Re: [BUG?] git http connection reuse

From: Daniel Stenberg <daniel@haxx.se>
Date: Feb 18, 2014, 09:09 UTC
Message-ID: <alpine.DEB.2.00.1402181001540.15465@tvnag.unkk.fr>
In-Reply-To: <20140218075534.GB29804@sigill.intra.peff.net>

On Tue, 18 Feb 2014, Jeff King wrote:

> I'm not clear whether you mean by this that it is _expected_ in my test 
> program for curl not to reuse the connection. Or that curl may simply have 
> to do a little more work, and it is still a bug that the connection is not 
> reused.

Okey, I checked this closer now and this is the full explanation to what happens. It seems to work as intended:

It's all about where the connection cache is held by libcurl. When you create a multi handle, it will create a connection cache that will automatically be shared by all easy handles that are added to it.

If you create an easy handle and make a curl_easy_perform() on that, it will create its own connection cache and keep it associated with this easy handle.

When first using an easy handle within a multi handle it will use the shared connection cache in there as long as it is in that multi handle family, but as soon as you remove it from there it will be detached from that connection cache.

Then, when doing a fresh request with easy_perform using the handle that was detached from the multi handle, it will create and use its own private cache as it can't re-use the previous connection that is cached within the multi handle.

> We can certainly teach git to use the multi interface, even when doing a 
> single blocking request.

For connection re-use purposes, that may make a lot of sense.

-- 
  / daniel.haxx.se