Reland "Using simulated rtc::Thread for peer connection scenario tests."

This is a reland of b70c5c5ce97e7dcf2e1d8453f5ea0639d4b60453

Original change's description:
> Using simulated rtc::Thread for peer connection scenario tests.
> 
> Bug: webrtc:11255
> Change-Id: I5d29e997a7209ffc64595082358cca9b2115d07a
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/165689
> Commit-Queue: Sebastian Jansson <srte@webrtc.org>
> Reviewed-by: Steve Anton <steveanton@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#30258}

Bug: webrtc:11255
Change-Id: If65cd56b59158cebec5609407a721fbdb47cfd1b
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/166046
Reviewed-by: Steve Anton <steveanton@webrtc.org>
Commit-Queue: Sebastian Jansson <srte@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30294}

api/DEPS

@@ -265,6 +265,10 @@ specific_include_rules = {
     "+rtc_base/thread_checker.h",
   ],
 
+  "time_controller\.h": [
+    "+rtc_base/thread.h",
+  ],
+
   "videocodec_test_fixture\.h": [
     "+modules/video_coding/include/video_codec_interface.h"
   ],

api/test/time_controller.h

@@ -12,12 +12,14 @@
 
 #include <functional>
 #include <memory>
+#include <string>
 
 #include "api/task_queue/task_queue_factory.h"
 #include "api/units/time_delta.h"
 #include "api/units/timestamp.h"
 #include "modules/utility/include/process_thread.h"
 #include "rtc_base/synchronization/yield_policy.h"
+#include "rtc_base/thread.h"
 #include "system_wrappers/include/clock.h"
 
 namespace webrtc {
@@ -37,6 +39,15 @@ class TimeController {
   // Creates a process thread.
   virtual std::unique_ptr<ProcessThread> CreateProcessThread(
       const char* thread_name) = 0;
+  // Creates an rtc::Thread instance. If |socket_server| is nullptr, a default
+  // noop socket server is created.
+  virtual std::unique_ptr<rtc::Thread> CreateThread(
+      const std::string& name,
+      std::unique_ptr<rtc::SocketServer> socket_server = nullptr) = 0;
+
+  // Creates an rtc::Thread instance that ensure that it's set as the current
+  // thread.
+  virtual rtc::Thread* GetMainThread() = 0;
   // Allow task queues and process threads created by this instance to execute
   // for the given |duration|.
   virtual void AdvanceTime(TimeDelta duration) = 0;

test/network/emulated_network_manager.cc

@@ -20,18 +20,16 @@ namespace webrtc {
 namespace test {
 
 EmulatedNetworkManager::EmulatedNetworkManager(
-    Clock* clock,
+    TimeController* time_controller,
     TaskQueueForTest* task_queue,
     EndpointsContainer* endpoints_container)
     : task_queue_(task_queue),
       endpoints_container_(endpoints_container),
-      network_thread_(std::make_unique<rtc::Thread>(
+      network_thread_(time_controller->CreateThread(
+          "net_thread",
           std::make_unique<FakeNetworkSocketServer>(endpoints_container))),
       sent_first_update_(false),
-      start_count_(0) {
+      start_count_(0) {}
-  network_thread_->SetName("net_thread", nullptr);
-  network_thread_->Start();
-}
 
 void EmulatedNetworkManager::EnableEndpoint(EmulatedEndpointImpl* endpoint) {
   RTC_CHECK(endpoints_container_->HasEndpoint(endpoint))

test/network/emulated_network_manager.h

@@ -15,6 +15,7 @@
 #include <vector>
 
 #include "api/test/network_emulation_manager.h"
+#include "api/test/time_controller.h"
 #include "rtc_base/critical_section.h"
 #include "rtc_base/ip_address.h"
 #include "rtc_base/network.h"
@@ -31,7 +32,7 @@ class EmulatedNetworkManager : public rtc::NetworkManagerBase,
                                public sigslot::has_slots<>,
                                public EmulatedNetworkManagerInterface {
  public:
-  EmulatedNetworkManager(Clock* clock,
+  EmulatedNetworkManager(TimeController* time_controller,
                          TaskQueueForTest* task_queue,
                          EndpointsContainer* endpoints_container);
 

test/network/network_emulation_manager.cc

@@ -34,7 +34,8 @@ NetworkEmulationManagerImpl::NetworkEmulationManagerImpl()
 
