再看filezilla，一款ftp工具的服务器端，它采用的是Windows的WSAAsyncSelect模型（代码下载地址：https://github.com/baloonwj/filezilla）：
代码语言：javascript复制//Processes event notifications sent by the sockets or the layers
static LRESULT CALLBACK WindowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
if (message>=WM_SOCKETEX_NOTIFY)
{
//Verify parameters
ASSERT(hWnd);
CAsyncSocketExHelperWindow *pWnd=(CAsyncSocketExHelperWindow *)GetWindowLongPtr(hWnd, GWLP_USERDATA);
ASSERT(pWnd);
if (!pWnd)
return 0;
if (message < static_cast<UINT>(WM_SOCKETEX_NOTIFY pWnd->m_nWindowDataSize)) //Index is within socket storage
{
//Lookup socket and verify if it's valid
CAsyncSocketEx *pSocket=pWnd->m_pAsyncSocketExWindowData[message - WM_SOCKETEX_NOTIFY].m_pSocket;
SOCKET hSocket = wParam;
if (!pSocket)
return 0;
if (hSocket == INVALID_SOCKET)
return 0;
if (pSocket->m_SocketData.hSocket != hSocket)
return 0;
int nEvent = lParam & 0xFFFF;
int nErrorCode = lParam >> 16;
//Dispatch notification
if (!pSocket->m_pFirstLayer) {
//Dispatch to CAsyncSocketEx instance
switch (nEvent)
{
case FD_READ:
#ifndef NOSOCKETSTATES
if (pSocket->GetState() == connecting && !nErrorCode)
{
pSocket->m_nPendingEvents |= FD_READ;
break;
}
else if (pSocket->GetState() == attached)
pSocket->SetState(connected);
if (pSocket->GetState() != connected)
break;
// Ignore further FD_READ events after FD_CLOSE has been received
if (pSocket->m_SocketData.onCloseCalled)
break;
#endif //NOSOCKETSTATES
#ifndef NOSOCKETSTATES
if (nErrorCode)
pSocket->SetState(aborted);
#endif //NOSOCKETSTATES
if (pSocket->m_lEvent & FD_READ) {
pSocket->OnReceive(nErrorCode);
}
break;
case FD_FORCEREAD: //Forceread does not check if there's data waiting
#ifndef NOSOCKETSTATES
if (pSocket->GetState() == connecting && !nErrorCode)
{
pSocket->m_nPendingEvents |= FD_FORCEREAD;
break;
}
else if (pSocket->GetState() == attached)
pSocket->SetState(connected);
if (pSocket->GetState() != connected)
break;
#endif //NOSOCKETSTATES
if (pSocket->m_lEvent & FD_READ)
{
#ifndef NOSOCKETSTATES
if (nErrorCode)
pSocket->SetState(aborted);
#endif //NOSOCKETSTATES
pSocket->OnReceive(nErrorCode);
}
break;
case FD_WRITE:
#ifndef NOSOCKETSTATES
if (pSocket->GetState() == connecting && !nErrorCode)
{
pSocket->m_nPendingEvents |= FD_WRITE;
break;
}
else if (pSocket->GetState() == attached && !nErrorCode)
pSocket->SetState(connected);
if (pSocket->GetState() != connected)
break;
#endif //NOSOCKETSTATES
if (pSocket->m_lEvent & FD_WRITE)
{
#ifndef NOSOCKETSTATES
if (nErrorCode)
pSocket->SetState(aborted);
#endif //NOSOCKETSTATES
pSocket->OnSend(nErrorCode);
}
break;
case FD_CONNECT:
#ifndef NOSOCKETSTATES
if (pSocket->GetState() == connecting)
{
if (nErrorCode && pSocket->m_SocketData.nextAddr)
{
if (pSocket->TryNextProtocol())
break;
}
pSocket->SetState(connected);
}
else if (pSocket->GetState() == attached && !nErrorCode)
pSocket->SetState(connected);
