Clear a refused pin's condition once the controller's pins agree, and take over a previous process's conditions only once the findings are read (issue 774)

A pin made by hand, as the condition's Needs asks, changed nothing the assigner looked at, so its urgent condition
never cleared, and a restart left every one raised. The assigner now reads the controller's pins (placement-export,
asked again only after the controller's compositions change, never on a timer) and clears a pin's condition once
they agree with the placement's after being seen differing, as a module's place already did. The first pass takes
over the call conditions a previous process raised, pins and places alike, and retries at the next pass when the
findings cannot be read.

modules/mesh-delivery-assigner/cmd/mesh-delivery-assigner/pass.go

@@ -58,9 +58,11 @@ type passer struct {
 	// nodeFailed is, by node and module, the words of the condition last raised for a failure that is the node's own (ADR 0557
 	// §1, issue 1496): raised once per words, cleared once when it ends.
 	nodeFailed map[string]string
-	// callSaid is, by the key of a refused controller call's condition, what this process raised (issue 774); nil until the
+	// callSaid is, by the key of a refused controller call's condition, what is raised (issue 774): by this process, or by
-	// first pass after a start, which clears what a previous process raised for a pair the two sources agree on.
+	// a previous one and taken over from the findings.
 	callSaid map[string]*callSaid
+	// callsSwept says the first pass took over the refused calls' conditions a previous process raised (sweepCalls).
+	callsSwept bool
 	// The seat mesh-placement's holder (seat.go, ADR 0567): its calls of the controller (nil: none is made), how it says
 	// the seat's events (nil: none is said), the proposals it said, and what Intended computed by proposal and base.
 	seat         *seatActs

modules/mesh-delivery-assigner/cmd/mesh-delivery-assigner/pass_test.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"slices"
 	"strings"
+	"sync"
 	"testing"
 	"time"
 
@@ -976,9 +977,28 @@ func aPlacedNodesWantsNameTheBuildAloneAndItsYesComesFromItsHave(t *testing.T) {
 type refusingBus struct {
 	fakeBus
 	refuse map[string]string
+	// pins are the controller's pins its placement-export answers, by node.
+	mu   sync.Mutex
+	pins map[string]map[string]delivery.Provider
+}
+
+func (b *refusingBus) setPins(node string, pins map[string]delivery.Provider) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	if b.pins == nil {
+		b.pins = map[string]map[string]delivery.Provider{}
+	}
+	b.pins[node] = pins
 }
 
