Delete Call dependency on ProcessThread as unused

Last usage or ProcessThread was removed in
https://webrtc-review.googlesource.com/c/src/+/265921

Bug: webrtc:7219
Change-Id: Ia46d9e2530cd0dbf56a5c0ca6e1bf0936fd62672
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/266363
Reviewed-by: Erik Språng <sprang@webrtc.org>
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#37287}

10 files changed, 22 insertions, 258 deletions

diff --git a/api/test/create_time_controller.cc b/api/test/create_time_controller.cc
index d4ec9876e2..d198f2b0fe 100644
--- a/api/test/create_time_controller.cc
+++ b/api/test/create_time_controller.cc
@@ -37,22 +37,15 @@ std::unique_ptr<CallFactoryInterface> CreateTimeControllerBasedCallFactory(
     explicit TimeControllerBasedCallFactory(TimeController* time_controller)
         : time_controller_(time_controller) {}
     Call* CreateCall(const Call::Config& config) override {
-      if (!module_thread_) {
-        module_thread_ = SharedModuleThread::Create(
-            time_controller_->CreateProcessThread("CallModules"),
-            [this]() { module_thread_ = nullptr; });
-      }
-
       RtpTransportConfig transportConfig = config.ExtractTransportConfig();
 
-      return Call::Create(config, time_controller_->GetClock(), module_thread_,
+      return Call::Create(config, time_controller_->GetClock(),
                           config.rtp_transport_controller_send_factory->Create(
                               transportConfig, time_controller_->GetClock()));
     }
 
    private:
     TimeController* time_controller_;
-    rtc::scoped_refptr<SharedModuleThread> module_thread_;
   };
   return std::make_unique<TimeControllerBasedCallFactory>(time_controller);
 }
diff --git a/call/BUILD.gn b/call/BUILD.gn
index 7e8eb6549d..c212bb09ff 100644
--- a/call/BUILD.gn
+++ b/call/BUILD.gn
@@ -67,7 +67,6 @@ rtc_library("call_interfaces") {
     "../modules/audio_processing:api",
     "../modules/audio_processing:audio_processing_statistics",
     "../modules/rtp_rtcp:rtp_rtcp_format",
-    "../modules/utility",
     "../rtc_base",
     "../rtc_base:audio_format_to_string",
     "../rtc_base:checks",
@@ -121,7 +120,6 @@ rtc_library("rtp_interfaces") {
     "../api/units:timestamp",
     "../common_video:frame_counts",
     "../modules/rtp_rtcp:rtp_rtcp_format",
-    "../modules/utility",
     "../rtc_base:checks",
     "../rtc_base:rtc_task_queue",
     "../rtc_base:stringutils",
@@ -203,7 +201,6 @@ rtc_library("rtp_sender") {
     "../modules/rtp_rtcp",
     "../modules/rtp_rtcp:rtp_rtcp_format",
     "../modules/rtp_rtcp:rtp_video_header",
-    "../modules/utility",
     "../modules/video_coding:chain_diff_calculator",
     "../modules/video_coding:codec_globals_headers",
     "../modules/video_coding:frame_dependencies_calculator",
@@ -316,7 +313,6 @@ rtc_library("call") {
     "../modules/pacing",
     "../modules/rtp_rtcp",
     "../modules/rtp_rtcp:rtp_rtcp_format",
-    "../modules/utility",
     "../modules/video_coding",
     "../rtc_base:checks",
     "../rtc_base:copy_on_write_buffer",
@@ -433,7 +429,6 @@ rtc_library("fake_network") {
     "../api:sequence_checker",
     "../api:simulated_network_api",
     "../api:transport_api",
-    "../modules/utility",
     "../rtc_base:checks",
     "../rtc_base:logging",
     "../rtc_base:macromagic",
@@ -484,7 +479,6 @@ if (rtc_include_tests) {
         "../api/video:video_frame",
         "../api/video:video_rtp_headers",
         "../audio",
-        "../modules:module_api",
         "../modules/audio_device:mock_audio_device",
         "../modules/audio_mixer",
         "../modules/audio_mixer:audio_mixer_impl",
@@ -494,7 +488,6 @@ if (rtc_include_tests) {
         "../modules/rtp_rtcp",
         "../modules/rtp_rtcp:mock_rtp_rtcp",
         "../modules/rtp_rtcp:rtp_rtcp_format",
-        "../modules/utility:mock_process_thread",
         "../modules/video_coding",
         "../modules/video_coding:codec_globals_headers",
         "../modules/video_coding:video_codec_interface",
diff --git a/call/call.cc b/call/call.cc
index b86cc10ac2..39772a2bad 100644
--- a/call/call.cc
+++ b/call/call.cc
@@ -50,7 +50,6 @@
 #include "modules/rtp_rtcp/source/byte_io.h"
 #include "modules/rtp_rtcp/source/rtp_packet_received.h"
 #include "modules/rtp_rtcp/source/rtp_util.h"
-#include "modules/utility/include/process_thread.h"
 #include "modules/video_coding/fec_controller_default.h"
 #include "rtc_base/checks.h"
 #include "rtc_base/location.h"
@@ -504,32 +503,14 @@ std::string Call::Stats::ToString(int64_t time_ms) const {
 }
 
