Project import generated by Copybara.
PiperOrigin-RevId: 237361882
Change-Id: I109a68f44db867b20f8c6a7732b0ce657133e52a
diff --git a/quic/test_tools/packet_dropping_test_writer.cc b/quic/test_tools/packet_dropping_test_writer.cc
new file mode 100644
index 0000000..87935d5
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+++ b/quic/test_tools/packet_dropping_test_writer.cc
@@ -0,0 +1,252 @@
+// Copyright 2013 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/packet_dropping_test_writer.h"
+
+#include "net/third_party/quiche/src/quic/core/quic_epoll_connection_helper.h"
+#include "net/third_party/quiche/src/quic/platform/api/quic_logging.h"
+#include "net/quic/platform/impl/quic_socket_utils.h"
+
+namespace quic {
+namespace test {
+
+const int32_t kMaxConsecutivePacketLoss = 3;
+
+// An alarm that is scheduled if a blocked socket is simulated to indicate
+// it's writable again.
+class WriteUnblockedAlarm : public QuicAlarm::Delegate {
+ public:
+ explicit WriteUnblockedAlarm(PacketDroppingTestWriter* writer)
+ : writer_(writer) {}
+
+ void OnAlarm() override {
+ QUIC_DLOG(INFO) << "Unblocking socket.";
+ writer_->OnCanWrite();
+ }
+
+ private:
+ PacketDroppingTestWriter* writer_;
+};
+
+// An alarm that is scheduled every time a new packet is to be written at a
+// later point.
+class DelayAlarm : public QuicAlarm::Delegate {
+ public:
+ explicit DelayAlarm(PacketDroppingTestWriter* writer) : writer_(writer) {}
+
+ void OnAlarm() override {
+ QuicTime new_deadline = writer_->ReleaseOldPackets();
+ if (new_deadline.IsInitialized()) {
+ writer_->SetDelayAlarm(new_deadline);
+ }
+ }
+
+ private:
+ PacketDroppingTestWriter* writer_;
+};
+
+PacketDroppingTestWriter::PacketDroppingTestWriter()
+ : clock_(nullptr),
+ cur_buffer_size_(0),
+ num_calls_to_write_(0),
+ fake_packet_loss_percentage_(0),
+ fake_drop_first_n_packets_(0),
+ fake_blocked_socket_percentage_(0),
+ fake_packet_reorder_percentage_(0),
+ fake_packet_delay_(QuicTime::Delta::Zero()),
+ fake_bandwidth_(QuicBandwidth::Zero()),
+ buffer_size_(0),
+ num_consecutive_packet_lost_(0) {
+ uint64_t seed = QuicRandom::GetInstance()->RandUint64();
+ QUIC_LOG(INFO) << "Seeding packet loss with " << seed;
+ simple_random_.set_seed(seed);
+}
+
+PacketDroppingTestWriter::~PacketDroppingTestWriter() = default;
+
+void PacketDroppingTestWriter::Initialize(
+ QuicConnectionHelperInterface* helper,
+ QuicAlarmFactory* alarm_factory,
+ std::unique_ptr<Delegate> on_can_write) {
+ clock_ = helper->GetClock();
+ write_unblocked_alarm_.reset(
+ alarm_factory->CreateAlarm(new WriteUnblockedAlarm(this)));
+ delay_alarm_.reset(alarm_factory->CreateAlarm(new DelayAlarm(this)));
+ on_can_write_ = std::move(on_can_write);
+}
+
+WriteResult PacketDroppingTestWriter::WritePacket(
+ const char* buffer,
+ size_t buf_len,
+ const QuicIpAddress& self_address,
+ const QuicSocketAddress& peer_address,
+ PerPacketOptions* options) {
+ ++num_calls_to_write_;
+ ReleaseOldPackets();
+
+ QuicWriterMutexLock lock(&config_mutex_);
+ if (fake_drop_first_n_packets_ > 0 &&
+ num_calls_to_write_ <=
+ static_cast<uint64_t>(fake_drop_first_n_packets_)) {
+ QUIC_DVLOG(1) << "Dropping first " << fake_drop_first_n_packets_
+ << " packets (packet number " << num_calls_to_write_ << ")";
+ return WriteResult(WRITE_STATUS_OK, buf_len);
+ }
+ const int32_t kMaxPacketLossPercentage =
+ kMaxConsecutivePacketLoss * 100.0 / (kMaxConsecutivePacketLoss + 1);
+ if (fake_packet_loss_percentage_ > 0 &&
+ // Do not allow too many consecutive packet drops to avoid test flakiness.
+ (num_consecutive_packet_lost_ <= kMaxConsecutivePacketLoss ||
+ // Allow as many consecutive packet drops as possbile if
+ // |fake_packet_lost_percentage_| is large enough. Without this exception
+ // it is hard to simulate high loss rate, like 100%.
+ fake_packet_loss_percentage_ > kMaxPacketLossPercentage) &&
+ (simple_random_.RandUint64() % 100 <
+ static_cast<uint64_t>(fake_packet_loss_percentage_))) {
+ QUIC_DVLOG(1) << "Dropping packet.";
+ ++num_consecutive_packet_lost_;
+ return WriteResult(WRITE_STATUS_OK, buf_len);
+ } else {
+ num_consecutive_packet_lost_ = 0;
+ }
+ if (fake_blocked_socket_percentage_ > 0 &&
+ simple_random_.RandUint64() % 100 <
+ static_cast<uint64_t>(fake_blocked_socket_percentage_)) {
+ CHECK(on_can_write_ != nullptr);
+ QUIC_DVLOG(1) << "Blocking socket.";
+ if (!write_unblocked_alarm_->IsSet()) {
+ // Set the alarm to fire immediately.
