Merge pull request #3050 from urbit/m/behn-improvements

behn, vere: some improvements

pkg/arvo/app/dbug.hoon

@@ -767,7 +767,7 @@
 ++  v-behn
   |%
   ++  timers
-    (scry ,(list [date=@da =duct]) %b %timers ~)
+    (scry ,(list [date=@da =duct]) %bx %$ /debug/timers)
   --
 ::
 ::  clay

pkg/arvo/gen/timers.hoon

@@ -1,5 +1,5 @@
 ::  Find list of currently running Behn timers
 :-  %say
-|=  *
+|=  [[now=@da *] *]
 :-  %tang
-[>.^((list [date=@da =duct]) %b /=timers=)< ~]
+[>.^((list [date=@da =duct]) %bx /=//(scot %da now)/debug/timers)< ~]

pkg/arvo/sys/arvo.hoon

@@ -191,7 +191,7 @@
   ?.  ?=({@ @ @ @ *} u.pux)  ~
   =+  :*  hyr=(slaw %tas i.u.pux)
           fal=(slaw %p i.t.u.pux)
-          dyc=(slaw %tas i.t.t.u.pux)
+          dyc=?~(i.t.t.u.pux (some %$) (slaw %tas i.t.t.u.pux))
           ved=(slay i.t.t.t.u.pux)
           tyl=t.t.t.t.u.pux
       ==

pkg/arvo/sys/vane/behn.hoon

@@ -389,18 +389,56 @@
 ++  scry
   |=  [fur=(unit (set monk)) ren=@tas why=shop syd=desk lot=coin tyl=path]
   ^-  (unit (unit cage))
+  ::  only respond for the local identity, %$ desk, current timestamp
   ::
-  ?.  ?=(%& -.why)
+  ?.  ?&  =(&+our why)
+          =([%$ %da now] lot)
+          =(%$ syd)
+      ==
     ~
-  ?.  ?=(%timers syd)
-    [~ ~]
-  =/  tiz=(list [@da duct])
+  ::  /bx/debug/timers  (list [@da duct])  all timers and their ducts
+  ::  /bx/timers        (list @da)         all timer timestamps
+  ::  /bx/timers/next   (unit @da)         the very next timer to fire
+  ::  /bx/timers/[da]   (list @da)         all timers up to and including da
+  ::
+  ?.  ?=(%x ren)  ~
+  ?+  tyl  [~ ~]
+      [%debug %timers ~]
+    :^  ~  ~  %noun
+    !>  ^-  (list [@da duct])
     %-  zing
     %+  turn  (tap:timer-map timers)
     |=  [date=@da q=(qeu duct)]
     %+  turn  ~(tap to q)
     |=(d=duct [date d])
-  [~ ~ %noun !>(tiz)]
+  ::
+      [%timers ~]
+    :^  ~  ~  %noun
+    !>  ^-  (list @da)
+    %-  zing
+    %+  turn  (tap:timer-map timers)
+    |=  [date=@da q=(qeu duct)]
+    (reap ~(wyt in q) date)
+  ::
+      [%timers %next ~]
+    :^  ~  ~  %noun
+    !>  ^-  (unit @da)
+    (bind (peek:timer-map timers) head)
+  ::
+      [%timers @ ~]
+    ?~  til=(slaw %da i.t.tyl)
+      [~ ~]
+    :^  ~  ~  %noun
+    !>  ^-  (list @da)
+    =/  tiz=(list [date=@da q=(qeu duct)])
+      (tap:timer-map timers)
+    |-  ^-  (list @da)
+    ?~  tiz  ~
+    ?:  (gth date.i.tiz u.til)  ~
+    %+  weld
+      (reap ~(wyt in q.i.tiz) date.i.tiz)
+    $(tiz t.tiz)
+  ==
 ::
 ++  stay  state
 ++  take

pkg/urbit/vere/io/behn.c

@@ -16,28 +16,36 @@
   typedef struct _u3_behn {
     u3_auto    car_u;                   //  driver
     uv_timer_t tim_u;                   //  behn timer
-    c3_o       alm;                     //  alarm
+    c3_o       alm_o;                   //  alarm
+    c3_o       see_o;                   //  can scry
   } u3_behn;
 
