fix: task lock by unreachable torrent (#431)

internal/protocol/bt/fetcher.go

@@ -33,6 +33,7 @@ type Fetcher struct {
 	meta    *fetcher.FetcherMeta
 
 	torrentReady atomic.Bool
+	torrentDrop  atomic.Bool
 	create       atomic.Bool
 	progress     fetcher.Progress
 }
@@ -143,6 +144,7 @@ func (f *Fetcher) Pause() (err error) {
 }
 
 func (f *Fetcher) Close() (err error) {
+	f.torrentDrop.Store(false)
 	f.safeDrop()
 	return nil
 }
@@ -158,6 +160,9 @@ func (f *Fetcher) safeDrop() {
 
 func (f *Fetcher) Wait() (err error) {
 	for {
+		if f.torrentDrop.Load() {
+			break
+		}
 		if f.torrentReady.Load() && len(f.meta.Opts.SelectFiles) > 0 {
 			done := true
 			for _, selectIndex := range f.meta.Opts.SelectFiles {

pkg/download/downloader.go

@@ -172,8 +172,8 @@ func (d *Downloader) Setup() error {
 			if len(d.tasks) > 0 {
 				for _, task := range d.tasks {
 					func() {
-						task.lock.Lock()
-						defer task.lock.Unlock()
+						task.statusLock.Lock()
+						defer task.statusLock.Unlock()
 						if task.Status != base.DownloadStatusRunning {
 							return
 						}
@@ -329,8 +329,7 @@ func (d *Downloader) Pause(id string) (err error) {
 		if task.Status == base.DownloadStatusPause {
 			return
 		}
-		err = d.doPause(task)
-		if err != nil {
+		if err = d.doPause(task); err != nil {
 			return
 		}
 		d.notifyRunning()
@@ -363,19 +362,7 @@ func (d *Downloader) Continue(id string) (err error) {
 		}
 	}()
 
-	func() {
-		task.lock.Lock()
-		defer task.lock.Unlock()
-
-		if task.Status == base.DownloadStatusRunning {
-			return
-		}
-
-		if err = d.doStart(task); err != nil {
-			return
-		}
-	}()
-	return
+	return d.doStart(task)
 }
 
 func (d *Downloader) PauseAll() (err error) {
@@ -388,13 +375,7 @@ func (d *Downloader) PauseAll() (err error) {
 	}()
 
 	for _, task := range d.tasks {
-		err = func() error {
-			task.lock.Lock()
-			defer task.lock.Unlock()
-
-			return d.doPause(task)
-		}()
-		if err != nil {
+		if err = d.doPause(task); err != nil {
 			return
 		}
 	}
@@ -424,13 +405,7 @@ func (d *Downloader) ContinueAll() (err error) {
 
 	for _, task := range continuedTasks {
 		tt := task
-		err = func() error {
-			tt.lock.Lock()
-			defer tt.lock.Unlock()
-
-			return d.doStart(tt)
-		}()
-		if err != nil {
+		if err = d.doStart(tt); err != nil {
 			return
 		}
 	}
@@ -522,17 +497,21 @@ func (d *Downloader) Stats(id string) (sr any, err error) {
 
 func (d *Downloader) doDelete(task *Task, force bool) (err error) {
 	err = func() error {
-		if task.fetcher != nil {
-			if err := task.fetcher.Close(); err != nil {
-				return err
-			}
-		}
+		d.lock.Lock()
+		defer d.lock.Unlock()
+
 		if err := d.storage.Delete(bucketTask, task.ID); err != nil {
 			return err
 		}
 		if err := d.storage.Delete(bucketSave, task.ID); err != nil {
 			return err
 		}
+
+		if task.fetcher != nil {
+			if err := task.fetcher.Close(); err != nil {
+				return err
+			}
+		}
 		if force && task.Meta.Res != nil {
 			if task.Meta.Res.Name != "" {
 				if err := os.RemoveAll(task.Meta.FolderPath()); err != nil {
@@ -794,31 +773,52 @@ func (d *Downloader) doCreate(fetcher fetcher.Fetcher, opts *base.Options) (task
 			return
 		}
 
