Moves ownership of time controller into NetworkEmulationManager.

This makes it easier to maintain consistency between real time
and simulated time modes.

The RealTimeController is updated to use an explicit main thread,
this ensures that pending destruction tasks are run as the network
emulator goes out of scope.

Bug: webrtc:11255
Change-Id: Ie73ab778c78a68d7c58c0f857f14a8d8ac027c67
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/166164
Commit-Queue: Sebastian Jansson <srte@webrtc.org>
Reviewed-by: Steve Anton <steveanton@webrtc.org>
Reviewed-by: Artem Titov <titovartem@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30342}

api/BUILD.gn

@@ -538,6 +538,7 @@ rtc_source_set("network_emulation_manager_api") {
   ]
   deps = [
     ":simulated_network_api",
+    ":time_controller",
     "../call:simulated_network",
     "../rtc_base",
     "test/network_emulation",
@@ -547,6 +548,24 @@ rtc_source_set("network_emulation_manager_api") {
   ]
 }
 
+rtc_source_set("time_controller") {
+  visibility = [ "*" ]
+  sources = [
+    "test/time_controller.cc",
+    "test/time_controller.h",
+  ]
+
+  deps = [
+    "../modules/utility",
+    "../rtc_base",
+    "../rtc_base/synchronization:yield_policy",
+    "../system_wrappers",
+    "task_queue",
+    "units:time_delta",
+    "units:timestamp",
+  ]
+}
+
 rtc_source_set("fec_controller_api") {
   visibility = [ "*" ]
   sources = [
@@ -913,29 +932,6 @@ if (rtc_include_tests) {
     ]
   }
 
-  rtc_library("time_controller") {
-    visibility = [ "*" ]
-    testonly = true
-    sources = [ "test/time_controller.h" ]
-
-    deps = [
-      "../modules:module_api",
-      "../modules/utility:utility",
-      "../rtc_base",
-      "../rtc_base:rtc_base_tests_utils",
-      "../rtc_base:rtc_event",
-      "../rtc_base/synchronization:sequence_checker",
-      "../rtc_base/synchronization:yield_policy",
-      "../rtc_base/task_utils:to_queued_task",
-      "../system_wrappers",
-      "task_queue",
-      "task_queue:default_task_queue_factory",
-      "units:time_delta",
-      "units:timestamp",
-      "//third_party/abseil-cpp/absl/strings",
-    ]
-  }
-
   rtc_library("create_time_controller") {
     visibility = [ "*" ]
     testonly = true

api/test/create_network_emulation_manager.cc

@@ -17,8 +17,9 @@
 
 namespace webrtc {
 
-std::unique_ptr<NetworkEmulationManager> CreateNetworkEmulationManager() {
-  return std::make_unique<test::NetworkEmulationManagerImpl>();
+std::unique_ptr<NetworkEmulationManager> CreateNetworkEmulationManager(
+    TimeMode mode) {
+  return std::make_unique<test::NetworkEmulationManagerImpl>(mode);
 }
 
 }  // namespace webrtc

api/test/create_network_emulation_manager.h

@@ -18,7 +18,8 @@
 
 namespace webrtc {
 
-std::unique_ptr<NetworkEmulationManager> CreateNetworkEmulationManager();
+std::unique_ptr<NetworkEmulationManager> CreateNetworkEmulationManager(
+    TimeMode mode = TimeMode::kRealTime);
 
 }  // namespace webrtc
 

api/test/network_emulation_manager.h

@@ -16,6 +16,7 @@
 
 #include "api/test/network_emulation/network_emulation_interfaces.h"
 #include "api/test/simulated_network.h"
+#include "api/test/time_controller.h"
 
 #include "api/units/timestamp.h"
 #include "rtc_base/network.h"
@@ -69,6 +70,8 @@ class EmulatedNetworkManagerInterface {
       std::function<void(EmulatedNetworkStats)> stats_callback) const = 0;
 };
 
+enum class TimeMode { kRealTime, kSimulated };
+
 // Provides an API for creating and configuring emulated network layer.
 // All objects returned by this API are owned by NetworkEmulationManager itself
 // and will be deleted when manager will be deleted.
@@ -103,6 +106,8 @@ class NetworkEmulationManager {
   };
   virtual ~NetworkEmulationManager() = default;
 
