lib: Add util.Service as suture.Service template (fixes #5801) (#5806)

lib/model/folder.go

@@ -28,6 +28,8 @@ import (
 	"github.com/syncthing/syncthing/lib/stats"
 	"github.com/syncthing/syncthing/lib/sync"
 	"github.com/syncthing/syncthing/lib/watchaggregator"
+
+	"github.com/thejerf/suture"
 )
 
 // scanLimiter limits the number of concurrent scans. A limit of zero means no limit.
@@ -36,6 +38,7 @@ var scanLimiter = newByteSemaphore(0)
 var errWatchNotStarted = errors.New("not started")
 
 type folder struct {
+	suture.Service
 	stateTracker
 	config.FolderConfiguration
 	*stats.FolderStatisticsReference
@@ -54,7 +57,6 @@ type folder struct {
 	scanNow             chan rescanRequest
 	scanDelay           chan time.Duration
 	initialScanFinished chan struct{}
-	stopped             chan struct{}
 	scanErrors          []FileError
 	scanErrorsMut       sync.Mutex
 
@@ -98,7 +100,6 @@ func newFolder(model *model, fset *db.FileSet, ignores *ignore.Matcher, cfg conf
 		scanNow:             make(chan rescanRequest),
 		scanDelay:           make(chan time.Duration),
 		initialScanFinished: make(chan struct{}),
-		stopped:             make(chan struct{}),
 		scanErrorsMut:       sync.NewMutex(),
 
 		pullScheduled: make(chan struct{}, 1), // This needs to be 1-buffered so that we queue a pull if we're busy when it comes.
@@ -109,7 +110,7 @@ func newFolder(model *model, fset *db.FileSet, ignores *ignore.Matcher, cfg conf
 	}
 }
 
-func (f *folder) Serve() {
+func (f *folder) serve(_ chan struct{}) {
 	atomic.AddInt32(&f.model.foldersRunning, 1)
 	defer atomic.AddInt32(&f.model.foldersRunning, -1)
 
@@ -119,7 +120,6 @@ func (f *folder) Serve() {
 	defer func() {
 		f.scanTimer.Stop()
 		f.setState(FolderIdle)
-		close(f.stopped)
 	}()
 
 	pause := f.basePause()
@@ -256,7 +256,7 @@ func (f *folder) Delay(next time.Duration) {
 
 func (f *folder) Stop() {
 	f.cancel()
-	<-f.stopped
+	f.Service.Stop()
 }
 
 // CheckHealth checks the folder for common errors, updates the folder state

lib/model/folder_sendonly.go

@@ -12,6 +12,7 @@ import (
 	"github.com/syncthing/syncthing/lib/fs"
 	"github.com/syncthing/syncthing/lib/ignore"
 	"github.com/syncthing/syncthing/lib/protocol"
+	"github.com/syncthing/syncthing/lib/util"
 	"github.com/syncthing/syncthing/lib/versioner"
 )
 
@@ -28,6 +29,7 @@ func newSendOnlyFolder(model *model, fset *db.FileSet, ignores *ignore.Matcher,
 		folder: newFolder(model, fset, ignores, cfg),
 	}
 	f.folder.puller = f
+	f.folder.Service = util.AsService(f.serve)
 	return f
 }
 

lib/model/folder_sendrecv.go

@@ -28,6 +28,7 @@ import (
 	"github.com/syncthing/syncthing/lib/scanner"
 	"github.com/syncthing/syncthing/lib/sha256"
 	"github.com/syncthing/syncthing/lib/sync"
+	"github.com/syncthing/syncthing/lib/util"
 	"github.com/syncthing/syncthing/lib/versioner"
 	"github.com/syncthing/syncthing/lib/weakhash"
 )
@@ -116,6 +117,7 @@ func newSendReceiveFolder(model *model, fset *db.FileSet, ignores *ignore.Matche
 		pullErrorsMut: sync.NewMutex(),
 	}
 	f.folder.puller = f
+	f.folder.Service = util.AsService(f.serve)
 
 	if f.Copiers == 0 {
 		f.Copiers = defaultCopiers

lib/model/folder_summary.go

@@ -11,11 +11,13 @@ import (
 	"strings"
 	"time"
 
+	"github.com/thejerf/suture"
+
 	"github.com/syncthing/syncthing/lib/config"
 	"github.com/syncthing/syncthing/lib/events"
 	"github.com/syncthing/syncthing/lib/protocol"
 	"github.com/syncthing/syncthing/lib/sync"
-	"github.com/thejerf/suture"
+	"github.com/syncthing/syncthing/lib/util"
 )
 
 const minSummaryInterval = time.Minute
@@ -34,7 +36,6 @@ type folderSummaryService struct {
 	cfg       config.Wrapper
 	model     Model
 	id        protocol.DeviceID
-	stop      chan struct{}
 	immediate chan string
 