-		d.doStart(task)
+		err = d.doStart(task)
 	}()
 
 	go d.watch(task)
 	return
 }
 
+func (d *Downloader) statusMut(task *Task, fn func() (bool, error)) (bool, error) {
+	task.statusLock.Lock()
+	defer task.statusLock.Unlock()
+
+	return fn()
+}
+
 func (d *Downloader) doStart(task *Task) (err error) {
-	if task.Status != base.DownloadStatusRunning && task.Status != base.DownloadStatusDone {
-		err := d.restoreFetcher(task)
+	var isCreate bool
+	isReturn, err := d.statusMut(task, func() (isReturn bool, err error) {
+		if task.Status == base.DownloadStatusRunning || task.Status == base.DownloadStatusDone {
+			isReturn = true
+			return
+		}
+
+		err = d.restoreFetcher(task)
 		if err != nil {
 			d.Logger.Error().Stack().Err(err).Msgf("restore fetcher failed, task id: %s", task.ID)
-			return err
+			return
 		}
-	}
-
-	isCreate := task.Status == base.DownloadStatusReady
-
-	doStart := func() error {
-		task.lock.Lock()
-		defer task.lock.Unlock()
+		isCreate = task.Status == base.DownloadStatusReady
 
 		d.triggerOnStart(task)
 		task.updateStatus(base.DownloadStatusRunning)
 
+		return
+	})
+	if err != nil {
+		d.Logger.Error().Stack().Err(err).Msgf("start task failed, task id: %s", task.ID)
+		return
+	}
+	if isReturn {
+		return
+	}
+
+	handler := func() error {
+		task.lock.Lock()
+		defer task.lock.Unlock()
+
 		if task.Meta.Res == nil {
 			err := task.fetcher.Resolve(task.Meta.Req)
 			if err != nil {
@@ -865,8 +865,7 @@ func (d *Downloader) doStart(task *Task) (err error) {
 		return nil
 	}
 	go func() {
-		err := doStart()
-		if err != nil {
+		if err := handler(); err != nil {
 			d.doOnError(task, err)
 		}
 	}()
@@ -875,27 +874,44 @@ func (d *Downloader) doStart(task *Task) (err error) {
 }
 
 func (d *Downloader) doPause(task *Task) (err error) {
-	err = func() error {
-		if task.Status != base.DownloadStatusDone {
-			task.updateStatus(base.DownloadStatusPause)
-			task.timer.Pause()
-			if task.fetcher != nil {
-				if err := task.fetcher.Pause(); err != nil {
-					return err
-				}
-			}
-			if err := d.storage.Put(bucketTask, task.ID, task.clone()); err != nil {
-				return err
-			}
-			d.emit(EventKeyPause, task)
+	isReturn, err := d.statusMut(task, func() (isReturn bool, err error) {
+		if task.Status == base.DownloadStatusPause || task.Status == base.DownloadStatusDone {
+			isReturn = true
+			return
 		}
-		return nil
-	}()
+
+		task.updateStatus(base.DownloadStatusPause)
+		task.timer.Pause()
+		return
+	})
 	if err != nil {
 		d.Logger.Error().Stack().Err(err).Msgf("pause task failed, task id: %s", task.ID)
 		return
 	}
+	if isReturn {
+		return
+	}
 
+	handler := func() error {
+		task.lock.Lock()
+		defer task.lock.Unlock()
+
+		if task.fetcher != nil {
+			if err := task.fetcher.Pause(); err != nil {
+				return err
+			}
+		}
+		if err := d.storage.Put(bucketTask, task.ID, task.clone()); err != nil {
+			return err
+		}
+		d.emit(EventKeyPause, task)
+		return nil
+	}
+	go func() {
+		if err := handler(); err != nil {
+			d.Logger.Error().Stack().Err(err).Msgf("pause task handle failed, task id: %s", task.ID)
+		}
+	}()
 	return
 }
 
@@ -923,6 +939,8 @@ func (d *Downloader) buildFetcher(url string) (fetcher.Fetcher, error) {
 
 func initTask(task *Task) {
 	task.timer = util.NewTimer(task.Progress.Used)
+
+	task.statusLock = &sync.Mutex{}
 	task.lock = &sync.Mutex{}
 	task.speedArr = make([]int64, 0)
 }

pkg/download/model.go

@@ -31,6 +31,7 @@ type Task struct {
 	fetcherBuilder fetcher.FetcherBuilder
 	fetcher        fetcher.Fetcher
 	timer          *util.Timer
+	statusLock     *sync.Mutex
 	lock           *sync.Mutex
 	speedArr       []int64
 }

ui/flutter/lib/api/model/options.dart

@@ -12,7 +12,7 @@ class Options {
   Options({
     required this.name,
     required this.path,
-    required this.selectFiles,
+    this.selectFiles = const [],
     this.extra,
   });
 

ui/flutter/lib/api/model/options.g.dart

@@ -9,8 +9,10 @@ part of 'options.dart';
 Options _$OptionsFromJson(Map<String, dynamic> json) => Options(
       name: json['name'] as String,
       path: json['path'] as String,
-      selectFiles:
-          (json['selectFiles'] as List<dynamic>).map((e) => e as int).toList(),
+      selectFiles: (json['selectFiles'] as List<dynamic>?)
+              ?.map((e) => e as int)
+              .toList() ??
+          const [],
       extra: json['extra'],
     );