Named Pipes (Windows) ERROR_PIPE_BUSY

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C++

C

Windows

IPC

Hello Fellow Programmers,
I'm developing two programs in 'C'. One is for sending data and second is for receiving(not simultaneously) Using 'NamedPipes'.

Here i really want to explain you that what i did in both programs:

* Sending Program--> lets say server.c

Here i created pipe with CreateNamedPipe(); 
create a file with CreateFile(); 
write data with WriteFile(); 
close file handle with Closehandle();

** Receiving Program--> Client.c

Create a file with CreateFile(); //Error :- 231 ERROR_PIPE_BUSY 
[ When i used WaitNamedPipe(), than it start waiting infinitely ] 

//The code written below will be run when the CreateFile() run successfully.....
Set pipe state to 'PIPE_READMODE_MESSAGE' with SetNamedPipeHandleState();
Reading data with ReadFile(); 
closehandle();

So now Please Tell me, why there is Error: 231 ERROR_PIPE_BUSY ???????


Thanks a lot in Advance.
:)

Sender.c:

//------------> Sender.c
 
#define buffersize 500
int main()
{
 
HANDLE mypipe;
HANDLE myfile;
HANDLE glerr;
LPCTSTR pipe_name=TEXT("\\\\.\\pipe\\mynewmsngr");
TCHAR inbuf[buffersize];
LPTSTR outbuf = TEXT("AMS_NDIS");
LPTSTR cmptrname;
char temp_out[buffersize];
DWORD nbytes,dwmode,nsend;
BOOL success=0;
printf("Program Started.\n");
//Creating New Pipe.
mypipe = CreateNamedPipe(/* lpName*/ pipe_name,                     
/* dwOpenMode */               PIPE_ACCESS_DUPLEX ,
/* dwPipeMode */               PIPE_TYPE_MESSAGE | PIPE_READMODE_MESSAGE | PIPE_WAIT,
/* nMaxInstances */            PIPE_UNLIMITED_INSTANCES,
/* nOutBufferSize */         buffersize,
/* nInBufferSize */            buffersize,
/* nDefaultTimeOut */         5000,
/* lpSecurityAttributes */ NULL);
 
if(mypipe!=NULL)
{
      printf("Named pipe created successfully.\n");
}
else
{
   printf("Program EXIT.\n");
   sleep(5000);
   exit(1);
}   
 
//-------------> Creating New File.
myfile = CreateFile(pipe_name,                                             //lpFileName
                              GENERIC_READ | GENERIC_WRITE,               //dwDesiredAccess
                              FILE_SHARE_READ | FILE_SHARE_WRITE,      //dwShareMode
                              NULL,                                             //lpSecurityAttributes
                              CREATE_ALWAYS,                              //dwCreationDisposition
                              0,                                             //dwFlagsAndAttributes
                              NULL);                                       //hTemplateFile
                              
// printf("GetLastError after File Creation on Sender Side: %d\n",GetLastError());
 
if( myfile == INVALID_HANDLE_VALUE )
   printf("Error in Creating File. ErrorCode:%d\n",GetLastError());
else
      {
      printf("Pipe File created successfully.\n");   
      }
 
      sleep(5000);
 
      
while(      ConnectNamedPipe(mypipe,NULL) )
{
      if(GetLastError()==535)         //ERROR_PIPE_CONNECTED.
      {
                                                   
 
/*                                                   
//Receiving Message.
         success = 0;
         success = ReadFile(mypipe,inbuf, buffersize, &nbytes, NULL);
                  if(success!=0)
                  {
                        printf("Message Received: %s\n",inbuf);
                        sleep(3000);
                  }
                  else
                  {
                        printf("Message Receiving failed. Error: %d\n",GetLastError());
                  getch();
                  exit(1);
                  }
*/                     
                        