 func (b *refusingBus) Call(key string, body any) (json.RawMessage, error) {
+	if key == exportCall {
+		b.mu.Lock()
+		defer b.mu.Unlock()
+		node, _ := body.(map[string]any)["node"].(string)
+		answer, _ := json.Marshal(map[string]delivery.Placement{node: {V: delivery.Version, Node: node, Pins: b.pins[node]}})
+		return json.Marshal(map[string]any{"ok": true, "answer": json.RawMessage(answer)})
+	}
 	for verb, words := range b.refuse {
 		if strings.HasSuffix(key, "."+verb) {
 			return nil, errors.New(words)
@@ -1040,3 +1060,91 @@ func TestARefusedControllerCallIsACondition(t *testing.T) {
 		t.Fatalf("said again after the clear: %+v", conds)
 	}
 }
+
+// Issue 774: a refused pin's condition, and one a previous process raised, clear once the pair agrees after it was seen differing:
+// the controller's pins (its placement-export, read again when its compositions change) against the placement's, the controller's
+// assignments against the placement for a module's place. A start whose findings cannot be read takes them over at a later pass.
+func TestARefusedCallClearsWhenTheSourcesAgree(t *testing.T) {
+	store := delivery.Provider{Node: "anchor", Module: "store"}
+	pinDB := assign.ControllerCall{Verb: "pin", Node: "laptop", Module: "db",
+		Args: map[string]any{"node": "laptop", "provision": "db", "from": "anchor", "module": "store"}}
+	placeWeb := assign.ControllerCall{Verb: "assign", Node: "anchor", Module: "web", Args: map[string]any{"node": "anchor", "module": "web"}}
+	webDiffers := []assign.Pair{{Node: "anchor", Module: "web", Only: assign.OnlyPlacement}}
+	for name, c := range map[string]struct {
+		call     *assign.ControllerCall // refused in this process; nil: raised by a previous one
+		findings []string               // the findings a previous process left
+		keysFail int                    // how many first reads of the findings fail
+		differ   []assign.Pair          // the pairs the two sources name apart, while they differ
+		agree    func(*refusingBus)     // the person's hand call
+		key      string
+	}{
+		"a pin refused, pinned by hand": {call: &pinDB, agree: func(b *refusingBus) { b.setPins("laptop", map[string]delivery.Provider{"db": store}) },
+			key: "mesh-delivery-assigner.controller-pin.laptop.db"},
+		"a place refused, assigned by hand": {call: &placeWeb, differ: webDiffers, agree: func(*refusingBus) {},
+			key: "mesh-delivery-assigner.controller-call.anchor.web"},
+		"a pin raised before a start": {findings: []string{"module.laptop.db.controller-pin"}, keysFail: 1,
+			agree: func(b *refusingBus) { b.setPins("laptop", map[string]delivery.Provider{"db": store}) },
+			key:   "mesh-delivery-assigner.controller-pin.laptop.db"},
+		"a place raised before a start": {findings: []string{"module.anchor.web.controller-call"}, differ: webDiffers, agree: func(*refusingBus) {},
+			key: "mesh-delivery-assigner.controller-call.anchor.web"},
+	} {
+		t.Run(name, func(t *testing.T) {
+			p := newPasser(buckets{}, time.Date(2026, 10, 30, 21, 4, 0, 0, time.UTC))
+			var conds []asks.Condition
+			p.say = func(c asks.Condition) error { conds = append(conds, c); return nil }
+			fails := c.keysFail
+			p.findings.Keys = func() ([]string, error) {
+				if fails > 0 {
+					fails--
+					return nil, errors.New("the bucket is not there yet")
+				}
+				return c.findings, nil
+			}
+			bus := &refusingBus{refuse: map[string]string{"pin": "refused", "assign": "refused"}}
+			woke := make(chan struct{}, 16)
+			p.seat = newSeatActs(bus, func() { woke <- struct{}{} }, func(string, ...any) {}, func() bool { return false })
+			// The placement pins db on laptop; the controller does not.
+			raw, _ := delivery.EncodePlacement(delivery.Placement{V: delivery.Version, Node: "laptop", Pins: map[string]delivery.Provider{"db": store}})
+			key, _ := delivery.PlacementKey("laptop")
+			p.w.put(delivery.PlacementBucket, key, raw)
+			// pass is a pass, then one more for each background read it started.
+			pass := func(differ []assign.Pair) {
+				p.sayCalls(differ)
+				for {
+					select {
+					case <-woke:
+						p.sayCalls(differ)
+					case <-time.After(20 * time.Millisecond):
+						return
+					}
+				}
+			}
+			if c.call != nil {
+				p.seat.callAll([]assign.ControllerCall{*c.call})
+				<-woke
+			}
+			pass(c.differ)
+			pass(c.differ)
+			for _, cond := range conds {
+				if cond.State == asks.StateCleared {
+					t.Fatalf("cleared while the sources differ: %+v", conds)
+				}
+			}
+			c.agree(bus)
+			p.w.put(delivery.ControllerComposedBucket, "laptop.x", []byte("moved")) // a pin changes a composition
+			pass(nil)
+			if len(conds) == 0 {
+				t.Fatal("nothing was raised")
+			}
+			last := conds[len(conds)-1]
+			if last.Key != c.key || last.State != asks.StateCleared || !strings.Contains(last.Resolved, "agree") {
+				t.Fatalf("the hand call does not clear it: %+v", conds)
+			}
+			n := len(conds)
+			pass(nil)
+			if len(conds) != n {
+				t.Errorf("said again after the clear: %+v", conds[n:])
+			}
+		})
+	}
+}