+  virtual TimeController* time_controller() = 0;
+
   // Creates an emulated network node, which represents single network in
   // the emulated network layer.
   virtual EmulatedNetworkNode* CreateEmulatedNode(

api/test/time_controller.cc

@@ -0,0 +1,27 @@
+/*
+ *  Copyright (c) 2020 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+#include "api/test/time_controller.h"
+
+namespace webrtc {
+bool TimeController::Wait(const std::function<bool()>& done,
+                          TimeDelta max_duration) {
+  // Step size is chosen to be short enough to not significantly affect latency
+  // in real time tests while being long enough to avoid adding too much load to
+  // the system.
+  const auto kStep = TimeDelta::ms(5);
+  for (auto elapsed = TimeDelta::Zero(); elapsed < max_duration;
+       elapsed += kStep) {
+    if (done())
+      return true;
+    AdvanceTime(kStep);
+  }
+  return done();
+}
+}  // namespace webrtc

api/test/time_controller.h

@@ -23,7 +23,6 @@
 #include "system_wrappers/include/clock.h"
 
 namespace webrtc {
-
 // Interface for controlling time progress. This allows us to execute test code
 // in either real time or simulated time by using different implementation of
 // this interface.
@@ -51,6 +50,10 @@ class TimeController {
   // Allow task queues and process threads created by this instance to execute
   // for the given |duration|.
   virtual void AdvanceTime(TimeDelta duration) = 0;
+
+  // Waits until done() == true, polling done() in small time intervals.
+  bool Wait(const std::function<bool()>& done,
+            TimeDelta max_duration = TimeDelta::seconds(5));
 };
 
 // Interface for telling time, scheduling an event to fire at a particular time,

rtc_base/thread.h

@@ -425,6 +425,21 @@ class RTC_LOCKABLE RTC_EXPORT Thread : public webrtc::TaskQueueBase {
 #endif
 
  protected:
+  class CurrentThreadSetter : CurrentTaskQueueSetter {
+   public:
+    explicit CurrentThreadSetter(Thread* thread)
+        : CurrentTaskQueueSetter(thread),
+          manager_(rtc::ThreadManager::Instance()),
+          previous_(manager_->CurrentThread()) {
+      manager_->ChangeCurrentThreadForTest(thread);
+    }
+    ~CurrentThreadSetter() { manager_->ChangeCurrentThreadForTest(previous_); }
+
+   private:
+    rtc::ThreadManager* const manager_;
+    rtc::Thread* const previous_;
+  };
+
   // DelayedMessage goes into a priority queue, sorted by trigger time. Messages
   // with the same trigger time are processed in num_ (FIFO) order.
   class DelayedMessage {

test/network/cross_traffic_unittest.cc

@@ -113,8 +113,7 @@ TEST(CrossTrafficTest, RandomWalkCrossTraffic) {
 }
 
 TEST(TcpMessageRouteTest, DeliveredOnLossyNetwork) {
-  GlobalSimulatedTimeController time(Timestamp::seconds(0));
-  NetworkEmulationManagerImpl net(&time);
+  NetworkEmulationManagerImpl net(TimeMode::kSimulated);
   BuiltInNetworkBehaviorConfig send;
   // 800 kbps means that the 100 kB message would be delivered in ca 1 second
   // under ideal conditions and no overhead.
@@ -134,17 +133,16 @@ TEST(TcpMessageRouteTest, DeliveredOnLossyNetwork) {
   constexpr size_t kMessageSize = 100000;
 
   tcp_route->SendMessage(kMessageSize, [&] {
-    RTC_LOG(LS_INFO) << "Received at "
-                     << ToString(time.GetClock()->CurrentTime());
+    RTC_LOG(LS_INFO) << "Received at " << ToString(net.Now());
     deliver_count++;
   });
 
   // If there was no loss, we would have delivered the message in ca 1 second,
   // with 50% it should take much longer.
-  time.AdvanceTime(TimeDelta::seconds(5));
+  net.time_controller()->AdvanceTime(TimeDelta::seconds(5));
   ASSERT_EQ(deliver_count, 0);
   // But given enough time the messsage will be delivered, but only once.
-  time.AdvanceTime(TimeDelta::seconds(60));
+  net.time_controller()->AdvanceTime(TimeDelta::seconds(60));
   EXPECT_EQ(deliver_count, 1);
 }
 

test/network/feedback_generator.cc

@@ -17,8 +17,7 @@ namespace webrtc {
 FeedbackGeneratorImpl::FeedbackGeneratorImpl(
     FeedbackGeneratorImpl::Config config)
     : conf_(config),
-      time_controller_{Timestamp::seconds(100000)},
-      net_{&time_controller_},
+      net_(TimeMode::kSimulated),
       send_link_{new SimulatedNetwork(conf_.send_link)},
       ret_link_{new SimulatedNetwork(conf_.return_link)},
       route_(this,
@@ -28,11 +27,11 @@ FeedbackGeneratorImpl::FeedbackGeneratorImpl(
                  {net_.CreateEmulatedNode(absl::WrapUnique(ret_link_))})) {}
 
