ERROR_IO_PENDING))
{
Pipe[i].fPendingIO = TRUE;
continue;
}
DisconnectAndReconnect(i);
break;
default:
{
debug_log("Invalid pipe state.",DEBUG_LOG);
return 0;
}
break;
}
}
}
int responsePipeConnectionHandler(VOID)
{
char log_buf[512];
BOOL fConnected = FALSE;
HANDLE hPipe = INVALID_HANDLE_VALUE;
while (1)
{
memset(log_buf,0,sizeof(log_buf));
sprintf(log_buf,"Pipe Server: Main thread awaiting client connection on %s", "\\\\.\\Pipe\\ptrSend");
debug_log(log_buf,DEBUG_LOG);
hPipe = CreateNamedPipe("\\\\.\\Pipe\\ptrSend", PIPE_ACCESS_DUPLEX, PIPE_TYPE_MESSAGE | PIPE_READMODE_MESSAGE | PIPE_WAIT, PIPE_UNLIMITED_INSTANCES,BUFFER_SIZE, BUFFER_SIZE,0, NULL);
if (hPipe == INVALID_HANDLE_VALUE)
{
memset(log_buf,0,sizeof(log_buf));
sprintf(log_buf,"CreateNamedPipe failed, GLE=%d.", GetLastError());
debug_log(log_buf,DEBUG_LOG);
return -1;
}
fConnected = ConnectNamedPipe(hPipe, NULL) ? TRUE : (GetLastError() == ERROR_PIPE_CONNECTED);
if(fConnected)
{
int *clientProcessId = (int *)malloc(sizeof(int));
int clientSessionId = 0;
GetNamedPipeClientProcessId(hPipe,&clientProcessId);
GetNamedPipeClientSessionId(hPipe,&clientSessionId);
memset(log_buf,0,sizeof(log_buf));
sprintf(log_buf,"APP response Process id: %d with sessio nID : %d ",clientProcessId,clientSessionId);
debug_log(log_buf,DEBUG_LOG);
}
}
return 0;
}
BOOL WriteBackToPipe(int EventType, HANDLE whPipe,MSG_STRUCT *message, int size)
{
if(EventType == REGULAR_EVENTS_AND_MESSSAGES && message->msgBuffer.m_dwCategory == CAM_SERVICE_OFFSET)
{
ParseAndSendErrorEvents(message);
message->msgBuffer.m_dwCategory = CAM_SERVICE_OFFSET;
}
g_mutex_lock(write_mutex);
BOOL wr_status = FALSE;
DWORD cbBytes = 0;
if(whPipe != NULL)
{
wr_status = WriteFile(whPipe,message, size,&cbBytes,NULL);
if(wr_status == FALSE)
{
debug_log("Write to pipe failed....",DEBUG_LOG);
}
}
g_mutex_unlock(write_mutex);
return wr_status;
}
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Please edit your question and format your code properly by using the code button above the edit box, or add <pre></pre> tags around it. you also need to indicate where in the code things are going wrong.
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Dear all:
I am new one in win ce 6.0 driver developement.
My question is:
1.How to implement usb touch driver in win ce 6.0?
I am not sure implemented touch driver by usb client driver in win ce 6.0 or this way https://msdn.microsoft.com/en-us/library/ms895471.aspx[^]
Thank for your help, Victor
modified 21-Apr-15 4:42am.
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Hello,
I wonder if there are compatibility issues with "exe" created by my project and Windows.
I use Visual Studio 2008 for MFC projects.
When I compile I create a project file that run on my PC (Windows XP)
Can the "exe" file be executed in every Windows (XP, Vista, 7,8) without problems or do I have put some particular settings during compilation in order to get a universal exe that works in every machine?
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lor75 wrote:
Can the "exe" file be executed in every Windows (XP, Vista, 7,8) without problems or do I have put some particular settings during compilation in order to get a universal exe that works in every machine?
Read up on Visual C++ Redistributable for Visual Studio.
"One man's wage rise is another man's price increase." - Harold Wilson
"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons
"You can easily judge the character of a man by how he treats those who can do nothing for him." - James D. Miles
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They already gave you some good links. Anyway if your problem is to understand if the exe structure itself is compatible between last 5 Os's the answer is yes. The executable format (PECOFF) is the same as the resources format.
More different is the situation from system calls point of view. If an exe using very 'basic' functions can happily run from NT4.0 to WIN10, the things changes as you use new functions from OS or libraries (ie MFC) that were not present in former releases.
So if you want to know if your exec from VC2008 under XP will run on Win7 and Win8 it will do it on 99% of cases.
Instead if you want to build an exe that can run on all OS's from NT on carefully choose the functions you use in your code (or prefer API programming).
P.S. The graphical aspect can be changed between the OS's using an external manifest file with the compatibility fields correctly compiled allowing each OS to use last version of GUI DLL's.
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It should work... however, the libraries used have to be present on that system (unless you explicitly used static linking, which is not the default). MS does package the "redistributables" nicely into an installer for you though. Just make sure that gets installed first or include it along with an installer for your own program and you'll be set.
