由于大多讲解winsock的代码都是c++的，而winsock只是一些windows api的使用，为了帮助.net程序员深入的理解winsock2，我把.net下同 步socket的实现代码拆了出来，简化了一下，大家有空可以调试一下看看。
注意
1、只能跑在win2000以上的系统
2、只支持tcp协议,
3、支持ipv4
改动
1、去掉计数器、日志等逻辑
2、不支持异步，完成端口模型，等有时间了，把完成端口那部分也拆分出来给大家。
为了不让本帖太短，贴一些代码中使用到的winsock函数的原型，大家要想开发高性能的网络程序，就得去深入理解winsock的那几个函数， 可以看看《windows网络编程》的第7、8、9章
OSSOCK#region OSSOCK
[SuppressUnmanagedCodeSecurity]
internal static class OSSOCK
{
[DllImport("ws2_32.dll", CharSet = CharSet.Ansi, SetLastError = true)]
internal static extern SocketError WSAStartup([In] short wVersionRequested, out WSAData lpWSAData);
[DllImport("ws2_32.dll", CharSet = CharSet.Auto, SetLastError = true)]
internal static extern SafeCloseSocket.InnerSafeCloseSocket WSASocket([In] AddressFamily addressFamily, [In] SocketType socketType, [In] ProtocolType protocolType, [In] IntPtr protocolInfo, [In] uint group, [In] SocketConstructorFlags flags);
[DllImport("ws2_32.dll", CharSet = CharSet.Auto, SetLastError = true)]
internal static extern unsafe SafeCloseSocket.InnerSafeCloseSocket WSASocket([In] AddressFamily addressFamily, [In] SocketType socketType, [In] ProtocolType protocolType, [In] byte* pinnedBuffer, [In] uint group, [In] SocketConstructorFlags flags);
[DllImport("ws2_32.dll", SetLastError = true)]
internal static extern SocketError bind([In] SafeCloseSocket socketHandle, [In] byte[] socketAddress, [In] int socketAddressSize);
[DllImport("ws2_32.dll", SetLastError = true)]
internal static extern SocketError listen([In] SafeCloseSocket socketHandle, [In] int backlog);
[ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail), DllImport("ws2_32.dll", SetLastError = true)]
internal static extern SocketError ioctlsocket([In] SafeCloseSocket socketHandle, [In] int cmd, [In, Out] ref int argp);
[DllImport("ws2_32.dll", SetLastError = true)]
internal static extern unsafe int recv([In] IntPtr socketHandle, [In] byte* pinnedBuffer, [In] int len, [In] SocketFlags socketFlags);
[DllImport("ws2_32.dll", SetLastError = true)]
internal static extern unsafe int send([In] IntPtr socketHandle, [In] byte* pinnedBuffer, [In] int len, [In] SocketFlags socketFlags);
[DllImport("ws2_32.dll", SetLastError = true)]
internal static extern SocketError shutdown([In] SafeCloseSocket socketHandle, [In] int how);
[DllImport("ws2_32.dll", SetLastError = true)]
internal static extern SocketError setsockopt([In] SafeCloseSocket socketHandle, [In] SocketOptionLevel optionLevel, [In] SocketOptionName optionName, [In] ref int optionValue, [In] int optionLength);
}
#endregion
研究了几天.net socket里对IOCP的封装，发现确实有些复杂，不打算往出拆代码了，自己理解IOCP的代码，用平台调用写一个示例吧。甭 管.net再发展，remoting,wcf啥的，底层还是有限的这么几个函数，真的推荐大家好好看看，到时候网络程序出问题了，抓dump，看调用栈也 知道到底阻塞到哪个API了，为什么会阻塞。学windbg也就是那几个命令而已，关键你还得了解clr的内部运行机理，win32api,crt,il甚至汇编 等。
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