 Timestamp FeedbackGeneratorImpl::Now() {
-  return time_controller_.GetClock()->CurrentTime();
+  return net_.Now();
 }
 
 void FeedbackGeneratorImpl::Sleep(TimeDelta duration) {
-  time_controller_.AdvanceTime(duration);
+  net_.time_controller()->AdvanceTime(duration);
 }
 
 void FeedbackGeneratorImpl::SendPacket(size_t size) {

test/network/feedback_generator.h

@@ -44,7 +44,6 @@ class FeedbackGeneratorImpl
 
  private:
   Config conf_;
-  GlobalSimulatedTimeController time_controller_;
   ::webrtc::test::NetworkEmulationManagerImpl net_;
   SimulatedNetwork* const send_link_;
   SimulatedNetwork* const ret_link_;

test/network/network_emulation_manager.cc

@@ -18,6 +18,7 @@
 #include "call/simulated_network.h"
 #include "rtc_base/fake_network.h"
 #include "test/time_controller/real_time_controller.h"
+#include "test/time_controller/simulated_time_controller.h"
 
 namespace webrtc {
 namespace test {
@@ -27,18 +28,27 @@ namespace {
 constexpr uint32_t kMinIPv4Address = 0xC0A80000;
 // uint32_t representation of 192.168.255.255 address
 constexpr uint32_t kMaxIPv4Address = 0xC0A8FFFF;
+
+std::unique_ptr<TimeController> CreateTimeController(TimeMode mode) {
+  switch (mode) {
+    case TimeMode::kRealTime:
+      return std::make_unique<RealTimeController>();
+    case TimeMode::kSimulated:
+      // Using an offset of 100000 to get nice fixed width and readable
+      // timestamps in typical test scenarios.
+      const Timestamp kSimulatedStartTime = Timestamp::seconds(100000);
+      return std::make_unique<GlobalSimulatedTimeController>(
+          kSimulatedStartTime);
+  }
+}
 }  // namespace
 
-NetworkEmulationManagerImpl::NetworkEmulationManagerImpl()
-    : NetworkEmulationManagerImpl(GlobalRealTimeController()) {}
-
-NetworkEmulationManagerImpl::NetworkEmulationManagerImpl(
-    TimeController* time_controller)
-    : time_controller_(time_controller),
-      clock_(time_controller->GetClock()),
+NetworkEmulationManagerImpl::NetworkEmulationManagerImpl(TimeMode mode)
+    : time_controller_(CreateTimeController(mode)),
+      clock_(time_controller_->GetClock()),
       next_node_id_(1),
       next_ip4_address_(kMinIPv4Address),
-      task_queue_(time_controller->GetTaskQueueFactory()->CreateTaskQueue(
+      task_queue_(time_controller_->GetTaskQueueFactory()->CreateTaskQueue(
           "NetworkEmulation",
           TaskQueueFactory::Priority::NORMAL)) {}
 
@@ -266,7 +276,7 @@ NetworkEmulationManagerImpl::CreateEmulatedNetworkManagerInterface(
   auto endpoints_container =
       std::make_unique<EndpointsContainer>(endpoint_impls);
   auto network_manager = std::make_unique<EmulatedNetworkManager>(
-      time_controller_, &task_queue_, endpoints_container.get());
+      time_controller_.get(), &task_queue_, endpoints_container.get());
   for (auto* endpoint : endpoints) {
     // Associate endpoint with network manager.
     bool insertion_result =

test/network/network_emulation_manager.h

@@ -39,8 +39,7 @@ namespace test {
 
 class NetworkEmulationManagerImpl : public NetworkEmulationManager {
  public:
-  NetworkEmulationManagerImpl();
-  explicit NetworkEmulationManagerImpl(TimeController* time_controller);
+  explicit NetworkEmulationManagerImpl(TimeMode mode);
   ~NetworkEmulationManagerImpl();
 