 NetworkEmulationManagerImpl::NetworkEmulationManagerImpl(
     TimeController* time_controller)
-    : clock_(time_controller->GetClock()),
+    : time_controller_(time_controller),
+      clock_(time_controller->GetClock()),
       next_node_id_(1),
       next_ip4_address_(kMinIPv4Address),
       task_queue_(time_controller->GetTaskQueueFactory()->CreateTaskQueue(
@@ -265,7 +266,7 @@ NetworkEmulationManagerImpl::CreateEmulatedNetworkManagerInterface(
   auto endpoints_container =
       std::make_unique<EndpointsContainer>(endpoint_impls);
   auto network_manager = std::make_unique<EmulatedNetworkManager>(
-      clock_, &task_queue_, endpoints_container.get());
+      time_controller_, &task_queue_, endpoints_container.get());
   for (auto* endpoint : endpoints) {
     // Associate endpoint with network manager.
     bool insertion_result =

test/network/network_emulation_manager.h

@@ -88,6 +88,7 @@ class NetworkEmulationManagerImpl : public NetworkEmulationManager {
   absl::optional<rtc::IPAddress> GetNextIPv4Address();
   Timestamp Now() const;
 
+  TimeController* const time_controller_;
   Clock* const clock_;
   int next_node_id_;
 

test/peer_scenario/BUILD.gn

@@ -30,12 +30,14 @@ if (rtc_include_tests) {
       "../../api:libjingle_peerconnection_api",
       "../../api:network_emulation_manager_api",
       "../../api:rtc_stats_api",
+      "../../api:time_controller",
       "../../api/audio_codecs:builtin_audio_decoder_factory",
       "../../api/audio_codecs:builtin_audio_encoder_factory",
       "../../api/rtc_event_log:rtc_event_log_factory",
       "../../api/task_queue:default_task_queue_factory",
       "../../api/video_codecs:builtin_video_decoder_factory",
       "../../api/video_codecs:builtin_video_encoder_factory",
+      "../../call:call_interfaces",
       "../../media:rtc_audio_video",
       "../../media:rtc_media_base",
       "../../modules/audio_device:audio_device_impl",
@@ -43,10 +45,12 @@ if (rtc_include_tests) {
       "../../p2p:rtc_p2p",
       "../../pc:pc_test_utils",
       "../../pc:rtc_pc_base",
+      "../../rtc_base",
       "../../rtc_base:stringutils",
       "..//network:emulated_network",
       "../logging:log_writer",
       "../scenario",
+      "../time_controller",
       "//third_party/abseil-cpp/absl/flags:flag",
       "//third_party/abseil-cpp/absl/memory",
     ]

test/peer_scenario/peer_scenario.cc

@@ -11,10 +11,13 @@
 
 #include "absl/flags/flag.h"
 #include "absl/memory/memory.h"
+#include "rtc_base/null_socket_server.h"
 #include "rtc_base/string_encode.h"
 #include "rtc_base/strings/string_builder.h"
 #include "test/logging/file_log_writer.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, peer_logs, false, "Save logs from peer scenario framework.");
 ABSL_FLAG(std::string,
@@ -38,19 +41,34 @@ 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)
+PeerScenario::PeerScenario(const testing::TestInfo& test_info, bool real_time)
-    : PeerScenario(std::string(test_info.test_suite_name()) + "/" +
+    : PeerScenario(
-                   test_info.name()) {}
+          std::string(test_info.test_suite_name()) + "/" + test_info.name(),
+          real_time) {}
 
-PeerScenario::PeerScenario(std::string file_name)
+PeerScenario::PeerScenario(std::string file_name, bool real_time)
-    : PeerScenario(GetPeerScenarioLogManager(file_name)) {}
+    : PeerScenario(GetPeerScenarioLogManager(file_name), real_time) {}
 
 PeerScenario::PeerScenario(
-    std::unique_ptr<LogWriterFactoryInterface> log_writer_manager)
+    std::unique_ptr<LogWriterFactoryInterface> log_writer_manager,
-    : signaling_thread_(rtc::Thread::Current()),
+    bool real_time)
-      log_writer_manager_(std::move(log_writer_manager)) {}
+    : log_writer_manager_(std::move(log_writer_manager)),
+      time_controller_(CreateTimeController(real_time)),
+      signaling_thread_(time_controller_->GetMainThread()),
+      net_(time_controller_.get()) {}
 