modules/mesh-delivery-assigner/cmd/mesh-delivery-assigner/seat.go

@@ -71,6 +71,8 @@ type seatActs struct {
 	// outcomes is, by the key of a call's condition, the last call made for its pair once answered or refused: refused
 	// "" when the controller answered it (issue 774: a refused call is a condition, never only a journal line).
 	outcomes map[string]callOutcome
+	// pins is, by node, the controller's pins as its placement-export last answered them (pinsOf).
+	pins map[string]pinRead
 	// rec records the seat's acts in the hand-act log (ADR 0565 §11).
 	rec handacts.Recorder
 }
@@ -90,7 +92,7 @@ type exportCheck struct {
 
 func newSeatActs(bus caller, wake func(), logf func(string, ...any), leaseAway func() bool) *seatActs {
 	return &seatActs{bus: bus, wake: wake, logf: logf, export: map[string]exportCheck{}, calls: map[string]string{},
-		outcomes: map[string]callOutcome{}, rec: handacts.Recorder{Ask: bus.Call, LeaseAway: leaseAway}}
+		outcomes: map[string]callOutcome{}, pins: map[string]pinRead{}, rec: handacts.Recorder{Ask: bus.Call, LeaseAway: leaseAway}}
 }
 
 // exportOf is the export read again for a proposal, asked once in the background.
@@ -193,66 +195,86 @@ func (a *seatActs) outcomesNow() map[string]callOutcome {
 	return maps.Clone(a.outcomes)
 }
 
