Only process cross traffic simulation if added.

This avoids extra processing overhead when there's no cross traffic
simulation active. To allow the use of SendTask, GlobalTimeController
is adjusted so it always overrides yield behavior.

Also adding sequence checkers to protect against races on
read access.

Bug: webrtc:10365
Change-Id: I55c6ceb22f36ec19a4fca48cff500905192d1a16
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/133167
Reviewed-by: Niels Moller <nisse@webrtc.org>
Reviewed-by: Artem Titov <titovartem@webrtc.org>
Commit-Queue: Sebastian Jansson <srte@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27658}

test/scenario/network/BUILD.gn

@@ -46,6 +46,7 @@ rtc_source_set("emulated_network") {
     "../../../rtc_base:rtc_task_queue",
     "../../../rtc_base:safe_minmax",
     "../../../rtc_base:task_queue_for_test",
+    "../../../rtc_base/synchronization:sequence_checker",
     "../../../rtc_base/task_utils:repeating_task",
     "../../../rtc_base/third_party/sigslot",
     "../../../system_wrappers",

test/scenario/network/cross_traffic.cc

@@ -25,10 +25,13 @@ RandomWalkCrossTraffic::RandomWalkCrossTraffic(RandomWalkConfig config,
                                                TrafficRoute* traffic_route)
     : config_(config),
       traffic_route_(traffic_route),
-      random_(config_.random_seed) {}
+      random_(config_.random_seed) {
+  sequence_checker_.Detach();
+}
 RandomWalkCrossTraffic::~RandomWalkCrossTraffic() = default;
 
 void RandomWalkCrossTraffic::Process(Timestamp at_time) {
+  RTC_DCHECK_RUN_ON(&sequence_checker_);
   if (last_process_time_.IsMinusInfinity()) {
     last_process_time_ = at_time;
   }
@@ -52,6 +55,7 @@ void RandomWalkCrossTraffic::Process(Timestamp at_time) {
 }
 
 DataRate RandomWalkCrossTraffic::TrafficRate() const {
+  RTC_DCHECK_RUN_ON(&sequence_checker_);
   return config_.peak_rate * intensity_;
 }
 
@@ -66,10 +70,13 @@ ColumnPrinter RandomWalkCrossTraffic::StatsPrinter() {
 
 PulsedPeaksCrossTraffic::PulsedPeaksCrossTraffic(PulsedPeaksConfig config,
                                                  TrafficRoute* traffic_route)
-    : config_(config), traffic_route_(traffic_route) {}
+    : config_(config), traffic_route_(traffic_route) {
+  sequence_checker_.Detach();
+}
 PulsedPeaksCrossTraffic::~PulsedPeaksCrossTraffic() = default;
 
 void PulsedPeaksCrossTraffic::Process(Timestamp at_time) {
+  RTC_DCHECK_RUN_ON(&sequence_checker_);
   TimeDelta time_since_toggle = at_time - last_update_time_;
   if (time_since_toggle.IsInfinite() ||
       (sending_ && time_since_toggle >= config_.send_duration)) {
@@ -94,6 +101,7 @@ void PulsedPeaksCrossTraffic::Process(Timestamp at_time) {
 }
 
 DataRate PulsedPeaksCrossTraffic::TrafficRate() const {
+  RTC_DCHECK_RUN_ON(&sequence_checker_);
   return sending_ ? config_.peak_rate : DataRate::Zero();
 }
 

test/scenario/network/cross_traffic.h

@@ -18,6 +18,7 @@
 #include "api/units/time_delta.h"
 #include "api/units/timestamp.h"
 #include "rtc_base/random.h"
+#include "rtc_base/synchronization/sequence_checker.h"
 #include "test/scenario/column_printer.h"
 #include "test/scenario/network/traffic_route.h"
 
@@ -44,15 +45,19 @@ class RandomWalkCrossTraffic {
   ColumnPrinter StatsPrinter();
 
  private:
-  RandomWalkConfig config_;
-  TrafficRoute* const traffic_route_;
-  webrtc::Random random_;
+  SequenceChecker sequence_checker_;
+  const RandomWalkConfig config_;
+  TrafficRoute* const traffic_route_ RTC_PT_GUARDED_BY(sequence_checker_);
+  webrtc::Random random_ RTC_GUARDED_BY(sequence_checker_);
 