 PeerScenarioClient* PeerScenario::CreateClient(
     PeerScenarioClient::Config config) {
@@ -61,8 +79,8 @@ PeerScenarioClient* PeerScenario::CreateClient(
 PeerScenarioClient* PeerScenario::CreateClient(
     std::string name,
     PeerScenarioClient::Config config) {
-  peer_clients_.emplace_back(net(), thread(), GetLogWriterFactory(name),
+  peer_clients_.emplace_back(net(), time_controller_.get(), thread(),
-                             config);
+                             GetLogWriterFactory(name), config);
   return &peer_clients_.back();
 }
 
@@ -106,7 +124,7 @@ bool PeerScenario::WaitAndProcess(std::atomic<bool>* event,
     return true;
   for (auto elapsed = TimeDelta::Zero(); elapsed < max_duration;
        elapsed += kStep) {
-    thread()->ProcessMessages(kStep.ms());
+    time_controller_->AdvanceTime(kStep);
     if (*event)
       return true;
   }
@@ -114,7 +132,7 @@ bool PeerScenario::WaitAndProcess(std::atomic<bool>* event,
 }
 
 void PeerScenario::ProcessMessages(TimeDelta duration) {
-  thread()->ProcessMessages(duration.ms());
+  time_controller_->AdvanceTime(duration);
 }
 
 std::unique_ptr<LogWriterFactoryInterface> PeerScenario::GetLogWriterFactory(

test/peer_scenario/peer_scenario.h

@@ -21,6 +21,7 @@
 #include <list>
 #include <vector>
 
+#include "api/test/time_controller.h"
 #include "test/gtest.h"
 #include "test/logging/log_writer.h"
 #include "test/network/network_emulation_manager.h"
@@ -31,7 +32,6 @@
 
 namespace webrtc {
 namespace test {
-
 // The PeerScenario class represents a PeerConnection simulation scenario. The
 // main purpose is to maintain ownership and ensure safe destruction order of
 // clients and network emulation. Additionally it reduces the amount of boiler
@@ -46,10 +46,12 @@ class PeerScenario {
   // The name is used for log output when those are enabled by the --peer_logs
   // 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);
+  explicit PeerScenario(const testing::TestInfo& test_info,
-  explicit PeerScenario(std::string file_name);
+                        bool real_time = false);
+  explicit PeerScenario(std::string file_name, bool real_time = false);
   explicit PeerScenario(
-      std::unique_ptr<LogWriterFactoryInterface> log_writer_manager);
+      std::unique_ptr<LogWriterFactoryInterface> log_writer_manager,
+      bool real_time = false);
 
   NetworkEmulationManagerImpl* net() { return &net_; }
   rtc::Thread* thread() { return signaling_thread_; }
@@ -102,13 +104,15 @@ class PeerScenario {
     CapturedFrameTap capture_tap_;
     DecodedFrameTap decode_tap_;
   };
+
   Clock* clock() { return Clock::GetRealTimeClock(); }
 
   std::unique_ptr<LogWriterFactoryInterface> GetLogWriterFactory(
       std::string name);
 
-  rtc::Thread* const signaling_thread_;
   const std::unique_ptr<LogWriterFactoryInterface> log_writer_manager_;
+  const std::unique_ptr<TimeController> time_controller_;
+  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

@@ -19,6 +19,7 @@
 #include "api/task_queue/default_task_queue_factory.h"
 #include "api/video_codecs/builtin_video_decoder_factory.h"
 #include "api/video_codecs/builtin_video_encoder_factory.h"
+#include "call/call.h"
 #include "media/engine/webrtc_media_engine.h"
 #include "modules/audio_device/include/test_audio_device.h"
 #include "p2p/client/basic_port_allocator.h"
@@ -112,22 +113,51 @@ class LambdaPeerConnectionObserver final : public PeerConnectionObserver {
  private:
   PeerScenarioClient::CallbackHandlers* handlers_;
 };
+
+// Used to supply a unique_ptr for an unowned TaskQueueFactory.
+class TaskQueueFactoryWrapper final : public TaskQueueFactory {
+ public:
+  explicit TaskQueueFactoryWrapper(TaskQueueFactory* inner_factory)
+      : inner_factory_(inner_factory) {}
+  std::unique_ptr<TaskQueueBase, TaskQueueDeleter> CreateTaskQueue(
+      absl::string_view name,
+      Priority priority) const override {
+    return inner_factory_->CreateTaskQueue(name, priority);
+  }
+
+ private:
+  TaskQueueFactory* const inner_factory_;
+};
+
+class TimeControllerBasedCallFactory : public CallFactoryInterface {
+ public:
+  explicit TimeControllerBasedCallFactory(TimeController* time_controller)
+      : time_controller_(time_controller) {}
+  Call* CreateCall(const Call::Config& config) override {
+    return Call::Create(config, time_controller_->GetClock(),
+                        time_controller_->CreateProcessThread("CallModules"),
+                        time_controller_->CreateProcessThread("Pacer"));
+  }
+
+ private:
+  TimeController* time_controller_;
+};
+
 }  // namespace
 
