3da
Subj : Re: double-checked locking in C
To   : comp.programming.threads
From : Alexander Terekhov
Date : Thu Jul 07 2005 08:28 pm


Joe Seigh wrote:
[...]
> > "The behavior of pthread_once() is undefined if once_control has
> >  automatic storage duration or is not initialized by
> >  PTHREAD_ONCE_INIT."
> >
> So what kind of value could PTHREAD_ONCE_INIT have that couldn't be
> memcpy'd from an initialized pthread_once_t object never otherwise
> used?

Same magic stuff as PTHREAD_MUTEX_INIT.

> 
> >
> >>I don't even know what pthread_once_reset() even means.
> >
> >
> > Effect is the same as pthread_once_destroy()+pthread_once_init()
> > (with pthread_once_destroy() invoking optional destructor function)
> > except that it is throw()-nothing operation (vs pthread_once_init()
> > that can throw).
> >
> If C had exceptions.

In C/POSIX terms, throw()-nothing means no "shall fail" errors,
only "may fail" (if any).

regards,
alexander.

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