Attenuate and sync

src/syndicate/actors.nim

@@ -144,7 +144,7 @@ proc `$`*(actor: Actor): string =
 proc `$`*(t: Turn): string =
   "<Turn:" & $t.desc.id & ">"
 
-proc attenuate(r: Cap; a: Attenuation): Cap =
+proc attenuate*(r: Cap; a: Attenuation): Cap =
   if a.len == 0: result = r
   else: result = Cap(
     target: r.target,
@@ -530,10 +530,12 @@ proc spawnLink*(name: string; turn: var Turn; bootProc: TurnAction; initialAsser
   halfLink(turn.facet, result.root)
   halfLink(result.root, turn.facet)
 
+var inertActor {.threadvar.}: Actor
+
 proc newInertCap*(): Cap =
-  new result
-  let a = bootActor("inert") do (turn: Turn): turn.stop()
-  Cap(relay: a.root)
+  if inertActor.isNil:
+    inertActor = bootActor("inert") do (turn: var Turn): turn.stop()
+  Cap(relay: inertActor.root)
 
 proc atExit*(actor; action) = actor.exitHooks.add action
 

src/syndicate/relays.nim

@@ -158,8 +158,8 @@ using
 
 proc lookupLocal(relay; oid: Oid): Cap =
   let sym = relay.exported.grab oid
-  if sym.isNil: newInertCap()
-  else: sym.cap
+  if not sym.isNil:
+    result = sym.cap
 
 proc isInert(r: Cap): bool =
   r.target.isNil
@@ -177,9 +177,11 @@ proc rewriteCapIn(relay; facet; n: WireRef, imported: var seq[WireSymbol]): Cap
     imported.add e
     result = e.cap
   of WireRefKind.yours:
-    let r = relay.lookupLocal(n.yours.oid)
-    if n.yours.attenuation.len == 0 or r.isInert: result = r
-    else: raiseAssert "attenuation not implemented"
+    result = relay.lookupLocal(n.yours.oid)
+    if result.isNil:
+      result = newInertCap()
+    elif n.yours.attenuation.len > 0:
+      result = attenuate(result, n.yours.attenuation)
 
 proc rewriteIn(relay; facet; v: Value):
     tuple[rewritten: Assertion; imported: seq[WireSymbol]] =
@@ -212,14 +214,13 @@ proc dispatch(relay: Relay; turn: var Turn; cap: Cap; event: Event) =
     turn.message(cap, a)
 
   of EventKind.Sync:
-    discard # TODO
-    #[
-    var imported: seq[WireSymbol]
-    let k = relay.rewriteCapIn(turn, evenr.sync.peer, imported)
     turn.sync(cap) do (turn: var Turn):
-      turn.message(k, true)
-      for e in imported: relay.imported.del e
-      ]#
+      var
+        (v, imported) = rewriteIn(relay, turn.facet, event.sync.peer)
+        peer = unembed(v, Cap)
+      if peer.isSome:
+        turn.message(get peer, true)
+      for e in imported: relay.imported.drop e
 
 proc dispatch(relay: Relay; v: Value) =
   trace "S: ", v
@@ -231,10 +232,8 @@ proc dispatch(relay: Relay; v: Value) =
         # https://synit.org/book/protocol.html#turn-packets
         for te in pkt.turn:
           let r = lookupLocal(relay, te.oid.Oid)
-          if not r.isInert:
+          if not r.isNil:
             dispatch(relay, t, r, te.event)
-          else:
-            stderr.writeLine("discarding event for unknown Cap; ", te.event)
       of PacketKind.Error:
         # https://synit.org/book/protocol.html#error-packets
         when defined(posix):