Multi tool use

Error while writing into pipe in c++

I'm trying to implement basic named pipe implementation.
In my client code if I call fun() only one time then my program runs completely fine.
But when I call fun() more than one time then it fails alternatively(e.g. if I call fun() 3 times, first call will be successful, second call will fail and third call runs fine.
When the call fails in GetLastError() I get 231 as output on my screen.
If I use Sleep() after every fun() call in client then my program runs fine for every fun() call.
If I use Sleep() in my server program then it reads from from buffer only one time and all the calls (after the first call) to fun() fail in client side.

fun()

fun()

fun()

GetLastError()

231

Sleep()

fun()

fun()

Sleep()

fun()

Server Code:

#include<stdio.h>
#include<windows.h>
#include<iostream>
#include<stdlib.h>
using namespace std;
int main(void)
{
HANDLE hPipe;
char buffer[1024];
DWORD dwRead;

hPipe = CreateNamedPipe(TEXT("\.pipePipe"),
PIPE_ACCESS_INBOUND | FILE_FLAG_FIRST_PIPE_INSTANCE,
PIPE_TYPE_BYTE | PIPE_READMODE_BYTE | PIPE_WAIT, // FILE_FLAG_FIRST_PIPE_INSTANCE is not needed but forces CreateNamedPipe(..) to fail if the pipe already exists...
1,
1024 * 16,
1024 * 16,
INFINITE,
NULL);
while (hPipe != INVALID_HANDLE_VALUE)
{
switch (ConnectNamedPipe(hPipe, NULL) ? NOERROR : GetLastError())
{
case NOERROR:
case ERROR_PIPE_CONNECTED: // STATUS_PIPE_CONNECTED
case ERROR_NO_DATA: // STATUS_PIPE_CLOSING

while (ReadFile(hPipe, buffer, sizeof(buffer)-1, &dwRead, NULL))
{
// do something with data in buffer
//Sleep(2000);
buffer[dwRead] = '';
printf("%s", buffer);
}
DisconnectNamedPipe(hPipe);

break;
}
//CloseHandle(hPipe);
}
return 0;
}


Client Code:

#include<stdio.h>
#include<windows.h>
#include<iostream>
#include<stdlib.h>
using namespace std;


void fun()
{
HANDLE hPipe;
DWORD dwWritten;

hPipe = CreateFile(TEXT("\.pipePipe"),
GENERIC_WRITE,
0,
NULL,
OPEN_EXISTING,
0,
NULL);

if (hPipe != INVALID_HANDLE_VALUE)
{
WriteFile(hPipe,
"Hello Pipen",
12, // = length of string + ''
&dwWritten,
NULL);

CloseHandle(hPipe);
}
else
{
cout<<"****";
cout<<GetLastError();
cout<<"****";
}
}

int main(void)
{
fun(); //Success
//Sleep(2000);
fun(); //failure
//Sleep(2000);
fun(); //Success
//Sleep(2000);
fun(); //failure
//Sleep(2000);
fun(); //Success

return (0);
}


WaitNamedPipe

nMaxInstances

CreateNamedPipe()

PIPE_UNLIMITED_INSTANCES

while (hPipe != INVALID_HANDLE_VALUE)

if (hPipe != INVALID_HANDLE_VALUE)

hPipe

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