在调试时，当调用WSARecv时，我为该函数提供了 PerIoData-＆gt; WSABUF 结构的地址。这应该将发送的数据分配给 WSABUF.buf char *数组，它似乎是这样。当工作线程循环回等待的 GetQueuedCompletionStatus 时，它似乎以某种方式（神奇地）将该数据发送到PerIoData.Buffer（char * array）。基本上， PerIoData.Buffer 和 PerIoData.WSABUF.buf 都等于相同的char *数组。当我从 PER_IO_DATA Struct中删除 PerIoData.Buffer 时（以及对它的所有引用），当客户端发送数据时， GetQueuedCompletionStaus 永远不会返回我知道 WSABUF.buf 应填充数据。
相关信息：
per_io_data struct就是这样：
struct _PER_IO_DATA{ //in the interests of an efficient question, i'm omitting the
//constructor/destructor code
public:
OVERLAPPED Overlapped;
WSABUF DataBuf;
char myBuffer[BUFFER_LENGTH];
int BufferLen;
int OperationType;
};
typedef _PER_IO_DATA PER_IO_DATA;
typedef _PER_IO_DATA *PPER_IO_DATA;
我的GetQueuedCompletionStatus函数被调用如下：
ret = GetQueuedCompletionStatus(CompletionPort,
&BytesTransferred,
(LPDWORD)&PerHandleData,
(LPOVERLAPPED *)&PerIoData,
INFINITE);
我的WSARecv函数被调用如下：
WSARecv(PerHandleData->Socket, &(PerIoData->DataBuf), 1, NULL, &Flags, ((LPWSAOVERLAPPED)&PerIoData->Overlapped), NULL);
//i know casting the Overlapped structure as LPWSAOVERLAPPED is unnecessary, but I was tweaking the
//code when I didn't fully understand the problems I was having.
我的问题是我从未明确地将任何内容分配给 PerIoData-＆gt;缓冲区，但似乎总是会填充已发送的数据。我相信GetQueuedCompletionStatus“知道”将此数据发送到 PerIoData-＆gt;缓冲区，尽管它期望指向 LPOVERLAPPED 结构（我通过我的指针） PerIoData 包含所讨论的缓冲区 char数组的struct实例。它真的让我烦恼......也许它的行为并不像我想的那样，但我唯一可以看到 PerIoData-＆gt; Buffer 的地方来自 GetQueuedCompletionStatus < / strong>方法。如果情况并非如此，那么 PerIoData-＆gt;缓冲区似乎无处不在？我已经搜索了MSDN和google好几天了。我会继续寻找，如果我找到答案，我会发布更新。请帮忙？提前谢谢！
*注意：我会创建标签WSABUF和GetQueuedCompletionStatus，但这是我的第一篇文章。
- 编辑：我发布了结构和工作线程，遗漏了所有其他不相关的代码.-- 您会注意到_PER_IO_DATA :: DataBuf.buf已分配内存，然后清零。没有指向myBuffer数组......
#include "stdafx.h"
#define SEND_POSTED 1
#define RECV_POSTED 2
#define BUFFER_LENGTH 1024
HANDLE CompletionPort;
SOCKADDR_IN serverAddress, *clientAddress;
SOCKET listener, client;
unsigned short port = 5000;
SYSTEM_INFO SystemInfo;
int i;
struct _PER_HANDLE_DATA{//Per handle data structure
SOCKET Socket;
SOCKADDR_STORAGE Address;
_PER_HANDLE_DATA(){
Socket = 0;
ZeroMemory(&Address, sizeof(SOCKADDR_STORAGE));
}
~_PER_HANDLE_DATA(){
Socket = NULL;
ZeroMemory(&Address, sizeof(SOCKADDR_STORAGE));
}
};typedef _PER_HANDLE_DATA PER_HANDLE_DATA;typedef _PER_HANDLE_DATA *PPER_HANDLE_DATA;
struct _PER_IO_DATA{
public:
OVERLAPPED Overlapped;
WSABUF DataBuf;
char myBuffer[BUFFER_LENGTH];
int BufferLen;
int OperationType;
_PER_IO_DATA(){
OperationType = 0;
DataBuf.len = BUFFER_LENGTH;
DataBuf.buf = (char*)malloc(BUFFER_LENGTH+1);
BufferLen = BUFFER_LENGTH;
ZeroMemory(DataBuf.buf, (sizeof(BUFFER_LENGTH+1)));
ZeroMemory(&myBuffer, (sizeof(char)*BUFFER_LENGTH));
SecureZeroMemory((PVOID)&Overlapped, sizeof(Overlapped));
}
~_PER_IO_DATA(){
free(&DataBuf.buf);
}
};
typedef _PER_IO_DATA PER_IO_DATA;
typedef _PER_IO_DATA *PPER_IO_DATA;
unsigned _stdcall ServerWorkerThread(LPVOID CompletionPortID);
int _tmain(int argc, _TCHAR* argv[])
{
/*
INITIALIZE WINSOCK AND COMPLETION PORT, AND ACCEPT CONNECTIONS
*/
}
unsigned _stdcall ServerWorkerThread(LPVOID CompletionPortID){
printf("ServerWorkerThread(%d) Working\n", GetCurrentThreadId());
HANDLE CompletionPort = (HANDLE) CompletionPortID;
DWORD BytesTransferred;
PPER_HANDLE_DATA PerHandleData = new PER_HANDLE_DATA;
PPER_IO_DATA PerIoData = new PER_IO_DATA;
DWORD SendBytes = 0, RecvBytes = 0;
DWORD Flags;
BOOL ret;
Sleep(2000);
while(TRUE){
ret = GetQueuedCompletionStatus(CompletionPort,
&BytesTransferred,
(LPDWORD)&PerHandleData,
(LPOVERLAPPED *)&PerIoData,
INFINITE);
//printf("\n\nBytesTransferred: %d\n\n", BytesTransferred);
if(BytesTransferred == 0 && (PerIoData->OperationType == RECV_POSTED || PerIoData->OperationType == SEND_POSTED)){
closesocket(PerHandleData->Socket);
GlobalFree(PerHandleData);
GlobalFree(PerIoData);
continue;
}
if(PerIoData->OperationType == RECV_POSTED){
//output received data
if(!strcmp(PerIoData->DataBuf.buf, "Disconnect") || !strcmp(PerIoData->DataBuf.buf, "disconnect")){
printf("Disconnecting...\n");
if(!shutdown(PerHandleData->Socket, SD_BOTH)){
closesocket(PerHandleData->Socket);
delete(PerHandleData);
}
}else{
printf("RECV_POSTED: %s\n", PerIoData->DataBuf.buf);
}
}
Flags = 0;
SecureZeroMemory((PVOID)&PerIoData->Overlapped, sizeof(WSAOVERLAPPED));
PerIoData->DataBuf.len = BUFFER_LENGTH;
//***************************************************************************
//Even though the following is commented out, PerIoData->DataBuf.buf
//is still being populated and so is PerIoData-myBuffer
//So why is myBuffer being populated with data when DataBuf.buf is not pointing to it??
//PerIoData->DataBuf.buf = PerIoData->myBuffer;
//Also, if you comment out all references of myBuffer, GetQueuedCompletionStatus(),
//will never return if myBuffer doesn't exist...how does it seem to be 'aware' of myBuffer?
//***************************************************************************
PerIoData->OperationType = RECV_POSTED;
WSARecv(PerHandleData->Socket, &(PerIoData->DataBuf), 1, NULL, &Flags, ((LPWSAOVERLAPPED)&PerIoData->Overlapped), NULL);
}
return 0;
}