ford lightning (#953)

adds a new memo bucket for the ford cache so those entries are omitted
during brass pill construction.
requires: urbit/urbit#7291

Author: pkova

pkg/c3/motes.h

@@ -452,6 +452,7 @@
 #   define c3__fond   c3_s4('f','o','n','d')
 #   define c3__for    c3_s3('f','o','r')
 #   define c3__forb   c3_s4('f','o','r','b')
+#   define c3__ford   c3_s4('f','o','r','d')
 #   define c3__fore   c3_s4('f','o','r','e')
 #   define c3__fork   c3_s4('f','o','r','k')
 #   define c3__form   c3_s4('f','o','r','m')

pkg/noun/allocate.c

@@ -1660,7 +1660,7 @@ u3a_print_quac(FILE* fil_u, c3_w den_w, u3m_quac* mas_u)
 u3m_quac*
 u3a_mark_road()
 {
-  u3m_quac** qua_u = c3_malloc(sizeof(*qua_u) * 15);
+  u3m_quac** qua_u = c3_malloc(sizeof(*qua_u) * 16);
 
   qua_u[0] = c3_calloc(sizeof(*qua_u[0]));
   qua_u[0]->nam_c = strdup("namespace");
@@ -1757,7 +1757,11 @@ u3a_mark_road()
   qua_u[13]->nam_c = strdup("timer stack");
   qua_u[13]->siz_w = u3a_mark_noun(u3R->tim) * 4;
 
-  qua_u[14] = NULL;
+  qua_u[14] = c3_calloc(sizeof(*qua_u[14]));
+  qua_u[14]->nam_c = strdup("ford memoization cache");
+  qua_u[14]->siz_w = u3h_mark(u3R->cax.for_p) * 4;
+
+  qua_u[15] = NULL;
 
   c3_w sum_w = 0;
   for (c3_w i_w = 0; qua_u[i_w]; i_w++) {
@@ -1799,6 +1803,7 @@ u3a_rewrite_compact(void)
   u3h_relocate(&(u3R->cax.har_p));
   u3h_relocate(&(u3R->cax.per_p));
   u3h_relocate(&(u3R->lop_p));
+  u3h_relocate(&(u3R->cax.for_p));
 }
 
 /* u3a_idle(): measure free-lists in [rod_u]

pkg/noun/allocate.h

@@ -211,6 +211,7 @@ STATIC_ASSERT( u3a_vits <= u3a_min_log,
         struct {                              //  memoization caches
           u3p(u3h_root) har_p;                //  transient
           u3p(u3h_root) per_p;                //  persistent
+          u3p(u3h_root) for_p;                //  ford
         } cax;
       } u3a_road;
       typedef u3a_road u3_road;
@@ -219,7 +220,7 @@ STATIC_ASSERT( u3a_vits <= u3a_min_log,
     */
       enum u3a_flag {
         u3a_flag_sand  = 1 << 1,              //  bump allocation (XX not impl)
-        u3a_flag_cash  = 1 << 2,              //  memo cache harvesting
+        u3a_flag_cash  = 1 << 2,              //  memo cache harvesting, flows forward
       };
 
     /* u3a_pile: stack control, abstracted over road direction.

pkg/noun/manage.c

@@ -517,6 +517,7 @@ _pave_parts(void)
 
   u3R->cax.har_p = u3h_new_cache(u3C.hap_w);  //  transient
   u3R->cax.per_p = u3h_new_cache(u3C.per_w);  //  persistent
+  u3R->cax.for_p = u3h_new_cache(u3C.per_w);  //  ford
   u3R->jed.war_p = u3h_new();
   u3R->jed.cod_p = u3h_new();
   u3R->jed.han_p = u3h_new();
@@ -663,12 +664,11 @@ _find_home(void)
     u3H->pam_d = _pave_params();
   }
 
-  //  if lop_p is zero than it is an old pier pre %loop hint, initialize the
-  //  HAMT
+  //  properly initialize things from zero-initialize future proof buffer
+  //  XX cax.for_p
   //
-  if (!u3R->lop_p) {
-    u3R->lop_p = u3h_new();
-  }
+  if ( !u3R->lop_p )     u3R->lop_p = u3h_new();
+  if ( !u3R->cax.for_p ) u3R->cax.for_p = u3h_new_cache(u3C.per_w);
 }
 