+static void _behn_scry_cb(void* vod_p, u3_noun nun);
+
 /* _behn_time_cb(): timer callback.
 */
 static void
 _behn_time_cb(uv_timer_t* tim_u)
 {
   u3_behn* teh_u = tim_u->data;
-  teh_u->alm = c3n;
+  teh_u->alm_o = c3n;
 
-  //  start another timer for 10 minutes
+  //  take initiative to start the next timer, just in case
   //
   //  This is a backstop to deal with the case where a %doze is not
   //  properly sent, for example after a crash.  If the timer continues
   //  to fail, we can't proceed with the timers, but if it was a
   //  transient error, this will get us past it.
   //
-  {
-    c3_d gap_d = 10 * 60 * 1000;
-    teh_u->alm = c3y;
-    uv_timer_start(&teh_u->tim_u, _behn_time_cb, gap_d, 0);
+  if (c3y == teh_u->see_o) {
+    u3_noun pax = u3i_trel(u3i_string("timers"), u3i_string("next"), u3_nul);
+    u3_lord_peek_last(teh_u->car_u.pir_u->god_u, u3_nul,
+                      c3_s2('b', 'x'), u3_nul, pax,
+                      teh_u, _behn_scry_cb);
+  }
+  else {
+    //  if scry is known to not work, short-circuit
+    _behn_scry_cb(teh_u, u3_nul);
   }
 
   // send timer event
@@ -59,13 +67,12 @@ _behn_ef_doze(u3_behn* teh_u, u3_noun wen)
     teh_u->car_u.liv_o = c3y;
   }
 
-  if ( c3y == teh_u->alm ) {
+  if ( c3y == teh_u->alm_o ) {
     uv_timer_stop(&teh_u->tim_u);
-    teh_u->alm = c3n;
+    teh_u->alm_o = c3n;
   }
 
-  if ( (u3_nul != wen) &&
-       (c3y == u3du(wen)) &&
+  if ( (c3y == u3du(wen)) &&
        (c3y == u3ud(u3t(wen))) )
   {
     struct timeval tim_tv;
@@ -74,13 +81,39 @@ _behn_ef_doze(u3_behn* teh_u, u3_noun wen)
     u3_noun now = u3_time_in_tv(&tim_tv);
     c3_d gap_d = u3_time_gap_ms(now, u3k(u3t(wen)));
 
-    teh_u->alm = c3y;
+    teh_u->alm_o = c3y;
     uv_timer_start(&teh_u->tim_u, _behn_time_cb, gap_d, 0);
+  } else if (u3_nul != wen) {
+    u3m_p("behn: invalid doze", wen);
   }
 
   u3z(wen);
 }
 
+/* _behn_scry_cb(): next timer scry result callback.
+*/
+static void
+_behn_scry_cb(void* vod_p, u3_noun nun)
+{
+  u3_behn* teh_u = vod_p;
+  u3_weak  tim   = u3r_at(7, nun);
+
+  if (c3y == teh_u->alm_o) {
+    //  timer already set while we were scrying, no-op
+  }
+  else if (u3_none == tim) {
+    //  remember scry doesn't work, fall back to a timer for 10 minutes
+    //
+    teh_u->see_o = c3n;
+    c3_d gap_d = 10 * 60 * 1000;
+    teh_u->alm_o = c3y;
+    uv_timer_start(&teh_u->tim_u, _behn_time_cb, gap_d, 0);
+  } else {
+    _behn_ef_doze(teh_u, u3k(tim));
+  }
+  u3z(nun);
+}
+
 /* _behn_io_talk(): notify %behn that we're live
 */
 static void
@@ -143,7 +176,8 @@ u3_auto*
 u3_behn_io_init(u3_pier* pir_u)
 {
   u3_behn* teh_u = c3_calloc(sizeof(*teh_u));
-  teh_u->alm = c3n;
+  teh_u->alm_o = c3n;
+  teh_u->see_o = c3y;
 
   uv_timer_init(u3L, &teh_u->tim_u);
   teh_u->tim_u.data = teh_u;