Looks good in general, see comments below On 2014-10-28 20:46, Peter Meerwald wrote: > From: Peter Meerwald <p.meerwald at bct-electronic.com> Missing a good commit message. > Signed-off-by: Peter Meerwald <pmeerw at pmeerw.net> > --- > src/pulsecore/once.c | 18 +----------------- > src/pulsecore/once.h | 27 +++++++++++++++++++++++---- > 2 files changed, 24 insertions(+), 21 deletions(-) > > diff --git a/src/pulsecore/once.c b/src/pulsecore/once.c > index 16059c3..cac8cda 100644 > --- a/src/pulsecore/once.c > +++ b/src/pulsecore/once.c > @@ -30,14 +30,9 @@ > /* See http://www.hpl.hp.com/research/linux/atomic_ops/example.php4 for the > * reference algorithm used here. */ > > -bool pa_once_begin(pa_once *control) { > +bool pa_once_doit(pa_once *control) { > pa_mutex *m; > > - pa_assert(control); > - > - if (pa_atomic_load(&control->done)) > - return false; > - > /* Caveat: We have to make sure that the once func has completed > * before returning, even if the once func is not actually > * executed by us. Hence the awkward locking. */ > @@ -64,14 +59,3 @@ void pa_once_end(pa_once *control) { > m = pa_static_mutex_get(&control->mutex, false, false); > pa_mutex_unlock(m); > } > - > -/* Not reentrant -- how could it be? */ > -void pa_run_once(pa_once *control, pa_once_func_t func) { > - pa_assert(control); > - pa_assert(func); > - > - if (pa_once_begin(control)) { > - func(); > - pa_once_end(control); > - } > -} > diff --git a/src/pulsecore/once.h b/src/pulsecore/once.h > index 460a700..3d528a7 100644 > --- a/src/pulsecore/once.h > +++ b/src/pulsecore/once.h > @@ -26,18 +26,27 @@ > #include <pulsecore/mutex.h> > > typedef struct pa_once { > - pa_static_mutex mutex; > pa_atomic_t done; > + pa_static_mutex mutex; Any particular reason these changed order? > } pa_once; > > #define PA_ONCE_INIT \ > { \ > + .done = PA_ATOMIC_INIT(0), \ > .mutex = PA_STATIC_MUTEX_INIT, \ > - .done = PA_ATOMIC_INIT(0) \ Ditto > } > > /* Not to be called directly, use the macros defined below instead */ > -bool pa_once_begin(pa_once *o); > +bool pa_once_doit(pa_once *control); You would typically not like to expose this function, but it is necessary as the beginning of the function was inlined. Should perhaps be called "pa_once_begin_internal" and have a comment saying that one should call pa_once_begin instead of this function. > + > +static inline bool pa_once_begin(pa_once *control) { > + pa_assert(control); > + > + if (pa_atomic_load(&control->done)) > + return false; > + > + return pa_once_doit(control); > +} > void pa_once_end(pa_once *o); > > #define PA_ONCE_BEGIN \ > @@ -68,6 +77,16 @@ void pa_once_end(pa_once *o); > > /* Same API but calls a function */ > typedef void (*pa_once_func_t) (void); > -void pa_run_once(pa_once *o, pa_once_func_t f); > + > +/* Not reentrant -- how could it be? */ > +static inline void pa_run_once(pa_once *control, pa_once_func_t func) { > + pa_assert(control); > + pa_assert(func); > + > + if (pa_once_begin(control)) { > + func(); > + pa_once_end(control); > + } > +} > > #endif > -- David Henningsson, Canonical Ltd. https://launchpad.net/~diwic