 Call* Call::Create(const Call::Config& config) {
-  rtc::scoped_refptr<SharedModuleThread> call_thread =
-      SharedModuleThread::Create(ProcessThread::Create("ModuleProcessThread"),
-                                 nullptr);
-  return Create(config, Clock::GetRealTimeClock(), std::move(call_thread),
-                ProcessThread::Create("PacerThread"));
+  Clock* clock = Clock::GetRealTimeClock();
+  return Create(config, clock,
+                RtpTransportControllerSendFactory().Create(
+                    config.ExtractTransportConfig(), clock));
 }
 
 Call* Call::Create(const Call::Config& config,
                    Clock* clock,
-                   rtc::scoped_refptr<SharedModuleThread> /*call_thread*/,
-                   std::unique_ptr<ProcessThread> pacer_thread) {
-  RTC_DCHECK(config.task_queue_factory);
-
-  RtpTransportControllerSendFactory transport_controller_factory_;
-
-  RtpTransportConfig transportConfig = config.ExtractTransportConfig();
-
-  return new internal::Call(
-      clock, config,
-      transport_controller_factory_.Create(transportConfig, clock),
-      config.task_queue_factory);
-}
-
-Call* Call::Create(const Call::Config& config,
-                   Clock* clock,
-                   rtc::scoped_refptr<SharedModuleThread> /*call_thread*/,
                    std::unique_ptr<RtpTransportControllerSendInterface>
                        transportControllerSend) {
   RTC_DCHECK(config.task_queue_factory);
@@ -537,99 +518,6 @@ Call* Call::Create(const Call::Config& config,
                             config.task_queue_factory);
 }
 
-class SharedModuleThread::Impl {
- public:
-  Impl(std::unique_ptr<ProcessThread> process_thread,
-       std::function<void()> on_one_ref_remaining)
-      : module_thread_(std::move(process_thread)),
-        on_one_ref_remaining_(std::move(on_one_ref_remaining)) {}
-
-  void EnsureStarted() {
-    RTC_DCHECK_RUN_ON(&sequence_checker_);
-    if (started_)
-      return;
-    started_ = true;
-    module_thread_->Start();
-  }
-
-  ProcessThread* process_thread() {
-    RTC_DCHECK_RUN_ON(&sequence_checker_);
-    return module_thread_.get();
-  }
-
-  void AddRef() const {
-    RTC_DCHECK_RUN_ON(&sequence_checker_);
-    ++ref_count_;
-  }
-
-  rtc::RefCountReleaseStatus Release() const {
-    RTC_DCHECK_RUN_ON(&sequence_checker_);
-    --ref_count_;
-
-    if (ref_count_ == 0) {
-      module_thread_->Stop();
-      return rtc::RefCountReleaseStatus::kDroppedLastRef;
-    }
-
-    if (ref_count_ == 1 && on_one_ref_remaining_) {
-      auto moved_fn = std::move(on_one_ref_remaining_);
-      // NOTE: after this function returns, chances are that `this` has been
-      // deleted - do not touch any member variables.
-      // If the owner of the last reference implements a lambda that releases
-      // that last reference inside of the callback (which is legal according
-      // to this implementation), we will recursively enter Release() above,
-      // call Stop() and release the last reference.
-      moved_fn();
-    }
-
-    return rtc::RefCountReleaseStatus::kOtherRefsRemained;
-  }
-
- private:
-  RTC_NO_UNIQUE_ADDRESS SequenceChecker sequence_checker_;
-  mutable int ref_count_ RTC_GUARDED_BY(sequence_checker_) = 0;
-  std::unique_ptr<ProcessThread> const module_thread_;
-  std::function<void()> const on_one_ref_remaining_;
-  bool started_ = false;
-};
-
-SharedModuleThread::SharedModuleThread(
-    std::unique_ptr<ProcessThread> process_thread,
-    std::function<void()> on_one_ref_remaining)
-    : impl_(std::make_unique<Impl>(std::move(process_thread),
-                                   std::move(on_one_ref_remaining))) {}
-
-SharedModuleThread::~SharedModuleThread() = default;
-
-// static
-
-rtc::scoped_refptr<SharedModuleThread> SharedModuleThread::Create(
-    std::unique_ptr<ProcessThread> process_thread,
-    std::function<void()> on_one_ref_remaining) {
-  // Using `new` to access a non-public constructor.
-  return rtc::scoped_refptr<SharedModuleThread>(new SharedModuleThread(
-      std::move(process_thread), std::move(on_one_ref_remaining)));
-}
-
-void SharedModuleThread::EnsureStarted() {
-  impl_->EnsureStarted();
-}
-
-ProcessThread* SharedModuleThread::process_thread() {
-  return impl_->process_thread();
-}
-
-void SharedModuleThread::AddRef() const {
-  impl_->AddRef();
-}
-
-rtc::RefCountReleaseStatus SharedModuleThread::Release() const {
-  auto ret = impl_->Release();
-  if (ret == rtc::RefCountReleaseStatus::kDroppedLastRef)
-    delete this;
-  return ret;
-}
-
 // This method here to avoid subclasses has to implement this method.
 // Call perf test will use Internal::Call::CreateVideoSendStream() to inject
 // FecController.
diff --git a/call/call.h b/call/call.h
index a4d5974898..366978392e 100644
--- a/call/call.h
+++ b/call/call.h
@@ -27,7 +27,6 @@
 #include "call/rtp_transport_controller_send_interface.h"
 #include "call/video_receive_stream.h"
 #include "call/video_send_stream.h"
-#include "modules/utility/include/process_thread.h"
 #include "rtc_base/copy_on_write_buffer.h"
 #include "rtc_base/network/sent_packet.h"
 #include "rtc_base/network_route.h"
@@ -35,36 +34,6 @@
 
