> -----Original Message----- > From: Andrew Stitcher [mailto:astitc...@redhat.com] > ... > On Mon, 2011-03-14 at 10:12 -0400, Carl Trieloff wrote: > > On 03/14/2011 10:07 AM, Gordon Sim wrote: > > > Its the iterator that is the issue, not the smart pointer that it > > > points to. You test (it == bindingCache.end()) outside > the lock and > > > that is not safe. > > > > FYI -- .end() function is independent of the validity of the > > iterator. > > 'it' will either == the const of end, or ref the smart pointer which > > is then safe, even if cleared. I maintain it it safe. > > It's not clear to me from a quick squint at the standard > whether map::end is required to be a constant valid > irrespective of further changes to a map in a different > thread so I can't say for sure who is correct here. However > changing the code to use a temporary bool to hold the value > of it==bindCache.end() inside the mutex makes the code > uncontroversial and the compiler will optimise it away if it > truly is a constant (well if it's defined in the header).
And any section of code which inspires such spirited debate amongst three heavy hitters could probably benefit from some explanatory comments and maybe some clarification so us mere mortals won't get tripped up later :-) -Steve --------------------------------------------------------------------- Apache Qpid - AMQP Messaging Implementation Project: http://qpid.apache.org Use/Interact: mailto:dev-subscr...@qpid.apache.org