   EmulatedNetworkNode* CreateEmulatedNode(
@@ -84,11 +83,13 @@ class NetworkEmulationManagerImpl : public NetworkEmulationManager {
   EmulatedNetworkManagerInterface* CreateEmulatedNetworkManagerInterface(
       const std::vector<EmulatedEndpoint*>& endpoints) override;
 
- private:
-  absl::optional<rtc::IPAddress> GetNextIPv4Address();
+  TimeController* time_controller() override { return time_controller_.get(); }
+
   Timestamp Now() const;
 
-  TimeController* const time_controller_;
+ private:
+  absl::optional<rtc::IPAddress> GetNextIPv4Address();
+  const std::unique_ptr<TimeController> time_controller_;
   Clock* const clock_;
   int next_node_id_;
 

test/network/network_emulation_pc_unittest.cc

@@ -99,7 +99,7 @@ TEST(NetworkEmulationManagerPCTest, Run) {
   signaling_thread->Start();
 
   // Setup emulated network
-  NetworkEmulationManagerImpl emulation;
+  NetworkEmulationManagerImpl emulation(TimeMode::kRealTime);
 
   EmulatedNetworkNode* alice_node = emulation.CreateEmulatedNode(
       std::make_unique<SimulatedNetwork>(BuiltInNetworkBehaviorConfig()));

test/network/network_emulation_unittest.cc

@@ -28,8 +28,8 @@ namespace webrtc {
 namespace test {
 namespace {
 
-constexpr int kNetworkPacketWaitTimeoutMs = 100;
-constexpr int kStatsWaitTimeoutMs = 1000;
+constexpr TimeDelta kNetworkPacketWaitTimeout = TimeDelta::Millis<100>();
+constexpr TimeDelta kStatsWaitTimeout = TimeDelta::Seconds<1>();
 constexpr int kOverheadIpv4Udp = 20 + 8;
 
 class SocketReader : public sigslot::has_slots<> {
@@ -128,7 +128,7 @@ class NetworkEmulationManagerThreeNodesRoutingTest : public ::testing::Test {
         rtc::CopyOnWriteBuffer(10));
 
     // Sleep at the end to wait for async packets delivery.
-    SleepMs(kNetworkPacketWaitTimeoutMs);
+    emulation_.time_controller()->AdvanceTime(kNetworkPacketWaitTimeout);
   }
 
  private:
@@ -139,7 +139,7 @@ class NetworkEmulationManagerThreeNodesRoutingTest : public ::testing::Test {
   MockReceiver r_e1_e3_;
   MockReceiver r_e3_e1_;
 
-  NetworkEmulationManagerImpl emulation_;
+  NetworkEmulationManagerImpl emulation_{TimeMode::kRealTime};
   EmulatedEndpoint* e1_;
   EmulatedEndpoint* e2_;
   EmulatedEndpoint* e3_;
@@ -156,7 +156,7 @@ EmulatedNetworkNode* CreateEmulatedNodeWithDefaultBuiltInConfig(
 using ::testing::_;
 
 TEST(NetworkEmulationManagerTest, GeneratedIpv4AddressDoesNotCollide) {
-  NetworkEmulationManagerImpl network_manager;
+  NetworkEmulationManagerImpl network_manager(TimeMode::kRealTime);
   std::set<rtc::IPAddress> ips;
   EmulatedEndpointConfig config;
   config.generated_ip_family = EmulatedEndpointConfig::IpAddressFamily::kIpv4;
@@ -169,7 +169,7 @@ TEST(NetworkEmulationManagerTest, GeneratedIpv4AddressDoesNotCollide) {
 }
 
 TEST(NetworkEmulationManagerTest, GeneratedIpv6AddressDoesNotCollide) {
-  NetworkEmulationManagerImpl network_manager;
+  NetworkEmulationManagerImpl network_manager(TimeMode::kRealTime);
   std::set<rtc::IPAddress> ips;
   EmulatedEndpointConfig config;
   config.generated_ip_family = EmulatedEndpointConfig::IpAddressFamily::kIpv6;
@@ -182,7 +182,7 @@ TEST(NetworkEmulationManagerTest, GeneratedIpv6AddressDoesNotCollide) {
 }
 
 TEST(NetworkEmulationManagerTest, Run) {
-  NetworkEmulationManagerImpl network_manager;
+  NetworkEmulationManagerImpl network_manager(TimeMode::kRealTime);
 