#endif //NOSOCKETSTATES
if (pSocket->m_lEvent & FD_CONNECT)
pSocket->OnConnect(nErrorCode);
#ifndef NOSOCKETSTATES
if (!nErrorCode)
{
if ((pSocket->m_nPendingEvents&FD_READ) && pSocket->GetState() == connected)
pSocket->OnReceive(0);
if ((pSocket->m_nPendingEvents&FD_FORCEREAD) && pSocket->GetState() == connected)
pSocket->OnReceive(0);
if ((pSocket->m_nPendingEvents&FD_WRITE) && pSocket->GetState() == connected)
pSocket->OnSend(0);
}
pSocket->m_nPendingEvents = 0;
#endif
break;
case FD_ACCEPT:
#ifndef NOSOCKETSTATES
if (pSocket->GetState() != listening && pSocket->GetState() != attached)
break;
#endif //NOSOCKETSTATES
if (pSocket->m_lEvent & FD_ACCEPT)
pSocket->OnAccept(nErrorCode);
break;
case FD_CLOSE:
#ifndef NOSOCKETSTATES
if (pSocket->GetState() != connected && pSocket->GetState() != attached)
break;
// If there are still bytes left to read, call OnReceive instead of
// OnClose and trigger a new OnClose
DWORD nBytes = 0;
if (!nErrorCode && pSocket->IOCtl(FIONREAD, &nBytes))
{
if (nBytes > 0)
{
// Just repeat message.
pSocket->ResendCloseNotify();
pSocket->m_SocketData.onCloseCalled = true;
pSocket->OnReceive(WSAESHUTDOWN);
break;
}
}
pSocket->SetState(nErrorCode ? aborted : closed);
#endif //NOSOCKETSTATES
pSocket->OnClose(nErrorCode);
break;
}
}
else //Dispatch notification to the lowest layer
{
if (nEvent == FD_READ)
{
// Ignore further FD_READ events after FD_CLOSE has been received
if (pSocket->m_SocketData.onCloseCalled)
return 0;
DWORD nBytes;
if (!pSocket->IOCtl(FIONREAD, &nBytes))
nErrorCode = WSAGetLastError();
if (pSocket->m_pLastLayer)
pSocket->m_pLastLayer->CallEvent(nEvent, nErrorCode);
}
else if (nEvent == FD_CLOSE)
{
// If there are still bytes left to read, call OnReceive instead of
// OnClose and trigger a new OnClose
DWORD nBytes = 0;
if (!nErrorCode && pSocket->IOCtl(FIONREAD, &nBytes))
{
if (nBytes > 0)
{
// Just repeat message.
pSocket->ResendCloseNotify();
if (pSocket->m_pLastLayer)
pSocket->m_pLastLayer->CallEvent(FD_READ, 0);
return 0;
}
}
pSocket->m_SocketData.onCloseCalled = true;
if (pSocket->m_pLastLayer)
pSocket->m_pLastLayer->CallEvent(nEvent, nErrorCode);
}
else if (pSocket->m_pLastLayer)
pSocket->m_pLastLayer->CallEvent(nEvent, nErrorCode);
}
}
return 0;
}
else if (message == WM_USER) //Notification event sent by a layer
{
//Verify parameters, lookup socket and notification message
//Verify parameters
ASSERT(hWnd);
CAsyncSocketExHelperWindow *pWnd=(CAsyncSocketExHelperWindow *)GetWindowLongPtr(hWnd, GWLP_USERDATA);
ASSERT(pWnd);
if (!pWnd)
return 0;
if (wParam >= static_cast<UINT>(pWnd->m_nWindowDataSize)) //Index is within socket storage
{
return 0;
}
CAsyncSocketEx *pSocket = pWnd->m_pAsyncSocketExWindowData[wParam].m_pSocket;
CAsyncSocketExLayer::t_LayerNotifyMsg *pMsg = (CAsyncSocketExLayer::t_LayerNotifyMsg *)lParam;
if (!pMsg || !pSocket || pSocket->m_SocketData.hSocket != pMsg->hSocket)