//Sending Message.   
               printf("Message:");
               scanf("%s",&temp_out);
               nsend=strlen(temp_out);
               outbuf=TEXT(temp_out);      
               printf("Sending Message of %d bytes.\n",nsend);
               success = 0;               
               success = WriteFile(myfile,outbuf, nsend, &nbytes, NULL);
               if ( success!=0)
                        {
                              printf("Message Sent successfully.\n");   
                              printf("Message: %s\n\n",outbuf);   
                              //CloseHandle(myfile);
                              //CloseHandle(mypipe);
                              DisconnectNamedPipe(mypipe);
                                    /*
                                          printf("Do you want to Continue To Reading(press 1 if YES):");
                                          int choice;
                                          scanf("%d",&choice);
                                          if(choice==1)
                                             {
                                             
                                                success = ReadFile(mypipe,inbuf, buffersize, &nbytes, NULL);
                                                if(success==1)
                                                {
                                                      printf("Message Received: %s\n",inbuf);
                                                      sleep(3000);
                                                }
                                                else
                                                      printf("Message Receiving failed. Error: %d\n",GetLastError());
                                             }
                                             else
                                             exit(1);
                                       */
                           }
         else
               {
               printf("Message Sending failed.\n");
               }
      }
      else
      {
            printf("Client not connected. ErrorCode: %d",GetLastError());
            getch();
      }
};
printf("GetLastError: %d\n",GetLastError());
 
getch();
   return 0;

Receiver.c:

///--------------> Receiver.c
 
#include<stdio.h>
#include<stdlib.h>
#include<windows.h>
#include<tchar.h>
#define buffersize 500
int main()
{
HANDLE mypipe,myfile=NULL;
LPCTSTR pipe_name=TEXT("\\\\.\\pipe\\mynewmsngr");
LPVOID inbuf;
LPVOID outbuf = TEXT ("Default_Message.");
LPDWORD nbytes;
DWORD dwmode;
BOOL success=0;
printf("Program Started.\n");
 
///------------------> Opening Pipe
printf("GetLastError: %d\n",GetLastError());
while(success!=1)
{
myfile = CreateFile(pipe_name,                  //lpFileName
                              GENERIC_READ ,            //dwDesiredAccess
                              FILE_SHARE_WRITE,      //dwShareMode
                              NULL,                        //lpSecurityAttributes
                              OPEN_EXISTING,            //dwCreationDisposition
                              0,                              //dwFlagsAndAttributes
                              NULL);                        //hTemplateFile
                              
if (GetLastError()==0)
{
      printf("Handle Found Successfully.\n");
      success=1;
}
else if(GetLastError()==231)
{
         printf("Instances are Busy; Program will Wait 2 Secs and Then Try again.\n");
         WaitNamedPipe(pipe_name, 2000) ;                     
   }
   else if(GetLastError()==2)
   {
   printf("\nThe File not Found.\n");
   printf("EXIT");
         getch();
         exit(1);
   }
   else
   {
         printf("Error: %d\n",GetLastError()); 
         getch();
         exit(1);
   }
}
                              
      printf("File Found.\n"); 
      dwmode=PIPE_READMODE_MESSAGE; 
      success = 0;
      success = SetNamedPipeHandleState(myfile,
                                          &dwmode,
                                          0,
                                          0);
      if(success!=1)
      {
      printf("File mode not changed Successfully; ErrorCode: %d",GetLastError());
      getch();
      exit(1);                  
      }
      
   /* 
//---------------------> Writing Message.                  
      if ( WriteFile(myfile,outbuf, buffersize, nbytes, NULL) )
                  {
                        printf("Message Sent successfully.\n");   
                        printf("Message: %s\n\n",outbuf);   
                  }
      else
            {
                  printf("Message Sending Failed. Error: %d\n",GetLastError());
            }
   */      
      
//---------------------> Reading Message.      
      if( ReadFile(myfile,inbuf, buffersize, nbytes, NULL) )
            {
                  printf("Program is receiving data.\n");
                  printf("Message Received: %s\n",TEXT(inbuf));
                  
            }
      else
            {
                  printf("Message Receiving Failed. Error: %d\n",GetLastError());
            }
 
getch();
exit(1);         
return 0;   
}