   EmulatedNetworkNode* alice_node = network_manager.CreateEmulatedNode(
       std::make_unique<SimulatedNetwork>(BuiltInNetworkBehaviorConfig()));
@@ -233,8 +233,8 @@ TEST(NetworkEmulationManagerTest, Run) {
                    [&]() { s2->Send(data.data(), data.size()); });
     }
 
-    rtc::Event wait;
-    wait.Wait(1000);
+    network_manager.time_controller()->AdvanceTime(TimeDelta::seconds(1));
+
     EXPECT_EQ(r1.ReceivedCount(), 1000);
     EXPECT_EQ(r2.ReceivedCount(), 1000);
 
@@ -262,11 +262,13 @@ TEST(NetworkEmulationManagerTest, Run) {
     EXPECT_EQ(st.bytes_dropped.bytes(), 0l);
     received_stats_count++;
   });
-  ASSERT_EQ_WAIT(received_stats_count.load(), 2, kStatsWaitTimeoutMs);
+  ASSERT_EQ_SIMULATED_WAIT(received_stats_count.load(), 2,
+                           kStatsWaitTimeout.ms(),
+                           *network_manager.time_controller());
 }
 
 TEST(NetworkEmulationManagerTest, ThroughputStats) {
-  NetworkEmulationManagerImpl network_manager;
+  NetworkEmulationManagerImpl network_manager(TimeMode::kRealTime);
 
   EmulatedNetworkNode* alice_node = network_manager.CreateEmulatedNode(
       std::make_unique<SimulatedNetwork>(BuiltInNetworkBehaviorConfig()));
@@ -313,12 +315,11 @@ TEST(NetworkEmulationManagerTest, ThroughputStats) {
 
   // Send 11 packets, totalizing 1 second between the first and the last.
   const int kNumPacketsSent = 11;
-  const int kDelayMs = 100;
-  rtc::Event wait;
+  const TimeDelta kDelay = TimeDelta::ms(100);
   for (int i = 0; i < kNumPacketsSent; i++) {
     t1->PostTask(RTC_FROM_HERE, [&]() { s1->Send(data.data(), data.size()); });
     t2->PostTask(RTC_FROM_HERE, [&]() { s2->Send(data.data(), data.size()); });
-    wait.Wait(kDelayMs);
+    network_manager.time_controller()->AdvanceTime(kDelay);
   }
 
   std::atomic<int> received_stats_count{0};
@@ -328,11 +329,15 @@ TEST(NetworkEmulationManagerTest, ThroughputStats) {
 
     const double tolerance = 0.95;  // Accept 5% tolerance for timing.
     EXPECT_GE(st.last_packet_sent_time - st.first_packet_sent_time,
-              TimeDelta::ms((kNumPacketsSent - 1) * kDelayMs * tolerance));
+              (kNumPacketsSent - 1) * kDelay * tolerance);
     EXPECT_GT(st.AverageSendRate().bps(), 0);
     received_stats_count++;
   });
-  ASSERT_EQ_WAIT(received_stats_count.load(), 1, kStatsWaitTimeoutMs);
+
+  ASSERT_EQ_SIMULATED_WAIT(received_stats_count.load(), 1,
+                           kStatsWaitTimeout.ms(),
+                           *network_manager.time_controller());
+
   EXPECT_EQ(r1.ReceivedCount(), 11);
   EXPECT_EQ(r2.ReceivedCount(), 11);
 

test/peer_scenario/peer_scenario.cc

@@ -41,34 +41,22 @@ std::unique_ptr<FileLogWriterFactory> GetPeerScenarioLogManager(
   }
   return nullptr;
 }
-
-std::unique_ptr<TimeController> CreateTimeController(bool real_time) {
-  if (real_time) {
-    return std::make_unique<RealTimeController>();
-  } else {
-    // Using an offset of 100000 to get nice fixed width and readable timestamps
-    // in typical test scenarios.
-    const Timestamp kSimulatedStartTime = Timestamp::seconds(100000);
-    return std::make_unique<GlobalSimulatedTimeController>(kSimulatedStartTime);
-  }
-}
 }  // namespace
 
-PeerScenario::PeerScenario(const testing::TestInfo& test_info, bool real_time)
+PeerScenario::PeerScenario(const testing::TestInfo& test_info, TimeMode mode)
     : PeerScenario(
           std::string(test_info.test_suite_name()) + "/" + test_info.name(),
-          real_time) {}
+          mode) {}
 