+// pinRead is the controller's pins of one node as its placement-export answered them, for the generation of the
+// controller's compositions it was asked at: a pin made at the controller changes a composition, which the assigner
+// watches, so a read is asked again only after such a change, never on a timer.
+type pinRead struct {
+	gen     uint64
+	running bool
+	known   bool
+	pins    map[string]delivery.Provider
+}
+
+// pinsOf is the controller's pins of node as last read, and whether a read answered; a read is asked in the background
+// when none was made at gen, and wakes a pass when it answers.
+func (a *seatActs) pinsOf(node string, gen uint64) (map[string]delivery.Provider, bool) {
+	if a == nil {
+		return nil, false
+	}
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	r, ok := a.pins[node]
+	if !ok || (r.gen != gen && !r.running) {
+		r.gen, r.running = gen, true
+		a.pins[node] = r
+		go func() {
+			defer a.wake()
+			raw, err := a.bus.Call(exportCall, map[string]any{"node": node})
+			var pins map[string]delivery.Provider
+			var known bool
+			if err == nil {
+				var export map[string]delivery.Placement
+				if export, err = assign.ExportOf(raw); err == nil {
+					pins, known = export[node].Pins, true
+				}
+			}
+			if err != nil {
+				a.logf("the controller's pins of %s were not read, so a refused pin's condition there waits: %v", node, err)
+			}
+			a.mu.Lock()
+			now := a.pins[node]
+			now.running = false
+			if known {
+				now.pins, now.known = pins, true
+			}
+			a.pins[node] = now
+			a.mu.Unlock()
+		}()
+	}
+	return r.pins, r.known
+}
+
 // sayCalls makes a refused call of the controller loud (issue 774): the condition of each pair whose last call was refused
-// is raised once per refusal, naming the verb, the node, the module and the controller's words; it is cleared when a later
+// is raised once per refusal, naming the verb, the node, the module and the controller's words. It is cleared when a later
-// call for the pair is answered, or, for a module's place, once the pair differed after the refusal and the two sources now
+// call for the pair is answered, or once the pair, seen differing since the refusal, agrees between the two sources (a
-// agree (a person called the verb by hand). The first pass after a start clears what a previous process raised for a pair
+// person made the call by hand): for a module's place the controller's assignments and the placement, for a pin the
-// the two sources agree on; a pin's stays, since nothing here can tell it was made since. A say that fails is made again at
+// controller's pins (its placement-export, read again after its compositions change) and the placement's. The first pass
-// the next pass.
+// after a start takes over what a previous process raised (its findings) and clears each whose pair agrees; until the
+// findings are read it is tried again at every pass. A say that fails is made again at the next pass.
 func (p *passer) sayCalls(differ []assign.Pair) {
 	if p.say == nil {
 		return
 	}
+	if p.callSaid == nil {
+		p.callSaid = map[string]*callSaid{}
+	}
 	differs := map[string]bool{}
 	for _, d := range differ {
 		differs[d.Node+"."+d.Module] = true
 	}
 	outcomes := p.seat.outcomesNow()
-	if p.callSaid == nil {
+	if !p.callsSwept {
-		p.callSaid = map[string]*callSaid{}
+		p.callsSwept = p.sweepCalls(outcomes)
-		if p.findings.Keys != nil {
-			if keys, err := p.findings.Keys(); err == nil {
-				for _, k := range keys {
-					pair, ok := strings.CutSuffix(strings.TrimPrefix(k, "module."), "."+assign.KindControllerCall)
-					node, module, two := strings.Cut(pair, ".")
-					if !ok || !two || !strings.HasPrefix(k, "module.") || differs[pair] {
-						continue
-					}
-					c := assign.ControllerCall{Verb: "assign", Node: node, Module: module}
-					if _, made := outcomes[assign.CallConditionKey(c)]; made {
-						continue
-					}
-					if err := p.say(assign.CallRefusedCondition(c, "", false, "the controller's assignments and the placement agree on "+module+" on "+node+".")); err != nil {
-						p.logf("the refused call's condition of %s on %s could not be cleared: %v", module, node, err)
-					}
-				}
-			}
-		}
 	}
 	for key, o := range outcomes {
 		said := p.callSaid[key]
-		pair := o.call.Node + "." + o.call.Module
 		switch {
-		case o.refused != "" && (said == nil || said.refused != o.refused):
+		case o.refused != "" && (said == nil || said.adopted || said.refused != o.refused):
 			if err := p.say(assign.CallRefusedCondition(o.call, o.refused, true, "")); err != nil {
 				p.logf("that %s was refused could not be said, and is said at the next pass: %v", o.call.Key(), err)
 				continue
 			}
-			p.callSaid[key] = &callSaid{refused: o.refused, differed: differs[pair]}
+			p.callSaid[key] = &callSaid{call: o.call, refused: o.refused}
-		case o.refused != "" && o.call.CallKind() == assign.KindControllerCall:
-			if differs[pair] {
-				said.differed = true
-				continue
-			}
-			if !said.differed {
-				continue // the pair was not seen differing since the refusal: the world may not hold the write yet
-			}
-			if err := p.say(assign.CallRefusedCondition(o.call, "", false, "the controller's assignments and the placement agree on "+o.call.Module+" on "+o.call.Node+".")); err != nil {
-				p.logf("the condition of %s could not be cleared, and is cleared at the next pass: %v", o.call.Key(), err)
-				continue
-			}
-			p.seat.forgetOutcome(key, o)
-			delete(p.callSaid, key)
 		case o.refused == "" && said != nil:
 			if err := p.say(assign.CallRefusedCondition(o.call, "", false, o.call.Key()+" was answered.")); err != nil {
 				p.logf("the condition of %s could not be cleared, and is cleared at the next pass: %v", o.call.Key(), err)
@@ -261,12 +283,93 @@ func (p *passer) sayCalls(differ []assign.Pair) {
 			delete(p.callSaid, key)
 		}
 	}
+	var placements map[string]delivery.Placement
+	for key, said := range p.callSaid {
+		c := said.call
+		var apart bool
+		if c.CallKind() == assign.KindControllerCall {
+			apart = differs[c.Node+"."+c.Module]
+		} else {
+			theirs, known := p.seat.pinsOf(c.Node, p.w.bucketGen(delivery.ControllerComposedBucket))
+			if !known {
+				continue
+			}
+			if placements == nil {
+				placements, _ = p.seatPlacements()
+			}
+			ours, has := placements[c.Node].Pins[c.Module]
+			to, had := theirs[c.Module]
+			apart = has != had || ours != to
+		}
+		if apart {
+			said.differed = true
+			continue
+		}
+		if !said.differed {
+			continue // not seen differing since the refusal: the world may not hold the write yet
+		}
+		if err := p.say(assign.CallRefusedCondition(c, "", false, agreeWords(c))); err != nil {
+			p.logf("the condition of %s could not be cleared, and is cleared at the next pass: %v", c.Key(), err)
+			continue
+		}
+		if o, ok := outcomes[key]; ok {
+			p.seat.forgetOutcome(key, o)
+		}
+		delete(p.callSaid, key)
+	}
 }
 