-  Timestamp last_process_time_ = Timestamp::MinusInfinity();
-  Timestamp last_update_time_ = Timestamp::MinusInfinity();
-  Timestamp last_send_time_ = Timestamp::MinusInfinity();
-  double intensity_ = 0;
-  DataSize pending_size_ = DataSize::Zero();
+  Timestamp last_process_time_ RTC_GUARDED_BY(sequence_checker_) =
+      Timestamp::MinusInfinity();
+  Timestamp last_update_time_ RTC_GUARDED_BY(sequence_checker_) =
+      Timestamp::MinusInfinity();
+  Timestamp last_send_time_ RTC_GUARDED_BY(sequence_checker_) =
+      Timestamp::MinusInfinity();
+  double intensity_ RTC_GUARDED_BY(sequence_checker_) = 0;
+  DataSize pending_size_ RTC_GUARDED_BY(sequence_checker_) = DataSize::Zero();
 };
 
 struct PulsedPeaksConfig {
@@ -74,12 +79,15 @@ class PulsedPeaksCrossTraffic {
   ColumnPrinter StatsPrinter();
 
  private:
-  PulsedPeaksConfig config_;
-  TrafficRoute* const traffic_route_;
+  SequenceChecker sequence_checker_;
+  const PulsedPeaksConfig config_;
+  TrafficRoute* const traffic_route_ RTC_PT_GUARDED_BY(sequence_checker_);
 
-  Timestamp last_update_time_ = Timestamp::MinusInfinity();
-  Timestamp last_send_time_ = Timestamp::MinusInfinity();
-  bool sending_ = false;
+  Timestamp last_update_time_ RTC_GUARDED_BY(sequence_checker_) =
+      Timestamp::MinusInfinity();
+  Timestamp last_send_time_ RTC_GUARDED_BY(sequence_checker_) =
+      Timestamp::MinusInfinity();
+  bool sending_ RTC_GUARDED_BY(sequence_checker_) = false;
 };
 
 }  // namespace test

test/scenario/network/network_emulation_manager.cc

@@ -23,12 +23,33 @@ namespace webrtc {
 namespace test {
 namespace {
 
-constexpr int64_t kPacketProcessingIntervalMs = 1;
 // uint32_t representation of 192.168.0.0 address
 constexpr uint32_t kMinIPv4Address = 0xC0A80000;
 // uint32_t representation of 192.168.255.255 address
 constexpr uint32_t kMaxIPv4Address = 0xC0A8FFFF;
 
+template <typename T, typename Closure>
+class ResourceOwningTask final : public QueuedTask {
+ public:
+  ResourceOwningTask(T&& resource, Closure&& handler)
+      : resource_(std::move(resource)),
+        handler_(std::forward<Closure>(handler)) {}
+
+  bool Run() override {
+    handler_(std::move(resource_));
+    return true;
+  }
+
+ private:
+  T resource_;
+  Closure handler_;
+};
+template <typename T, typename Closure>
+std::unique_ptr<QueuedTask> CreateResourceOwningTask(T resource,
+                                                     Closure&& closure) {
+  return absl::make_unique<ResourceOwningTask<T, Closure>>(
+      std::forward<T>(resource), std::forward<Closure>(closure));
+}
 }  // namespace
 
 NetworkEmulationManagerImpl::NetworkEmulationManagerImpl()
@@ -42,10 +63,6 @@ NetworkEmulationManagerImpl::NetworkEmulationManagerImpl(
       task_queue_(time_controller->GetTaskQueueFactory()->CreateTaskQueue(
           "NetworkEmulation",
           TaskQueueFactory::Priority::NORMAL)) {
-  process_task_handle_ = RepeatingTaskHandle::Start(task_queue_.Get(), [this] {
-    ProcessNetworkPackets();
-    return TimeDelta::ms(kPacketProcessingIntervalMs);
-  });
 }
 
