Improved documentation and definition of atomic and ordered queue synchronisation.
Signed-off-by: Petri Savolainen <petri.savolai...@linaro.org> --- This is the ordered queue definition (in patch format) promised in the call yesterday. --- include/odp/api/queue.h | 25 +++++++++++++++++++++++-- include/odp/api/schedule.h | 15 ++++++++++++--- 2 files changed, 35 insertions(+), 5 deletions(-) diff --git a/include/odp/api/queue.h b/include/odp/api/queue.h index 9519edf..6a8b15f 100644 --- a/include/odp/api/queue.h +++ b/include/odp/api/queue.h @@ -104,16 +104,37 @@ extern "C" { /** * @def ODP_SCHED_SYNC_NONE * Queue not synchronised + * + * The scheduler does not provide event synchronisation or ordering, only load + * balancing. Events can be scheduled freely to multiple threads for concurrent + * processing. */ /** * @def ODP_SCHED_SYNC_ATOMIC - * Atomic queue + * Atomic queue synchronisation + * + * Events from an atomic queue can be scheduled only to a single thread at a + * time. The thread is guaranteed to have exclusive (atomic) access to the + * associated queue context and event ordering is maintained. This enables the + * user to avoid SW synchronisation for those two. + * + * The atomic queue is dedicated to the thread until it requests another event + * from the scheduler (which implicitly releases the queue) or calls + * odp_schedule_release_atomic(), which allows the scheduler to release the + * queue immediately. */ /** * @def ODP_SCHED_SYNC_ORDERED - * Ordered queue + * Ordered queue synchronisation + * + * Events from an ordered queue can be scheduled to multiple threads for + * concurrent processing. The source queue (dequeue) ordering is maintained when + * events are enqueued to their destination queue(s) before another schedule + * call. Events from the same (source) queue appear in their original order + * when dequeued from a destination queue. The destination queue can have any + * queue type and synchronisation method. */ /** diff --git a/include/odp/api/schedule.h b/include/odp/api/schedule.h index 5c08357..3bf0578 100644 --- a/include/odp/api/schedule.h +++ b/include/odp/api/schedule.h @@ -93,9 +93,9 @@ int odp_schedule_multi(odp_queue_t *from, uint64_t wait, odp_event_t events[], * Pause scheduling * * Pause global scheduling for this thread. After this call, all schedule calls - * will return only locally reserved buffers (if any). User can exit the + * will return only locally pre-scheduled events (if any). User can exit the * schedule loop only after the schedule function indicates that there's no more - * buffers (no more locally reserved buffers). + * (pre-scheduled) events. * * Must be used with odp_schedule() and odp_schedule_multi() before exiting (or * stalling) the schedule loop. @@ -111,7 +111,16 @@ void odp_schedule_pause(void); void odp_schedule_resume(void); /** - * Release currently hold atomic context + * Release the current atomic context + * + * This call is valid only for source queues with atomic synchronisation. It + * hints the scheduler that the user has completed processing of the critical + * section (which depends on the atomic synchronisation). The scheduler is now + * allowed to schedule events from the same queue to some other thread. + * + * Early atomic context release may increase parallelism and thus system + * performance, but user needs to design carefully the split into critical vs. + * non-critical sections. */ void odp_schedule_release_atomic(void); -- 2.3.0 _______________________________________________ lng-odp mailing list lng-odp@lists.linaro.org http://lists.linaro.org/mailman/listinfo/lng-odp