-// callSaid is the refusal a raised call's condition said, and whether its pair was seen differing since.
+// sweepCalls takes over the refused calls' conditions a previous process raised, from the findings: each is followed as
+// one seen differing, so it clears at the first pass its pair agrees. It answers whether the findings were read.
+func (p *passer) sweepCalls(outcomes map[string]callOutcome) bool {
+	if p.findings.Keys == nil {
+		return true
+	}
+	keys, err := p.findings.Keys()
+	if err != nil {
+		p.logf("the findings were not read, so the refused calls a previous process raised are taken over at the next pass: %v", err)
+		return false
+	}
+	for _, k := range keys {
+		rest, ok := strings.CutPrefix(k, "module.")
+		if !ok {
+			continue
+		}
+		for _, kind := range []string{assign.KindControllerCall, assign.KindControllerPin} {
+			pair, ok := strings.CutSuffix(rest, "."+kind)
+			node, module, two := strings.Cut(pair, ".")
+			if !ok || !two {
+				continue
+			}
+			verb := "assign"
+			if kind == assign.KindControllerPin {
+				verb = "pin"
+			}
+			c := assign.ControllerCall{Verb: verb, Node: node, Module: module}
+			key := assign.CallConditionKey(c)
+			if _, made := outcomes[key]; made || p.callSaid[key] != nil {
+				continue
+			}
+			p.callSaid[key] = &callSaid{call: c, differed: true, adopted: true}
+		}
+	}
+	return true
+}
+
+func agreeWords(c assign.ControllerCall) string {
+	if c.CallKind() == assign.KindControllerPin {
+		return "the controller's pins and the placement agree on " + c.Module + " for " + c.Node + "."
+	}
+	return "the controller's assignments and the placement agree on " + c.Module + " on " + c.Node + "."
+}
+
+// callSaid is a raised call's condition: its call, the refusal it said, whether its pair was seen differing since, and
+// whether it was taken over from a previous process.
 type callSaid struct {
+	call     assign.ControllerCall
 	refused  string
 	differed bool
+	adopted  bool
 }
 
 // forgetOutcome drops a refused call's outcome once its condition is cleared, unless a later call replaced it.

modules/mesh-delivery-assigner/cmd/mesh-delivery-assigner/world.go

@@ -100,6 +100,7 @@ func (w *world) put(bucket, key string, value []byte) {
 	if w.values[bucket] == nil {
 		w.values[bucket] = map[string][]byte{}
 	}
+	w.changes[bucket]++ // the bucket's generation (bucketGen), a delete included
 	if value == nil {
 		delete(w.values[bucket], key)
 		return
@@ -662,6 +663,14 @@ func (w *world) answer(key string) (delivery.Answer, bool) {
 	return a, err == nil
 }
 
+// bucketGen is how many times any key of the bucket was written or deleted in this process: a read of what it shows
+// elsewhere is asked again only after it moves.
+func (w *world) bucketGen(bucket string) uint64 {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+	return w.changes[bucket]
+}
+
 // changed is how many values the key has taken in this process (see world.changes).
 func (w *world) changed(bucket, key string) uint64 {
 	w.mu.Lock()