HTTP 1.1 20 second delay compared to HTTP 1.0

I've written a program in C that sends a HTTP 1.1 POST request to a web server.

Well monitoring it with wireshark, takes less then a second for the 开发者_StackOverflow中文版server to respond and to get the HTTP/1.1 200 OK message, but then it takes another 20 seconds to get the FIN, ACK packet, which I believe this is what causes recv to return 0, specifying no more data.

Causing my program to hang for 20ish seconds well it waits for the server to send the FIN, ACK packet.

I've tested this with HTTP 1.0, and there isn't a delay. So I think this is because HTTP 1.1 by default considers all connections as persistent connections.

But my web browser uses HTTP 1.1 and there's no delay, so I think i'm not doing something right.

One idea I had was instead of waiting for recv to return 0, I should check if i'm at the end of the document some other way, but I can't think of any way to do this.

So if anyone could explain to me how I should be doing this? Thanks in advance.

HTTP 1.1 defaults to keep-alive connections while 1.0 does not. You can request a non-keep-alive by adding in the header

Connection: close

which instructs the server to close the connection as soon as it's complete.