MS VS2008 x86 Redistributable [^] (there is also a 64bit version, if you don't know which one you're using, it's likely x86 since that's the default build type in 2008 if I remember correctly)
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Hi,
I am creating a child process from a console project way back when I think VS2008
I used to code a _asm { int 3 } to debug the child process the assembler interface is
no longer supported under VS2012 so I have tried DebugBreak(); __debugbreak
In the constructer of the CwinApp or in the InitInstance but nothing happens
When I right click on it to run nothing happens
The CreateProcess in the console process gets a 1 so that works
The only way I can get into the code is if I bring up another instance of VS2012
as this app is another project in the solution and debug from there
any ideas as to why the debugger isn't being invoked would be helpful
thanks
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Hi
This is a follow up to previous message I went back to the parent process
and used the following two flags in the CreateProcess DEBUG_PROCESS and DEBUG_ONLY_THIS_PROCESS
Well back when I was using VS2008 I would get a dialog box informing the VSDebugger
was debugging the process
Now nothing maybe the app crashed before it hit CWinApp constructer where I had the
DebugBreak();
when I went to the "DEBUG" menu item -> Attach to Process I noticed my app on the selection list
When I tried to attach it I got a message Already attached to Debugger
I have no idea what debugger as I only had the original instance to VS2012 running (at least that I could see)
Any help would be appreciated
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Hi
It is apparent there is a issue with debugbreak()
Whether it's windows 8.1 or VS 2012 I don't know
I know I did _asm
{ int 3 }
On my window 7 vs 2010 and it worked
So I am thinking how about this
CreateProces(NULL,
if DEBUG
"C:\windows\system32\vsjitdebugger.exe myprog.exe",
end
else
"myprog.exe",
end
Rest of paramters
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Can you not run the process directly in VS and debug it in the normal way?
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Hi
it just dies somewhere my feeling is there is something amiss in the startup code
as I put DebugBreak(); In The CWinapp constructer
The only way I can debug it if I right click on it VS it gives the option to debug
I know the startup code for a MFC app is somewhere in VS->VC->ATLMFC folder
just trying to figure which one and put a Debugbreak() there
thanks
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hi,
still looking at my problem with debugbreak
for some reason vsjitdebugger which would normally being up a dialog box to chose a debugger
doesn't do that on windows 8.1 vs 2012 pro laptop I think that's part of the problem
Thanks
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Hi 
Before I say I can't English writing. So, Understand me please.
I want to change property of CMFCShellTreeCtrl in MFC.
But, I can't see anywhere.
Question 1.
Now, I can change CMFCShellTreeCtrl property to see filename. But I can't filtering of file in CMFCShellTreeCtrl.
Question 2.
How can I set start directory of CMFCShellTreeCtrl to 'C drive' from 'Desktop'.
Help me please
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limseungkyun wrote:
Now, I can change CMFCShellTreeCtrl property to see filename. But I can't filtering of file in CMFCShellTreeCtrl.
Just guessing but that almost sounds like you'd need a second pane to show the contents of the selected folder (the tree control in the first pane).
limseungkyun wrote:
How can I set start directory of CMFCShellTreeCtrl to 'C drive' from 'Desktop'.
Is it not as simple as calling:
CMFCShellTreeCtrl::SelectPath(_T("C:\\"))
I've not ever used CMFCShellTreeCtrl so my suggestions may be way off.
"One man's wage rise is another man's price increase." - Harold Wilson
"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons
"You can easily judge the character of a man by how he treats those who can do nothing for him." - James D. Miles
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How to write a cross platform tcp c program?
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You write it by coding according to the rules that apply for each platform.
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Sockets aren't exactly implemented the same way across multiple platforms. To achieve a cross-platform program that uses sockets, you can either use compile time switches (#defines) to use the appropriate platform-specific calls and system libraries or use a third party library that already has this compile time switching internally.
A few cross-platform socket libraries:
0) http://zeromq.org/[^]
1) www.boost.org (asio library)[^]
2) Larger frameworks have this too (Qt[^], wxWidgets[^])
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Hi
I am somewhat new to TCP/IP, I have been doing some reading on blocking vs non blocking sockets. So my question is when creating a CAsyncsocket object is constructed and created is there a option for what type of socket
Secondly when you get a notification from one of the callback on receive onsend etc
With an error say WSAEINPROGRESS
From the call backs I guess you should just return
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Thanks I see there are also some other options with ioctl
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Hi,
I have the following Code:
</#include "stdafx.h"
struct DB_FIELD{
const char* FieldName;
const char* DesignerComments;
const unsigned int FieldFlags;
const int FieldType;
const int FieldEltSize;
const int FieldEltCount;
const int FieldOffset;
const unsigned char PaddingChar;
};
struct DB_FIELD TestFieldItem={
"Key", NULL, 0X00000000, 13, 8, 1, 0, 0 };
This refuses to compile with the following error message:
"error C2552: 'TestFieldItem' : non-aggregates cannot be initialized with initializer list".
I must be doing something stupid, that I cannot see. Initialising Static Structures is the Cut and Trust of CPP!
Can anyone see the Obvious?
Bram van Kampen
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I just tried that and it compiled fine. Maybe there is something more that you are not showing us.
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