talloc: use the system pytalloc-util for python3 as well
[sfrench/samba-autobuild/.git] / lib / tevent / tevent_timed.c
index e06102c2f53940b2bc7348ea7e18b33a0e41f2cd..92f3ed17b26ee749de270af3b4411a79af21de86 100644 (file)
@@ -36,7 +36,7 @@
   Return 0 if tv1 == tv2
   Return 1 if tv1 > tv2
 */
-static int ev_timeval_compare(const struct timeval *tv1, const struct timeval *tv2)
+int tevent_timeval_compare(const struct timeval *tv1, const struct timeval *tv2)
 {
        if (tv1->tv_sec  > tv2->tv_sec)  return 1;
        if (tv1->tv_sec  < tv2->tv_sec)  return -1;
@@ -48,7 +48,7 @@ static int ev_timeval_compare(const struct timeval *tv1, const struct timeval *t
 /**
   return a zero timeval
 */
-struct timeval ev_timeval_zero(void)
+struct timeval tevent_timeval_zero(void)
 {
        struct timeval tv;
        tv.tv_sec = 0;
@@ -59,7 +59,7 @@ struct timeval ev_timeval_zero(void)
 /**
   return a timeval for the current time
 */
-static struct timeval ev_timeval_current(void)
+struct timeval tevent_timeval_current(void)
 {
        struct timeval tv;
        gettimeofday(&tv, NULL);
@@ -69,7 +69,7 @@ static struct timeval ev_timeval_current(void)
 /**
   return a timeval struct with the given elements
 */
-static struct timeval ev_timeval_set(uint32_t secs, uint32_t usecs)
+struct timeval tevent_timeval_set(uint32_t secs, uint32_t usecs)
 {
        struct timeval tv;
        tv.tv_sec = secs;
@@ -82,12 +82,12 @@ static struct timeval ev_timeval_set(uint32_t secs, uint32_t usecs)
   if tv1 comes after tv2, then return a zero timeval
   (this is *tv2 - *tv1)
 */
-static struct timeval ev_timeval_until(const struct timeval *tv1,
-                                       const struct timeval *tv2)
+struct timeval tevent_timeval_until(const struct timeval *tv1,
+                                   const struct timeval *tv2)
 {
        struct timeval t;
-       if (ev_timeval_compare(tv1, tv2) >= 0) {
-               return ev_timeval_zero();
+       if (tevent_timeval_compare(tv1, tv2) >= 0) {
+               return tevent_timeval_zero();
        }
        t.tv_sec = tv2->tv_sec - tv1->tv_sec;
        if (tv1->tv_usec > tv2->tv_usec) {
@@ -102,23 +102,49 @@ static struct timeval ev_timeval_until(const struct timeval *tv1,
 /**
   return true if a timeval is zero
 */
-bool ev_timeval_is_zero(const struct timeval *tv)
+bool tevent_timeval_is_zero(const struct timeval *tv)
 {
        return tv->tv_sec == 0 && tv->tv_usec == 0;
 }
 
+struct timeval tevent_timeval_add(const struct timeval *tv, uint32_t secs,
+                                 uint32_t usecs)
+{
+       struct timeval tv2 = *tv;
+       tv2.tv_sec += secs;
+       tv2.tv_usec += usecs;
+       tv2.tv_sec += tv2.tv_usec / 1000000;
+       tv2.tv_usec = tv2.tv_usec % 1000000;
+
+       return tv2;
+}
+
+/**
+  return a timeval in the future with a specified offset
+*/
+struct timeval tevent_timeval_current_ofs(uint32_t secs, uint32_t usecs)
+{
+       struct timeval tv = tevent_timeval_current();
+       return tevent_timeval_add(&tv, secs, usecs);
+}
+
 /*
   destroy a timed event
 */
 static int tevent_common_timed_destructor(struct tevent_timer *te)
 {
+       if (te->event_ctx == NULL) {
+               return 0;
+       }
+
        tevent_debug(te->event_ctx, TEVENT_DEBUG_TRACE,
                     "Destroying timer event %p \"%s\"\n",
                     te, te->handler_name);
 
