WinSock学习笔记6：IOCP完成端口模型

unit Unit1;  
  
interface  
  
uses  
  WinSock2, Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,  
  Dialogs, StdCtrls, ExtCtrls;  
  
type  
  //单IO数据结构  
  LPER_IO_OPERATION_DATA = ^TPER_IO_OPERATION_DATA;  
  TPER_IO_OPERATION_DATA = packed record  
    Overlapped: WSAOverlapped;  
    DataBuf: WSABuf;  
    Buff: array [0..10] of Char;  
    BytesSend: DWORD;  
    BytesRecv: DWORD;  
  end;  
  
  //单句柄数据结构  
  LPER_HANDLE_DATA = ^TPER_HANDLE_DATA;  
  TPER_HANDLE_DATA = packed record  
    Socket: TSocket;  
  end;  
  
  TListenThread = class(TThread)  
  private  
  protected  
    procedure Execute;override;  
  public  
    constructor Create;  
  end;  
  
  TForm1 = class(TForm)  
    Memo1: TMemo;  
    Button1: TButton;  
    procedure FormCreate(Sender: TObject);  
  private  
    { Private declarations }  
  public  
    { Public declarations }  
  end;  
  
var  
  Form1: TForm1;  
  ServerSocket: TSocket;  
  
implementation  
  
{$R *.dfm}  
  
//工作者线程  
function WorkThread(CompletionPortID: Pointer):DWORD; stdcall;  
var  
  CompletionPort: THandle;  
  BytesTransferred: DWORD;  
  PerHandleData: LPER_HANDLE_DATA;  
  PerIOData: LPER_IO_OPERATION_DATA;  
  Flags: DWORD;  
  RecvBytes: DWORD;  
begin  
  CompletionPort:= THandle(CompletionPortID);  
  
  while True do  
  begin  
    //获取完成端口上的队列的完成状态  
    GetQueuedCompletionStatus(CompletionPort, BytesTransferred, DWORD(PerHandleData),  
      POverlapped(PerIOData), INFINITE);  
  
    //判断是客户端发来的数据还是服务端发出的数据  
    if PerIOData.BytesRecv = 0 then  
    begin  
      PerIOData.BytesRecv:= BytesTransferred;  
      PerIOData.BytesSend:= 0;  
    end else  
      PerIOData.BytesSend:= PerIOData.BytesSend + BytesTransferred;  
  
    if PerIOData.BytesRecv > PerIOData.BytesSend then  
    begin  
      ZeroMemory(@(PerIOData.Overlapped), SizeOf(WSAOverlapped));  
      PerIOData.DataBuf.buf:= PerIOData.Buff + PerIOData.BytesSend;  
      PerIOData.DataBuf.len:= PerIOData.BytesRecv - PerIOData.BytesSend;  
  
      //显示收到的数据，这样做是不安全的，示例而已 :)  
      Form1.Memo1.Lines.Add(PerIOData.Buff);  
    end;  
  
    //重置数据  
    PerIOData.BytesRecv:= 0;  
    PerIOData.DataBuf.len:= 22;  
    PerIOData.DataBuf.buf:= @PerIOData.Buff;  
  
    //再次投递  
    WSARecv(PerHandleData.Socket, @(PerIOData.DataBuf), 1, RecvBytes, Flags,  
      @(PerIOData.Overlapped), nil);  
  end;  
end;  
  
{ TWorkThread }  
  
constructor TListenThread.Create;  
begin  
  inherited Create(False);  
  FreeOnTerminate:= True;  
end;  
  
procedure TListenThread.Execute;  
var  
  WSData: TWSAData;  
  CompletionPort: THandle;  
  lpSystemInfo: TSystemInfo;  
  Idx: Integer;  
  ThreadID: DWORD;  
  LocalAddr: TSockaddr;  
  ClientAddr: TSockaddr;  
  ClientSocket: TSocket;  
  
  PER_HANDLE_DATA: LPER_HANDLE_DATA;  
  PER_IO_OPERATION_DATA: LPER_IO_OPERATION_DATA;  
  
  RecvBytes: DWORD;  
  Flags: DWORD;  
begin  
  inherited;  
  
  //初始化Winsock  
  WSAStartUp($202, WSData);  
  //创建完成端口  
  CompletionPort:= CreateIOCompletionPort(INVALID_HANDLE_VALUE, 0, 0, 0);  
  //根据处理器数量创建工作者线程的数量(网上流传的说法是线程数量=cpu数量*2+2)  
  GetSystemInfo(lpSystemInfo);  
  for Idx := 1 to lpSystemInfo.dwNumberOfProcessors *2 + 2 do  
    //创建工作者线程，并将完成端口句柄传递给线程  
    CreateThread(nil, 0, @WorkThread, Pointer(CompletionPort), 0, ThreadID);  
  //创建监听套接字  
  ServerSocket:= WSASocket(AF_INET, SOCK_STREAM, IPPROTO_TCP, nil, 0, WSA_FLAG_OVERLAPPED);  
  //设置LocalAddr的参数  
  LocalAddr.sin_family:= AF_INET;   //IPV4族  
  LocalAddr.sin_addr.S_addr:= INADDR_ANY;//这里不能写Inet_addr('127.0.0.1')，否则会绑定失败，不清楚原因是什么;  
  LocalAddr.sin_port:= Htons(1077); //Host To Net Short，主机字节顺序转为网络字节顺序  
  //绑定本机IP地址、端口，绑定之前先设置好LocalAddr的参数  
  Bind(ServerSocket, @LocalAddr, SizeOf(LocalAddr));  
  //开始监听  
  Listen(ServerSocket, 5);  
  
  while not Terminated do  
  begin  
    ClientSocket:= WSAAccept(ServerSocket, ClientAddr, nil, nil, 0);  
    //创建TPER_HANDLE_DATA结构的变量保存客户端Socket  
    PER_HANDLE_DATA:= LPER_HANDLE_DATA(GlobalAlloc(GPTR, SizeOf(TPER_HANDLE_DATA)));  
    PER_HANDLE_DATA.Socket:= ClientSocket;  
    //把完成端口和客户端套接字关联起来  
    CreateIOCompletionPort(ClientSocket, CompletionPort, DWORD(PER_HANDLE_DATA), 0);  
    //创建TPER_IO_OPERATION_DATA结构的变量，关联WSARecv函数  
    PER_IO_OPERATION_DATA:= LPER_IO_OPERATION_DATA(GlobalAlloc(GPTR, SizeOf(TPER_IO_OPERATION_DATA)));  
    ZeroMemory(@PER_IO_OPERATION_DATA.Overlapped, SizeOf(WSAOverlapped));  
    PER_IO_OPERATION_DATA.BytesSend:= 0;  
    PER_IO_OPERATION_DATA.BytesRecv:= 0;  
    PER_IO_OPERATION_DATA.DataBuf.len:= 22;  
    PER_IO_OPERATION_DATA.DataBuf.buf:= @PER_IO_OPERATION_DATA.Buff;  
  
    WSARecv(ClientSocket, @(PER_IO_OPERATION_DATA.DataBuf), 1, RecvBytes,  
      Flags, @(PER_IO_OPERATION_DATA.Overlapped), nil);  
  end;  
end;  
  
  
procedure TForm1.FormCreate(Sender: TObject);  
begin  
  //创建监听线程  
  TListenThread.Create();  
end;  
  
  
end.  

该代码仅仅是练习IOCP的函数使用和大体的实现步骤，里面很多细节并不是唯一的方法，例如单IO数据结构和单句柄数据结构的定义等等。

 

本文转载自http://blog.csdn.net/dropme/article/details/4562171