From f92d871f4f319fb727911de5a0ae155557c2c361 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Niels=20M=C3=B6ller?= <nisse@webrtc.org>
Date: Mon, 23 Oct 2017 14:26:10 +0200
Subject: [PATCH] Let ChanneOwner use scoped_refptr and RefCountedBase.

Eliminates manual reference counting logic, and one of the few
remaining uses of the Atomic32 type.

Bug: webrtc:8270
Change-Id: Ibbbf227c710f7e8f68a98bac46d3e24b7cb5ee2f
Reviewed-on: https://webrtc-review.googlesource.com/14600
Commit-Queue: Niels Moller <nisse@webrtc.org>
Reviewed-by: Fredrik Solenberg <solenberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20393}
---
 voice_engine/BUILD.gn           |  1 +
 voice_engine/channel_manager.cc | 25 +------------------------
 voice_engine/channel_manager.h  | 13 ++++++-------
 3 files changed, 8 insertions(+), 31 deletions(-)

diff --git a/voice_engine/BUILD.gn b/voice_engine/BUILD.gn
index 2e18810fc3..f4bbd96b2a 100644
--- a/voice_engine/BUILD.gn
+++ b/voice_engine/BUILD.gn
@@ -58,6 +58,7 @@ rtc_static_library("voice_engine") {
     "../api:call_api",
     "../api:libjingle_peerconnection_api",
     "../api:optional",
+    "../api:refcountedbase",
     "../api:transport_api",
     "../api/audio_codecs:audio_codecs_api",
     "../api/audio_codecs:builtin_audio_decoder_factory",
diff --git a/voice_engine/channel_manager.cc b/voice_engine/channel_manager.cc
index f841a6e200..9a82d2445f 100644
--- a/voice_engine/channel_manager.cc
+++ b/voice_engine/channel_manager.cc
@@ -19,31 +19,8 @@ namespace voe {
 ChannelOwner::ChannelOwner(class Channel* channel)
     : channel_ref_(new ChannelRef(channel)) {}
 
-ChannelOwner::ChannelOwner(const ChannelOwner& channel_owner)
-    : channel_ref_(channel_owner.channel_ref_) {
-  ++channel_ref_->ref_count;
-}
-
-ChannelOwner::~ChannelOwner() {
-  if (--channel_ref_->ref_count == 0)
-    delete channel_ref_;
-}
-
-ChannelOwner& ChannelOwner::operator=(const ChannelOwner& other) {
-  if (other.channel_ref_ == channel_ref_)
-    return *this;
-
-  if (--channel_ref_->ref_count == 0)
-    delete channel_ref_;
-
-  channel_ref_ = other.channel_ref_;
-  ++channel_ref_->ref_count;
-
-  return *this;
-}
-
 ChannelOwner::ChannelRef::ChannelRef(class Channel* channel)
-    : channel(channel), ref_count(1) {}
+    : channel(channel) {}
 
 ChannelManager::ChannelManager(uint32_t instance_id)
     : instance_id_(instance_id),
diff --git a/voice_engine/channel_manager.h b/voice_engine/channel_manager.h
index 7dfdc32a03..f7cf5f4dac 100644
--- a/voice_engine/channel_manager.h
+++ b/voice_engine/channel_manager.h
@@ -14,6 +14,7 @@
 #include <memory>
 #include <vector>
 
+#include "api/refcountedbase.h"
 #include "rtc_base/constructormagic.h"
 #include "rtc_base/criticalsection.h"
 #include "rtc_base/random.h"
@@ -49,26 +50,24 @@ class Channel;
 class ChannelOwner {
  public:
   explicit ChannelOwner(Channel* channel);
-  ChannelOwner(const ChannelOwner& channel_owner);
+  ChannelOwner(const ChannelOwner& channel_owner) = default;
 
-  ~ChannelOwner();
+  ~ChannelOwner() = default;
 
-  ChannelOwner& operator=(const ChannelOwner& other);
+  ChannelOwner& operator=(const ChannelOwner& other) = default;
 
   Channel* channel() const { return channel_ref_->channel.get(); }
   bool IsValid() { return channel_ref_->channel.get() != NULL; }
-  int use_count() const { return channel_ref_->ref_count.Value(); }
  private:
   // Shared instance of a Channel. Copying ChannelOwners increase the reference
   // count and destroying ChannelOwners decrease references. Channels are
   // deleted when no references to them are held.
-  struct ChannelRef {
+  struct ChannelRef : public rtc::RefCountedBase {
     ChannelRef(Channel* channel);
     const std::unique_ptr<Channel> channel;
-    Atomic32 ref_count;
   };
 
-  ChannelRef* channel_ref_;
+  rtc::scoped_refptr<ChannelRef> channel_ref_;
 };
 
 class ChannelManager {