 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()),
       signaling_thread_(signaling_thread),
       log_writer_factory_(std::move(log_writer_factory)),
-      worker_thread_(rtc::Thread::Create()),
+      worker_thread_(time_controller->CreateThread("worker")),
       handlers_(config.handlers),
       observer_(new LambdaPeerConnectionObserver(&handlers_)) {
-  worker_thread_->SetName("worker", this);
-  worker_thread_->Start();
-
   handlers_.on_track.push_back(
       [this](rtc::scoped_refptr<RtpTransceiverInterface> transceiver) {
         auto track = transceiver->receiver()->track().get();
@@ -160,9 +190,10 @@ PeerScenarioClient::PeerScenarioClient(
   pcf_deps.network_thread = manager->network_thread();
   pcf_deps.signaling_thread = signaling_thread_;
   pcf_deps.worker_thread = worker_thread_.get();
-  pcf_deps.call_factory = CreateCallFactory();
+  pcf_deps.call_factory =
-  pcf_deps.task_queue_factory = CreateDefaultTaskQueueFactory();
+      std::make_unique<TimeControllerBasedCallFactory>(time_controller);
-  task_queue_factory_ = pcf_deps.task_queue_factory.get();
+  pcf_deps.task_queue_factory =
+      std::make_unique<TaskQueueFactoryWrapper>(task_queue_factory_);
   pcf_deps.event_log_factory =
       std::make_unique<RtcEventLogFactory>(task_queue_factory_);
 

test/peer_scenario/peer_scenario_client.h

@@ -20,6 +20,7 @@
 #include "absl/memory/memory.h"
 #include "api/peer_connection_interface.h"
 #include "api/test/network_emulation_manager.h"
+#include "api/test/time_controller.h"
 #include "pc/test/frame_generator_capturer_video_track_source.h"
 #include "test/logging/log_writer.h"
 
@@ -107,6 +108,7 @@ class PeerScenarioClient {
 
   PeerScenarioClient(
       NetworkEmulationManager* net,
+      TimeController* time_controller,
       rtc::Thread* signaling_thread,
       std::unique_ptr<LogWriterFactoryInterface> log_writer_factory,
       Config config);
@@ -147,7 +149,7 @@ class PeerScenarioClient {
 
  private:
   const std::map<int, EmulatedEndpoint*> endpoints_;
-  TaskQueueFactory* task_queue_factory_;
+  TaskQueueFactory* const task_queue_factory_;
   rtc::Thread* const signaling_thread_;
   const std::unique_ptr<LogWriterFactoryInterface> log_writer_factory_;
   const std::unique_ptr<rtc::Thread> worker_thread_;

test/time_controller/BUILD.gn

@@ -20,6 +20,8 @@ if (rtc_include_tests) {
       "simulated_process_thread.h",
       "simulated_task_queue.cc",
       "simulated_task_queue.h",
+      "simulated_thread.cc",
+      "simulated_thread.h",
       "simulated_time_controller.cc",
       "simulated_time_controller.h",
     ]
@@ -33,6 +35,7 @@ if (rtc_include_tests) {
       "../../modules:module_api",
       "../../modules/utility:utility",
       "../../rtc_base",
+      "../../rtc_base:checks",
       "../../rtc_base:rtc_base_tests_utils",
       "../../rtc_base:rtc_event",
       "../../rtc_base/synchronization:sequence_checker",

test/time_controller/external_time_controller.cc

@@ -21,6 +21,7 @@
 #include "api/units/timestamp.h"
 #include "modules/include/module.h"
 #include "modules/utility/include/process_thread.h"
+#include "rtc_base/checks.h"
 #include "rtc_base/synchronization/yield_policy.h"
 #include "test/time_controller/simulated_time_controller.h"
 