 /* u3m_pave(): instantiate or activate image.
@@ -1002,6 +1002,12 @@ u3m_bail(u3_noun how)
     }
   }
 
+  // Reset the spin stack pointer
+  if ( NULL != u3t_Spin ) {
+    u3t_Spin->off_w = u3R->off_w;
+    u3t_Spin->fow_w = u3R->fow_w;
+  }
+
   _longjmp(u3R->esc.buf, how);
 }
 
@@ -1214,8 +1220,14 @@ u3m_hate(c3_w pad_w)
   u3_assert(0 == u3R->ear_p);
 
   u3R->ear_p = u3R->cap_p;
+
+  c3_w fag_w = u3R->how.fag_w;
   u3m_leap(pad_w);
 
+  //  inherit forward-flowing flags
+  //
+  u3R->how.fag_w |= (fag_w & u3a_flag_cash);
+
   u3R->bug.mer = u3i_string(
     "emergency buffer with sufficient space to cons the trace and bail"
   );
@@ -1340,6 +1352,7 @@ u3m_love(u3_noun pro)
   u3p(u3h_root) byc_p = u3R->byc.har_p;
   u3a_jets      jed_u = u3R->jed;
   u3p(u3h_root) per_p = u3R->cax.per_p;
+  u3p(u3h_root) for_p = u3R->cax.for_p;
 
   //  are there any timers on the road?
   //
@@ -1363,6 +1376,7 @@ u3m_love(u3_noun pro)
   jed_u = u3j_take(jed_u);
   byc_p = u3n_take(byc_p);
   per_p = u3h_take(per_p);
+  for_p = u3h_take(for_p);
 
   //  pop the stack
   //
@@ -1375,6 +1389,7 @@ u3m_love(u3_noun pro)
   u3j_reap(jed_u);
   u3n_reap(byc_p);
   u3z_reap(u3z_memo_keep, per_p);
+  u3z_reap(u3z_memo_ford, for_p);
 
   return pro;
 }
@@ -1719,7 +1734,7 @@ u3m_soft_run(u3_noun gul,
   */
 
   {
-    if ( (u3_nul == gul) || cash_t ) {
+    if ( (u3_nul == gul) || (u3R->how.fag_w & u3a_flag_cash) ) {
       u3R->ski.gul = u3_nul;
     }
     else {

pkg/noun/nock.c

@@ -1143,7 +1143,15 @@ _n_bint(u3_noun* ops, u3_noun hif, u3_noun nef, c3_o los_o, c3_o tel_o)
         {
           u3_weak con = u3r_skip(hod);
           if ( (u3_none != con) && (c3y == u3du(con)) ) {
-            cid = u3z_memo_keep;
+            if (  (c3y == u3du(u3t(con)))
+               && (c3__clay == u3h(con))
+               && (c3__ford == u3h(u3t(con))) )
+            {
+              cid = u3z_memo_ford;
+            }
+            else {
+              cid = u3z_memo_keep;
+            }
           }
         }
         ++tot_w; _n_emit(ops, u3nq(op_y, cid, mem_w, u3k(nef)));
@@ -2754,7 +2762,14 @@ _n_burn(u3n_prog* pog_u, u3_noun bus, c3_ys mov, c3_ys off)
     skim_out:
       o     = u3k(mem_u->key);
       x     = u3nc(x, o);
-      o     = u3z_find_m(mem_u->cid, 144 + c3__nock, x);
+      switch ( mem_u->cid ) {
+        case u3z_memo_ford: {
+          o = u3z_find_m(mem_u->cid, 136 + c3__ford, x);
+        } break;
+        default: {
+          o = u3z_find_m(mem_u->cid, 144 + c3__nock, x);
+        }
+      }
       if ( u3_none == o ) {
         _n_push(mov, off, u3nc(mem_u->cid, x));
         _n_push(mov, off, u3k(u3h(x)));
@@ -2770,7 +2785,10 @@ _n_burn(u3n_prog* pog_u, u3_noun bus, c3_ys mov, c3_ys off)
       x   = _n_pep(mov, off);  // product
       top = _n_peek(off);
       o   = *top;
-      if ( ( u3z_memo_toss == u3h(o) )
+      if ( u3z_memo_ford == u3h(o) ) {
+        u3z_save_m(u3h(o), 136 + c3__ford, u3t(o), x);
+      }
+      else if ( ( u3z_memo_toss == u3h(o) )
          ? ( &(u3H->rod_u) != u3R )
          : ( 0 == u3R->ski.gul ) ) {  //  prevents userspace from persistence
         u3z_save_m(u3h(o), 144 + c3__nock, u3t(o), x);

pkg/noun/urth.c

@@ -553,6 +553,9 @@ u3u_melt(void)
   u3h_free(u3R->cax.per_p);
   u3R->cax.per_p = u3h_new_cache(u3C.per_w);
 