-       if (te->event_ctx) {
-               DLIST_REMOVE(te->event_ctx->timer_events, te);
+       if (te->event_ctx->last_zero_timer == te) {
+               te->event_ctx->last_zero_timer = DLIST_PREV(te);
        }
+       DLIST_REMOVE(te->event_ctx->timer_events, te);
 
        return 0;
 }
@@ -128,18 +154,72 @@ static int tevent_common_timed_deny_destructor(struct tevent_timer *te)
        return -1;
 }
 
+static void tevent_common_insert_timer(struct tevent_context *ev,
+                                      struct tevent_timer *te,
+                                      bool optimize_zero)
+{
+       struct tevent_timer *prev_te = NULL;
+
+       /* keep the list ordered */
+       if (optimize_zero && tevent_timeval_is_zero(&te->next_event)) {
+               /*
+                * Some callers use zero tevent_timer
+                * instead of tevent_immediate events.
+                *
+                * As these can happen very often,
+                * we remember the last zero timer
+                * in the list.
+                */
+               prev_te = ev->last_zero_timer;
+               ev->last_zero_timer = te;
+       } else {
+               struct tevent_timer *cur_te;
+
+               /*
+                * 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;
+                       }
+
+                       break;
+               }
+
+               prev_te = cur_te;
+       }
+
+       DLIST_ADD_AFTER(ev->timer_events, te, prev_te);
+}
+
 /*
   add a timed event
   return NULL on failure (memory allocation error)
 */
-struct tevent_timer *tevent_common_add_timer(struct tevent_context *ev, TALLOC_CTX *mem_ctx,
-                                            struct timeval next_event,
-                                            tevent_timer_handler_t handler,
-                                            void *private_data,
-                                            const char *handler_name,
-                                            const char *location)
+static struct tevent_timer *tevent_common_add_timer_internal(
+                                       struct tevent_context *ev,
+                                       TALLOC_CTX *mem_ctx,
+                                       struct timeval next_event,
+                                       tevent_timer_handler_t handler,
+                                       void *private_data,
+                                       const char *handler_name,
+                                       const char *location,
+                                       bool optimize_zero)
 {
-       struct tevent_timer *te, *last_te, *cur_te;
+       struct tevent_timer *te;
 
        te = talloc(mem_ctx?mem_ctx:ev, struct tevent_timer);
        if (te == NULL) return NULL;
@@ -152,18 +232,11 @@ struct tevent_timer *tevent_common_add_timer(struct tevent_context *ev, TALLOC_C
        te->location            = location;
        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 (ev_timeval_compare(&te->next_event, &cur_te->next_event) < 0) {
-                       break;
-               }
-
-               last_te = cur_te;
+       if (ev->timer_events == NULL) {
+               ev->last_zero_timer = NULL;
        }
 
-       DLIST_ADD_AFTER(ev->timer_events, te, last_te);
+       tevent_common_insert_timer(ev, te, optimize_zero);
 
        talloc_set_destructor(te, tevent_common_timed_destructor);
 
@@ -173,22 +246,78 @@ struct tevent_timer *tevent_common_add_timer(struct tevent_context *ev, TALLOC_C
        return te;
 }
 
