Fix hangs & crashes in teardown-during-Seek.

media/filters/ffmpeg_demuxer.cc

Index: media/filters/ffmpeg_demuxer.cc
diff --git a/media/filters/ffmpeg_demuxer.cc b/media/filters/ffmpeg_demuxer.cc
index 56981e4710f59e92d4139c7421d9860bbf6e9546..b3cdc700b471fd99370d1f8360cd6c7eb7719dbd 100644
--- a/media/filters/ffmpeg_demuxer.cc
+++ b/media/filters/ffmpeg_demuxer.cc
@@ -52,6 +52,15 @@ class AVPacketBuffer : public Buffer {
 };
 
 
+// Helper class that is always at end of stream.  Used to signal the demuxer
+// that a stream has seen Stop().
+class EndOfStreamBuffer : public Buffer {

[acolwell GONE FROM CHROMIUM, 2011/10/07 15:50:47]

It feels like this should go in media/base somewhere. Perhaps it could even be
hidden behind a Buffer.newEndOfStreamBuffer() static method or something like
that.

[Ami GONE FROM CHROMIUM, 2011/10/07 16:44:47]

As soon as there's another customer, I'm happy for that to be the case.  Until
then I don't think it's a good idea.

[acolwell GONE FROM CHROMIUM, 2011/10/07 16:56:59]

ChunkDemuxer could be that customer. It currently uses a static function called
CreateEOSBuffer() to do this same thing in a slightly different way. In fact,
you might just mimic that solution instead of creating a class here. Up to you.

[Ami GONE FROM CHROMIUM, 2011/10/07 17:11:10]

Doing the latter (mimicking).

+ public:
+  virtual const uint8* GetData() const { return NULL; }
+  virtual size_t GetDataSize() const { return 0; }
+};
+
+
 //
 // FFmpegDemuxerStream
 //
@@ -139,6 +148,10 @@ void FFmpegDemuxerStream::Stop() {
   DCHECK_EQ(MessageLoop::current(), demuxer_->message_loop());
   base::AutoLock auto_lock(lock_);
   buffer_queue_.clear();
+  for (ReadQueue::iterator it = read_queue_.begin();
+       it != read_queue_.end(); ++it) {
+    it->Run(new EndOfStreamBuffer());
+  }
   read_queue_.clear();
   stopped_ = true;
 }
@@ -289,13 +302,13 @@ FFmpegDemuxer::~FFmpegDemuxer() {
 
 void FFmpegDemuxer::PostDemuxTask() {
   message_loop_->PostTask(FROM_HERE,
-      base::Bind(&FFmpegDemuxer::DemuxTask, this));
+                          base::Bind(&FFmpegDemuxer::DemuxTask, this));
 }
 
 void FFmpegDemuxer::Stop(const base::Closure& callback) {
   // Post a task to notify the streams to stop as well.
   message_loop_->PostTask(FROM_HERE,
-      base::Bind(&FFmpegDemuxer::StopTask, this, callback));
+                          base::Bind(&FFmpegDemuxer::StopTask, this, callback));
 
   // Then wakes up the thread from reading.
   SignalReadCompleted(DataSource::kReadError);
@@ -303,7 +316,7 @@ void FFmpegDemuxer::Stop(const base::Closure& callback) {
 
 void FFmpegDemuxer::Seek(base::TimeDelta time, const FilterStatusCB& cb) {
   message_loop_->PostTask(FROM_HERE,
-      base::Bind(&FFmpegDemuxer::SeekTask, this, time, cb));
+                          base::Bind(&FFmpegDemuxer::SeekTask, this, time, cb));
 }
 
 void FFmpegDemuxer::SetPlaybackRate(float playback_rate) {
@@ -317,8 +330,8 @@ void FFmpegDemuxer::SetPreload(Preload preload) {
 }
 
 void FFmpegDemuxer::OnAudioRendererDisabled() {
-  message_loop_->PostTask(FROM_HERE,
-      base::Bind(&FFmpegDemuxer::DisableAudioStreamTask, this));
+  message_loop_->PostTask(FROM_HERE, base::Bind(
+      &FFmpegDemuxer::DisableAudioStreamTask, this));
 }
 
 void FFmpegDemuxer::set_host(FilterHost* filter_host) {
@@ -473,7 +486,7 @@ void FFmpegDemuxer::InitializeTask(DataSource* data_source,
       AVStream* stream = format_context_->streams[i];
       // WebM is currently strictly VP8 and Vorbis.
       if (kDemuxerIsWebm && (stream->codec->codec_id != CODEC_ID_VP8 &&
-        stream->codec->codec_id != CODEC_ID_VORBIS)) {
+                             stream->codec->codec_id != CODEC_ID_VORBIS)) {
         packet_streams_.push_back(NULL);
         continue;
       }
@@ -487,7 +500,7 @@ void FFmpegDemuxer::InitializeTask(DataSource* data_source,
 
         if (stream->first_dts != static_cast<int64_t>(AV_NOPTS_VALUE)) {
           const base::TimeDelta first_dts = ConvertFromTimeBase(
-            stream->time_base, stream->first_dts);
+              stream->time_base, stream->first_dts);
           if (start_time_ == kNoTimestamp || first_dts < start_time_)
             start_time_ = first_dts;
         }