Tab Audio Capture: Browser-side connect/disconnect functionality.

content/browser/renderer_host/media/audio_renderer_host.cc

Index: content/browser/renderer_host/media/audio_renderer_host.cc
diff --git a/content/browser/renderer_host/media/audio_renderer_host.cc b/content/browser/renderer_host/media/audio_renderer_host.cc
index c043c2cb33317c31064f20ea215d70bfd5e4ad59..252b499dc7beee17856de87b3893429e30f6b346 100644
--- a/content/browser/renderer_host/media/audio_renderer_host.cc
+++ b/content/browser/renderer_host/media/audio_renderer_host.cc
@@ -10,8 +10,10 @@
 #include "base/shared_memory.h"
 #include "content/browser/browser_main_loop.h"
 #include "content/browser/renderer_host/media/audio_sync_reader.h"
+#include "content/browser/renderer_host/media/web_contents_audio_input_stream.h"
 #include "content/common/media/audio_messages.h"
 #include "content/public/browser/media_observer.h"
+#include "media/audio/audio_io.h"
 #include "media/audio/shared_memory_util.h"
 #include "media/base/audio_bus.h"
 #include "media/base/limits.h"
@@ -30,6 +32,9 @@ struct AudioRendererHost::AudioEntry {
   // The audio stream ID.
   int stream_id;
 
+  // The routing ID of the source render view.
+  int render_view_id;
+
   // Shared memory for transmission of the audio data.
   base::SharedMemory shared_memory;
 
@@ -37,27 +42,46 @@ struct AudioRendererHost::AudioEntry {
   // ownership of the reader.
   scoped_ptr<media::AudioOutputController::SyncReader> reader;
 
+  // When non-NULL, normal audio output is being diverted for audio mirroring.
+  media::AudioOutputStream::AudioSourceCallback* diverted_callback;
+
   // Set to true after we called Close() for the controller.
   bool pending_close;
 };
 
 AudioRendererHost::AudioEntry::AudioEntry()
     : stream_id(0),
+      render_view_id(MSG_ROUTING_NONE),
+      diverted_callback(NULL),
       pending_close(false) {
 }
 
-AudioRendererHost::AudioEntry::~AudioEntry() {}
+AudioRendererHost::AudioEntry::~AudioEntry() {
+  DCHECK(!diverted_callback);
+}
 
 ///////////////////////////////////////////////////////////////////////////////
 // AudioRendererHost implementations.
 AudioRendererHost::AudioRendererHost(
+    int render_process_id,
     media::AudioManager* audio_manager, MediaObserver* media_observer)
-    : audio_manager_(audio_manager),
+    : render_process_id_(render_process_id),
+      audio_manager_(audio_manager),
       media_observer_(media_observer) {
 }
 
 AudioRendererHost::~AudioRendererHost() {
   DCHECK(audio_entries_.empty());
+  DCHECK(mirror_sessions_.empty());
+}
+
+base::LazyInstance<AudioRendererHost::ActiveHostMap>::Leaky
+    AudioRendererHost::g_host_map_ = LAZY_INSTANCE_INITIALIZER;
+
+void AudioRendererHost::OnChannelConnected(int32 peer_pid) {
+  g_host_map_.Get().insert(std::make_pair(render_process_id_, this));
+
+  BrowserMessageFilter::OnChannelConnected(peer_pid);
 }
 
 void AudioRendererHost::OnChannelClosing() {
@@ -65,6 +89,13 @@ void AudioRendererHost::OnChannelClosing() {
 
   // Since the IPC channel is gone, close all requested audio streams.
   DeleteEntries();
+
+  while (!mirror_sessions_.empty()) {
+    MirrorSessionMap::iterator it = mirror_sessions_.begin();
+    DoStopMirroring(render_process_id_, it->first, it->second);
+  }
+
+  g_host_map_.Get().erase(render_process_id_);
 }
 
 void AudioRendererHost::OnDestruct() const {
@@ -214,6 +245,116 @@ bool AudioRendererHost::OnMessageReceived(const IPC::Message& message,
   return handled;
 }
 
+// static
+AudioRendererHost* AudioRendererHost::FromRenderProcessID(
+    int render_process_id) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  ActiveHostMap& host_map = g_host_map_.Get();
+  ActiveHostMap::const_iterator it = host_map.find(render_process_id);
+  return it == host_map.end() ? NULL : it->second;
+}
+
+// static
+void AudioRendererHost::StartMirroring(
+    int render_process_id, int render_view_id,

[Alpha Left Google, 2012/11/28 20:02:25]

This is called on the IO thread, why the extra thread jumping?

[miu, 2012/11/28 22:05:50]

It's called from the audio thread.  To make this clearer, I just changed code in
WCAIS to explicitly grab a ref to the audio thread's message loop from
AudioManager so that the DCHECKs are making it clear where code is running on
the audio thread.

