转自：http://www.winsocketdotnetworkprogramming.com/winsock2programming/winsock2advancediomethod5d.html
What do we have in this chapter 5 part 5?
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The WSAEventSelect server/receiver model Program Example
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Running the Client and Server Program
The WSAEventSelect server/receiver model Program Example
The following program example tries to demonstrate the WSAEventSelect server/receiver model.
Add the following source code. |
// Description:
//
// This sample illustrates how to develop a simple echo server Winsock
// application using the WSAEventSelect() I/O model. This sample is
// implemented as a console-style application and simply prints
// messages when connections are established and removed from the server.
// The application listens for TCP connections on port 5150 and accepts them
// as they arrive. When this application receives data from a client, it
// simply echoes (this is why we call it an echo server) the data back in
// it's original form until the client closes the connection.
//
// Note: There are no command line options for this sample.
// Link to ws2_32.lib
#include <winsock2.h>
#include <windows.h>
#include <stdio.h>
#define PORT 5150
#define DATA_BUFSIZE 8192
typedef struct _SOCKET_INFORMATION {
CHAR Buffer[DATA_BUFSIZE];
WSABUF DataBuf;
SOCKET Socket;
DWORD BytesSEND;
DWORD BytesRECV;
} SOCKET_INFORMATION, * LPSOCKET_INFORMATION;
BOOL CreateSocketInformation(SOCKET s);
void FreeSocketInformation(DWORD Event);
DWORD EventTotal = 0;
WSAEVENT EventArray[WSA_MAXIMUM_WAIT_EVENTS];
LPSOCKET_INFORMATION SocketArray[WSA_MAXIMUM_WAIT_EVENTS];
int main(int argc, char **argv)
{
SOCKET Listen;
SOCKET Accept;
SOCKADDR_IN InternetAddr;
LPSOCKET_INFORMATION SocketInfo;
DWORD Event;
WSANETWORKEVENTS NetworkEvents;
WSADATA wsaData;
DWORD Flags;
DWORD RecvBytes;
DWORD SendBytes;
if (WSAStartup(0x0202, &wsaData) != 0)
{
printf("WSAStartup() failed with error %d/n", WSAGetLastError());
return 1;
}
else
printf("WSAStartup() is OK!/n");
if ((Listen = socket(AF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET)
{
printf("socket() failed with error %d/n", WSAGetLastError());
return 1;
}
else
printf("socket() is OK!/n");
if(CreateSocketInformation(Listen) == FALSE)
printf("CreateSocketInformation() failed!/n");
else
printf("CreateSocketInformation() is OK lol!/n");
if (WSAEventSelect(Listen, EventArray[EventTotal - 1], FD_ACCEPT|FD_CLOSE) == SOCKET_ERROR)
{
printf("WSAEventSelect() failed with error %d/n", WSAGetLastError());
return 1;
}
else
printf("WSAEventSelect() is pretty fine!/n");
InternetAddr.sin_family = AF_INET;
InternetAddr.sin_addr.s_addr = htonl(INADDR_ANY);
InternetAddr.sin_port = htons(PORT);
if (bind(Listen, (PSOCKADDR) &InternetAddr, sizeof(InternetAddr)) == SOCKET_ERROR)
{
printf("bind() failed with error %d/n", WSAGetLastError());
return 1;
}
else
printf("bind() is OK!/n");
if (listen(Listen, 5))
{
printf("listen() failed with error %d/n", WSAGetLastError());
return 1;
}
else
printf("listen() is OK!/n");
while(TRUE)
{
// Wait for one of the sockets to receive I/O notification and
if ((Event = WSAWaitForMultipleEvents(EventTotal, EventArray, FALSE,WSA_INFINITE, FALSE)) == WSA_WAIT_FAILED)
{
printf("WSAWaitForMultipleEvents() failed with error %d/n", WSAGetLastError());
return 1;
}
else
printf("WSAWaitForMultipleEvents() is pretty damn OK!/n");
if (WSAEnumNetworkEvents(SocketArray[Event - WSA_WAIT_EVENT_0]->Socket,
EventArray[Event - WSA_WAIT_EVENT_0], &NetworkEvents) == SOCKET_ERROR)
{
printf("WSAEnumNetworkEvents() failed with error %d/n", WSAGetLastError());
return 1;
}
else
printf("WSAEnumNetworkEvents() should be fine!/n");
if (NetworkEvents.lNetworkEvents & FD_ACCEPT)
{
if (NetworkEvents.iErrorCode[FD_ACCEPT_BIT] != 0)
{
printf("FD_ACCEPT failed with error %d/n", NetworkEvents.iErrorCode[FD_ACCEPT_BIT]);
break;
}
if ((Accept = accept(SocketArray[Event - WSA_WAIT_EVENT_0]->Socket, NULL, NULL)) == INVALID_SOCKET)
{
printf("accept() failed with error %d/n", WSAGetLastError());
break;
}
else
printf("accept() should be OK!/n");
if (EventTotal > WSA_MAXIMUM_WAIT_EVENTS)
{