 namespace webrtc {
 
-// A restricted way to share the module process thread across multiple instances
-// of Call that are constructed on the same worker thread (which is what the
-// peer connection factory guarantees).
-// SharedModuleThread supports a callback that is issued when only one reference
-// remains, which is used to indicate to the original owner that the thread may
-// be discarded.
-class SharedModuleThread final {
- public:
-  // Allows injection of an externally created process thread.
-  static rtc::scoped_refptr<SharedModuleThread> Create(
-      std::unique_ptr<ProcessThread> process_thread,
-      std::function<void()> on_one_ref_remaining);
-
-  void EnsureStarted();
-
-  ProcessThread* process_thread();
-
- private:
-  friend class rtc::scoped_refptr<SharedModuleThread>;
-  SharedModuleThread(std::unique_ptr<ProcessThread> process_thread,
-                     std::function<void()> on_one_ref_remaining);
-  ~SharedModuleThread();
-
-  void AddRef() const;
-  rtc::RefCountReleaseStatus Release() const;
-
-  class Impl;
-  mutable std::unique_ptr<Impl> impl_;
-};
-
 // A Call represents a two-way connection carrying zero or more outgoing
 // and incoming media streams, transported over one or more RTP transports.
 
@@ -92,11 +61,6 @@ class Call {
   static Call* Create(const Call::Config& config);
   static Call* Create(const Call::Config& config,
                       Clock* clock,
-                      rtc::scoped_refptr<SharedModuleThread> call_thread,
-                      std::unique_ptr<ProcessThread> pacer_thread);
-  static Call* Create(const Call::Config& config,
-                      Clock* clock,
-                      rtc::scoped_refptr<SharedModuleThread> call_thread,
                       std::unique_ptr<RtpTransportControllerSendInterface>
                           transportControllerSend);
 
diff --git a/call/call_factory.cc b/call/call_factory.cc
index 7d3581d2d7..9fe4c2999e 100644
--- a/call/call_factory.cc
+++ b/call/call_factory.cc
@@ -17,6 +17,7 @@
 #include <utility>
 #include <vector>
 
+#include "absl/memory/memory.h"
 #include "absl/types/optional.h"
 #include "api/test/simulated_network.h"
 #include "api/units/time_delta.h"
@@ -155,29 +156,18 @@ Call* CallFactory::CreateCall(const Call::Config& config) {
 
   RtpTransportConfig transportConfig = config.ExtractTransportConfig();
 