+ write_unblocked_alarm_->Set(clock_->ApproximateNow());
+ }
+ return WriteResult(WRITE_STATUS_BLOCKED, EAGAIN);
+ }
+
+ if (!fake_packet_delay_.IsZero() || !fake_bandwidth_.IsZero()) {
+ if (buffer_size_ > 0 && buf_len + cur_buffer_size_ > buffer_size_) {
+ // Drop packets which do not fit into the buffer.
+ QUIC_DVLOG(1) << "Dropping packet because the buffer is full.";
+ return WriteResult(WRITE_STATUS_OK, buf_len);
+ }
+
+ // Queue it to be sent.
+ QuicTime send_time = clock_->ApproximateNow() + fake_packet_delay_;
+ if (!fake_bandwidth_.IsZero()) {
+ // Calculate a time the bandwidth limit would impose.
+ QuicTime::Delta bandwidth_delay = QuicTime::Delta::FromMicroseconds(
+ (buf_len * kNumMicrosPerSecond) / fake_bandwidth_.ToBytesPerSecond());
+ send_time = delayed_packets_.empty()
+ ? send_time + bandwidth_delay
+ : delayed_packets_.back().send_time + bandwidth_delay;
+ }
+ std::unique_ptr<PerPacketOptions> delayed_options;
+ if (options != nullptr) {
+ delayed_options = options->Clone();
+ }
+ delayed_packets_.push_back(
+ DelayedWrite(buffer, buf_len, self_address, peer_address,
+ std::move(delayed_options), send_time));
+ cur_buffer_size_ += buf_len;
+
+ // Set the alarm if it's not yet set.
+ if (!delay_alarm_->IsSet()) {
+ delay_alarm_->Set(send_time);
+ }
+
+ return WriteResult(WRITE_STATUS_OK, buf_len);
+ }
+
+ return QuicPacketWriterWrapper::WritePacket(buffer, buf_len, self_address,
+ peer_address, options);
+}
+
+bool PacketDroppingTestWriter::IsWriteBlocked() const {
+ if (write_unblocked_alarm_ != nullptr && write_unblocked_alarm_->IsSet()) {
+ return true;
+ }
+ return QuicPacketWriterWrapper::IsWriteBlocked();
+}
+
+void PacketDroppingTestWriter::SetWritable() {
+ if (write_unblocked_alarm_ != nullptr && write_unblocked_alarm_->IsSet()) {
+ write_unblocked_alarm_->Cancel();
+ }
+ QuicPacketWriterWrapper::SetWritable();
+}
+
+QuicTime PacketDroppingTestWriter::ReleaseNextPacket() {
+ if (delayed_packets_.empty()) {
+ return QuicTime::Zero();
+ }
+ QuicReaderMutexLock lock(&config_mutex_);
+ auto iter = delayed_packets_.begin();
+ // Determine if we should re-order.
+ if (delayed_packets_.size() > 1 && fake_packet_reorder_percentage_ > 0 &&
+ simple_random_.RandUint64() % 100 <
+ static_cast<uint64_t>(fake_packet_reorder_percentage_)) {
+ QUIC_DLOG(INFO) << "Reordering packets.";
+ ++iter;
+ // Swap the send times when re-ordering packets.
+ delayed_packets_.begin()->send_time = iter->send_time;
+ }
+
+ QUIC_DVLOG(1) << "Releasing packet. " << (delayed_packets_.size() - 1)
+ << " remaining.";
+ // Grab the next one off the queue and send it.
+ QuicPacketWriterWrapper::WritePacket(
+ iter->buffer.data(), iter->buffer.length(), iter->self_address,
+ iter->peer_address, iter->options.get());
+ DCHECK_GE(cur_buffer_size_, iter->buffer.length());
+ cur_buffer_size_ -= iter->buffer.length();
+ delayed_packets_.erase(iter);
+
+ // If there are others, find the time for the next to be sent.
+ if (delayed_packets_.empty()) {
+ return QuicTime::Zero();
+ }
+ return delayed_packets_.begin()->send_time;
+}
+
+QuicTime PacketDroppingTestWriter::ReleaseOldPackets() {
+ while (!delayed_packets_.empty()) {
+ QuicTime next_send_time = delayed_packets_.front().send_time;
+ if (next_send_time > clock_->Now()) {
+ return next_send_time;
+ }
+ ReleaseNextPacket();
+ }
+ return QuicTime::Zero();
+}
+
+void PacketDroppingTestWriter::SetDelayAlarm(QuicTime new_deadline) {
+ delay_alarm_->Set(new_deadline);
+}
+
+void PacketDroppingTestWriter::OnCanWrite() {
+ on_can_write_->OnCanWrite();
+}
+
+void PacketDroppingTestWriter::set_fake_packet_loss_percentage(
+ int32_t fake_packet_loss_percentage) {
+ QuicWriterMutexLock lock(&config_mutex_);
+ fake_packet_loss_percentage_ = fake_packet_loss_percentage;
+ num_consecutive_packet_lost_ = 0;
+}
+
+PacketDroppingTestWriter::DelayedWrite::DelayedWrite(
+ const char* buffer,
+ size_t buf_len,
+ const QuicIpAddress& self_address,
+ const QuicSocketAddress& peer_address,
+ std::unique_ptr<PerPacketOptions> options,
+ QuicTime send_time)
+ : buffer(buffer, buf_len),
+ self_address(self_address),
+ peer_address(peer_address),
+ options(std::move(options)),
+ send_time(send_time) {}
+
+PacketDroppingTestWriter::DelayedWrite::~DelayedWrite() = default;
+
+} // namespace test
+} // namespace quic
