Late initialize MediaController, for less resource i.e. ProcessThread, usage by PeerConnection.

webrtc/api/webrtcsession.cc

Index: webrtc/api/webrtcsession.cc
diff --git a/webrtc/api/webrtcsession.cc b/webrtc/api/webrtcsession.cc
index c693cb1077ee6e1d072bfd9a1308ad1175b6350e..7fa28e7da7c1d17a7f151a23d20a1c900b7e1bfd 100644
--- a/webrtc/api/webrtcsession.cc
+++ b/webrtc/api/webrtcsession.cc
@@ -521,8 +521,7 @@ class IceRestartAnswerLatch {
   bool ice_restart_;
 };
 
-WebRtcSession::WebRtcSession(webrtc::MediaControllerInterface* media_controller,
-                             rtc::Thread* signaling_thread,
+WebRtcSession::WebRtcSession(rtc::Thread* signaling_thread,
                              rtc::Thread* worker_thread,
                              cricket::PortAllocator* port_allocator)
     : signaling_thread_(signaling_thread),
@@ -535,13 +534,9 @@ WebRtcSession::WebRtcSession(webrtc::MediaControllerInterface* media_controller,
       transport_controller_(new cricket::TransportController(signaling_thread,
                                                              worker_thread,
                                                              port_allocator)),
-      media_controller_(media_controller),
-      channel_manager_(media_controller_->channel_manager()),
       ice_observer_(NULL),
       ice_connection_state_(PeerConnectionInterface::kIceConnectionNew),
       ice_connection_receiving_(true),
-      older_version_remote_peer_(false),
-      dtls_enabled_(false),
       data_channel_type_(cricket::DCT_NONE),
       ice_restart_latch_(new IceRestartAnswerLatch),
       metrics_observer_(NULL) {
@@ -561,16 +556,22 @@ WebRtcSession::~WebRtcSession() {
   // Destroy video_channel_ first since it may have a pointer to the
   // voice_channel_.
   if (video_channel_) {
+    RTC_DCHECK(media_controller_);
     SignalVideoChannelDestroyed();
-    channel_manager_->DestroyVideoChannel(video_channel_.release());
+    media_controller_->channel_manager()->DestroyVideoChannel(
+        video_channel_.release());
   }
   if (voice_channel_) {
+    RTC_DCHECK(media_controller_);
     SignalVoiceChannelDestroyed();
-    channel_manager_->DestroyVoiceChannel(voice_channel_.release());
+    media_controller_->channel_manager()->DestroyVoiceChannel(
+        voice_channel_.release());
   }
   if (data_channel_) {
+    RTC_DCHECK(media_controller_);
     SignalDataChannelDestroyed();
-    channel_manager_->DestroyDataChannel(data_channel_.release());
+    media_controller_->channel_manager()->DestroyDataChannel(
+        data_channel_.release());
   }
   SignalDestroyed();
 
@@ -585,14 +586,14 @@ bool WebRtcSession::Initialize(
   bundle_policy_ = rtc_configuration.bundle_policy;
   rtcp_mux_policy_ = rtc_configuration.rtcp_mux_policy;
   transport_controller_->SetSslMaxProtocolVersion(options.ssl_max_version);
+  dtls_identity_store_ = std::move(dtls_identity_store);
 
   // Obtain a certificate from RTCConfiguration if any were provided (optional).
-  rtc::scoped_refptr<rtc::RTCCertificate> certificate;
   if (!rtc_configuration.certificates.empty()) {
     // TODO(hbos,torbjorng): Decide on certificate-selection strategy instead of
     // just picking the first one. The decision should be made based on the DTLS
     // handshake. The DTLS negotiations need to know about all certificates.
-    certificate = rtc_configuration.certificates[0];
+    certificate_ = rtc_configuration.certificates[0];
   }
 
   SetIceConfig(ParseIceConfig(rtc_configuration));
@@ -604,9 +605,10 @@ bool WebRtcSession::Initialize(
 
   if (options.disable_encryption) {
     dtls_enabled_ = false;
+    disable_encryption_ = true;
   } else {
     // Enable DTLS by default if we have an identity store or a certificate.
-    dtls_enabled_ = (dtls_identity_store || certificate);
+    dtls_enabled_ = (dtls_identity_store_ || certificate_);
     // |constraints| can override the default |dtls_enabled_| value.
     if (FindConstraint(constraints, MediaConstraintsInterface::kEnableDtlsSrtp,
                        &value, nullptr)) {
@@ -653,35 +655,45 @@ bool WebRtcSession::Initialize(
   audio_options_.audio_jitter_buffer_fast_accelerate = rtc::Optional<bool>(
       rtc_configuration.audio_jitter_buffer_fast_accelerate);
 
+  port_allocator()->set_candidate_filter(
+      ConvertIceTransportTypeToCandidateFilter(rtc_configuration.type));
+
+  return true;
+}
+
+void WebRtcSession::LateInitialize(
+    webrtc::MediaControllerInterface* media_controller) {
+  RTC_DCHECK(media_controller);
+  RTC_DCHECK(!media_controller_);
+  media_controller_ = media_controller;
+
   if (!dtls_enabled_) {
     // Construct with DTLS disabled.
     webrtc_session_desc_factory_.reset(new WebRtcSessionDescriptionFactory(
-        signaling_thread(), channel_manager_, this, id()));
+        signaling_thread(), media_controller_->channel_manager(), this, id()));
   } else {
     // Construct with DTLS enabled.
-    if (!certificate) {
+    if (!certificate_) {
       // Use the |dtls_identity_store| to generate a certificate.
-      RTC_DCHECK(dtls_identity_store);
+      RTC_DCHECK(dtls_identity_store_);
       webrtc_session_desc_factory_.reset(new WebRtcSessionDescriptionFactory(
-          signaling_thread(), channel_manager_, std::move(dtls_identity_store),
-          this, id()));
+          signaling_thread(), media_controller_->channel_manager(),
+          std::move(dtls_identity_store_), this, id()));
     } else {
       // Use the already generated certificate.
       webrtc_session_desc_factory_.reset(new WebRtcSessionDescriptionFactory(
-          signaling_thread(), channel_manager_, certificate, this, id()));
+          signaling_thread(), media_controller_->channel_manager(),
+          certificate_, this, id()));
+      certificate_ = rtc::scoped_refptr<rtc::RTCCertificate>(nullptr);
     }
   }
 