+  u3h_free(u3R->cax.for_p);
+  u3R->cax.for_p = u3h_new_cache(u3C.per_w);
+
   u3h_free(u3R->jed.cod_p);
   u3R->jed.cod_p = u3h_new();
 

pkg/noun/zave.c

@@ -46,6 +46,8 @@ _har(u3a_road* rod_u, u3z_cid cid)
       return rod_u->cax.har_p;
     case u3z_memo_keep:
       return rod_u->cax.per_p;
+    case u3z_memo_ford:
+      return rod_u->cax.for_p;  // design cache key to handle arvo changes that invalidate
   }
   u3_assert(0);
 }

pkg/noun/zave.h

@@ -19,7 +19,7 @@
       typedef enum {
         u3z_memo_toss  = 0,
         u3z_memo_keep  = 1,
-        // u3z_memo_ford  = 2,
+        u3z_memo_ford  = 2,
         // u3z_memo_ames  = 3,
         // ...
       } u3z_cid;

pkg/vere/mars.c

@@ -737,8 +737,10 @@ _mars_post(u3_mars* mar_u)
   if ( mar_u->fag_w & _mars_fag_hit1 ) {
     if ( u3C.wag_w & u3o_verbose ) {
       u3l_log("mars: threshold 1: %u", u3h_wyt(u3R->cax.per_p));
+      u3l_log("mars: threshold 1: %u", u3h_wyt(u3R->cax.for_p));
     }
     u3h_trim_to(u3R->cax.per_p, u3h_wyt(u3R->cax.per_p) / 2);
+    u3h_trim_to(u3R->cax.for_p, u3h_wyt(u3R->cax.for_p) / 2);
     u3m_reclaim();
   }
 
@@ -748,6 +750,7 @@ _mars_post(u3_mars* mar_u)
 
   if ( mar_u->fag_w & _mars_fag_vega ) {
     u3h_trim_to(u3R->cax.per_p, u3h_wyt(u3R->cax.per_p) / 2);
+    u3h_trim_to(u3R->cax.for_p, u3h_wyt(u3R->cax.for_p) / 2);
     u3m_reclaim();
   }
 
@@ -761,9 +764,12 @@ _mars_post(u3_mars* mar_u)
   if ( mar_u->fag_w & _mars_fag_hit0 ) {
     if ( u3C.wag_w & u3o_verbose ) {
       u3l_log("mars: threshold 0: per_p %u", u3h_wyt(u3R->cax.per_p));
+      u3l_log("mars: threshold 0: for_p %u", u3h_wyt(u3R->cax.for_p));
     }
     u3h_free(u3R->cax.per_p);
     u3R->cax.per_p = u3h_new_cache(u3C.per_w);
+    u3h_free(u3R->cax.for_p);
+    u3R->cax.for_p = u3h_new_cache(u3C.per_w);
     u3a_print_memory(stderr, "mars: pack: gained", u3m_pack());
     u3l_log("");
   }

pkg/vere/melt.c

@@ -177,6 +177,7 @@ u3_melt_all(FILE *fil_u)
 
   u3h_walk_with(u3R->jed.cod_p, _melt_walk_hamt, &can_u);
   u3h_walk_with(u3R->cax.per_p, _melt_walk_hamt, &can_u);
+  u3h_walk_with(u3R->cax.for_p, _melt_walk_hamt, &can_u);
 
   u3j_boot(c3n);
   u3j_ream();
@@ -204,6 +205,9 @@ u3_meld_all(FILE *fil_u)
   u3h_free(u3R->cax.per_p);
   u3R->cax.per_p = u3h_new_cache(u3C.per_w);
 
+  u3h_free(u3R->cax.for_p);
+  u3R->cax.for_p = u3h_new_cache(u3C.per_w);
+
   (void)u3_melt_all(fil_u);
   (void)u3m_pack();