-PeerScenario::PeerScenario(std::string file_name, bool real_time)
-    : PeerScenario(GetPeerScenarioLogManager(file_name), real_time) {}
+PeerScenario::PeerScenario(std::string file_name, TimeMode mode)
+    : PeerScenario(GetPeerScenarioLogManager(file_name), mode) {}
 
 PeerScenario::PeerScenario(
     std::unique_ptr<LogWriterFactoryInterface> log_writer_manager,
-    bool real_time)
+    TimeMode mode)
     : log_writer_manager_(std::move(log_writer_manager)),
-      time_controller_(CreateTimeController(real_time)),
-      signaling_thread_(time_controller_->GetMainThread()),
-      net_(time_controller_.get()) {}
+      net_(mode),
+      signaling_thread_(net_.time_controller()->GetMainThread()) {}
 
 PeerScenarioClient* PeerScenario::CreateClient(
     PeerScenarioClient::Config config) {
@@ -79,7 +67,7 @@ PeerScenarioClient* PeerScenario::CreateClient(
 PeerScenarioClient* PeerScenario::CreateClient(
     std::string name,
     PeerScenarioClient::Config config) {
-  peer_clients_.emplace_back(net(), time_controller_.get(), thread(),
+  peer_clients_.emplace_back(net(), signaling_thread_,
                              GetLogWriterFactory(name), config);
   return &peer_clients_.back();
 }
@@ -119,20 +107,12 @@ void PeerScenario::AttachVideoQualityAnalyzer(VideoQualityAnalyzer* analyzer,
 
 bool PeerScenario::WaitAndProcess(std::atomic<bool>* event,
                                   TimeDelta max_duration) {
-  const auto kStep = TimeDelta::ms(5);
-  if (*event)
-    return true;
-  for (auto elapsed = TimeDelta::Zero(); elapsed < max_duration;
-       elapsed += kStep) {
-    time_controller_->AdvanceTime(kStep);
-    if (*event)
-      return true;
-  }
-  return false;
+  return net_.time_controller()->Wait([event] { return event->load(); },
+                                      max_duration);
 }
 
 void PeerScenario::ProcessMessages(TimeDelta duration) {
-  time_controller_->AdvanceTime(duration);
+  net_.time_controller()->AdvanceTime(duration);
 }
 
 std::unique_ptr<LogWriterFactoryInterface> PeerScenario::GetLogWriterFactory(

test/peer_scenario/peer_scenario.h

@@ -47,14 +47,14 @@ class PeerScenario {
   // command line flag. Optionally, the TestInfo struct available in gtest can
   // be used to automatically generate a path based on the test name.
   explicit PeerScenario(const testing::TestInfo& test_info,
-                        bool real_time = false);
-  explicit PeerScenario(std::string file_name, bool real_time = false);
+                        TimeMode mode = TimeMode::kSimulated);
+  explicit PeerScenario(std::string file_name,
+                        TimeMode mode = TimeMode::kSimulated);
   explicit PeerScenario(
       std::unique_ptr<LogWriterFactoryInterface> log_writer_manager,
-      bool real_time = false);
+      TimeMode mode = TimeMode::kSimulated);
 
   NetworkEmulationManagerImpl* net() { return &net_; }
-  rtc::Thread* thread() { return signaling_thread_; }
 
   // Creates a client wrapping a peer connection conforming to the given config.
   // The client  will share the signaling thread with the scenario. To maintain
@@ -111,10 +111,9 @@ class PeerScenario {
       std::string name);
 
   const std::unique_ptr<LogWriterFactoryInterface> log_writer_manager_;
-  const std::unique_ptr<TimeController> time_controller_;
+  NetworkEmulationManagerImpl net_;
   rtc::Thread* const signaling_thread_;
   std::list<PeerVideoQualityPair> video_quality_pairs_;
-  NetworkEmulationManagerImpl net_;
   std::list<PeerScenarioClient> peer_clients_;
 };
 

test/peer_scenario/peer_scenario_client.cc

@@ -147,15 +147,14 @@ class TimeControllerBasedCallFactory : public CallFactoryInterface {
 
