Re: [PATCH 06/23] libxl: init: libxl__poller_init and _get take gc

From: Ian Campbell <Ian.Campbell@citrix.com>
To: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Shriram Rajagopalan <rshriram@cs.ubc.ca>,
	George Dunlap <George.Dunlap@eu.citrix.com>,
	xen-devel@lists.xensource.com,
	Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Subject: Re: [PATCH 06/23] libxl: init: libxl__poller_init and _get take gc
Date: Thu, 19 Dec 2013 13:00:52 +0000	[thread overview]
Message-ID: <1387458052.9925.65.camel@kazak.uk.xensource.com> (raw)
In-Reply-To: <1387305337-15355-7-git-send-email-ian.jackson@eu.citrix.com>

On Tue, 2013-12-17 at 18:35 +0000, Ian Jackson wrote:
> @@ -1622,7 +1617,7 @@ libxl__ao *libxl__ao_create(libxl_ctx *ctx, uint32_t domid,
>      if (how) {
>          ao->how = *how;
>      } else {
> -        ao->poller = libxl__poller_get(ctx);
> +        ao->poller = libxl__poller_get(&ao->gc);

this is a bit subtle, libxl__poller_get would previously have gotten the
toplevel ctx gc and not the ao-gc, if it had thought to init a GC at
all.

It only actually uses whatever it gets for logging, so that's ok, but
I'm not sure which would be the correct/expected gc to use. I take it
you considered this?

libxl__poller_get does a NOGC allocation and the associated manual
memory mgmt -- now that it has the ao->gc in hand could it use that? Is
the poller's lifecycle entirely contained within the ao?

Ian.