Reland: Fix race / crash in OnNetworkRouteChanged().

webrtc/modules/remote_bitrate_estimator/transport_feedback_adapter.cc

-/*
- *  Copyright (c) 2015 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 "webrtc/modules/remote_bitrate_estimator/transport_feedback_adapter.h"
-
-#include <algorithm>
-#include <limits>
-
-#include "webrtc/base/checks.h"
-#include "webrtc/base/logging.h"
-#include "webrtc/modules/remote_bitrate_estimator/include/remote_bitrate_estimator.h"
-#include "webrtc/modules/rtp_rtcp/source/rtcp_packet/transport_feedback.h"
-#include "webrtc/modules/utility/include/process_thread.h"
-
-namespace webrtc {
-
-const int64_t kNoTimestamp = -1;
-const int64_t kSendTimeHistoryWindowMs = 10000;
-const int64_t kBaseTimestampScaleFactor =
-    rtcp::TransportFeedback::kDeltaScaleFactor * (1 << 8);
-const int64_t kBaseTimestampRangeSizeUs = kBaseTimestampScaleFactor * (1 << 24);
-
-class PacketInfoComparator {
- public:
-  inline bool operator()(const PacketInfo& lhs, const PacketInfo& rhs) {
-    if (lhs.arrival_time_ms != rhs.arrival_time_ms)
-      return lhs.arrival_time_ms < rhs.arrival_time_ms;
-    if (lhs.send_time_ms != rhs.send_time_ms)
-      return lhs.send_time_ms < rhs.send_time_ms;
-    return lhs.sequence_number < rhs.sequence_number;
-  }
-};
-
-TransportFeedbackAdapter::TransportFeedbackAdapter(
-    Clock* clock)
-    : send_time_history_(clock, kSendTimeHistoryWindowMs),
-      clock_(clock),
-      current_offset_ms_(kNoTimestamp),
-      last_timestamp_us_(kNoTimestamp) {}
-
-TransportFeedbackAdapter::~TransportFeedbackAdapter() {
-}
-
-void TransportFeedbackAdapter::SetBitrateEstimator(
-    RemoteBitrateEstimator* rbe) {
-  if (bitrate_estimator_.get() != rbe) {
-    bitrate_estimator_.reset(rbe);
-  }
-}
-
-void TransportFeedbackAdapter::AddPacket(uint16_t sequence_number,
-                                         size_t length,
-                                         int probe_cluster_id) {
-  rtc::CritScope cs(&lock_);
-  send_time_history_.AddAndRemoveOld(sequence_number, length, probe_cluster_id);
-}
-
-void TransportFeedbackAdapter::OnSentPacket(uint16_t sequence_number,
-                                            int64_t send_time_ms) {
-  rtc::CritScope cs(&lock_);
-  send_time_history_.OnSentPacket(sequence_number, send_time_ms);
-}
-
-std::vector<PacketInfo> TransportFeedbackAdapter::GetPacketFeedbackVector(
-    const rtcp::TransportFeedback& feedback) {
-  int64_t timestamp_us = feedback.GetBaseTimeUs();
-  // Add timestamp deltas to a local time base selected on first packet arrival.
-  // This won't be the true time base, but makes it easier to manually inspect
-  // time stamps.
-  if (last_timestamp_us_ == kNoTimestamp) {
-    current_offset_ms_ = clock_->TimeInMilliseconds();
-  } else {
-    int64_t delta = timestamp_us - last_timestamp_us_;
-
-    // Detect and compensate for wrap-arounds in base time.
-    if (std::abs(delta - kBaseTimestampRangeSizeUs) < std::abs(delta)) {
-      delta -= kBaseTimestampRangeSizeUs;  // Wrap backwards.
-    } else if (std::abs(delta + kBaseTimestampRangeSizeUs) < std::abs(delta)) {
-      delta += kBaseTimestampRangeSizeUs;  // Wrap forwards.
-    }
-
-    current_offset_ms_ += delta / 1000;
-  }
-  last_timestamp_us_ = timestamp_us;
-
-  uint16_t sequence_number = feedback.GetBaseSequence();
-  std::vector<int64_t> delta_vec = feedback.GetReceiveDeltasUs();
-  auto delta_it = delta_vec.begin();
-  std::vector<PacketInfo> packet_feedback_vector;
-  packet_feedback_vector.reserve(delta_vec.size());
-
-  {
-    rtc::CritScope cs(&lock_);
-    size_t failed_lookups = 0;
-    int64_t offset_us = 0;
-    for (auto symbol : feedback.GetStatusVector()) {
-      if (symbol != rtcp::TransportFeedback::StatusSymbol::kNotReceived) {
-        RTC_DCHECK(delta_it != delta_vec.end());
-        offset_us += *(delta_it++);
-        int64_t timestamp_ms = current_offset_ms_ + (offset_us / 1000);
-        PacketInfo info(timestamp_ms, sequence_number);
-        if (send_time_history_.GetInfo(&info, true) && info.send_time_ms >= 0) {
-          packet_feedback_vector.push_back(info);
-        } else {
-          ++failed_lookups;
-        }
-      }
-      ++sequence_number;
-    }
-    std::sort(packet_feedback_vector.begin(), packet_feedback_vector.end(),
-              PacketInfoComparator());
-    RTC_DCHECK(delta_it == delta_vec.end());
-    if (failed_lookups > 0) {
-      LOG(LS_WARNING) << "Failed to lookup send time for " << failed_lookups
-                      << " packet" << (failed_lookups > 1 ? "s" : "")
-                      << ". Send time history too small?";
-    }
-  }
-  return packet_feedback_vector;
-}
-
-void TransportFeedbackAdapter::OnTransportFeedback(
-    const rtcp::TransportFeedback& feedback) {
-  last_packet_feedback_vector_ = GetPacketFeedbackVector(feedback);
-  if (bitrate_estimator_.get())
-    bitrate_estimator_->IncomingPacketFeedbackVector(
-        last_packet_feedback_vector_);
-}
-
-std::vector<PacketInfo> TransportFeedbackAdapter::GetTransportFeedbackVector()
-    const {
-  return last_packet_feedback_vector_;
-}
-
-void TransportFeedbackAdapter::OnRttUpdate(int64_t avg_rtt_ms,
-                                           int64_t max_rtt_ms) {
-  RTC_DCHECK(bitrate_estimator_.get() != nullptr);
-  bitrate_estimator_->OnRttUpdate(avg_rtt_ms, max_rtt_ms);
-}
-
-}  // namespace webrtc