@@ -184,6 +185,18 @@ void ExternalTimeController::AdvanceTime(TimeDelta duration) {
   alarm_->Sleep(duration);
 }
 
+std::unique_ptr<rtc::Thread> ExternalTimeController::CreateThread(
+    const std::string& name,
+    std::unique_ptr<rtc::SocketServer> socket_server) {
+  RTC_NOTREACHED();
+  return nullptr;
+}
+
+rtc::Thread* ExternalTimeController::GetMainThread() {
+  RTC_NOTREACHED();
+  return nullptr;
+}
+
 std::unique_ptr<TaskQueueBase, TaskQueueDeleter>
 ExternalTimeController::CreateTaskQueue(
     absl::string_view name,

test/time_controller/external_time_controller.h

@@ -38,6 +38,10 @@ class ExternalTimeController : public TimeController, public TaskQueueFactory {
   std::unique_ptr<ProcessThread> CreateProcessThread(
       const char* thread_name) override;
   void AdvanceTime(TimeDelta duration) override;
+  std::unique_ptr<rtc::Thread> CreateThread(
+      const std::string& name,
+      std::unique_ptr<rtc::SocketServer> socket_server) override;
+  rtc::Thread* GetMainThread() override;
 
   // Implementation of TaskQueueFactory.
   std::unique_ptr<TaskQueueBase, TaskQueueDeleter> CreateTaskQueue(

test/time_controller/real_time_controller.cc

@@ -10,10 +10,10 @@
 #include "test/time_controller/real_time_controller.h"
 
 #include "api/task_queue/default_task_queue_factory.h"
+#include "rtc_base/null_socket_server.h"
 #include "system_wrappers/include/sleep.h"
 
 namespace webrtc {
-
 RealTimeController::RealTimeController()
     : task_queue_factory_(CreateDefaultTaskQueueFactory()) {}
 
@@ -30,8 +30,23 @@ std::unique_ptr<ProcessThread> RealTimeController::CreateProcessThread(
   return ProcessThread::Create(thread_name);
 }
 
+std::unique_ptr<rtc::Thread> RealTimeController::CreateThread(
+    const std::string& name,
+    std::unique_ptr<rtc::SocketServer> socket_server) {
+  if (!socket_server)
+    socket_server = std::make_unique<rtc::NullSocketServer>();
+  auto res = std::make_unique<rtc::Thread>(std::move(socket_server));
+  res->SetName(name, nullptr);
+  res->Start();
+  return res;
+}
+
+rtc::Thread* RealTimeController::GetMainThread() {
+  return rtc::Thread::Current();
+}
+
 void RealTimeController::AdvanceTime(TimeDelta duration) {
-  SleepMs(duration.ms());
+  GetMainThread()->ProcessMessages(duration.ms());
 }
 
 RealTimeController* GlobalRealTimeController() {

test/time_controller/real_time_controller.h

@@ -28,10 +28,14 @@ class RealTimeController : public TimeController {
   TaskQueueFactory* GetTaskQueueFactory() override;
   std::unique_ptr<ProcessThread> CreateProcessThread(
       const char* thread_name) override;
+  std::unique_ptr<rtc::Thread> CreateThread(
+      const std::string& name,
+      std::unique_ptr<rtc::SocketServer> socket_server) override;
+  rtc::Thread* GetMainThread() override;
   void AdvanceTime(TimeDelta duration) override;
 
  private:
-  std::unique_ptr<TaskQueueFactory> task_queue_factory_;
+  const std::unique_ptr<TaskQueueFactory> task_queue_factory_;
 };
 
 RealTimeController* GlobalRealTimeController();

