Unable to send data over windows UDP sockets:Error Code 10035 - c++

Question

I am trying to receive data on a program from another program running on the same windows 7 pc through sockets. For this i have made two separate program, one for sending and other for receiving.Send program is showing success but receive program is waiting indefinitely.when i put the receive socket in non blocking mode i am receiving error code 10035 ie resource unavailable. Is there any system setting i have to do like firewall or any thing. Although after disabling firewall i am getting same error.I searched the stackoverflow.com but could not get solution to my problem.
I am giving the code below for send and receive functions.
For Send Function:
#include "stdafx.h"
#ifndef UNICODE
#define UNICODE
#endif
#define WIN32_LEAN_AND_MEAN
#include <winsock2.h>
#include <Ws2tcpip.h>
#include <stdio.h>
// Link with ws2_32.lib
#pragma comment(lib, "Ws2_32.lib")
using namespace System;
int main(array<System::String ^> ^args)
{
char ch;
int iRun =1;
int iResult;
WSADATA wsaData;
SOCKET SendSocket = INVALID_SOCKET;
sockaddr_in RecvAddr;
unsigned short Port = 51234;
char SendBuf[1024]="Testing";
int BufLen = 1024;
//----------------------
// Initialize Winsock
iResult = WSAStartup(MAKEWORD(2, 2), &wsaData);
if (iResult != NO_ERROR) {
wprintf(L"WSAStartup failed with error: %d\n", iResult);
return 1;
}
//---------------------------------------------
// Create a socket for sending data
SendSocket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
if (SendSocket == INVALID_SOCKET) {
wprintf(L"socket failed with error: %ld\n", WSAGetLastError());
WSACleanup();
return 1;
}
//---------------------------------------------
// Set up the RecvAddr structure with the IP address of
// the receiver (in this example case "178.0.0.100")
// and the specified port number.
RecvAddr.sin_family = AF_INET;
RecvAddr.sin_port = htons(Port);
RecvAddr.sin_addr.s_addr = inet_addr("178.0.0.100");
//---------------------------------------------
// Send a datagram to the receiver
wprintf(L"Sending a datagram to the receiver...\n");
while(iRun) {
iResult = sendto(SendSocket,
SendBuf, BufLen, 0, (SOCKADDR *) & RecvAddr, sizeof (RecvAddr));
if (iResult == SOCKET_ERROR) {
wprintf(L"sendto failed with error: %d\n", WSAGetLastError());
//closesocket(SendSocket);
//WSACleanup();
//return 1;
}
wprintf(L"send success :data bytes: %d\n", iResult);
}
//---------------------------------------------
// When the application is finished sending, close the socket.
wprintf(L"Finished sending. Closing socket.\n");
iResult = closesocket(SendSocket);
if (iResult == SOCKET_ERROR) {
wprintf(L"closesocket failed with error: %d\n", WSAGetLastError());
WSACleanup();
return 1;
}
//---------------------------------------------
scanf("enter any number to terminate %c",&ch);
// Clean up and quit.
wprintf(L"Exiting.\n");
WSACleanup();
return 0;
//Console::WriteLine(L"Hello World");
//return 0;
}
For Receive Function
#include "stdafx.h"
#ifndef UNICODE
#define UNICODE
#endif
#define WIN32_LEAN_AND_MEAN
#include <winsock2.h>
#include <Ws2tcpip.h>
#include <stdio.h>
// Link with ws2_32.lib
#pragma comment(lib, "Ws2_32.lib")
using namespace System;
int main(array<System::String ^> ^args)
{
char ch;
int iRun =1;
int iResult = 0;
WSADATA wsaData;
DWORD nonBlocking =1;
SOCKET RecvSocket;
sockaddr_in RecvAddr;
unsigned short Port = 51234;
char RecvBuf[1024];
int BufLen = 1024;
sockaddr_in SenderAddr;
int SenderAddrSize = sizeof (SenderAddr);
//-----------------------------------------------
// Initialize Winsock
iResult = WSAStartup(MAKEWORD(2, 2), &wsaData);
if (iResult != NO_ERROR) {
wprintf(L"WSAStartup failed with error %d\n", iResult);
return 1;
}
//-----------------------------------------------
// Create a receiver socket to receive datagrams
RecvSocket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
if (RecvSocket == INVALID_SOCKET) {
wprintf(L"socket failed with error %d\n", WSAGetLastError());
return 1;
}
// Setting socket to non blocking mode
if(ioctlsocket(RecvSocket, FIONBIO, &nonBlocking)!= 0)
printf("can't Set socket to non blocking mode \n");
//-----------------------------------------------
// Bind the socket to any address and the specified port.
RecvAddr.sin_family = AF_INET;
RecvAddr.sin_port = htons(Port);
RecvAddr.sin_addr.s_addr = htonl(INADDR_ANY);
iResult = bind(RecvSocket, (SOCKADDR *) & RecvAddr, sizeof (RecvAddr));
if (iResult != 0) {
wprintf(L"bind failed with error %d\n", WSAGetLastError());
return 1;
}
//-----------------------------------------------
// Call the recvfrom function to receive datagrams
// on the bound socket.
wprintf(L"Receiving datagrams...\n");
while(iRun) {
iResult = recvfrom(RecvSocket,
RecvBuf, BufLen, 0, (SOCKADDR *) & SenderAddr, &SenderAddrSize);
if (iResult == SOCKET_ERROR) {
wprintf(L"recvfrom failed with error %d\n", WSAGetLastError());
Sleep(10);
}
//wprintf(L"recvfrom Success %d\n", iResult);
//wprintf(L"Received Data %s \n",RecvBuf[BufLen]);
}
//-----------------------------------------------
// Close the socket when finished receiving datagrams
wprintf(L"Finished receiving. Closing socket.\n");
iResult = closesocket(RecvSocket);
if (iResult == SOCKET_ERROR) {
wprintf(L"closesocket failed with error %d\n", WSAGetLastError());
return 1;
}
//-----------------------------------------------
scanf("enter any number to terminate %c",&ch);
// Clean up and exit.
wprintf(L"Exiting.\n");
WSACleanup();
return 0;
//Console::WriteLine(L"Hello World");
//return 0;
}
Can any one please help.
Regards
Mahendra

Answer 1

Did you look it up? Winsock error code 10035 is WSAEWOULDBLOCK. You are in non-blocking mode, and the operation you are attempting cannot be completed, because either your send buffer is full when sending or your receive buffer is empty when receiving.