{
delete pMsg;
return 0;
}
int nEvent=pMsg->lEvent&0xFFFF;
int nErrorCode=pMsg->lEvent>>16;
//Dispatch to layer
if (pMsg->pLayer)
pMsg->pLayer->CallEvent(nEvent, nErrorCode);
else
{
//Dispatch to CAsyncSocketEx instance
switch (nEvent)
{
case FD_READ:
#ifndef NOSOCKETSTATES
if (pSocket->GetState() == connecting && !nErrorCode)
{
pSocket->m_nPendingEvents |= FD_READ;
break;
}
else if (pSocket->GetState() == attached && !nErrorCode)
pSocket->SetState(connected);
if (pSocket->GetState() != connected)
break;
#endif //NOSOCKETSTATES
if (pSocket->m_lEvent & FD_READ)
{
#ifndef NOSOCKETSTATES
if (nErrorCode)
pSocket->SetState(aborted);
#endif //NOSOCKETSTATES
pSocket->OnReceive(nErrorCode);
}
break;
case FD_FORCEREAD: //Forceread does not check if there's data waiting
#ifndef NOSOCKETSTATES
if (pSocket->GetState() == connecting && !nErrorCode)
{
pSocket->m_nPendingEvents |= FD_FORCEREAD;
break;
}
else if (pSocket->GetState() == attached && !nErrorCode)
pSocket->SetState(connected);
if (pSocket->GetState() != connected)
break;
#endif //NOSOCKETSTATES
if (pSocket->m_lEvent & FD_READ)
{
#ifndef NOSOCKETSTATES
if (nErrorCode)
pSocket->SetState(aborted);
#endif //NOSOCKETSTATES
pSocket->OnReceive(nErrorCode);
}
break;
case FD_WRITE:
#ifndef NOSOCKETSTATES
if (pSocket->GetState() == connecting && !nErrorCode)
{
pSocket->m_nPendingEvents |= FD_WRITE;
break;
}
else if (pSocket->GetState() == attached && !nErrorCode)
pSocket->SetState(connected);
if (pSocket->GetState() != connected)
break;
#endif //NOSOCKETSTATES
if (pSocket->m_lEvent & FD_WRITE)
{
#ifndef NOSOCKETSTATES
if (nErrorCode)
pSocket->SetState(aborted);
#endif //NOSOCKETSTATES
pSocket->OnSend(nErrorCode);
}
break;
case FD_CONNECT:
#ifndef NOSOCKETSTATES
if (pSocket->GetState() == connecting)
pSocket->SetState(connected);
else if (pSocket->GetState() == attached && !nErrorCode)
pSocket->SetState(connected);
#endif //NOSOCKETSTATES
if (pSocket->m_lEvent & FD_CONNECT)
pSocket->OnConnect(nErrorCode);
#ifndef NOSOCKETSTATES
if (!nErrorCode)
{
if (((pSocket->m_nPendingEvents&FD_READ) && pSocket->GetState() == connected) && (pSocket->m_lEvent & FD_READ))
pSocket->OnReceive(0);
if (((pSocket->m_nPendingEvents&FD_FORCEREAD) && pSocket->GetState() == connected) && (pSocket->m_lEvent & FD_READ))
pSocket->OnReceive(0);
if (((pSocket->m_nPendingEvents&FD_WRITE) && pSocket->GetState() == connected) && (pSocket->m_lEvent & FD_WRITE))
pSocket->OnSend(0);
}
pSocket->m_nPendingEvents = 0;
#endif //NOSOCKETSTATES
break;
case FD_ACCEPT:
#ifndef NOSOCKETSTATES
if ((pSocket->GetState() == listening || pSocket->GetState() == attached) && (pSocket->m_lEvent & FD_ACCEPT))
#endif //NOSOCKETSTATES
{
pSocket->OnAccept(nErrorCode);
}
break;
case FD_CLOSE:
#ifndef NOSOCKETSTATES
if ((pSocket->GetState() == connected || pSocket->GetState() == attached) && (pSocket->m_lEvent & FD_CLOSE))