test/time_controller/simulated_thread.cc

@@ -0,0 +1,135 @@
+/*
+ *  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 "test/time_controller/simulated_thread.h"
+
+#include <algorithm>
+#include <utility>
+
+#include "rtc_base/task_utils/to_queued_task.h"
+
+namespace webrtc {
+namespace {
+
+// A socket server that does nothing. It's different from NullSocketServer in
+// that it does allow sleep/wakeup. This avoids usage of an Event instance which
+// otherwise would cause issues with the simulated Yeild behavior.
+class DummySocketServer : public rtc::SocketServer {
+ public:
+  rtc::Socket* CreateSocket(int family, int type) override {
+    RTC_NOTREACHED();
+    return nullptr;
+  }
+  rtc::AsyncSocket* CreateAsyncSocket(int family, int type) override {
+    RTC_NOTREACHED();
+    return nullptr;
+  }
+  bool Wait(int cms, bool process_io) override {
+    RTC_CHECK_EQ(cms, 0);
+    return true;
+  }
+  void WakeUp() override {}
+};
+
+}  // namespace
+
+SimulatedThread::SimulatedThread(
+    sim_time_impl::SimulatedTimeControllerImpl* handler,
+    absl::string_view name,
+    std::unique_ptr<rtc::SocketServer> socket_server)
+    : rtc::Thread(socket_server ? std::move(socket_server)
+                                : std::make_unique<DummySocketServer>()),
+      handler_(handler),
+      name_(new char[name.size()]) {
+  std::copy_n(name.begin(), name.size(), name_);
+}
+
+SimulatedThread::~SimulatedThread() {
+  handler_->Unregister(this);
+  delete[] name_;
+}
+
+void SimulatedThread::RunReady(Timestamp at_time) {
+  CurrentThreadSetter set_current(this);
+  ProcessMessages(0);
+  int delay_ms = GetDelay();
+  rtc::CritScope lock(&lock_);
+  if (delay_ms == kForever) {
+    next_run_time_ = Timestamp::PlusInfinity();
+  } else {
+    next_run_time_ = at_time + TimeDelta::ms(delay_ms);
+  }
+}
+
+void SimulatedThread::Send(const rtc::Location& posted_from,
+                           rtc::MessageHandler* phandler,
+                           uint32_t id,
+                           rtc::MessageData* pdata) {
+  if (IsQuitting())
+    return;
+  rtc::Message msg;
+  msg.posted_from = posted_from;
+  msg.phandler = phandler;
+  msg.message_id = id;
+  msg.pdata = pdata;
+  if (IsCurrent()) {
+    msg.phandler->OnMessage(&msg);
+  } else {
+    CurrentThreadSetter set_current(this);
+    msg.phandler->OnMessage(&msg);
+  }
+}
+
+void SimulatedThread::Post(const rtc::Location& posted_from,
+                           rtc::MessageHandler* phandler,
+                           uint32_t id,
+                           rtc::MessageData* pdata,
+                           bool time_sensitive) {
+  rtc::Thread::Post(posted_from, phandler, id, pdata, time_sensitive);
+  rtc::CritScope lock(&lock_);
+  next_run_time_ = Timestamp::MinusInfinity();
+}
+
+void SimulatedThread::PostDelayed(const rtc::Location& posted_from,
+                                  int delay_ms,
+                                  rtc::MessageHandler* phandler,
+                                  uint32_t id,
+                                  rtc::MessageData* pdata) {
+  rtc::Thread::PostDelayed(posted_from, delay_ms, phandler, id, pdata);
+  rtc::CritScope lock(&lock_);
+  next_run_time_ =
+      std::min(next_run_time_, Timestamp::ms(rtc::TimeMillis() + delay_ms));
+}
+
+void SimulatedThread::PostAt(const rtc::Location& posted_from,
+                             int64_t target_time_ms,
+                             rtc::MessageHandler* phandler,
+                             uint32_t id,
+                             rtc::MessageData* pdata) {
+  rtc::Thread::PostAt(posted_from, target_time_ms, phandler, id, pdata);
+  rtc::CritScope lock(&lock_);
+  next_run_time_ = std::min(next_run_time_, Timestamp::ms(target_time_ms));
+}
+
+void SimulatedThread::Stop() {
+  Thread::Quit();
+}
+
+SimulatedMainThread::SimulatedMainThread(
+    sim_time_impl::SimulatedTimeControllerImpl* handler)
+    : SimulatedThread(handler, "main", nullptr), current_setter_(this) {}
+
+SimulatedMainThread::~SimulatedMainThread() {
+  // Removes pending tasks in case they keep shared pointer references to
+  // objects whose destructor expects to run before the Thread destructor.
+  Stop();
+  DoDestroy();
+}
+
+}  // namespace webrtc

