Project import generated by Copybara.
PiperOrigin-RevId: 237361882
Change-Id: I109a68f44db867b20f8c6a7732b0ce657133e52a
diff --git a/quic/test_tools/simulator/simulator.cc b/quic/test_tools/simulator/simulator.cc
new file mode 100644
index 0000000..fdb59db
--- /dev/null
+++ b/quic/test_tools/simulator/simulator.cc
@@ -0,0 +1,167 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/third_party/quiche/src/quic/test_tools/simulator/simulator.h"
+
+#include "net/third_party/quiche/src/quic/core/crypto/quic_random.h"
+#include "net/third_party/quiche/src/quic/platform/api/quic_logging.h"
+
+namespace quic {
+namespace simulator {
+
+Simulator::Simulator()
+ : random_generator_(nullptr),
+ alarm_factory_(this, "Default Alarm Manager"),
+ run_for_should_stop_(false),
+ enable_random_delays_(false) {
+ run_for_alarm_.reset(
+ alarm_factory_.CreateAlarm(new RunForDelegate(&run_for_should_stop_)));
+}
+
+Simulator::~Simulator() {
+ // Ensure that Actor under run_for_alarm_ is removed before Simulator data
+ // structures are destructed.
+ run_for_alarm_.reset();
+}
+
+Simulator::Clock::Clock() : now_(kStartTime) {}
+
+QuicTime Simulator::Clock::ApproximateNow() const {
+ return now_;
+}
+
+QuicTime Simulator::Clock::Now() const {
+ return now_;
+}
+
+QuicWallTime Simulator::Clock::WallNow() const {
+ return QuicWallTime::FromUNIXMicroseconds(
+ (now_ - QuicTime::Zero()).ToMicroseconds());
+}
+
+void Simulator::AddActor(Actor* actor) {
+ auto emplace_times_result =
+ scheduled_times_.insert(std::make_pair(actor, QuicTime::Infinite()));
+ auto emplace_names_result = actor_names_.insert(actor->name());
+
+ // Ensure that the object was actually placed into the map.
+ DCHECK(emplace_times_result.second);
+ DCHECK(emplace_names_result.second);
+}
+
+void Simulator::RemoveActor(Actor* actor) {
+ auto scheduled_time_it = scheduled_times_.find(actor);
+ auto actor_names_it = actor_names_.find(actor->name());
+ DCHECK(scheduled_time_it != scheduled_times_.end());
+ DCHECK(actor_names_it != actor_names_.end());
+
+ QuicTime scheduled_time = scheduled_time_it->second;
+ if (scheduled_time != QuicTime::Infinite()) {
+ Unschedule(actor);
+ }
+
+ scheduled_times_.erase(scheduled_time_it);
+ actor_names_.erase(actor_names_it);
+}
+
+void Simulator::Schedule(Actor* actor, QuicTime new_time) {
+ auto scheduled_time_it = scheduled_times_.find(actor);
+ DCHECK(scheduled_time_it != scheduled_times_.end());
+ QuicTime scheduled_time = scheduled_time_it->second;
+
+ if (scheduled_time <= new_time) {
+ return;
+ }
+
+ if (scheduled_time != QuicTime::Infinite()) {
+ Unschedule(actor);
+ }
+
+ scheduled_time_it->second = new_time;
+ schedule_.insert(std::make_pair(new_time, actor));
+}
+
+void Simulator::Unschedule(Actor* actor) {
+ auto scheduled_time_it = scheduled_times_.find(actor);
+ DCHECK(scheduled_time_it != scheduled_times_.end());
+ QuicTime scheduled_time = scheduled_time_it->second;
+
+ DCHECK(scheduled_time != QuicTime::Infinite());
+ auto range = schedule_.equal_range(scheduled_time);
+ for (auto it = range.first; it != range.second; ++it) {
+ if (it->second == actor) {
+ schedule_.erase(it);
+ scheduled_time_it->second = QuicTime::Infinite();
+ return;
+ }
+ }
+ DCHECK(false);
+}
+
+const QuicClock* Simulator::GetClock() const {
+ return &clock_;
+}
+
+QuicRandom* Simulator::GetRandomGenerator() {
+ if (random_generator_ == nullptr) {
+ random_generator_ = QuicRandom::GetInstance();
+ }
+
+ return random_generator_;
+}
+
+QuicBufferAllocator* Simulator::GetStreamSendBufferAllocator() {
+ return &buffer_allocator_;
+}
+
+QuicAlarmFactory* Simulator::GetAlarmFactory() {
+ return &alarm_factory_;
+}
+
+Simulator::RunForDelegate::RunForDelegate(bool* run_for_should_stop)
+ : run_for_should_stop_(run_for_should_stop) {}
+
+void Simulator::RunForDelegate::OnAlarm() {
+ *run_for_should_stop_ = true;
+}
+
+void Simulator::RunFor(QuicTime::Delta time_span) {
+ DCHECK(!run_for_alarm_->IsSet());
+
+ // RunFor() ensures that the simulation stops at the exact time specified by
+ // scheduling an alarm at that point and using that alarm to abort the
+ // simulation. An alarm is necessary because otherwise it is possible that
+ // nothing is scheduled at |end_time|, so the simulation will either go
+ // further than requested or stop before reaching |end_time|.
+ const QuicTime end_time = clock_.Now() + time_span;
+ run_for_alarm_->Set(end_time);
+ run_for_should_stop_ = false;
+ bool simulation_result = RunUntil([this]() { return run_for_should_stop_; });
+
+ DCHECK(simulation_result);
+ DCHECK(clock_.Now() == end_time);
+}
+
+void Simulator::HandleNextScheduledActor() {
+ const auto current_event_it = schedule_.begin();
+ QuicTime event_time = current_event_it->first;
+ Actor* actor = current_event_it->second;
+ QUIC_DVLOG(3) << "At t = " << event_time.ToDebuggingValue() << ", calling "
+ << actor->name();
+
+ Unschedule(actor);
+
+ if (clock_.Now() > event_time) {
+ QUIC_BUG << "Error: event registered by [" << actor->name()
+ << "] requires travelling back in time. Current time: "
+ << clock_.Now().ToDebuggingValue()
+ << ", scheduled time: " << event_time.ToDebuggingValue();
+ }
+ clock_.now_ = event_time;
+
+ actor->Act();
+}
+
+} // namespace simulator
+} // namespace quic
