From b6e2886168b4033474d3821947ac41c2d9e2d698 Mon Sep 17 00:00:00 2001 From: Stefan Metzmacher Date: Fri, 22 Feb 2013 12:45:39 +0100 Subject: [PATCH] tevent: optimize adding new timer events As new timestamps typically get higher:-) it's better to traverse the existing list from the tail. This is not completely optimal, but it should be better than before. A second optimization could be done for zero timestamps, we would just remember the last_zero_timer, but that would change the internal ABI. Normally thatshould not be a poblem, but the Samba's source3/lib/events.c abuses tevent_internal.h from the current source tree, even if an external tevent.h is used. The other problem is that it makes use of tevent_common_add_timer() without using tevent_common_loop_timer_delay(). Signed-off-by: Stefan Metzmacher --- lib/tevent/tevent_timed.c | 32 ++++++++++++++++++++++++-------- 1 file changed, 24 insertions(+), 8 deletions(-) diff --git a/lib/tevent/tevent_timed.c b/lib/tevent/tevent_timed.c index d3ec8f5913e2..fd954f42d834 100644 --- a/lib/tevent/tevent_timed.c +++ b/lib/tevent/tevent_timed.c @@ -160,7 +160,7 @@ struct tevent_timer *tevent_common_add_timer(struct tevent_context *ev, TALLOC_C const char *handler_name, const char *location) { - struct tevent_timer *te, *last_te, *cur_te; + struct tevent_timer *te, *prev_te, *cur_te; te = talloc(mem_ctx?mem_ctx:ev, struct tevent_timer); if (te == NULL) return NULL; @@ -174,17 +174,33 @@ struct tevent_timer *tevent_common_add_timer(struct tevent_context *ev, TALLOC_C te->additional_data = NULL; /* keep the list ordered */ - last_te = NULL; - for (cur_te = ev->timer_events; cur_te; cur_te = cur_te->next) { - /* if the new event comes before the current one break */ - if (tevent_timeval_compare(&te->next_event, &cur_te->next_event) < 0) { - break; + prev_te = NULL; + /* + * we traverse the list from the tail + * because it's much more likely that + * timers are added at the end of the list + */ + for (cur_te = DLIST_TAIL(ev->timer_events); + cur_te != NULL; + cur_te = DLIST_PREV(cur_te)) + { + int ret; + + /* + * if the new event comes before the current + * we continue searching + */ + ret = tevent_timeval_compare(&te->next_event, + &cur_te->next_event); + if (ret < 0) { + continue; } - last_te = cur_te; + break; } + prev_te = cur_te; - DLIST_ADD_AFTER(ev->timer_events, te, last_te); + DLIST_ADD_AFTER(ev->timer_events, te, prev_te); talloc_set_destructor(te, tevent_common_timed_destructor); -- 2.34.1