Re: [Valgrind-developers] coregrind: semaphore remapping rewritten

[Aleksander S. <A....@os...>]

On Mon, 2004-03-15 at 17:22, Jeremy Fitzhardinge wrote:
> It looks pretty good, but I have a few comments:
> 
> Why still keep the big array?  Can't this be made dynamic so that
> there's no need for VG_N_SEMAPHORES?

Maybe I will implement this in the future. But first I have to perform
benchmarks to check performance penalty caused by additional malloc in
every sem_init. It is really important in my use cases. Maybe I will
allocate memory for vg_sem_t structures in big chunks, I don't know yet.
If I will find the time, I will write an allocation scheme that
eliminates VG_N_SEMAPHORES.

> Also, barf() seems to be mostly used for reporting vg_libpthread
> internal errors, where as the places you use it seem to be all client
> bugs; maybe just using VG_INTERNAL_PRINTF_BACKTRACE.

I've decided to change that barf() to pthread_error(). It seems most
reasonable in these cases. Also added setting of errno to EINVAL -
according to POSIX.

> And finally, could you write a regression test case and add it to
> none/tests?  Something which would have failed before, but now works,
> and exercises as much of the semaphore machinery as possible.

I'm very busy, so it may take a week or two before I find the time for
it. But I hope I will do it.

New patch (eliminated barf()) attached. I hope you can commit it now, as
it only makes things better - elimination of VG_N_SEMAPHORES may be done
later.


Olek S.