 // TODO(srte): Ensure that any pending task that must be run for consistency
@@ -170,17 +187,21 @@ RandomWalkCrossTraffic*
 NetworkEmulationManagerImpl::CreateRandomWalkCrossTraffic(
     TrafficRoute* traffic_route,
     RandomWalkConfig config) {
-  auto traffic = absl::make_unique<RandomWalkCrossTraffic>(std::move(config),
-                                                           traffic_route);
+  auto traffic =
+      absl::make_unique<RandomWalkCrossTraffic>(config, traffic_route);
   RandomWalkCrossTraffic* out = traffic.get();
-  struct Closure {
-    void operator()() {
-      manager->random_cross_traffics_.push_back(std::move(traffic));
-    }
-    NetworkEmulationManagerImpl* manager;
-    std::unique_ptr<RandomWalkCrossTraffic> traffic;
-  };
-  task_queue_.PostTask(Closure{this, std::move(traffic)});
+
+  task_queue_.PostTask(CreateResourceOwningTask(
+      std::move(traffic),
+      [this, config](std::unique_ptr<RandomWalkCrossTraffic> traffic) {
+        auto* traffic_ptr = traffic.get();
+        random_cross_traffics_.push_back(std::move(traffic));
+        RepeatingTaskHandle::Start(task_queue_.Get(),
+                                   [this, config, traffic_ptr] {
+                                     traffic_ptr->Process(Now());
+                                     return config.min_packet_interval;
+                                   });
+      }));
   return out;
 }
 
@@ -188,17 +209,20 @@ PulsedPeaksCrossTraffic*
 NetworkEmulationManagerImpl::CreatePulsedPeaksCrossTraffic(
     TrafficRoute* traffic_route,
     PulsedPeaksConfig config) {
-  auto traffic = absl::make_unique<PulsedPeaksCrossTraffic>(std::move(config),
-                                                            traffic_route);
+  auto traffic =
+      absl::make_unique<PulsedPeaksCrossTraffic>(config, traffic_route);
   PulsedPeaksCrossTraffic* out = traffic.get();
-  struct Closure {
-    void operator()() {
-      manager->pulsed_cross_traffics_.push_back(std::move(traffic));
-    }
-    NetworkEmulationManagerImpl* manager;
-    std::unique_ptr<PulsedPeaksCrossTraffic> traffic;
-  };
-  task_queue_.PostTask(Closure{this, std::move(traffic)});
+  task_queue_.PostTask(CreateResourceOwningTask(
+      std::move(traffic),
+      [this, config](std::unique_ptr<PulsedPeaksCrossTraffic> traffic) {
+        auto* traffic_ptr = traffic.get();
+        pulsed_cross_traffics_.push_back(std::move(traffic));
+        RepeatingTaskHandle::Start(task_queue_.Get(),
+                                   [this, config, traffic_ptr] {
+                                     traffic_ptr->Process(Now());
+                                     return config.min_packet_interval;
+                                   });
+      }));
   return out;
 }
 
@@ -242,16 +266,6 @@ NetworkEmulationManagerImpl::GetNextIPv4Address() {
   return absl::nullopt;
 }
 
-void NetworkEmulationManagerImpl::ProcessNetworkPackets() {
-  Timestamp current_time = Now();
-  for (auto& traffic : random_cross_traffics_) {
-    traffic->Process(current_time);
-  }
-  for (auto& traffic : pulsed_cross_traffics_) {
-    traffic->Process(current_time);
-  }
-}
-
 Timestamp NetworkEmulationManagerImpl::Now() const {
   return Timestamp::us(clock_->TimeInMicroseconds());
 }

test/scenario/network/network_emulation_manager.h

@@ -69,7 +69,6 @@ class NetworkEmulationManagerImpl : public NetworkEmulationManager {
   FakeNetworkSocketServer* CreateSocketServer(
       const std::vector<EmulatedEndpoint*>& endpoints);
   absl::optional<rtc::IPAddress> GetNextIPv4Address();
-  void ProcessNetworkPackets();
   Timestamp Now() const;
 
   Clock* const clock_;