 	// For keeping track of folders to recalculate for
@@ -54,24 +55,18 @@ func NewFolderSummaryService(cfg config.Wrapper, m Model, id protocol.DeviceID)
 		cfg:             cfg,
 		model:           m,
 		id:              id,
-		stop:            make(chan struct{}),
 		immediate:       make(chan string),
 		folders:         make(map[string]struct{}),
 		foldersMut:      sync.NewMutex(),
 		lastEventReqMut: sync.NewMutex(),
 	}
 
-	service.Add(serviceFunc(service.listenForUpdates))
-	service.Add(serviceFunc(service.calculateSummaries))
+	service.Add(util.AsService(service.listenForUpdates))
+	service.Add(util.AsService(service.calculateSummaries))
 
 	return service
 }
 
-func (c *folderSummaryService) Stop() {
-	c.Supervisor.Stop()
-	close(c.stop)
-}
-
 func (c *folderSummaryService) String() string {
 	return fmt.Sprintf("FolderSummaryService@%p", c)
 }
@@ -148,7 +143,7 @@ func (c *folderSummaryService) OnEventRequest() {
 
 // listenForUpdates subscribes to the event bus and makes note of folders that
 // need their data recalculated.
-func (c *folderSummaryService) listenForUpdates() {
+func (c *folderSummaryService) listenForUpdates(stop chan struct{}) {
 	sub := events.Default.Subscribe(events.LocalIndexUpdated | events.RemoteIndexUpdated | events.StateChanged | events.RemoteDownloadProgress | events.DeviceConnected | events.FolderWatchStateChanged | events.DownloadProgress)
 	defer events.Default.Unsubscribe(sub)
 
@@ -158,7 +153,7 @@ func (c *folderSummaryService) listenForUpdates() {
 		select {
 		case ev := <-sub.C():
 			c.processUpdate(ev)
-		case <-c.stop:
+		case <-stop:
 			return
 		}
 	}
@@ -237,7 +232,7 @@ func (c *folderSummaryService) processUpdate(ev events.Event) {
 
 // calculateSummaries periodically recalculates folder summaries and
 // completion percentage, and sends the results on the event bus.
-func (c *folderSummaryService) calculateSummaries() {
+func (c *folderSummaryService) calculateSummaries(stop chan struct{}) {
 	const pumpInterval = 2 * time.Second
 	pump := time.NewTimer(pumpInterval)
 
@@ -258,7 +253,7 @@ func (c *folderSummaryService) calculateSummaries() {
 		case folder := <-c.immediate:
 			c.sendSummary(folder)
 
-		case <-c.stop:
+		case <-stop:
 			return
 		}
 	}
@@ -319,10 +314,3 @@ func (c *folderSummaryService) sendSummary(folder string) {
 		events.Default.Log(events.FolderCompletion, comp)
 	}
 }
-
-// serviceFunc wraps a function to create a suture.Service without stop
-// functionality.
-type serviceFunc func()
-
-func (f serviceFunc) Serve() { f() }
-func (f serviceFunc) Stop()  {}

lib/model/model.go

@@ -32,6 +32,7 @@ import (
 	"github.com/syncthing/syncthing/lib/stats"
 	"github.com/syncthing/syncthing/lib/sync"
 	"github.com/syncthing/syncthing/lib/upgrade"
+	"github.com/syncthing/syncthing/lib/util"
 	"github.com/syncthing/syncthing/lib/versioner"
 	"github.com/thejerf/suture"
 )
@@ -1169,19 +1170,19 @@ func (m *model) ClusterConfig(deviceID protocol.DeviceID, cm protocol.ClusterCon
 			}
 		}
 
-		// The token isn't tracked as the service stops when the connection
-		// terminates and is automatically removed from supervisor (by
-		// implementing suture.IsCompletable).
-		m.Add(&indexSender{
+		is := &indexSender{
 			conn:         conn,
 			connClosed:   closed,
 			folder:       folder.ID,
 			fset:         fs,
 			prevSequence: startSequence,
 			dropSymlinks: dropSymlinks,
-			stop:         make(chan struct{}),
-			stopped:      make(chan struct{}),
-		})
+		}
+		is.Service = util.AsService(is.serve)
+		// The token isn't tracked as the service stops when the connection
+		// terminates and is automatically removed from supervisor (by
+		// implementing suture.IsCompletable).
+		m.Add(is)
 	}
 
 	m.pmut.Lock()
@@ -1896,6 +1897,7 @@ func (m *model) deviceWasSeen(deviceID protocol.DeviceID) {
 }
 
 type indexSender struct {
+	suture.Service
 	conn         protocol.Connection
 	folder       string
 	dev          string
@@ -1903,13 +1905,9 @@ type indexSender struct {
 	prevSequence int64
 	dropSymlinks bool
 	connClosed   chan struct{}
-	stop         chan struct{}
-	stopped      chan struct{}
 }
 
