Improve pause manager

service/pause/default.go

@@ -3,13 +3,19 @@ package pause
 import (
 	"context"
 	"sync"
+
+	"github.com/sagernet/sing/common/atomic"
+	"github.com/sagernet/sing/common/x/list"
 )
 
 type defaultManager struct {
-	ctx          context.Context
-	access       sync.Mutex
-	devicePause  chan struct{}
-	networkPause chan struct{}
+	ctx           context.Context
+	access        sync.Mutex
+	devicePause   chan struct{}
+	devicePaused  atomic.Bool
+	networkPause  chan struct{}
+	networkPaused atomic.Bool
+	callbacks     list.List[Callback]
 }
 
 func NewDefaultManager(ctx context.Context) Manager {
@@ -29,7 +35,9 @@ func (d *defaultManager) DevicePause() {
 	defer d.access.Unlock()
 	select {
 	case <-d.devicePause:
+		d.devicePaused.Store(true)
 		d.devicePause = make(chan struct{})
+		d.emit(EventDevicePaused)
 	default:
 	}
 }
@@ -40,20 +48,20 @@ func (d *defaultManager) DeviceWake() {
 	select {
 	case <-d.devicePause:
 	default:
+		d.devicePaused.Store(false)
 		close(d.devicePause)
+		d.emit(EventDeviceWake)
 	}
 }
 
-func (d *defaultManager) DevicePauseChan() <-chan struct{} {
-	return d.devicePause
-}
-
 func (d *defaultManager) NetworkPause() {
 	d.access.Lock()
 	defer d.access.Unlock()
 	select {
 	case <-d.networkPause:
+		d.networkPaused.Store(true)
 		d.networkPause = make(chan struct{})
+		d.emit(EventNetworkPause)
 	default:
 	}
 }
@@ -64,12 +72,30 @@ func (d *defaultManager) NetworkWake() {
 	select {
 	case <-d.networkPause:
 	default:
+		d.networkPaused.Store(false)
 		close(d.networkPause)
+		d.emit(EventNetworkWake)
 	}
 }
 
-func (d *defaultManager) NetworkPauseChan() <-chan struct{} {
-	return d.networkPause
+func (d *defaultManager) RegisterCallback(callback Callback) *list.Element[Callback] {
+	d.access.Lock()
+	defer d.access.Unlock()
+	return d.callbacks.PushBack(callback)
+}
+
+func (d *defaultManager) UnregisterCallback(element *list.Element[Callback]) {
+	d.access.Lock()
+	defer d.access.Unlock()
+	d.callbacks.Remove(element)
+}
+
+func (d *defaultManager) IsDevicePaused() bool {
+	return d.devicePaused.Load()
+}
+
+func (d *defaultManager) IsNetworkPaused() bool {
+	return d.networkPaused.Load()
 }
 
 func (d *defaultManager) IsPaused() bool {
@@ -99,3 +125,9 @@ func (d *defaultManager) WaitActive() {
 	case <-d.ctx.Done():
 	}
 }
+
+func (d *defaultManager) emit(event int) {
+	for element := d.callbacks.Front(); element != nil; element = element.Next() {
+		element.Value(event)
+	}
+}

service/pause/manager.go

@@ -1,12 +1,25 @@
 package pause
 
+import "github.com/sagernet/sing/common/x/list"
+
 type Manager interface {
 	DevicePause()
 	DeviceWake()
-	DevicePauseChan() <-chan struct{}
 	NetworkPause()
 	NetworkWake()
-	NetworkPauseChan() <-chan struct{}
+	IsDevicePaused() bool
+	IsNetworkPaused() bool
 	IsPaused() bool
 	WaitActive()
+	RegisterCallback(callback Callback) *list.Element[Callback]
+	UnregisterCallback(element *list.Element[Callback])
 }
+
+const (
+	EventDevicePaused int = iota
+	EventDeviceWake
+	EventNetworkPause
+	EventNetworkWake
+)
+
+type Callback = func(event int)