test/time_controller/simulated_thread.h

@@ -0,0 +1,91 @@
+/*
+ *  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.
+ */
+#ifndef TEST_TIME_CONTROLLER_SIMULATED_THREAD_H_
+#define TEST_TIME_CONTROLLER_SIMULATED_THREAD_H_
+
+#include <memory>
+
+#include "test/time_controller/simulated_time_controller.h"
+
+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_;
+  };
+  SimulatedThread(sim_time_impl::SimulatedTimeControllerImpl* handler,
+                  absl::string_view name,
+                  std::unique_ptr<rtc::SocketServer> socket_server);
+  ~SimulatedThread() override;
+
+  void RunReady(Timestamp at_time) override;
+
+  Timestamp GetNextRunTime() const override {
+    rtc::CritScope lock(&lock_);
+    return next_run_time_;
+  }
+
+  TaskQueueBase* GetAsTaskQueue() override { return this; }
+
+  // Thread interface
+  void Send(const rtc::Location& posted_from,
+            rtc::MessageHandler* phandler,
+            uint32_t id,
+            rtc::MessageData* pdata) override;
+  void Post(const rtc::Location& posted_from,
+            rtc::MessageHandler* phandler,
+            uint32_t id,
+            rtc::MessageData* pdata,
+            bool time_sensitive) override;
+  void PostDelayed(const rtc::Location& posted_from,
+                   int delay_ms,
+                   rtc::MessageHandler* phandler,
+                   uint32_t id,
+                   rtc::MessageData* pdata) override;
+  void PostAt(const rtc::Location& posted_from,
+              int64_t target_time_ms,
+              rtc::MessageHandler* phandler,
+              uint32_t id,
+              rtc::MessageData* pdata) override;
+
+  void Stop() override;
+
+ private:
+  sim_time_impl::SimulatedTimeControllerImpl* const handler_;
+  // Using char* to be debugger friendly.
+  char* name_;
+  rtc::CriticalSection lock_;
+  Timestamp next_run_time_ RTC_GUARDED_BY(lock_) = Timestamp::PlusInfinity();
+};
+
+class SimulatedMainThread : public SimulatedThread {
+ public:
+  explicit SimulatedMainThread(
+      sim_time_impl::SimulatedTimeControllerImpl* handler);
+  ~SimulatedMainThread();
+
+ private:
+  CurrentThreadSetter current_setter_;
+};
+}  // namespace webrtc
+#endif  // TEST_TIME_CONTROLLER_SIMULATED_THREAD_H_

test/time_controller/simulated_time_controller.cc

@@ -20,6 +20,7 @@
 #include "absl/strings/string_view.h"
 #include "test/time_controller/simulated_process_thread.h"
 #include "test/time_controller/simulated_task_queue.h"
+#include "test/time_controller/simulated_thread.h"
 
 namespace webrtc {
 namespace {
@@ -49,8 +50,8 @@ SimulatedTimeControllerImpl::CreateTaskQueue(
   auto mutable_this = const_cast<SimulatedTimeControllerImpl*>(this);
   auto task_queue = std::unique_ptr<SimulatedTaskQueue, TaskQueueDeleter>(
       new SimulatedTaskQueue(mutable_this, name));
-  rtc::CritScope lock(&mutable_this->lock_);
+  ;
-  mutable_this->runners_.push_back(task_queue.get());
+  mutable_this->Register(task_queue.get());
   return task_queue;
 }
 
@@ -59,10 +60,19 @@ std::unique_ptr<ProcessThread> SimulatedTimeControllerImpl::CreateProcessThread(
   rtc::CritScope lock(&lock_);
   auto process_thread =
       std::make_unique<SimulatedProcessThread>(this, thread_name);
-  runners_.push_back(process_thread.get());
+  Register(process_thread.get());
   return process_thread;
 }
 
+std::unique_ptr<rtc::Thread> SimulatedTimeControllerImpl::CreateThread(
+    const std::string& name,
+    std::unique_ptr<rtc::SocketServer> socket_server) {
+  auto thread =
+      std::make_unique<SimulatedThread>(this, name, std::move(socket_server));
+  Register(thread.get());
+  return thread;
+}
+
 void SimulatedTimeControllerImpl::YieldExecution() {
   if (rtc::CurrentThreadId() == thread_id_) {
     TaskQueueBase* yielding_from = TaskQueueBase::Current();
@@ -83,6 +93,9 @@ void SimulatedTimeControllerImpl::YieldExecution() {
 }
 
 void SimulatedTimeControllerImpl::RunReadyRunners() {
+  // Using a dummy thread rather than nullptr to avoid implicit thread creation
+  // by Thread::Current().
+  SimulatedThread::CurrentThreadSetter set_current(dummy_thread_.get());
   rtc::CritScope lock(&lock_);
   RTC_DCHECK_EQ(rtc::CurrentThreadId(), thread_id_);
   Timestamp current_time = CurrentTime();
@@ -136,6 +149,11 @@ void SimulatedTimeControllerImpl::AdvanceTime(Timestamp target_time) {
   current_time_ = target_time;
 }
 
