AsyncPath improvments

fixed occasional data race in Close() function. added Destroy()
interface to window manager

Author: JetSetIlly

archivefs/async.go

@@ -24,14 +24,18 @@ type FilenameSetter interface {
 type AsyncResults struct {
 	Entries  []Node
 	Selected string
+	IsDir    bool
 	Dir      string
 	Base     string
 }
 
 // AsyncPath provides asynchronous access to an archivefs
 type AsyncPath struct {
 	setter FilenameSetter
-	afs    Path
+
+	Set     chan string
+	Close   chan bool
+	Destroy chan bool
 
 	results chan AsyncResults
 	err     chan error
@@ -42,40 +46,48 @@ type AsyncPath struct {
 
 // NewAsyncPath is the preferred method of initialisation for the AsyncPath type
 func NewAsyncPath(setter FilenameSetter) AsyncPath {
-	return AsyncPath{
+	pth := AsyncPath{
 		setter:  setter,
+		Set:     make(chan string, 1),
+		Close:   make(chan bool, 1),
+		Destroy: make(chan bool, 1),
 		results: make(chan AsyncResults, 1),
 		err:     make(chan error, 1),
 	}
-}
 
-// Close any open zip files and reset path
-func (pth *AsyncPath) Close() {
-	// not sure how safe this is if it is called when the Set() goroutine is running
-	pth.afs.Close()
-}
-
-// Set archivefs path. Process() must be called in order to retreive the results
-// of the Set()
-func (pth *AsyncPath) Set(path string) error {
 	go func() {
-		pth.afs.Set(path)
-
-		entries, err := pth.afs.List()
-		if err != nil {
-			pth.err <- err
-			return
-		}
-
-		pth.results <- AsyncResults{
-			Entries:  entries,
-			Selected: pth.afs.String(),
-			Dir:      pth.afs.Dir(),
-			Base:     pth.afs.Base(),
+		var afs Path
+		var done bool
+
+		for !done {
+			select {
+			case <-pth.Destroy:
+				done = true
+
+			case <-pth.Close:
+				afs.Close()
+
+			case path := <-pth.Set:
+				afs.Set(path)
+
+				entries, err := afs.List()
+				if err != nil {
+					pth.err <- err
+					return
+				}
+
+				pth.results <- AsyncResults{
+					Entries:  entries,
+					Selected: afs.String(),
+					IsDir:    afs.IsDir(),
+					Dir:      afs.Dir(),
+					Base:     afs.Base(),
+				}
+			}
 		}
 	}()
 
-	return nil
+	return pth
 }
 
 // Process asynchronous requests. Must be called in order to receive the results
@@ -89,7 +101,7 @@ func (pth *AsyncPath) Process() error {
 		pth.Results = results
 
 		if pth.setter != nil {
-			if pth.afs.IsDir() {
+			if pth.Results.IsDir {
 				pth.setter.SetSelectedFilename("")
 			} else {
 				pth.setter.SetSelectedFilename(pth.Results.Selected)

gui/sdlimgui/manager.go

@@ -138,6 +138,14 @@ func newManager(img *SdlImgui) (*manager, error) {
 	return wm, nil
 }
 
+func (wm *manager) destroy() {
+	for _, w := range wm.windows {
+		if c, ok := w.(windowDestroy); ok {
+			c.destroy()
+		}
+	}
+}
+
 func (wm *manager) draw() {
 	// there's no good place to call the managedWindow.init() function except
 	// here when we know everything else has been initialised

gui/sdlimgui/manager_window.go

@@ -32,6 +32,11 @@ type window interface {
 	id() string
 }
 
+// windows that require special destruction implement the windowDestroy interface
+type windowDestroy interface {
+	destroy()
+}
+
 // information about the window, including window geometry
 //
 // is embedded in playmodeWin and debuggerWin interfaces. for window type that

gui/sdlimgui/sdlimgui.go

@@ -276,6 +276,8 @@ func (img *SdlImgui) Destroy() {
 		logger.Log("sdlimgui", err.Error())
 	}
 
+	img.wm.destroy()
+
 	err = img.plt.destroy()
 	if err != nil {
 		logger.Log("sdlimgui", err.Error())

gui/sdlimgui/win_rom_select.go

@@ -137,22 +137,22 @@ func newSelectROM(img *SdlImgui) (window, error) {
 func (win *winSelectROM) init() {
 }
 
+func (win *winSelectROM) destroy() {
+	win.path.Destroy <- true
+}
+
 func (win winSelectROM) id() string {
 	return winSelectROMID
 }
 
 func (win *winSelectROM) setOpen(open bool) {
 	if !open {
-		win.path.Close()
+		win.path.Close <- true
 		return
 	}
 
 	// open at the most recently selected ROM
-	recent := win.img.dbg.Prefs.RecentROM.String()
-	err := win.path.Set(recent)
-	if err != nil {
-		logger.Logf("sdlimgui", err.Error())
-	}
+	win.path.Set <- win.img.dbg.Prefs.RecentROM.String()
 }
 
 func (win *winSelectROM) playmodeSetOpen(open bool) {
@@ -285,10 +285,7 @@ func (win *winSelectROM) draw() {
 	}()
 
 	if imgui.Button("Parent") {
-		err := win.path.Set(filepath.Dir(win.path.Results.Dir))
-		if err != nil {
-			logger.Logf("sdlimgui", err.Error())
-		}
+		win.path.Set <- filepath.Dir(win.path.Results.Dir)
 		win.scrollToTop = true
 	}
 
@@ -331,10 +328,7 @@ func (win *winSelectROM) draw() {
 				}
 
 				if imgui.Selectable(s.String()) {
-					err := win.path.Set(filepath.Join(win.path.Results.Dir, e.Name))
-					if err != nil {
-						logger.Logf("sdlimgui", err.Error())
-					}
+					win.path.Set <- filepath.Join(win.path.Results.Dir, e.Name)
 					win.scrollToTop = true
 				}
 			}
@@ -380,10 +374,7 @@ func (win *winSelectROM) draw() {
 				}
 
 				if imgui.SelectableV(e.Name, selected, 0, imgui.Vec2{0, 0}) {
-					err := win.path.Set(filepath.Join(win.path.Results.Dir, e.Name))
-					if err != nil {
-						logger.Logf("sdlimgui", err.Error())
-					}
+					win.path.Set <- filepath.Join(win.path.Results.Dir, e.Name)
 				}
 				if imgui.IsItemHovered() && imgui.IsMouseDoubleClicked(0) {
 					win.insertCartridge()