Re: [Valgrind-developers] How to write a function wrapper for pthread_spin_unlock() ?

[Julian S. <js...@ac...>]

On Wednesday 13 December 2006 09:26, Bart Van Assche wrote:
> On 12/13/06, Tom Hughes <to...@co...> wrote:
> > I think the problem is that pthread_spin_unlock is an alias for
> > pthread_spin_init (ie they are the same routine) and valgrind sees
> > the init routine first so attaches that name to the address:
> >
> >   dellow [~] % objdump -T /lib64/libpthread.so.0 | grep
> > pthread_spin_unlock 000000382700ab70 g    DF .text  0000000000000009 
> > GLIBC_2.2.5 pthread_spin_unlock
> >
> >   dellow [~] % objdump -T /lib64/libpthread.so.0 | grep 000000382700ab70
> >   000000382700ab70 g    DF .text  0000000000000009  GLIBC_2.2.5
> > pthread_spin_init 000000382700ab70 g    DF .text  0000000000000009 
> > GLIBC_2.2.5 pthread_spin_unlock
> >
> > I don't think valgrind's symbol table can cope with a many-one mapping
> > from names to addresses, so we just remember the first name we see.
> >
> > Given that the main use of the symbol table is mapping the other way
> > for backtraces, this makes some sense, as you can only show one name
> > for an address in a backtrace.
> >
> > Tom
>
> This explanation sounds perfectly reasonable, but doesn't give me a
> solution: does the above mean that it's impossible to implement a
> wrapper for pthread_spin_unlock() in a Valgrind tool ?

Well, you could write a wrapper for pthread_spin_init() instead?
Or supply wrappers for both, factoring the real work into a routine
shared by both wrappers.  The latter sounds like a more robust approach.

J