fprintf

[Nikos Mavrogiannopoulos]

On Thu, Jun 9, 2011 at 1:06 PM, Stef Walter <stefw at collabora.co.uk> wrote:

>> I'd suggest having a function that increases (and enables)
>> verbosity instead. I'll explain myself on why.
>> If p11-kit is used by libgnutls and librandom, both
>> used by an application random2, then if I call
>> p11_kit_be_quiet(), I'll disable verbosity even if
>> librandom specifically wanted that.
> I was hoping that it would go the other way around. That verbosity was
> the default, since it's useful for many applications.  If mod_gnutls
> knows that it is being used in an environment where printing to stderr
> is problematic, then it disables the verbosity.

mod_gnutls or similar servers, might never know they use p11-kit
on the background. Thus they shouldn't be expected to call a function
of it.

>> Moreover p11_kit_message() suggests it cannot be
>> thread-safe. So if two parallel runs of a p11_kit functions
>> are execute (maybe for a different module), what error
>> would sbd get?
> It is thread safe. It only returns the message for the last p11_kit
> function called on the same thread.

Can this be guarranteed in a portable way? The format is the
same as dlerror() which is an example of a non-reentrant
function.

> In addition p11-kit is designed to be used by more than one consumer
> (such as library or application) in the same process. We want any of
> these consumers to be able to 'veto' the verbose printing of messages to
> stderr. This is for the reason that you mentioned previously about daemons.

The problem then is who would veto? gnutls is a library, it cannot know whether
it is used in a daemon, thus it would not. The end application daemon, might not
know it is using p11-kit because it uses it via gnutls, thus it will
not veto as well.

regards,
Nikos