+void SimulatedTimeControllerImpl::Register(SimulatedSequenceRunner* runner) {
+  rtc::CritScope lock(&lock_);
+  runners_.push_back(runner);
+}
+
 void SimulatedTimeControllerImpl::Unregister(SimulatedSequenceRunner* runner) {
   rtc::CritScope lock(&lock_);
   bool removed = RemoveByValue(&runners_, runner);
@@ -148,6 +166,9 @@ GlobalSimulatedTimeController::GlobalSimulatedTimeController(
     Timestamp start_time)
     : sim_clock_(start_time.us()), impl_(start_time), yield_policy_(&impl_) {
   global_clock_.SetTime(start_time);
+  auto main_thread = std::make_unique<SimulatedMainThread>(&impl_);
+  impl_.Register(main_thread.get());
+  main_thread_ = std::move(main_thread);
 }
 
 GlobalSimulatedTimeController::~GlobalSimulatedTimeController() = default;
@@ -165,6 +186,16 @@ GlobalSimulatedTimeController::CreateProcessThread(const char* thread_name) {
   return impl_.CreateProcessThread(thread_name);
 }
 
+std::unique_ptr<rtc::Thread> GlobalSimulatedTimeController::CreateThread(
+    const std::string& name,
+    std::unique_ptr<rtc::SocketServer> socket_server) {
+  return impl_.CreateThread(name, std::move(socket_server));
+}
+
+rtc::Thread* GlobalSimulatedTimeController::GetMainThread() {
+  return main_thread_.get();
+}
+
 void GlobalSimulatedTimeController::AdvanceTime(TimeDelta duration) {
   rtc::ScopedYieldPolicy yield_policy(&impl_);
   Timestamp current_time = impl_.CurrentTime();

test/time_controller/simulated_time_controller.h

@@ -60,6 +60,10 @@ class SimulatedTimeControllerImpl : public TaskQueueFactory,
   void YieldExecution() override;
   // Create process thread with the name |thread_name|.
   std::unique_ptr<ProcessThread> CreateProcessThread(const char* thread_name);
+  // Create thread using provided |socket_server|.
+  std::unique_ptr<rtc::Thread> CreateThread(
+      const std::string& name,
+      std::unique_ptr<rtc::SocketServer> socket_server);
 
   // Runs all runners in |runners_| that has tasks or modules ready for
   // execution.
@@ -70,11 +74,14 @@ class SimulatedTimeControllerImpl : public TaskQueueFactory,
   Timestamp NextRunTime() const;
   // Set |current_time_| to |target_time|.
   void AdvanceTime(Timestamp target_time);
+  // Adds |runner| to |runners_|.
+  void Register(SimulatedSequenceRunner* runner);
   // Removes |runner| from |runners_|.
   void Unregister(SimulatedSequenceRunner* runner);
 
  private:
   const rtc::PlatformThreadId thread_id_;
+  const std::unique_ptr<rtc::Thread> dummy_thread_ = rtc::Thread::Create();
   rtc::CriticalSection time_lock_;
   Timestamp current_time_ RTC_GUARDED_BY(time_lock_);
   rtc::CriticalSection lock_;
@@ -119,6 +126,10 @@ class GlobalSimulatedTimeController : public TimeController {
   TaskQueueFactory* GetTaskQueueFactory() override;
   std::unique_ptr<ProcessThread> CreateProcessThread(
       const char* thread_name) override;
+  std::unique_ptr<rtc::Thread> CreateThread(
+      const std::string& name,
+      std::unique_ptr<rtc::SocketServer> socket_server) override;
+  rtc::Thread* GetMainThread() override;
 
   void AdvanceTime(TimeDelta duration) override;
 
@@ -128,6 +139,7 @@ class GlobalSimulatedTimeController : public TimeController {
   SimulatedClock sim_clock_;
   sim_time_impl::SimulatedTimeControllerImpl impl_;
   rtc::ScopedYieldPolicy yield_policy_;
+  std::unique_ptr<rtc::Thread> main_thread_;
 };
 }  // namespace webrtc