   webrtc_session_desc_factory_->SignalCertificateReady.connect(
       this, &WebRtcSession::OnCertificateReady);
 
-  if (options.disable_encryption) {
+  if (disable_encryption_) {
     webrtc_session_desc_factory_->SetSdesPolicy(cricket::SEC_DISABLED);
   }
-  port_allocator()->set_candidate_filter(
-      ConvertIceTransportTypeToCandidateFilter(rtc_configuration.type));
-
-  return true;
 }
 
 void WebRtcSession::Close() {
@@ -690,6 +702,7 @@ void WebRtcSession::Close() {
   ASSERT(!voice_channel_);
   ASSERT(!video_channel_);
   ASSERT(!data_channel_);
+  media_controller_ = nullptr;
 }
 
 void WebRtcSession::SetSdesPolicy(cricket::SecurePolicy secure_policy) {
@@ -1696,22 +1709,28 @@ void WebRtcSession::RemoveUnusedChannels(const SessionDescription* desc) {
   const cricket::ContentInfo* video_info =
       cricket::GetFirstVideoContent(desc);
   if ((!video_info || video_info->rejected) && video_channel_) {
+    RTC_DCHECK(media_controller_);
     SignalVideoChannelDestroyed();
-    channel_manager_->DestroyVideoChannel(video_channel_.release());
+    media_controller_->channel_manager()->DestroyVideoChannel(
+        video_channel_.release());

[pthatcher1, 2016/02/24 23:10:09]

Why not just make a channel_manager() method?

ChannelManager* channel_manager() {
  RTC_DCHECK(media_controller_);
  return media_controller_->channel_manager();
}

Then all of these would just change from channel_manager_-> to
channel_manager()->

   }
 
   const cricket::ContentInfo* voice_info =
       cricket::GetFirstAudioContent(desc);
   if ((!voice_info || voice_info->rejected) && voice_channel_) {
+    RTC_DCHECK(media_controller_);
     SignalVoiceChannelDestroyed();
-    channel_manager_->DestroyVoiceChannel(voice_channel_.release());
+    media_controller_->channel_manager()->DestroyVoiceChannel(
+        voice_channel_.release());
   }
 
   const cricket::ContentInfo* data_info =
       cricket::GetFirstDataContent(desc);
   if ((!data_info || data_info->rejected) && data_channel_) {
+    RTC_DCHECK(media_controller_);
     SignalDataChannelDestroyed();
-    channel_manager_->DestroyDataChannel(data_channel_.release());
+    media_controller_->channel_manager()->DestroyDataChannel(
+        data_channel_.release());
   }
 }
 
@@ -1774,7 +1793,8 @@ bool WebRtcSession::CreateChannels(const SessionDescription* desc) {
 }
 
 bool WebRtcSession::CreateVoiceChannel(const cricket::ContentInfo* content) {
-  voice_channel_.reset(channel_manager_->CreateVoiceChannel(
+  RTC_DCHECK(media_controller_);
+  voice_channel_.reset(media_controller_->channel_manager()->CreateVoiceChannel(
       media_controller_, transport_controller_.get(), content->name, true,
       audio_options_));
   if (!voice_channel_) {
@@ -1791,7 +1811,8 @@ bool WebRtcSession::CreateVoiceChannel(const cricket::ContentInfo* content) {
 }
 
 bool WebRtcSession::CreateVideoChannel(const cricket::ContentInfo* content) {
-  video_channel_.reset(channel_manager_->CreateVideoChannel(
+  RTC_DCHECK(media_controller_);
+  video_channel_.reset(media_controller_->channel_manager()->CreateVideoChannel(
       media_controller_, transport_controller_.get(), content->name, true,
       video_options_));
   if (!video_channel_) {
@@ -1808,8 +1829,9 @@ bool WebRtcSession::CreateVideoChannel(const cricket::ContentInfo* content) {
 }
 
 bool WebRtcSession::CreateDataChannel(const cricket::ContentInfo* content) {
+  RTC_DCHECK(media_controller_);
   bool sctp = (data_channel_type_ == cricket::DCT_SCTP);
-  data_channel_.reset(channel_manager_->CreateDataChannel(
+  data_channel_.reset(media_controller_->channel_manager()->CreateDataChannel(
       transport_controller_.get(), content->name, !sctp, data_channel_type_));
   if (!data_channel_) {
     return false;
@@ -2146,6 +2168,7 @@ void WebRtcSession::ReportNegotiatedCiphers(
 void WebRtcSession::OnSentPacket_w(cricket::TransportChannel* channel,
                                    const rtc::SentPacket& sent_packet) {
   RTC_DCHECK(worker_thread()->IsCurrent());
+  RTC_DCHECK(media_controller_);
   media_controller_->call_w()->OnSentPacket(sent_packet);
 }