itests/harmonytask_test.go

@@ -264,3 +264,40 @@ func TestTaskRetry(t *testing.T) {
 			{2, false, "error: intentional 'error'"}}, res)
 	})
 }
+
+func TestBoredom(t *testing.T) {
+	//t.Parallel()
+	withDbSetup(t, func(m *kit.TestMiner) {
+		cdb := m.BaseAPI.(*impl.StorageMinerAPI).HarmonyDB
+		harmonytask.POLL_DURATION = time.Millisecond * 100
+		var taskID harmonytask.TaskID
+		var ran bool
+		boredParty := &passthru{
+			dtl: harmonytask.TaskTypeDetails{
+				Name: "boredTest",
+				Max:  -1,
+				Cost: resources.Resources{},
+				IAmBored: func(add harmonytask.AddTaskFunc) error {
+					add(func(tID harmonytask.TaskID, tx *harmonydb.Tx) (bool, error) {
+						taskID = tID
+						return true, nil
+					})
+					return nil
+				},
+			},
+			canAccept: func(list []harmonytask.TaskID, e *harmonytask.TaskEngine) (*harmonytask.TaskID, error) {
+				require.Equal(t, harmonytask.WorkSourceIAmBored, e.WorkOrigin)
+				return &list[0], nil
+			},
+			do: func(tID harmonytask.TaskID, stillOwned func() bool) (done bool, err error) {
+				require.Equal(t, taskID, tID)
+				ran = true
+				return true, nil
+			},
+		}
+		ht, err := harmonytask.New(cdb, []harmonytask.TaskInterface{boredParty}, "test:1")
+		require.NoError(t, err)
+		require.Eventually(t, func() bool { return ran }, time.Second, time.Millisecond*100)
+		ht.GracefullyTerminate(time.Hour)
+	})
+}

lib/harmony/harmonytask/harmonytask.go

@@ -39,6 +39,12 @@ type TaskTypeDetails struct {
 	// NOTE: if refatoring tasks, see if your task is
 	// necessary. Ex: Is the sector state correct for your stage to run?
 	Follows map[string]func(TaskID, AddTaskFunc) (bool, error)
+
+	// IAmBored is called (when populated) when there's capacity but no work.
+	// Tasks added will be proposed to CanAccept() on this machine.
+	// CanAccept() can read taskEngine's WorkOrigin string to learn about a task.
+	// Ex: make new CC sectors, clean-up, or retrying pipelines that failed in later states.
+	IAmBored func(AddTaskFunc) error
 }
 
 // TaskInterface must be implemented in order to have a task used by harmonytask.
@@ -97,6 +103,7 @@ type TaskInterface interface {
 type AddTaskFunc func(extraInfo func(TaskID, *harmonydb.Tx) (shouldCommit bool, seriousError error))
 
 type TaskEngine struct {
+	// Static After New()
 	ctx         context.Context
 	handlers    []*taskTypeHandler
 	db          *harmonydb.DB
@@ -105,9 +112,12 @@ type TaskEngine struct {
 	taskMap     map[string]*taskTypeHandler
 	ownerID     int
 	follows     map[string][]followStruct
+	hostAndPort string
+
+	// synchronous to the single-threaded poller
 	lastFollowTime time.Time
 	lastCleanup    atomic.Value
-	hostAndPort    string
+	WorkOrigin     string
 }
 type followStruct struct {
 	f    func(TaskID, AddTaskFunc) (bool, error)
@@ -177,7 +187,7 @@ func New(
 					continue // not really fatal, but not great
 				}
 			}
-			if !h.considerWork(workSourceRecover, []TaskID{TaskID(w.ID)}) {
+			if !h.considerWork(WorkSourceRecover, []TaskID{TaskID(w.ID)}) {
 				log.Errorw("Strange: Unable to accept previously owned task", "id", w.ID, "type", w.Name)
 			}
 		}
@@ -327,13 +337,38 @@ func (e *TaskEngine) pollerTryAllWork() bool {
 			continue
 		}
 		if len(unownedTasks) > 0 {
-			accepted := v.considerWork(workSourcePoller, unownedTasks)
+			accepted := v.considerWork(WorkSourcePoller, unownedTasks)
 			if accepted {
 				return true // accept new work slowly and in priority order
 			}
 			log.Warn("Work not accepted for " + strconv.Itoa(len(unownedTasks)) + " " + v.Name + " task(s)")
 		}
 	}
+	// if no work was accepted, are we bored? Then find work in priority order.
+	for _, v := range e.handlers {
+		if v.AssertMachineHasCapacity() != nil {
+			continue
+		}
+		if v.TaskTypeDetails.IAmBored != nil {
+			var added []TaskID
+			err := v.TaskTypeDetails.IAmBored(func(extraInfo func(TaskID, *harmonydb.Tx) (shouldCommit bool, seriousError error)) {
+				v.AddTask(func(tID TaskID, tx *harmonydb.Tx) (shouldCommit bool, seriousError error) {
+					b, err := extraInfo(tID, tx)
+					if err == nil {
+						added = append(added, tID)
+					}
+					return b, err
+				})
+			})
+			if err != nil {
+				log.Error("IAmBored failed: ", err)
+				continue
+			}
+			if added != nil { // tiny chance a fail could make these bogus, but considerWork should then fail.
+				v.considerWork(WorkSourceIAmBored, added)
+			}
+		}
+	}
 
 	return false
 }

lib/harmony/harmonytask/task_type_handler.go

@@ -53,8 +53,9 @@ retryAddTask:
 }
 
 const (
-	workSourcePoller  = "poller"
+	WorkSourcePoller   = "poller"
-	workSourceRecover = "recovered"
+	WorkSourceRecover  = "recovered"
+	WorkSourceIAmBored = "bored"
 )
 
 // considerWork is called to attempt to start work on a task-id of this task type.
@@ -84,9 +85,14 @@ top:
 		return false
 	}
 
+	h.TaskEngine.WorkOrigin = from
+
 	// 3. What does the impl say?
 canAcceptAgain:
 	tID, err := h.CanAccept(ids, h.TaskEngine)
+
+	h.TaskEngine.WorkOrigin = ""
+
 	if err != nil {
 		log.Error(err)
 		return false
@@ -123,7 +129,7 @@ canAcceptAgain:
 	}
 
 	// if recovering we don't need to try to claim anything because those tasks are already claimed by us
-	if from != workSourceRecover {
+	if from != WorkSourceRecover {
 		// 4. Can we claim the work for our hostname?
 		ct, err := h.TaskEngine.db.Exec(h.TaskEngine.ctx, "UPDATE harmony_task SET owner_id=$1 WHERE id=$2 AND owner_id IS NULL", h.TaskEngine.ownerID, *tID)
 		if err != nil {