 PeerScenarioClient::PeerScenarioClient(
     NetworkEmulationManager* net,
-    TimeController* time_controller,
     rtc::Thread* signaling_thread,
     std::unique_ptr<LogWriterFactoryInterface> log_writer_factory,
     PeerScenarioClient::Config config)
     : endpoints_(CreateEndpoints(net, config.endpoints)),
-      task_queue_factory_(time_controller->GetTaskQueueFactory()),
+      task_queue_factory_(net->time_controller()->GetTaskQueueFactory()),
       signaling_thread_(signaling_thread),
       log_writer_factory_(std::move(log_writer_factory)),
-      worker_thread_(time_controller->CreateThread("worker")),
+      worker_thread_(net->time_controller()->CreateThread("worker")),
       handlers_(config.handlers),
       observer_(new LambdaPeerConnectionObserver(&handlers_)) {
   handlers_.on_track.push_back(
@@ -191,7 +190,7 @@ PeerScenarioClient::PeerScenarioClient(
   pcf_deps.signaling_thread = signaling_thread_;
   pcf_deps.worker_thread = worker_thread_.get();
   pcf_deps.call_factory =
-      std::make_unique<TimeControllerBasedCallFactory>(time_controller);
+      std::make_unique<TimeControllerBasedCallFactory>(net->time_controller());
   pcf_deps.task_queue_factory =
       std::make_unique<TaskQueueFactoryWrapper>(task_queue_factory_);
   pcf_deps.event_log_factory =

test/peer_scenario/peer_scenario_client.h

@@ -108,7 +108,6 @@ class PeerScenarioClient {
 
   PeerScenarioClient(
       NetworkEmulationManager* net,
-      TimeController* time_controller,
       rtc::Thread* signaling_thread,
       std::unique_ptr<LogWriterFactoryInterface> log_writer_factory,
       Config config);

test/scenario/scenario.cc

@@ -20,8 +20,6 @@
 #include "test/logging/file_log_writer.h"
 #include "test/network/network_emulation.h"
 #include "test/testsupport/file_utils.h"
-#include "test/time_controller/real_time_controller.h"
-#include "test/time_controller/simulated_time_controller.h"
 
 ABSL_FLAG(bool, scenario_logs, false, "Save logs from scenario framework.");
 ABSL_FLAG(std::string,
@@ -47,13 +45,6 @@ std::unique_ptr<FileLogWriterFactory> GetScenarioLogManager(
   }
   return nullptr;
 }
-std::unique_ptr<TimeController> CreateTimeController(bool real_time) {
-  if (real_time) {
-    return std::make_unique<RealTimeController>();
-  } else {
-    return std::make_unique<GlobalSimulatedTimeController>(kSimulatedStartTime);
-  }
-}
 }  // namespace
 
 Scenario::Scenario()
@@ -74,14 +65,14 @@ Scenario::Scenario(
     std::unique_ptr<LogWriterFactoryInterface> log_writer_factory,
     bool real_time)
     : log_writer_factory_(std::move(log_writer_factory)),
-      time_controller_(CreateTimeController(real_time)),
-      network_manager_(time_controller_.get()),
-      clock_(time_controller_->GetClock()),
+      network_manager_(real_time ? TimeMode::kRealTime : TimeMode::kSimulated),
+      clock_(network_manager_.time_controller()->GetClock()),
       audio_decoder_factory_(CreateBuiltinAudioDecoderFactory()),
       audio_encoder_factory_(CreateBuiltinAudioEncoderFactory()),
-      task_queue_(time_controller_->GetTaskQueueFactory()->CreateTaskQueue(
-          "Scenario",
-          TaskQueueFactory::Priority::NORMAL)) {}
+      task_queue_(network_manager_.time_controller()
+                      ->GetTaskQueueFactory()
+                      ->CreateTaskQueue("Scenario",
+                                        TaskQueueFactory::Priority::NORMAL)) {}
 
 Scenario::~Scenario() {
   if (start_time_.IsFinite())
@@ -116,8 +107,8 @@ StatesPrinter* Scenario::CreatePrinter(std::string name,
 }
 
 CallClient* Scenario::CreateClient(std::string name, CallClientConfig config) {
-  CallClient* client =
-      new CallClient(time_controller_.get(), GetLogWriterFactory(name), config);
+  CallClient* client = new CallClient(network_manager_.time_controller(),
+                                      GetLogWriterFactory(name), config);
   if (config.transport.state_log_interval.IsFinite()) {
     Every(config.transport.state_log_interval, [this, client]() {
       client->network_controller_factory_.LogCongestionControllerStats(Now());
@@ -282,7 +273,7 @@ void Scenario::At(TimeDelta offset, std::function<void()> function) {
 void Scenario::RunFor(TimeDelta duration) {
   if (start_time_.IsInfinite())
     Start();
-  time_controller_->AdvanceTime(duration);
+  network_manager_.time_controller()->AdvanceTime(duration);
 }
 
