From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: [PATCH v3 21/28] tools/libxl: Infrastructure for writing a v2 stream Date: Mon, 13 Jul 2015 16:56:35 +0100 Message-ID: <55A3DFB3.5060103@citrix.com> References: <1436788907-1921-1-git-send-email-andrew.cooper3@citrix.com> <1436788907-1921-22-git-send-email-andrew.cooper3@citrix.com> <21923.55174.537923.565239@mariner.uk.xensource.com> <55A3DA61.6020100@citrix.com> <21923.56749.595874.610549@mariner.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <21923.56749.595874.610549@mariner.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Jackson Cc: Ross Lagerwall , Wei Liu , Ian Campbell , Xen-devel List-Id: xen-devel@lists.xenproject.org On 13/07/15 16:47, Ian Jackson wrote: > Andrew Cooper writes ("Re: [PATCH v3 21/28] tools/libxl: Infrastructure for writing a v2 stream"): >> On 13/07/15 16:21, Ian Jackson wrote: >>> Sadly this pattern is not correct. I don't think this initialisation >>> ensures that the memory in hdr is all-bits-0. >> It guarantees that all object have their default values, which is 0 for >> PoD integers. (On a POSIX system, it is only floats/doubles/_Complex >> which have default representations with not all bits 0) > Yes. > >> From the standard, >> >> [6.7.8.21] If there are fewer initializers in a brace-enclosed list than >> there are elements or members of an aggregate, or fewer characters in a >> string literal used to initialize an array of known size than there are >> elements in the array, the remainder of the aggregate shall be >> initialized implicitly the same as objects that have static storage >> duration. >> >> i.e. everything will get the same value it would have done had it been >> declared static. > But it does not guarantee that the padding is initialised to > all-bits-0. > > >>>> +/*----- Success/error/cleanup handling. -----*/ >>> As with read, I would prefer these to be unified into one >>> stream_complete function. >> They can't, because of differing function signatures from callbacks. > You are right about stream_success but not AFAICT about > stream_complete. > > Ie, stream_success could be simply > > stream_complete(egc, stream, 0) > > But maybe you prefer not to, so I won't insist. stream_success is used as a callback, but I see your point. I had intended to refactor stream_success() in terms of stream_complete(). ~Andrew