+struct tevent_timer *tevent_common_add_timer(struct tevent_context *ev,
+                                            TALLOC_CTX *mem_ctx,
+                                            struct timeval next_event,
+                                            tevent_timer_handler_t handler,
+                                            void *private_data,
+                                            const char *handler_name,
+                                            const char *location)
+{
+       /*
+        * do not use optimization, there are broken Samba
+        * versions which use tevent_common_add_timer()
+        * without using tevent_common_loop_timer_delay(),
+        * it just uses DLIST_REMOVE(ev->timer_events, te)
+        * and would leave ev->last_zero_timer behind.
+        */
+       return tevent_common_add_timer_internal(ev, mem_ctx, next_event,
+                                               handler, private_data,
+                                               handler_name, location,
+                                               false);
+}
+
+struct tevent_timer *tevent_common_add_timer_v2(struct tevent_context *ev,
+                                               TALLOC_CTX *mem_ctx,
+                                               struct timeval next_event,
+                                               tevent_timer_handler_t handler,
+                                               void *private_data,
+                                               const char *handler_name,
+                                               const char *location)
+{
+       /*
+        * Here we turn on last_zero_timer optimization
+        */
+       return tevent_common_add_timer_internal(ev, mem_ctx, next_event,
+                                               handler, private_data,
+                                               handler_name, location,
+                                               true);
+}
+
+void tevent_update_timer(struct tevent_timer *te, struct timeval next_event)
+{
+       struct tevent_context *ev = te->event_ctx;
+
+       if (ev->last_zero_timer == te) {
+               te->event_ctx->last_zero_timer = DLIST_PREV(te);
+       }
+       DLIST_REMOVE(ev->timer_events, te);
+
+       te->next_event = next_event;
+
+       /*
+        * Not doing the zero_timer optimization. This is for new code
+        * that should know about immediates.
+        */
+       tevent_common_insert_timer(ev, te, false);
+}
+
 /*
   do a single event loop using the events defined in ev
 
-  return the delay untill the next timed event,
+  return the delay until the next timed event,
   or zero if a timed event was triggered
 */
 struct timeval tevent_common_loop_timer_delay(struct tevent_context *ev)
 {
-       struct timeval current_time = ev_timeval_zero();
+       struct timeval current_time = tevent_timeval_zero();
        struct tevent_timer *te = ev->timer_events;
 
        if (!te) {
                /* have a default tick time of 30 seconds. This guarantees
                   that code that uses its own timeout checking will be
-                  able to proceeed eventually */
-               return ev_timeval_set(30, 0);
+                  able to proceed eventually */
+               return tevent_timeval_set(30, 0);
        }
 
        /*
@@ -200,13 +329,13 @@ struct timeval tevent_common_loop_timer_delay(struct tevent_context *ev)
         * if there's a delay till the next timed event, we're done
         * with just returning the delay
         */
-       if (!ev_timeval_is_zero(&te->next_event)) {
+       if (!tevent_timeval_is_zero(&te->next_event)) {
                struct timeval delay;
 
-               current_time = ev_timeval_current();
+               current_time = tevent_timeval_current();
 
-               delay = ev_timeval_until(&current_time, &te->next_event);
-               if (!ev_timeval_is_zero(&delay)) {
+               delay = tevent_timeval_until(&current_time, &te->next_event);
+               if (!tevent_timeval_is_zero(&delay)) {
                        return delay;
                }
        }
@@ -221,8 +350,15 @@ struct timeval tevent_common_loop_timer_delay(struct tevent_context *ev)
        /* We need to remove the timer from the list before calling the
         * handler because in a semi-async inner event loop called from the
         * handler we don't want to come across this event again -- vl */
+       if (ev->last_zero_timer == te) {
+               ev->last_zero_timer = DLIST_PREV(te);
+       }
        DLIST_REMOVE(ev->timer_events, te);
 
+       tevent_debug(te->event_ctx, TEVENT_DEBUG_TRACE,
+                    "Running timer event %p \"%s\"\n",
+                    te, te->handler_name);
+
        /*
         * If the timed event was registered for a zero current_time,
         * then we pass a zero timeval here too! To avoid the
@@ -242,6 +378,6 @@ struct timeval tevent_common_loop_timer_delay(struct tevent_context *ev)
 
        talloc_free(te);
 
-       return ev_timeval_zero();
+       return tevent_timeval_zero();
 }