Re: [Condor-devel] daemonCore instance in DaemonCore class

[Marc Tardif <marc@xxxxxxxxxxxxx>]

* Matthew Farrellee <matt@xxxxxxxxxx> [2010-01-26 21:28 -0500]:
> On 01/19/2010 09:33 PM, Marc Tardif wrote:
> > I noticed that the DaemonCore member functions sometimes call the
> > global daemonCore instance directly instead of calling the "this"
> > instance. For example, in DaemonCore::Close_FD:
> > 
> >   retval = ( daemonCore->Close_Pipe ( fd ) ? 0 : -1 );
> > 
> > So, I was wondering under what circumstances both the global daemonCore
> > instance differed from the "this" instance. It seems an example of this
> > can be found in the main function in daemon_core_main.cpp. However, I'm
> > still not quite sure I understand why there is a need for having two
> > such instances co-existing. Can someone provide a little explanation?
> 
> I'd take the silence to mean no one knows off the top of their
> heads. It's entirely possible this is just an artifact of age that
> could be made more consistent.
> 
> Off the top of my head, I'd say maybe some functions only have access
> to the static context and must use daemonCore.

In the above example, DaemonCore::Close_FD is a member function
of DaemonCore, so I'm not sure how it might only have access to the
static context rather than the "this" pointer. As you say, perhaps this
is an artifact of a function written in C which accessed the static
context and was not updated to use "this" when copied over to a C++
member function. This would make sense in a C context because using
a global instance of the daemon core structure would've probably been
more convenient than passing the structure as argument to every daemon
core function.

-- 
Marc Tardif <marc@xxxxxxxxxxxxx>
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