TCP Keep Alive on idHttpServer(服务器)和 wininet(客户端) [英] TCP Keep Alive on idHttpServer (server) and wininet (client)

问题描述

我有一个使用 idHttpServer 开发的网络服务器应用程序.当客户端连接我的网络服务器时，由于某种未知原因，断开连接(不是正常断开连接)我的网络服务器没有得到通知.我知道这是正常行为，但我需要知道客户端何时死亡.

I have a webserver application developed using idHttpServer. When a client connects do my webserver and, for some unknown reason, got disconnect (not a gracefully disconnect) my webserver does not get notified. I know this is the normal behavior but I need to know when the client dies.

有几种方法可以做到这一点.我知道两个好方法:

There are a few ways of doing this. I know 2 good ways:

1 - 实现心跳机制.客户端套接字通知服务器它仍然活着(需要一些工作和一些代码才能使其工作)

1 - Implement a heart beat mechanism. The client socket notifies the server that it is still alive (need some work and some code to make it works)

2 - TCP 保持活动.这是我最喜欢的方式，因为它不需要太多的代码和工作.但我对此有一些疑问.

2 - TCP Keep Alive. This is the way I like most because it requires not too much code and work. But I got a few questions regarding this.

• 这是否可以与idHttpServer(用于服务器)和wininet 函数(用于客户端)?
• 这真的按预期工作吗?我的意思是，当客户端一直死掉时，服务器会收到通知?
• 有没有人有在 wininet 上设置这个的示例?(我想这必须在客户端设置，对吗?)
• 是否有更好的方法通知服务器客户端已死(当然使用 indy 和 wininet)

编辑

我使用的是 Delphi 2010 和来自他们 svn 的最新 Indy10 源代码.

I am using Delphi 2010 and last Indy10 source code from their svn.

推荐答案

如果您使用的是最新的 Indy 10 版本，那么您可以使用 TIdSocketHandle.SetKeepAliveValues() 方法:

If you are using an up-to-date Indy 10 release, then you can use the TIdSocketHandle.SetKeepAliveValues() method:

procedure SetKeepAliveValues(const AEnabled: Boolean; const ATimeMS, AInterval: Integer);

例如:

procedure TForm1.IdHTTPServer1Connect(AContext: TIdContext);
begin
  // send a keep-alive every 1 second after
  // 5 seconds of inactivity has been detected
  AContext.Binding.SetKeepAliveValues(True, 5000, 1000);
end;

请注意，ATimeMS 和 AInterval 参数仅在 Win2K 及更高版本上受支持.

Note that the ATimeMS and AInterval parameters are only supported on Win2K and later.

否则，直接使用TIdSocketHandle.SetSockOpt()方法手动开启TCP/IPSO_KEEPALIVE选项:

Otherwise, use the TIdSocketHandle.SetSockOpt() method directly to enable the TCP/IP SO_KEEPALIVE option manually:

procedure TIdSocketHandle.SetSockOpt(ALevel: TIdSocketOptionLevel; AOptName: TIdSocketOption; AOptVal: Integer);

例如:

procedure TForm1.IdHTTPServer1Connect(AContext: TIdContext);
begin
  AContext.Binding.SetSockOpt(Id_SOL_SOCKET, Id_SO_KEEPALIVE, 1);
end;

这篇关于TCP Keep Alive on idHttpServer(服务器)和 wininet(客户端)的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！