-func (s *indexSender) Serve() {
-	defer close(s.stopped)
-
+func (s *indexSender) serve(stop chan struct{}) {
 	var err error
 
 	l.Debugf("Starting indexSender for %s to %s at %s (slv=%d)", s.folder, s.dev, s.conn, s.prevSequence)
@@ -1930,7 +1928,7 @@ func (s *indexSender) Serve() {
 
 	for err == nil {
 		select {
-		case <-s.stop:
+		case <-stop:
 			return
 		case <-s.connClosed:
 			return
@@ -1943,7 +1941,7 @@ func (s *indexSender) Serve() {
 		// sending for.
 		if s.fset.Sequence(protocol.LocalDeviceID) <= s.prevSequence {
 			select {
-			case <-s.stop:
+			case <-stop:
 				return
 			case <-s.connClosed:
 				return
@@ -1963,11 +1961,6 @@ func (s *indexSender) Serve() {
 	}
 }
 
-func (s *indexSender) Stop() {
-	close(s.stop)
-	<-s.stopped
-}
-
 // Complete implements the suture.IsCompletable interface. When Serve terminates
 // before Stop is called, the supervisor will check for this method and if it
 // returns true removes the service instead of restarting it. Here it always

lib/model/progressemitter.go

@@ -10,13 +10,18 @@ import (
 	"fmt"
 	"time"
 
+	"github.com/thejerf/suture"
+
 	"github.com/syncthing/syncthing/lib/config"
 	"github.com/syncthing/syncthing/lib/events"
 	"github.com/syncthing/syncthing/lib/protocol"
 	"github.com/syncthing/syncthing/lib/sync"
+	"github.com/syncthing/syncthing/lib/util"
 )
 
 type ProgressEmitter struct {
+	suture.Service
+
 	registry           map[string]map[string]*sharedPullerState // folder: name: puller
 	interval           time.Duration
 	minBlocks          int
@@ -27,15 +32,12 @@ type ProgressEmitter struct {
 	mut                sync.Mutex
 
 	timer *time.Timer
-
-	stop chan struct{}
 }
 
 // NewProgressEmitter creates a new progress emitter which emits
 // DownloadProgress events every interval.
 func NewProgressEmitter(cfg config.Wrapper) *ProgressEmitter {
 	t := &ProgressEmitter{
-		stop:               make(chan struct{}),
 		registry:           make(map[string]map[string]*sharedPullerState),
 		timer:              time.NewTimer(time.Millisecond),
 		sentDownloadStates: make(map[protocol.DeviceID]*sentDownloadState),
@@ -43,6 +45,7 @@ func NewProgressEmitter(cfg config.Wrapper) *ProgressEmitter {
 		foldersByConns:     make(map[protocol.DeviceID][]string),
 		mut:                sync.NewMutex(),
 	}
+	t.Service = util.AsService(t.serve)
 
 	t.CommitConfiguration(config.Configuration{}, cfg.RawCopy())
 	cfg.Subscribe(t)
@@ -50,14 +53,14 @@ func NewProgressEmitter(cfg config.Wrapper) *ProgressEmitter {
 	return t
 }
 
-// Serve starts the progress emitter which starts emitting DownloadProgress
+// serve starts the progress emitter which starts emitting DownloadProgress
 // events as the progress happens.
-func (t *ProgressEmitter) Serve() {
+func (t *ProgressEmitter) serve(stop chan struct{}) {
 	var lastUpdate time.Time
 	var lastCount, newCount int
 	for {
 		select {
-		case <-t.stop:
+		case <-stop:
 			l.Debugln("progress emitter: stopping")
 			return
 		case <-t.timer.C:
@@ -212,11 +215,6 @@ func (t *ProgressEmitter) CommitConfiguration(from, to config.Configuration) boo
 	return true
 }
 
-// Stop stops the emitter.
-func (t *ProgressEmitter) Stop() {
-	t.stop <- struct{}{}
-}
-
 // Register a puller with the emitter which will start broadcasting pullers
 // progress.
 func (t *ProgressEmitter) Register(s *sharedPullerState) {