+  Call* call =
+      Call::Create(config, Clock::GetRealTimeClock(),
+                   config.rtp_transport_controller_send_factory->Create(
+                       transportConfig, Clock::GetRealTimeClock()));
+
   if (!send_degradation_configs.empty() ||
       !receive_degradation_configs.empty()) {
-    return new DegradedCall(
-        std::unique_ptr<Call>(Call::Create(
-            config, Clock::GetRealTimeClock(),
-            SharedModuleThread::Create(
-                ProcessThread::Create("ModuleProcessThread"), nullptr),
-            config.rtp_transport_controller_send_factory->Create(
-                transportConfig, Clock::GetRealTimeClock()))),
-        send_degradation_configs, receive_degradation_configs);
-  }
-
-  if (!module_thread_) {
-    module_thread_ = SharedModuleThread::Create(
-        ProcessThread::Create("SharedModThread"), [this]() {
-          RTC_DCHECK_RUN_ON(&call_thread_);
-          module_thread_ = nullptr;
-        });
+    return new DegradedCall(absl::WrapUnique(call), send_degradation_configs,
+                            receive_degradation_configs);
   }
 
-  return Call::Create(config, Clock::GetRealTimeClock(), module_thread_,
-                      config.rtp_transport_controller_send_factory->Create(
-                          transportConfig, Clock::GetRealTimeClock()));
+  return call;
 }
 
 std::unique_ptr<CallFactoryInterface> CreateCallFactory() {
diff --git a/call/call_factory.h b/call/call_factory.h
index 469bec39e1..9feed7bbb6 100644
--- a/call/call_factory.h
+++ b/call/call_factory.h
@@ -29,8 +29,6 @@ class CallFactory : public CallFactoryInterface {
   Call* CreateCall(const CallConfig& config) override;
 
   RTC_NO_UNIQUE_ADDRESS SequenceChecker call_thread_;
-  rtc::scoped_refptr<SharedModuleThread> module_thread_
-      RTC_GUARDED_BY(call_thread_);
 };
 
 }  // namespace webrtc
diff --git a/call/call_unittest.cc b/call/call_unittest.cc
index 5d30f45dc5..5db3f5902b 100644
--- a/call/call_unittest.cc
+++ b/call/call_unittest.cc
@@ -31,7 +31,6 @@
 #include "call/audio_state.h"
 #include "modules/audio_device/include/mock_audio_device.h"
 #include "modules/audio_processing/include/mock_audio_processing.h"
-#include "modules/include/module.h"
 #include "modules/rtp_rtcp/source/rtp_rtcp_interface.h"
 #include "test/fake_encoder.h"
 #include "test/gtest.h"
@@ -476,59 +475,4 @@ TEST(CallTest, AddAdaptationResourceBeforeCreatingVideoSendStream) {
   call->DestroyVideoSendStream(stream2);
 }
 
-TEST(CallTest, SharedModuleThread) {
-  class SharedModuleThreadUser : public Module {
-   public:
-    SharedModuleThreadUser(ProcessThread* expected_thread,
-                           rtc::scoped_refptr<SharedModuleThread> thread)
-        : expected_thread_(expected_thread), thread_(std::move(thread)) {
-      thread_->EnsureStarted();
-      thread_->process_thread()->RegisterModule(this, RTC_FROM_HERE);
-    }
-
-    ~SharedModuleThreadUser() override {
-      thread_->process_thread()->DeRegisterModule(this);
-      EXPECT_TRUE(thread_was_checked_);
-    }
-
-   private:
-    int64_t TimeUntilNextProcess() override { return 1000; }
-    void Process() override {}
-    void ProcessThreadAttached(ProcessThread* process_thread) override {
-      if (!process_thread) {
-        // Being detached.
-        return;
-      }
-      EXPECT_EQ(process_thread, expected_thread_);
-      thread_was_checked_ = true;
-    }
-
-    bool thread_was_checked_ = false;
-    ProcessThread* const expected_thread_;
-    rtc::scoped_refptr<SharedModuleThread> thread_;
-  };
-
-  // Create our test instance and pass a lambda to it that gets executed when
-  // the reference count goes back to 1 - meaning `shared` again is the only
-  // reference, which means we can free the variable and deallocate the thread.
-  rtc::scoped_refptr<SharedModuleThread> shared;
-  shared =
-      SharedModuleThread::Create(ProcessThread::Create("MySharedProcessThread"),
-                                 [&shared]() { shared = nullptr; });
-  ProcessThread* process_thread = shared->process_thread();
-
-  ASSERT_TRUE(shared.get());
-
-  {
-    // Create a couple of users of the thread.
-    // These instances are in a separate scope to trigger the callback to our
-    // lambda, which will run when these go out of scope.
-    SharedModuleThreadUser user1(process_thread, shared);
-    SharedModuleThreadUser user2(process_thread, shared);
-  }
-
-  // The thread should now have been stopped and freed.
-  EXPECT_FALSE(shared);
-}
-
 }  // namespace webrtc
diff --git a/call/rtp_transport_controller_send_factory_interface.h b/call/rtp_transport_controller_send_factory_interface.h
index 071af9b118..0f4c36c221 100644
--- a/call/rtp_transport_controller_send_factory_interface.h
+++ b/call/rtp_transport_controller_send_factory_interface.h
@@ -14,7 +14,6 @@
 
