GetQueuedCompletionStatus recevies old data - c++

Question

If you try and run my script you can see that GetQueuedCompletionStatus not will block after second wsarecv call. I don't understand why this code won't work.
The code is a bit messy but quite simple so it should work.
server:
#undef UNICODE
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <winsock2.h>
#include <ws2tcpip.h>
#include <stdlib.h>
#include <stdio.h>
#include <thread>
#include <iostream>
using namespace std;
// Need to link with Ws2_32.lib
#pragma comment (lib, "Ws2_32.lib")
// #pragma comment (lib, "Mswsock.lib")
WSADATA wsaData;
int iResult;
HANDLE CompletionPort;
SOCKET ListenSocket = INVALID_SOCKET;
SOCKET ClientSocket = INVALID_SOCKET;
OVERLAPPED Overlapped;
WSABUF DataBuf;
CHAR Buffer[200];
DWORD BytesSEND;
DWORD BytesRECV;
DWORD RecvBytes;
sockaddr_in local;
DWORD Flags;
int iSendResult;
void serverWorkerThread() {
OVERLAPPED lpol2;
DWORD Flags = 0;
DWORD BytesTransferred;
DWORD is = 0;
DWORD sentBytes;
bool kage = 0;
WSABUF wsabuf;
CHAR Buffer2[200];
while (true) {
if (GetQueuedCompletionStatus(CompletionPort, &BytesTransferred, &is, (LPOVERLAPPED*)& lpol2, INFINITE) == 0)
{
printf("GetQueuedCompletionStatus() failed with error %d\n", GetLastError());
}
else
printf("GetQueuedCompletionStatus() is OK!\n");
cout << DataBuf.buf << endl;
cout << is;
DataBuf.len = 14;
ZeroMemory(&(Overlapped), sizeof(OVERLAPPED));
if (WSASend(ClientSocket, &DataBuf, 1, &sentBytes, 0,
NULL, NULL) == SOCKET_ERROR)
{
if (WSAGetLastError() != ERROR_IO_PENDING)
{
printf("WSASend() failed with error %d\n", WSAGetLastError());
}
}
else
printf("WSASend() is OK!\n");
ZeroMemory(&(lpol2), sizeof(OVERLAPPED));
wsabuf.buf = Buffer2;
wsabuf.len = 200;
BytesTransferred = 0;
is = 0;
ZeroMemory(&(Overlapped), sizeof(OVERLAPPED));
Flags = 0;
if (WSARecv(ClientSocket, &wsabuf, 1, &RecvBytes, &Flags, &Overlapped, NULL) == SOCKET_ERROR)
{
if (WSAGetLastError() != ERROR_IO_PENDING)
{
printf("WSARecv() failed with error %d\n", WSAGetLastError());
}
}
else printf("WSARecv() is OK!\n");
}
}
int __cdecl main(void)
{
// Initialize Winsock
iResult = WSAStartup(MAKEWORD(2, 2), &wsaData);
if (iResult != 0) {
printf("WSAStartup failed with error: %d\n", iResult);
return 1;
}
CompletionPort = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, 0, 0);
//Now we populate the sockaddr_in structure
local.sin_family = AF_INET; //Address family
local.sin_addr.s_addr = INADDR_ANY; //Wild card IP address
local.sin_port = htons((u_short)20248); //port to use
// Create a SOCKET for connecting to server
ListenSocket = socket(AF_INET, SOCK_STREAM, 0);
if (ListenSocket == INVALID_SOCKET) {
printf("socket failed with error: %ld\n", WSAGetLastError());
WSACleanup();
return 1;
}
// Setup the TCP listening socket
iResult = bind(ListenSocket, (sockaddr*)& local, sizeof(local));
if (iResult == SOCKET_ERROR) {
printf("bind failed with error: %d\n", WSAGetLastError());
closesocket(ListenSocket);
WSACleanup();
return 1;
}
iResult = listen(ListenSocket, SOMAXCONN);
if (iResult == SOCKET_ERROR) {
printf("listen failed with error: %d\n", WSAGetLastError());
closesocket(ListenSocket);
WSACleanup();
return 1;
}
DataBuf.len = 2000;
DataBuf.buf = Buffer;
thread t1(serverWorkerThread);
t1.detach();
DWORD iss = 34543;
while (TRUE)
{
ClientSocket = WSAAccept(ListenSocket, NULL, NULL, NULL, 0);
if (ClientSocket == INVALID_SOCKET) {
printf("accept failed with error: %d\n", WSAGetLastError());
closesocket(ListenSocket);
WSACleanup();
return 1;
}
if (CreateIoCompletionPort((HANDLE)ClientSocket, CompletionPort, 43343, 0) == NULL)
