问题描述
第一次使用 IO 完成端口。我遇到了一个问题，即 GetQueuedCompletionStatus 为 Completion Key 返回 Null，我用它来传递带有代码其他部分句柄的数据结构。
GetQueuedCompletionStatus 似乎触发了接收到的消息，否则就好了。
我试图只包含涉及 IO 完成端口的代码：
数据结构：
typedef struct _THREAD_MESSAGE
{
mutex cmd_mtx;
string command;
} THREAD_MESSAGE,* LPTHREAD_MESSAGE;
typedef struct _LISTEN_SOCKET_DATA
{
SOCKET Socket;
int Port;
HANDLE hAcceptEvent;
HANDLE IOCP;
VOID* MessageProcessor;
ConfigHandler* CfgHandle;
// Other information useful to be associated with the handle
} LISTEN_SOCKET_DATA,* LPLISTEN_SOCKET_DATA;
typedef struct _CONNECTED_SOCKET_DATA
{
SOCKET Socket;
int Port;
HANDLE IOCP;
VOID* MessageProcessor;
ConfigHandler* CfgHandle;
} CONNECTED_SOCKET_DATA,* LPCONNECTED_SOCKET_DATA;
#define OPERATION_TYPE_UNKNowN 0
#define OPERATION_TYPE_SEND 1
#define OPERATION_TYPE_RECV 2
typedef struct
{
OVERLAPPED* Overlapped;
CHAR Buffer[DATA_BUFSIZE];
int BufferLen;
int OperationType;
string PacketName;
} PER_IO_OPERATION_DATA,* LPPER_IO_OPERATION_DATA;
完成端口初始化为：
m_CompletionPort = CreateIoCompletionPort(INVALID_HANDLE_VALUE,NULL,0);
听众：
//Thread for handling Listener sockets and Accepting connections
DWORD ListenThread(LPVOID lpParam)
{
LPLISTEN_SOCKET_DATA pSocketData = (LPLISTEN_SOCKET_DATA)(lpParam);
WSANETWORKEVENTS NetworkEvents;
DWORD dwRet;
SOCKADDR_IN NewSockAddr;
SOCKET NewSocket;
int nLen;
while (true) //run forever
{
//Wait for event
dwRet = WSAWaitForMultipleEvents(1,&(pSocketData->hAcceptEvent),false,100,false);
//nothing happened,back to top
if (dwRet == WSA_WAIT_TIMEOUT)
continue;
//We got a event,find out which one.
int nRet = WSAEnumNetworkEvents(pSocketData->Socket,pSocketData->hAcceptEvent,&NetworkEvents);
if (nRet == SOCKET_ERROR)
{
wprintf(L"WSAEnumNetworkEvents error %ld\n",WSAGetLastError());
break;
}
//We got a Accept event
if (NetworkEvents.lNetworkEvents & FD_ACCEPT)
{
//Check for errors
if (NetworkEvents.iErrorCode[FD_ACCEPT_BIT] == 0)
{
// Accept new connection
nLen = sizeof(SOCKADDR_IN);
NewSocket = accept(pSocketData->Socket,(LPSOCKADDR)&NewSockAddr,&nLen);
if (NewSocket == SOCKET_ERROR)
{
wprintf(L"accept() error %ld\n",WSAGetLastError());
break;
}
wprintf(L"Accepted Connection %ld",NewSockAddr.sin_addr.S_un.S_addr);
//Set new connection as TCP connection,No Delay
const char chOpt = 1;
int nErr = setsockopt(NewSocket,IPPROTO_TCP,TCP_NODELAY,&chOpt,sizeof(char));
if (nErr == -1)
{
wprintf(L"setsockopt() error %ld\n",WSAGetLastError());
break;
}
LPCONNECTED_SOCKET_DATA ConnectedSocketData = new CONNECTED_SOCKET_DATA;
ZeroMemory(ConnectedSocketData,sizeof(CONNECTED_SOCKET_DATA));
ConnectedSocketData->Socket = NewSocket;
ConnectedSocketData->Port = pSocketData->Port;
ConnectedSocketData->IOCP = pSocketData->IOCP;
ConnectedSocketData->CfgHandle = pSocketData->CfgHandle;
ConnectedSocketData->MessageProcessor = pSocketData->MessageProcessor;
//Add the new socket to the completion port,message from the socker will be queued up for proccessing by worker threads.
if (CreateIoCompletionPort((HANDLE)NewSocket,pSocketData->IOCP,(DWORD)ConnectedSocketData,0) == NULL)
{
wprintf(L"CreateIOCompletionPort error %ld\n",WSAGetLastError());
delete ConnectedSocketData;
ConnectedSocketData = NULL;
closesocket(NewSocket);
break;
}
//Set the PerIOData,will be used at completion time
LPPER_IO_OPERATION_DATA PerIOOperationData = new PER_IO_OPERATION_DATA;
PerIOOperationData->BufferLen = 0;
PerIOOperationData->OperationType = OPERATION_TYPE_RECV;
DWORD RecvBytes = 0;
DWORD Flags = 0;
WSABUF DataBuf;
DataBuf.len = DATA_BUFSIZE;
DataBuf.buf = PerIOOperationData->Buffer;
PerIOOperationData->Overlapped = new OVERLAPPED;
ZeroMemory(PerIOOperationData->Overlapped,sizeof(OVERLAPPED));
//Kick off the first Recv request for the Socket,will be handled by the completion Queue.