 #include "call/rtp_transport_config.h"
 #include "call/rtp_transport_controller_send_interface.h"
-#include "modules/utility/include/process_thread.h"
 
 namespace webrtc {
 // A factory used for dependency injection on the send side of the transport
diff --git a/test/scenario/call_client.cc b/test/scenario/call_client.cc
index 3c306675a3..4ae0a640fa 100644
--- a/test/scenario/call_client.cc
+++ b/test/scenario/call_client.cc
@@ -16,6 +16,8 @@
 #include "api/rtc_event_log/rtc_event_log.h"
 #include "api/rtc_event_log/rtc_event_log_factory.h"
 #include "api/transport/network_types.h"
+#include "call/call.h"
+#include "call/rtp_transport_controller_send_factory.h"
 #include "modules/audio_mixer/audio_mixer_impl.h"
 #include "modules/rtp_rtcp/source/rtp_util.h"
 
@@ -57,8 +59,7 @@ Call* CreateCall(TimeController* time_controller,
                  RtcEventLog* event_log,
                  CallClientConfig config,
                  LoggingNetworkControllerFactory* network_controller_factory,
-                 rtc::scoped_refptr<AudioState> audio_state,
-                 rtc::scoped_refptr<SharedModuleThread> call_thread) {
+                 rtc::scoped_refptr<AudioState> audio_state) {
   CallConfig call_config(event_log);
   call_config.bitrate_config.max_bitrate_bps =
       config.transport.rates.max_rate.bps_or(-1);
@@ -70,9 +71,10 @@ Call* CreateCall(TimeController* time_controller,
   call_config.network_controller_factory = network_controller_factory;
   call_config.audio_state = audio_state;
   call_config.trials = config.field_trials;
-  return Call::Create(call_config, time_controller->GetClock(),
-                      std::move(call_thread),
-                      time_controller->CreateProcessThread("Pacer"));
+  Clock* clock = time_controller->GetClock();
+  return Call::Create(call_config, clock,
+                      RtpTransportControllerSendFactory().Create(
+                          call_config.ExtractTransportConfig(), clock));
 }
 
 std::unique_ptr<RtcEventLog> CreateEventLog(
@@ -222,14 +224,10 @@ CallClient::CallClient(
     event_log_ = CreateEventLog(time_controller_->GetTaskQueueFactory(),
                                 log_writer_factory_.get());
     fake_audio_setup_ = InitAudio(time_controller_);
-    RTC_DCHECK(!module_thread_);
-    module_thread_ = SharedModuleThread::Create(
-        time_controller_->CreateProcessThread("CallThread"),
-        [this]() { module_thread_ = nullptr; });
 
     call_.reset(CreateCall(time_controller_, event_log_.get(), config,
                            &network_controller_factory_,
-                           fake_audio_setup_.audio_state, module_thread_));
+                           fake_audio_setup_.audio_state));
     transport_ = std::make_unique<NetworkNodeTransport>(clock_, call_.get());
   });
 }
@@ -237,7 +235,6 @@ CallClient::CallClient(
 CallClient::~CallClient() {
   SendTask([&] {
     call_.reset();
-    RTC_DCHECK(!module_thread_);  // Should be set to null in the lambda above.
     fake_audio_setup_ = {};
     rtc::Event done;
     event_log_->StopLogging([&done] { done.Set(); });
diff --git a/test/scenario/call_client.h b/test/scenario/call_client.h
index 489844039b..18aa67f77d 100644
--- a/test/scenario/call_client.h
+++ b/test/scenario/call_client.h
@@ -166,8 +166,6 @@ class CallClient : public EmulatedNetworkReceiverInterface {
   // Defined last so it's destroyed first.
   TaskQueueForTest task_queue_;
 
-  rtc::scoped_refptr<SharedModuleThread> module_thread_;
-
   const FieldTrialBasedConfig field_trials_;
 };