+    const scoped_refptr<WebContentsAudioInputStream>& destination) {
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&AudioRendererHost::DoStartMirroring,
+                 render_process_id, render_view_id, destination));
+}
+
+// static
+void AudioRendererHost::DoStartMirroring(
+    int render_process_id, int render_view_id,
+    const scoped_refptr<WebContentsAudioInputStream>& destination) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  DCHECK(destination);
+
+  AudioRendererHost* const host = FromRenderProcessID(render_process_id);
+  if (!host) {
+    return;
+  }
+
+  // If a mirroring session is already active for |render_process_id| +
+  // |render_view_id|, force-stop it.
+  MirrorSessionMap::iterator session_it =
+      host->mirror_sessions_.find(render_view_id);
+  if (session_it != host->mirror_sessions_.end()) {
+    DVLOG(1) << "Forcing StopMirroring(" << render_view_id
+             << ") on existing mirroring session (@" << session_it->second
+             << ").";
+    DoStopMirroring(render_process_id, render_view_id, session_it->second);
+  }
+
+  DVLOG(1) << "Start mirroring RenderProcess:View="
+           << render_process_id << ':' << render_view_id
+           << " --> WebContentsAudioInputStream@" << destination;
+
+  // Insert an entry into the set of active mirroring sessions and divert any
+  // existing audio outputs to |destination|.
+  host->mirror_sessions_.insert(std::make_pair(render_view_id, destination));
+  for (AudioEntryMap::const_iterator it = host->audio_entries_.begin();
+       it != host->audio_entries_.end(); ++it) {
+    AudioEntry* const entry = it->second;
+    if (entry->render_view_id == render_view_id &&
+        !entry->pending_close) {
+      entry->diverted_callback = entry->controller->Divert();
+      destination->AddInput(entry->diverted_callback,
+                            entry->controller->params());
+    }
+  }
+}
+
+// static
+void AudioRendererHost::StopMirroring(
+    int render_process_id, int render_view_id,
+    const scoped_refptr<WebContentsAudioInputStream>& destination) {
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&AudioRendererHost::DoStopMirroring,
+                 render_process_id, render_view_id, destination));
+}
+
+// static
+void AudioRendererHost::DoStopMirroring(
+    int render_process_id, int render_view_id,
+    const scoped_refptr<WebContentsAudioInputStream>& destination) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  AudioRendererHost* const host = FromRenderProcessID(render_process_id);
+  if (!host) {
+    return;
+  }
+
+  MirrorSessionMap::iterator session_it =
+      host->mirror_sessions_.find(render_view_id);
+  if (session_it == host->mirror_sessions_.end() ||
+      destination != session_it->second) {
+    return;
+  }
+
+  DVLOG(1) << "Stop mirroring RenderProcess:View="
+           << render_process_id << ':' << render_view_id
+           << " --> WebContentsAudioInputStream@" << destination;
+
+  // Revert the "divert" for each audio stream currently active in the mirroring
+  // session being stopped.
+  for (AudioEntryMap::const_iterator it = host->audio_entries_.begin();
+       it != host->audio_entries_.end(); ++it) {
+    AudioEntry* const entry = it->second;
+    if (entry->render_view_id == render_view_id &&
+        entry->diverted_callback) {
+      destination->RemoveInput(entry->diverted_callback);
+      entry->controller->Revert(entry->diverted_callback);
+      entry->diverted_callback = NULL;
+    }
+  }
+
+  host->mirror_sessions_.erase(session_it);
+}
+
 void AudioRendererHost::OnCreateStream(
     int stream_id, const media::AudioParameters& params, int input_channels) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
@@ -281,6 +422,52 @@ void AudioRendererHost::OnCreateStream(
     media_observer_->OnSetAudioStreamStatus(this, stream_id, "created");
 }
 
+void AudioRendererHost::OnAssociateStreamWithProducer(int stream_id,
+                                                      int render_view_id) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  AudioEntry* const entry = LookupById(stream_id);
+  if (!entry) {
+    SendErrorMessage(stream_id);
+    return;
+  }
+
+  if (entry->render_view_id == render_view_id)
+    return;  // No change.
+
+  // If this stream is currently being mirrored, remove it from that mirroring
+  // session.
+  MirrorSessionMap::const_iterator prev_session_it =
+      mirror_sessions_.find(entry->render_view_id);
+  if (prev_session_it != mirror_sessions_.end()) {
+    if (entry->diverted_callback) {
+      prev_session_it->second->RemoveInput(entry->diverted_callback);
+    }
+  }
+
+  entry->render_view_id = render_view_id;
+
+  // If a mirroring session is already active for the RenderView, add this
+  // stream to that mirroring session.
+  MirrorSessionMap::const_iterator next_session_it =
+      mirror_sessions_.find(render_view_id);
+  if (next_session_it != mirror_sessions_.end()) {
+    if (!entry->pending_close) {
+      if (!entry->diverted_callback) {
+        entry->diverted_callback = entry->controller->Divert();
+      }
+      next_session_it->second->AddInput(entry->diverted_callback,
+                                        entry->controller->params());
+    }
+  } else if (entry->diverted_callback) {
+    // Clean-up: The audio stream was removed from the previous mirroring
+    // session, but there is no other mirroring session for it to be added to.
+    // So, "revert the divert."
+    entry->controller->Revert(entry->diverted_callback);
+    entry->diverted_callback = NULL;
+  }
+}
+
 void AudioRendererHost::OnPlayStream(int stream_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
@@ -370,8 +557,21 @@ void AudioRendererHost::CloseAndDeleteStream(AudioEntry* entry) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
   if (!entry->pending_close) {
+    // If this stream is currently being mirrored, remove it from the mirroring
+    // session.
+    MirrorSessionMap::const_iterator session_it =
+        mirror_sessions_.find(entry->render_view_id);
+    if (session_it != mirror_sessions_.end() &&
+        entry->diverted_callback) {
+      session_it->second->RemoveInput(entry->diverted_callback);
+      // Note: We don't call AudioOutputController::Revert() since we're about
+      // to close the controller below.  If we did call Revert(), it would cause
+      // an unnecessary round of immediate starting and stopping.
+    }
+
     entry->controller->Close(
         base::Bind(&AudioRendererHost::DeleteEntry, this, entry));
+    entry->diverted_callback = NULL;
     entry->pending_close = true;
   }
 }