printf("Too many connections - closing socket.../n");
closesocket(Accept);
break;
}
CreateSocketInformation(Accept);
if (WSAEventSelect(Accept, EventArray[EventTotal - 1], FD_READ|FD_WRITE|FD_CLOSE) == SOCKET_ERROR)
{
printf("WSAEventSelect() failed with error %d/n", WSAGetLastError());
return 1;
}
else
printf("WSAEventSelect() is OK!/n");
printf("Socket %d got connected.../n", Accept);
}
// Try to read and write data to and from the data buffer if read and write events occur
if (NetworkEvents.lNetworkEvents & FD_READ || NetworkEvents.lNetworkEvents & FD_WRITE)
{
if (NetworkEvents.lNetworkEvents & FD_READ && NetworkEvents.iErrorCode[FD_READ_BIT] != 0)
{
printf("FD_READ failed with error %d/n", NetworkEvents.iErrorCode[FD_READ_BIT]);
break;
}
else
printf("FD_READ is OK!/n");
if (NetworkEvents.lNetworkEvents & FD_WRITE && NetworkEvents.iErrorCode[FD_WRITE_BIT] != 0)
{
printf("FD_WRITE failed with error %d/n", NetworkEvents.iErrorCode[FD_WRITE_BIT]);
break;
}
else
printf("FD_WRITE is OK!/n");
SocketInfo = SocketArray[Event - WSA_WAIT_EVENT_0];
// Read data only if the receive buffer is empty
if (SocketInfo->BytesRECV == 0)
{
SocketInfo->DataBuf.buf = SocketInfo->Buffer;
SocketInfo->DataBuf.len = DATA_BUFSIZE;
Flags = 0;
if (WSARecv(SocketInfo->Socket, &(SocketInfo->DataBuf), 1, &RecvBytes, &Flags, NULL, NULL) == SOCKET_ERROR)
{
if (WSAGetLastError() != WSAEWOULDBLOCK)
{
printf("WSARecv() failed with error %d/n", WSAGetLastError());
FreeSocketInformation(Event - WSA_WAIT_EVENT_0);
return 1;
}
}
else
{
printf("WSARecv() is working!/n");
SocketInfo->BytesRECV = RecvBytes;
}
}
// Write buffer data if it is available
if (SocketInfo->BytesRECV > SocketInfo->BytesSEND)
{
SocketInfo->DataBuf.buf = SocketInfo->Buffer + SocketInfo->BytesSEND;
SocketInfo->DataBuf.len = SocketInfo->BytesRECV - SocketInfo->BytesSEND;
if (WSASend(SocketInfo->Socket, &(SocketInfo->DataBuf), 1, &SendBytes, 0, NULL, NULL) == SOCKET_ERROR)
{
if (WSAGetLastError() != WSAEWOULDBLOCK)
{
printf("WSASend() failed with error %d/n", WSAGetLastError());
FreeSocketInformation(Event - WSA_WAIT_EVENT_0);
return 1;
}
// A WSAEWOULDBLOCK error has occurred. An FD_WRITE event will be posted
// when more buffer space becomes available
}
else
{
printf("WSASend() is fine! Thank you.../n");
SocketInfo->BytesSEND += SendBytes;
if (SocketInfo->BytesSEND == SocketInfo->BytesRECV)
{
SocketInfo->BytesSEND = 0;
SocketInfo->BytesRECV = 0;
}
}
}
}
if (NetworkEvents.lNetworkEvents & FD_CLOSE)
{
if (NetworkEvents.iErrorCode[FD_CLOSE_BIT] != 0)
{
printf("FD_CLOSE failed with error %d/n", NetworkEvents.iErrorCode[FD_CLOSE_BIT]);
break;
}
else
printf("FD_CLOSE is OK!/n");
printf("Closing socket information %d/n", SocketArray[Event - WSA_WAIT_EVENT_0]->Socket);
FreeSocketInformation(Event - WSA_WAIT_EVENT_0);
}
}
return 0;
}
BOOL CreateSocketInformation(SOCKET s)
{
LPSOCKET_INFORMATION SI;
if ((EventArray[EventTotal] = WSACreateEvent()) == WSA_INVALID_EVENT)
{
printf("WSACreateEvent() failed with error %d/n", WSAGetLastError());
return FALSE;
}
else
printf("WSACreateEvent() is OK!/n");
if ((SI = (LPSOCKET_INFORMATION) GlobalAlloc(GPTR, sizeof(SOCKET_INFORMATION))) == NULL)
{
printf("GlobalAlloc() failed with error %d/n", GetLastError());
return FALSE;
}
else
printf("GlobalAlloc() for LPSOCKET_INFORMATION is OK!/n");
// Prepare SocketInfo structure for use
SI->Socket = s;
SI->BytesSEND = 0;
SI->BytesRECV = 0;
SocketArray[EventTotal] = SI;
EventTotal++;
return(TRUE);
}
void FreeSocketInformation(DWORD Event)
{
LPSOCKET_INFORMATION SI = SocketArray[Event];
DWORD i;
closesocket(SI->Socket);
GlobalFree(SI);
if(WSACloseEvent(EventArray[Event]) == TRUE)
printf("WSACloseEvent() is OK!/n/n");
else
printf("WSACloseEvent() failed miserably!/n/n");
// Squash the socket and event arrays
for (i = Event; i < EventTotal; i++)
{
EventArray[i] = EventArray[i + 1];
SocketArray[i] = SocketArray[i + 1];
}
EventTotal--;
}
Build and run the project. The following screenshot shows the sample output.
---------------------------------------------------------
Running the Client and Server Programs.
Firstly we run the server program.
Then we run the client program.
The previous server sample output is shown below.
