Re: Threads docs updated in CVS

From: williamkempf_at_[hidden]
Date: 2001-08-13 07:22:15

--- In boost_at_y..., Ross Smith <ross.s_at_i...> wrote:
> williamkempf_at_h... wrote:
> > 
> > Usage of CVs is trivial and doesn't require any "careful analysis 
to
> > figure out how to use them properly in any particular situation".
> 
> I disagree. But of course, it's so obvious to any Real Programmer 
that
> you must be right and I must be wrong that it would be quite
> unreasonable to ask you to justify your claim.

No, but for someone who's never used CVs, and doesn't understand how 
to use them, to make such a claim...

> > lock mutex
> > check state data to see if we can proceed
> > if false
> >    unlock mutex so other threads can have access to sate data
> >    // This is where one race occurs
> >    wait for event signaled by other threads when state is true
> >    // This is where another race occurs
> >    lock mutex
> > make use of data
> 
> All I see there is yet another bare assertion that race conditions 
exist
> with no attempt to back it up with logic. And some broken code.

*sigh*  The race conditions are clearly marked with comments and are 
self evident to boot.  Any code can be executured from another thread 
during the two comments, including code that changes the state so 
that the event is no longer valid.  This by very definition is a race 
condition.
 
> I'm giving up on this whole thing as of now. You've made it totally
> clear that your mind is made up and you aren't prepared to engage 
in any
> sort of discussion. I'm going to stop beating my head against a 
stone
> wall and go do something more productive.

I'm sorry you feel that way.  I feel that it's you who's not open to 
discussion on this topic, so it's probably just a communication 
disconnect, but I don't know how to get past it.

As for having made my mind up on CVs, that's true.  I'm more than 
willing to include events at a later date, but I'm not going to budge 
from the inclusion of CVs from the very beginning.  I think you're 
the only one that's got a problem with that, and most people 
understand the reasoning behind this, and agree with it.

Bill Kempf