On Mon, Mar 12, 2007 at 03:35:21PM -0400, John Baldwin wrote:
> On Monday 12 March 2007 14:56, Pawel Jakub Dawidek wrote:
> > On Mon, Mar 12, 2007 at 11:16:23AM -0400, John Baldwin wrote:
> > > On Saturday 10 March 2007 15:52, Pawel Jakub Dawidek wrote:
> > > > What about something like this:
> > > >
> > > > #define cv_wait(cv, lock) do {
> > > > switch (LO_CLASSINDEX((struct lock_object *)(lock))) {
> > >
> > > The problem with a cast is you use type checking. Might as well do this:
> > >
> > > #define cv_wait(cv, lock) _cv_wait((cv), (struct lock_object
> > > *)(lock))
> >
> > This will skip type checking and my version only cast to provide type
> > checking, so when you pass some random variable it will give you an
> > error.
>
> Not really, you may pass some garbage and the LO_CLASSINDEX turns out to be a
> mutex. :) You only get a runtime error, not a compile-time one.
> Type-checking by the compiler is nice because you get compile-time errors.I'll get compile-time error, because cv_wait_mtx() takes 'struct condvar *' and 'struct mtx *' as arguments. So even if some garbage returns 1, which turns out to be a mutex, call to cv_wait_mtx() will generate compile-time error. But it seems the solution may not be that good if it is not very obvious on a first look. If typeof() thing works, its fine by me, just give me condvar(9) that works with sx(9) locks:) -- Pawel Jakub Dawidek http://www.wheel.pl [EMAIL PROTECTED] http://www.FreeBSD.org FreeBSD committer Am I Evil? Yes, I Am!
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