if (WSARecv(NewSocket,&DataBuf,1,&RecvBytes,&Flags,(PerIOOperationData->Overlapped),NULL) == SOCKET_ERROR)
{
wprintf(L"WSARecv error %ld\n",WSAGetLastError());
return 0;
}
}
else
{
wprintf(L"UnkNown network event error %ld\n",WSAGetLastError());
break;
}
}
}
}
工作线程，当它尝试使用 ConnectedSocketData 时，由于结构为空而崩溃：
// Worker thread,processes IOCP messages.
DWORD ServerWorkerThread(LPVOID lpParam)
{
HANDLE CompletionPort = (HANDLE)lpParam;
DWORD BytesTransferred = 0;
OVERLAPPED* lpOverlapped = NULL;
LPCONNECTED_SOCKET_DATA ConnectedSocketData = NULL;
LPPER_IO_OPERATION_DATA PerIoData = NULL;
DWORD Flags = 0;
WSABUF DataBuf;
DWORD RecvBytes = 0;
int DestinationAddress = 0;
while (TRUE)//run forever
{
//Check for new message
if (GetQueuedCompletionStatus(CompletionPort,&BytesTransferred,(PULONG_PTR)&ConnectedSocketData,(LPOVERLAPPED*)&lpOverlapped,INFINITE) == 0)
{
DWORD Err = GetLastError();
if (Err != WAIT_TIMEOUT)
{
printf("GetQueuedCompletionStatus() Failed with error %d\n",Err);
if (closesocket(ConnectedSocketData->Socket) == SOCKET_ERROR)
{
printf("closesocket() Failed with error %d\n",WSAGetLastError());
return 0;
}
GlobalFree(ConnectedSocketData);
}
continue;
}
// retrieve IO data
PerIoData = CONTAINING_RECORD(lpOverlapped,PER_IO_OPERATION_DATA,Overlapped);
vector<SiteData>::iterator SiteDataIterator;
vector<InstrumentData>::iterator InstrumentDataIterator;
for (SiteDataIterator = ConnectedSocketData->CfgHandle->SiteConnections.begin();
SiteDataIterator != ConnectedSocketData->CfgHandle->SiteConnections.end();
SiteDataIterator++)
{
if (SiteDataIterator->Port == ConnectedSocketData->Port)
{
break;
}
}
知道为什么 IOCP 没有传递完成密钥吗？
解决方法
知道为什么 IOCP 没有传递完成密钥吗？
当然它会准确地传回您传递给 CreateIoCompletionPort 的内容和指向 OVERLAPPED 的 I/O 指针
但一开始
CreateIoCompletionPort((HANDLE)NewSocket,pSocketData->IOCP,(DWORD)ConnectedSocketData,0)
是错误的 - 这里只使用了 ConnectedSocketData 的低 32 位，必须是
CreateIoCompletionPort((HANDLE)NewSocket,(DWORD_PTR)ConnectedSocketData,0)
那么，你对PER_IO_OPERATION_DATA的定义
typedef struct
{
OVERLAPPED* Overlapped;
CHAR Buffer[DATA_BUFSIZE];
int BufferLen;
int OperationType;
string PacketName;
} PER_IO_OPERATION_DATA,* LPPER_IO_OPERATION_DATA;
始终是严重错误。必须
typedef struct
{
OVERLAPPED Overlapped;
CHAR Buffer[DATA_BUFSIZE];
int BufferLen;
int OperationType;
string PacketName;
} PER_IO_OPERATION_DATA,* LPPER_IO_OPERATION_DATA;
by Overlapped（当它定义为 OVERLAPPED* Overlapped 时）不可能收回 PER_IO_OPERATION_DATA 的地址。但是从 &Overlapped （当它定义为 OVERLAPPED Overlapped 时）已经可能了。
我最好做下一个定义
struct PER_IO_OPERATION_DATA : public OVERLAPPED
{
CHAR Buffer[DATA_BUFSIZE];
int BufferLen;
int OperationType;
string PacketName;
};
并使用
WSARecv(NewSocket,&DataBuf,1,&RecvBytes,&Flags,PerIOOperationData,NULL)
和
PerIoData = static_cast<PER_IO_OPERATION_DATA*>(lpOverlapped);
当 GetQueuedCompletionStatus 返回 false 时，您错误地处理了案例 - 在这种情况下您泄漏了 PerIoData。
这只是您代码中的主要错误，与您的直接问题有关