fix(tasks): 任务队列 - 限制缓存回源并修复并发租约与过期写入

backend/internal/service/coordination_test.go

@@ -6,6 +6,41 @@ import (
 	"time"
 )
 
+func TestRuntimeCoordinatorLeaseRenewsAndCannotResurrect(t *testing.T) {
+	c := &runtimeCoordinator{instanceID: "test", localSlots: map[string]map[string]time.Time{}}
+	lease, acquired, err := c.acquireLease(context.Background(), "workers", 1, time.Minute)
+	if err != nil || !acquired {
+		t.Fatalf("acquire: %v %v", acquired, err)
+	}
+	c.localSlots["workers"][lease.token] = time.Now().Add(10 * time.Second)
+	if err := lease.renew(context.Background()); err != nil {
+		t.Fatal(err)
+	}
+	if time.Until(c.localSlots["workers"][lease.token]) < 50*time.Second {
+		t.Fatal("lease was not extended")
+	}
+	if _, ok, err := c.acquireLease(context.Background(), "workers", 1, time.Minute); err != nil || ok {
+		t.Fatalf("capacity exceeded: %v %v", ok, err)
+	}
+	c.localSlots["workers"][lease.token] = time.Now().Add(-time.Second)
+	if err := lease.renew(context.Background()); err == nil {
+		t.Fatal("expired lease resurrected")
+	}
+	replacement, acquired, err := c.acquireLease(context.Background(), "workers", 1, time.Minute)
+	if err != nil || !acquired {
+		t.Fatalf("abandoned slot not recovered: %v %v", acquired, err)
+	}
+	lease.release()
+	lease.release()
+	if err := replacement.renew(context.Background()); err != nil {
+		t.Fatalf("old release removed new lease: %v", err)
+	}
+	replacement.release()
+	if len(c.localSlots) != 0 {
+		t.Fatal("empty local slot scopes retained")
+	}
+}
+
 func TestRuntimeCoordinatorWaitsUntilChannelSlotIsReleased(t *testing.T) {
 	coordinator := &runtimeCoordinator{instanceID: "test", localRate: map[string]localRateEntry{}, localSlots: map[string]map[string]time.Time{}}
 	releaseFirst, acquired, err := coordinator.acquire(context.Background(), "channel:one", 1, time.Minute)
@@ -52,3 +87,13 @@ func TestRuntimeCoordinatorStopsWaitingWhenContextIsCancelled(t *testing.T) {
 		t.Fatal("acquireWithWait() error = nil after cancellation")
 	}
 }
+
+func TestChannelSlotRetryDelayStaysWithinBackoffWindow(t *testing.T) {
+	for _, base := range []time.Duration{200 * time.Millisecond, 400 * time.Millisecond, 800 * time.Millisecond, 1600 * time.Millisecond, 2 * time.Second} {
+		for range 100 {
+			if got := channelSlotRetryDelay(base); got < base/2 || got > base {
+				t.Fatalf("delay %s outside [%s, %s]", got, base/2, base)
+			}
+		}
+	}
+}