{
pSocket->SetState(nErrorCode?aborted:closed);
#else
{
#endif //NOSOCKETSTATES
pSocket->OnClose(nErrorCode);
}
break;
}
}
delete pMsg;
return 0;
}
else if (message == WM_USER 1)
{
// WSAAsyncGetHostByName reply
// Verify parameters
ASSERT(hWnd);
CAsyncSocketExHelperWindow *pWnd = (CAsyncSocketExHelperWindow *)GetWindowLongPtr(hWnd, GWLP_USERDATA);
ASSERT(pWnd);
if (!pWnd)
return 0;
CAsyncSocketEx *pSocket = NULL;
for (int i = 0; i < pWnd->m_nWindowDataSize; i) {
pSocket = pWnd->m_pAsyncSocketExWindowData[i].m_pSocket;
if (pSocket && pSocket->m_hAsyncGetHostByNameHandle &&
pSocket->m_hAsyncGetHostByNameHandle == (HANDLE)wParam &&
pSocket->m_pAsyncGetHostByNameBuffer)
break;
}
if (!pSocket || !pSocket->m_pAsyncGetHostByNameBuffer)
return 0;
int nErrorCode = lParam >> 16;
if (nErrorCode) {
pSocket->OnConnect(nErrorCode);
return 0;
}
SOCKADDR_IN sockAddr{};
sockAddr.sin_family = AF_INET;
sockAddr.sin_addr.s_addr = ((LPIN_ADDR)((LPHOSTENT)pSocket->m_pAsyncGetHostByNameBuffer)->h_addr)->s_addr;
sockAddr.sin_port = htons(pSocket->m_nAsyncGetHostByNamePort);
BOOL res = pSocket->Connect((SOCKADDR*)&sockAddr, sizeof(sockAddr));
delete [] pSocket->m_pAsyncGetHostByNameBuffer;
pSocket->m_pAsyncGetHostByNameBuffer = 0;
pSocket->m_hAsyncGetHostByNameHandle = 0;
if (!res)
if (GetLastError() != WSAEWOULDBLOCK)
pSocket->OnConnect(GetLastError());
return 0;
}
else if (message == WM_USER 2)
{
//Verify parameters, lookup socket and notification message
//Verify parameters
if (!hWnd)
return 0;
CAsyncSocketExHelperWindow *pWnd=(CAsyncSocketExHelperWindow *)GetWindowLongPtr(hWnd, GWLP_USERDATA);
if (!pWnd)
return 0;
if (wParam >= static_cast<UINT>(pWnd->m_nWindowDataSize)) //Index is within socket storage
return 0;
CAsyncSocketEx *pSocket = pWnd->m_pAsyncSocketExWindowData[wParam].m_pSocket;
if (!pSocket)
return 0;
// Process pending callbacks
std::list<t_callbackMsg> tmp;
tmp.swap(pSocket->m_pendingCallbacks);
pSocket->OnLayerCallback(tmp);
for (auto & cb : tmp) {
delete [] cb.str;
}
}
else if (message == WM_TIMER)
{
if (wParam != 1)
return 0;
ASSERT(hWnd);
CAsyncSocketExHelperWindow *pWnd=(CAsyncSocketExHelperWindow *)GetWindowLongPtr(hWnd, GWLP_USERDATA);
ASSERT(pWnd && pWnd->m_pThreadData);
if (!pWnd || !pWnd->m_pThreadData)
return 0;
if (pWnd->m_pThreadData->layerCloseNotify.empty())
{
KillTimer(hWnd, 1);
return 0;
}
CAsyncSocketEx* socket = pWnd->m_pThreadData->layerCloseNotify.front();
pWnd->m_pThreadData->layerCloseNotify.pop_front();
if (pWnd->m_pThreadData->layerCloseNotify.empty())
KillTimer(hWnd, 1);
if (socket)
PostMessage(hWnd, socket->m_SocketData.nSocketIndex WM_SOCKETEX_NOTIFY, socket->m_SocketData.hSocket, FD_CLOSE);
return 0;
}
return DefWindowProc(hWnd, message, wParam, lParam);
} 关于单个服务程序的框架，我已经介绍完了，如果你能完全理解我要表达的意思，我相信你也能构建出一套高性能服务程序来。
由于微信公众号文章字数的限制，本篇文章未完，下一篇是《服务器端编程心得（八）——高性能服务器架构设计总结4——以flamigo服务器代码为例》。
