I've verified that isPersistent is true, but CFNetwork is still closing the
TCP stream after each transaction.
This has been covered on the mailing list already. I've included a
copy of the relevant posts below.
S+E
--
Quinn "The Eskimo!" <http://www.apple.com/developer/>
Apple Developer Technical Support * Networking, Communications, Hardware
At 10:47 -0500 15/6/04, Marc Epard wrote:
Date: Tue, 15 Jun 2004 10:47:20 -0500
From: Marc Epard <xxx@yyy>
Subject: kCFStreamPropertyHTTPAttemptPersistentConnection
To: macnetworkprog <email@hidden>
I'm using CFNetwork for HTTP and I'd like to have persistent connections
because I'm doing several transactions in a row. Before calling
CFReadStreamOpen, I do this:
I've verified that isPersistent is true, but CFNetwork is still closing the
TCP stream after each transaction.
I'm making sure to read the entire response. I've tried keeping a reference
to a stream around and not releasing it each time and I've tried not calling
CFReadStreamClose. Still, CFNetwork closes the stream.
I've used tcpdump and tcpflow to verify that both ends are including the
Connection: Keep-Alive header and determined that it is the CFNetwork end
that initiates the TCP close rather than the server. This is on 10.3.4.
Any suggestions?
Thanks.
-Marc
At 9:44 -0500 19/8/04, Marc Epard wrote:
Date: Thu, 19 Aug 2004 09:44:46 -0500
From: Marc Epard <xxx@yyy>
Subject: Re: kCFStreamPropertyHTTPAttemptPersistentConnection
To: macnetworkprog <email@hidden>
In case someone searches for this in the future:
I talked to some Apple engineers at WWDC and found out the trick to get
persistent HTTP connections to work in Panther:
You must call CFReadStreamOpen to issue a subsequent request before calling
CFReadStreamRead to read *any* of the response for the previous request.
Issuing the next request before calling CFReadStreamClose on the previous
response is not sufficient.
[...]
-Marc
At 10:05 -0700 19/8/04, Jeremy Wyld wrote:
Date: Thu, 19 Aug 2004 10:05:10 -0700
From: Jeremy Wyld <xxx@yyy>
Subject: Re: kCFStreamPropertyHTTPAttemptPersistentConnection
To: macnetworkprog Programming <email@hidden>
Let me fill in the details.
CFNetwork on Panther is very aggressive about reaping the HTTP
sockets. If another request is queued before all the bytes are
received on the previous request, the persistent connection will be
maintained. The problem is that the act of reading could be the
call to close down your persistent connection. This is why the
described method will work. The open will cause the queueing, and
the persistent connection is still open until the read.
CFNetwork on Tiger has been changed to be less aggressive. An
underlying, persistent connection is open as long as the last stream
on that connection. Calling open before the previous request's
close will get the new request enqueued on the persistent
connection. "GET Example" in /Developer/Examples/Networking/ has
been changed on the Tiger CD to use this model.