 void Scenario::RunUntil(TimeDelta target_time_since_start) {
@@ -295,11 +286,12 @@ void Scenario::RunUntil(TimeDelta target_time_since_start,
   if (start_time_.IsInfinite())
     Start();
   while (check_interval >= TimeUntilTarget(target_time_since_start)) {
-    time_controller_->AdvanceTime(check_interval);
+    network_manager_.time_controller()->AdvanceTime(check_interval);
     if (exit_function())
       return;
   }
-  time_controller_->AdvanceTime(TimeUntilTarget(target_time_since_start));
+  network_manager_.time_controller()->AdvanceTime(
+      TimeUntilTarget(target_time_since_start));
 }
 
 void Scenario::Start() {

test/scenario/scenario.h

@@ -161,7 +161,6 @@ class Scenario {
   TimeDelta TimeUntilTarget(TimeDelta target_time_offset);
 
   const std::unique_ptr<LogWriterFactoryInterface> log_writer_factory_;
-  std::unique_ptr<TimeController> time_controller_;
   NetworkEmulationManagerImpl network_manager_;
   Clock* clock_;
 

test/time_controller/real_time_controller.cc

@@ -14,8 +14,28 @@
 #include "system_wrappers/include/sleep.h"
 
 namespace webrtc {
+namespace {
+class MainThread : public rtc::Thread {
+ public:
+  MainThread()
+      : Thread(std::make_unique<rtc::NullSocketServer>(), false),
+        current_setter_(this) {
+    DoInit();
+  }
+  ~MainThread() {
+    Stop();
+    DoDestroy();
+  }
+
+ private:
+  CurrentThreadSetter current_setter_;
+};
+}  // namespace
 RealTimeController::RealTimeController()
-    : task_queue_factory_(CreateDefaultTaskQueueFactory()) {}
+    : task_queue_factory_(CreateDefaultTaskQueueFactory()),
+      main_thread_(std::make_unique<MainThread>()) {
+  main_thread_->SetName("Main", this);
+}
 
 Clock* RealTimeController::GetClock() {
   return Clock::GetRealTimeClock();
@@ -42,16 +62,11 @@ std::unique_ptr<rtc::Thread> RealTimeController::CreateThread(
 }
 
 rtc::Thread* RealTimeController::GetMainThread() {
-  return rtc::Thread::Current();
+  return main_thread_.get();
 }
 
 void RealTimeController::AdvanceTime(TimeDelta duration) {
-  GetMainThread()->ProcessMessages(duration.ms());
-}
-
-RealTimeController* GlobalRealTimeController() {
-  static RealTimeController* time_controller = new RealTimeController();
-  return time_controller;
+  main_thread_->ProcessMessages(duration.ms());
 }
 
 }  // namespace webrtc

test/time_controller/real_time_controller.h

@@ -36,10 +36,9 @@ class RealTimeController : public TimeController {
 
  private:
   const std::unique_ptr<TaskQueueFactory> task_queue_factory_;
+  const std::unique_ptr<rtc::Thread> main_thread_;
 };
 
-RealTimeController* GlobalRealTimeController();
-
 }  // namespace webrtc
 
 #endif  // TEST_TIME_CONTROLLER_REAL_TIME_CONTROLLER_H_

test/time_controller/simulated_thread.h

@@ -19,20 +19,7 @@ namespace webrtc {
 class SimulatedThread : public rtc::Thread,
                         public sim_time_impl::SimulatedSequenceRunner {
  public:
-  class CurrentThreadSetter : CurrentTaskQueueSetter {
-   public:
-    explicit CurrentThreadSetter(Thread* thread)
-        : CurrentTaskQueueSetter(thread),
-          manager_(rtc::ThreadManager::Instance()),
-          previous_(manager_->CurrentThread()) {
-      manager_->ChangeCurrentThreadForTest(thread);
-    }
-    ~CurrentThreadSetter() { manager_->ChangeCurrentThreadForTest(previous_); }
-
-   private:
-    rtc::ThreadManager* const manager_;
-    rtc::Thread* const previous_;
-  };
+  using CurrentThreadSetter = CurrentThreadSetter;
   SimulatedThread(sim_time_impl::SimulatedTimeControllerImpl* handler,
                   absl::string_view name,
                   std::unique_ptr<rtc::SocketServer> socket_server);