feat: Prevent concurrent read and write issues when publishers catch up with subscribers after blocking them

desc: 防止订阅者阻塞后，发布者追上订阅者产生并发读写问题

subscriber.go

@@ -9,6 +9,7 @@ import (
 	"time"
 
 	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
 	"m7s.live/engine/v4/codec"
 	. "m7s.live/engine/v4/common"
 	"m7s.live/engine/v4/config"
@@ -206,9 +207,10 @@ func (s *Subscriber) PlayBlock(subType byte) {
 	ctx := s.TrackPlayer.Context
 	conf := s.Config
 	hasVideo, hasAudio := s.Video != nil && conf.SubVideo, s.Audio != nil && conf.SubAudio
-	defer s.onStop()
+	stopReason := zap.String("reason", "stop")
+	defer s.onStop(&stopReason)
 	if !hasAudio && !hasVideo {
-		s.Error("play neither video nor audio")
+		stopReason = zap.String("reason", "play neither video nor audio")
 		return
 	}
 	sendVideoDecConf := func() {
@@ -309,11 +311,12 @@ func (s *Subscriber) PlayBlock(subType byte) {
 	for ctx.Err() == nil {
 		if hasVideo {
 			for ctx.Err() == nil {
-				s.VideoReader.Read(ctx, subMode)
-				videoFrame = s.VideoReader.Frame
-				if videoFrame == nil || ctx.Err() != nil {
+				err := s.VideoReader.ReadFrame(subMode)
+				if err != nil {
+					stopReason = zap.Error(err)
 					return
 				}
+				videoFrame = s.VideoReader.Value
 				// fmt.Println("video", s.VideoReader.Track.PreFrame().Sequence-frame.Sequence)
 				if videoFrame.IFrame && s.VideoReader.DecConfChanged() {
 					s.VideoReader.ConfSeq = s.VideoReader.Track.SequenceHeadSeq
@@ -323,9 +326,7 @@ func (s *Subscriber) PlayBlock(subType byte) {
 					if audioFrame != nil {
 						if videoFrame.Timestamp > audioFrame.Timestamp {
 							// fmt.Println("switch audio", audioFrame.CanRead)
-							if audioFrame.CanRead {
-								sendAudioFrame(audioFrame)
-							}
+							sendAudioFrame(audioFrame)
 							audioFrame = nil
 							break
 						}
@@ -355,11 +356,12 @@ func (s *Subscriber) PlayBlock(subType byte) {
 						s.AudioReader.SkipTs = s.VideoReader.SkipTs
 					}
 				}
-				s.AudioReader.Read(ctx, subMode)
-				audioFrame = s.AudioReader.Frame
-				if audioFrame == nil || ctx.Err() != nil {
+				err := s.AudioReader.ReadFrame(subMode)
+				if err != nil {
+					stopReason = zap.Error(err)
 					return
 				}
+				audioFrame = s.AudioReader.Value
 				// fmt.Println("audio", s.AudioReader.Track.PreFrame().Sequence-frame.Sequence)
 				if s.AudioReader.DecConfChanged() {
 					s.AudioReader.ConfSeq = s.AudioReader.Track.SequenceHeadSeq
@@ -368,9 +370,7 @@ func (s *Subscriber) PlayBlock(subType byte) {
 				if hasVideo && videoFrame != nil {
 					if audioFrame.Timestamp > videoFrame.Timestamp {
 						// fmt.Println("switch video", videoFrame.CanRead)
-						if videoFrame.CanRead {
-							sendVideoFrame(videoFrame)
-						}
+						sendVideoFrame(videoFrame)
 						videoFrame = nil
 						break
 					}
@@ -383,11 +383,18 @@ func (s *Subscriber) PlayBlock(subType byte) {
 			}
 		}
 	}
+	if videoFrame != nil {
+		videoFrame.ReaderLeave()
+	}
+	if audioFrame != nil {
+		audioFrame.ReaderLeave()
+	}
+	stopReason = zap.Error(ctx.Err())
 }
 
-func (s *Subscriber) onStop() {
+func (s *Subscriber) onStop(reason *zapcore.Field) {
 	if !s.Stream.IsClosed() {
-		s.Info("stop")
+		s.Info("stop", *reason)
 		if !s.Config.Internal {
 			s.Stream.Receive(s.Spesific)
 		}