webrtc_m130/call/simulated_network.h
Christoffer Rodbro 813c79bff9 Fix network emulation behavior when changing bandwidth.
Calculate packet exit times "just in time" rather than at send time.
This allows changing bandwidth with packets in the queue being reflected
correctly.

Bug: webrtc:10265
Change-Id: I5a38663def4d2bfee64164f9ae62bc61277064bb
Reviewed-on: https://webrtc-review.googlesource.com/c/120403
Commit-Queue: Christoffer Rodbro <crodbro@webrtc.org>
Reviewed-by: Sebastian Jansson <srte@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26487}
2019-01-31 10:42:03 +00:00

89 lines
2.8 KiB
C++

/*
* Copyright 2018 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.
*/
#ifndef CALL_SIMULATED_NETWORK_H_
#define CALL_SIMULATED_NETWORK_H_
#include <stdint.h>
#include <deque>
#include <queue>
#include <vector>
#include "absl/types/optional.h"
#include "api/test/simulated_network.h"
#include "rtc_base/critical_section.h"
#include "rtc_base/random.h"
#include "rtc_base/thread_annotations.h"
namespace webrtc {
// Class simulating a network link. This is a simple and naive solution just
// faking capacity and adding an extra transport delay in addition to the
// capacity introduced delay.
class SimulatedNetwork : public NetworkBehaviorInterface {
public:
using Config = BuiltInNetworkBehaviorConfig;
explicit SimulatedNetwork(Config config, uint64_t random_seed = 1);
~SimulatedNetwork() override;
// Sets a new configuration. This won't affect packets already in the pipe.
void SetConfig(const Config& config);
void PauseTransmissionUntil(int64_t until_us);
// NetworkBehaviorInterface
bool EnqueuePacket(PacketInFlightInfo packet) override;
std::vector<PacketDeliveryInfo> DequeueDeliverablePackets(
int64_t receive_time_us) override;
absl::optional<int64_t> NextDeliveryTimeUs() const override;
private:
struct PacketInfo {
PacketInFlightInfo packet;
int64_t arrival_time_us;
};
// Moves packets from capacity- to delay link.
void UpdateCapacityQueue(int64_t time_now_us);
rtc::CriticalSection config_lock_;
// |process_lock| guards the data structures involved in delay and loss
// processes, such as the packet queues.
rtc::CriticalSection process_lock_;
std::queue<PacketInfo> capacity_link_ RTC_GUARDED_BY(process_lock_);
Random random_;
std::deque<PacketInfo> delay_link_ RTC_GUARDED_BY(process_lock_);
// Link configuration.
Config config_ RTC_GUARDED_BY(config_lock_);
absl::optional<int64_t> pause_transmission_until_us_
RTC_GUARDED_BY(config_lock_);
// Are we currently dropping a burst of packets?
bool bursting_;
// The probability to drop the packet if we are currently dropping a
// burst of packet
double prob_loss_bursting_ RTC_GUARDED_BY(config_lock_);
// The probability to drop a burst of packets.
double prob_start_bursting_ RTC_GUARDED_BY(config_lock_);
int64_t queue_size_bytes_ RTC_GUARDED_BY(process_lock_) = 0;
int64_t pending_drain_bits_ RTC_GUARDED_BY(process_lock_) = 0;
absl::optional<int64_t> last_capacity_link_visit_us_
RTC_GUARDED_BY(process_lock_);
};
} // namespace webrtc
#endif // CALL_SIMULATED_NETWORK_H_