{
printf("CreateIoCompletionPort() failed with error %d\n", GetLastError());
return 1;
}
else
printf("CreateIoCompletionPort() is OK!\n");
Flags = 0;
if (WSARecv(ClientSocket, &DataBuf, 1, &RecvBytes, &Flags, &Overlapped, NULL) == SOCKET_ERROR)
{
if (WSAGetLastError() != ERROR_IO_PENDING)
{
printf("WSARecv() failed with error %d\n", WSAGetLastError());
return 1;
}
}
else printf("WSARecv() is OK!\n");
}
// shutdown the connection since we're done
iResult = shutdown(ClientSocket, SD_SEND);
if (iResult == SOCKET_ERROR) {
printf("shutdown failed with error: %d\n", WSAGetLastError());
closesocket(ClientSocket);
WSACleanup();
return 1;
}
// cleanup
closesocket(ClientSocket);
WSACleanup();
return 0;
}
client:
#define WIN32_LEAN_AND_MEAN
#define _WINSOCK_DEPRECATED_NO_WARNINGS
#include <windows.h>
#include <winsock2.h>
#include <ws2tcpip.h>
#include <stdlib.h>
#include <stdio.h>
#include <iostream>
// Need to link with Ws2_32.lib, Mswsock.lib, and Advapi32.lib
#pragma comment (lib, "Ws2_32.lib")
#pragma comment (lib, "Mswsock.lib")
#pragma comment (lib, "AdvApi32.lib")
using namespace std;
#define DEFAULT_BUFLEN 512
#define DEFAULT_PORT "27015"
int __cdecl main(int argc, char** argv)
{
WSADATA wsaData;
SOCKET ConnectSocket = INVALID_SOCKET;
SOCKADDR_IN ServerAddr;
// Server/receiver port to connect to
unsigned int Port = 20248;
//struct addrinfo* result = NULL,
// * ptr = NULL,
// hints;
const char* sendbuf = "this is a test";
char recvbuf[DEFAULT_BUFLEN];
int iResult;
int recvbuflen = DEFAULT_BUFLEN;
cout << sendbuf << endl;
// Initialize Winsock
iResult = WSAStartup(MAKEWORD(2, 2), &wsaData);
if (iResult != 0) {
printf("WSAStartup failed with error: %d\n", iResult);
return 1;
}
// Create a SOCKET for connecting to server
ConnectSocket = WSASocket(AF_INET, SOCK_STREAM, 0, NULL, 0, WSA_FLAG_OVERLAPPED);
if (ConnectSocket == INVALID_SOCKET) {
printf("socket failed with error: %ld\n", WSAGetLastError());
WSACleanup();
return 2;
}
// IPv4
ServerAddr.sin_family = AF_INET;
// Port no.
ServerAddr.sin_port = htons(Port);
// The IP address
ServerAddr.sin_addr.s_addr = inet_addr("127.0.0.1");
// Connect to server.
iResult = connect(ConnectSocket, (SOCKADDR*)& ServerAddr, sizeof(ServerAddr));
if (iResult == SOCKET_ERROR) {
closesocket(ConnectSocket);
ConnectSocket = INVALID_SOCKET;
printf("socket failed with error: %ld\n", WSAGetLastError());
WSACleanup();
return 3;
}
if (ConnectSocket == INVALID_SOCKET) {
printf("Unable to connect to server!\n");
WSACleanup();
return 4;
}
// Send an initial buffer
iResult = send(ConnectSocket, sendbuf, (int)strlen(sendbuf), 0);
if (iResult == SOCKET_ERROR) {
printf("send failed with error: %d\n", WSAGetLastError());
closesocket(ConnectSocket);
WSACleanup();
return 5;
}
printf("Bytes Sent: %ld\n", iResult);
// shutdown the connection since no more data will be sent
iResult = shutdown(ConnectSocket, SD_SEND);
if (iResult == SOCKET_ERROR) {
printf("shutdown failed with error: %d\n", WSAGetLastError());
closesocket(ConnectSocket);
WSACleanup();
return 6;
}
// Receive until the peer closes the connection
do {
iResult = recv(ConnectSocket, recvbuf, recvbuflen, 0);
if (iResult > 0)
printf("Bytes received: %d\n", iResult);
else if (iResult == 0)
printf("Connection closed\n");
else
printf("recv failed with error: %d\n", WSAGetLastError());
} while (iResult > 0);
// cleanup
closesocket(ConnectSocket);
WSACleanup();
return 0;
}

Answer 1

i found the problem:
the clients shoutdown the connetion which made the GetQueuedCompletionStatus keep running