OLD | NEW |
1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | 1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 // | 4 // |
5 // Cubic algorithm, helper class to TCP cubic. | 5 // Cubic algorithm, helper class to TCP cubic. |
6 // For details see http://netsrv.csc.ncsu.edu/export/cubic_a_new_tcp_2008.pdf. | 6 // For details see http://netsrv.csc.ncsu.edu/export/cubic_a_new_tcp_2008.pdf. |
7 | 7 |
8 #ifndef NET_QUIC_CONGESTION_CONTROL_CUBIC_H_ | 8 #ifndef NET_QUIC_CONGESTION_CONTROL_CUBIC_H_ |
9 #define NET_QUIC_CONGESTION_CONTROL_CUBIC_H_ | 9 #define NET_QUIC_CONGESTION_CONTROL_CUBIC_H_ |
10 | 10 |
11 #include "base/basictypes.h" | 11 #include "base/basictypes.h" |
12 #include "net/base/net_export.h" | 12 #include "net/base/net_export.h" |
13 #include "net/quic/quic_clock.h" | 13 #include "net/quic/quic_clock.h" |
| 14 #include "net/quic/quic_connection_stats.h" |
14 #include "net/quic/quic_time.h" | 15 #include "net/quic/quic_time.h" |
15 | 16 |
16 namespace net { | 17 namespace net { |
17 | 18 |
18 // TCP congestion window in QUIC is in packets, not bytes. | 19 // TCP congestion window in QUIC is in packets, not bytes. |
19 typedef uint32 QuicTcpCongestionWindow; | 20 typedef uint32 QuicTcpCongestionWindow; |
20 | 21 |
21 class NET_EXPORT_PRIVATE Cubic { | 22 class NET_EXPORT_PRIVATE Cubic { |
22 public: | 23 public: |
23 explicit Cubic(const QuicClock* clock); | 24 Cubic(const QuicClock* clock, QuicConnectionStats* stats); |
24 | 25 |
25 // Call after a timeout to reset the cubic state. | 26 // Call after a timeout to reset the cubic state. |
26 void Reset(); | 27 void Reset(); |
27 | 28 |
28 // Compute a new congestion window to use after a loss event. | 29 // Compute a new congestion window to use after a loss event. |
29 // Returns the new congestion window in packets. The new congestion window is | 30 // Returns the new congestion window in packets. The new congestion window is |
30 // a multiplicative decrease of our current window. | 31 // a multiplicative decrease of our current window. |
31 QuicTcpCongestionWindow CongestionWindowAfterPacketLoss( | 32 QuicTcpCongestionWindow CongestionWindowAfterPacketLoss( |
32 QuicTcpCongestionWindow current); | 33 QuicTcpCongestionWindow current); |
33 | 34 |
34 // Compute a new congestion window to use after a received ACK. | 35 // Compute a new congestion window to use after a received ACK. |
35 // Returns the new congestion window in packets. The new congestion window | 36 // Returns the new congestion window in packets. The new congestion window |
36 // follows a cubic function that depends on the time passed since last | 37 // follows a cubic function that depends on the time passed since last |
37 // packet loss. | 38 // packet loss. |
38 QuicTcpCongestionWindow CongestionWindowAfterAck( | 39 QuicTcpCongestionWindow CongestionWindowAfterAck( |
39 QuicTcpCongestionWindow current, | 40 QuicTcpCongestionWindow current, |
40 QuicTime::Delta delay_min); | 41 QuicTime::Delta delay_min); |
41 | 42 |
42 private: | 43 private: |
43 static const QuicTime::Delta MaxCubicTimeInterval() { | 44 static const QuicTime::Delta MaxCubicTimeInterval() { |
44 return QuicTime::Delta::FromMilliseconds(30); | 45 return QuicTime::Delta::FromMilliseconds(30); |
45 } | 46 } |
46 | 47 |
| 48 // Update congestion control variables in QuicConnectionStats. |
| 49 void UpdateCongestionControlStats(QuicTcpCongestionWindow new_cubic_mode_cwnd, |
| 50 QuicTcpCongestionWindow new_reno_mode_cwnd); |
47 const QuicClock* clock_; | 51 const QuicClock* clock_; |
48 | 52 |
49 // Time when this cycle started, after last loss event. | 53 // Time when this cycle started, after last loss event. |
50 QuicTime epoch_; | 54 QuicTime epoch_; |
51 | 55 |
52 // Time when we updated last_congestion_window. | 56 // Time when we updated last_congestion_window. |
53 QuicTime last_update_time_; | 57 QuicTime last_update_time_; |
54 | 58 |
55 // Last congestion window (in packets) used. | 59 // Last congestion window (in packets) used. |
56 QuicTcpCongestionWindow last_congestion_window_; | 60 QuicTcpCongestionWindow last_congestion_window_; |
(...skipping 11 matching lines...) Expand all Loading... |
68 | 72 |
69 // Origin point of cubic function. | 73 // Origin point of cubic function. |
70 QuicTcpCongestionWindow origin_point_congestion_window_; | 74 QuicTcpCongestionWindow origin_point_congestion_window_; |
71 | 75 |
72 // Time to origin point of cubic function in 2^10 fractions of a second. | 76 // Time to origin point of cubic function in 2^10 fractions of a second. |
73 uint32 time_to_origin_point_; | 77 uint32 time_to_origin_point_; |
74 | 78 |
75 // Last congestion window in packets computed by cubic function. | 79 // Last congestion window in packets computed by cubic function. |
76 QuicTcpCongestionWindow last_target_congestion_window_; | 80 QuicTcpCongestionWindow last_target_congestion_window_; |
77 | 81 |
| 82 // QuicConnectionStats includes congestion control related stats. |
| 83 QuicConnectionStats* stats_; |
| 84 |
78 DISALLOW_COPY_AND_ASSIGN(Cubic); | 85 DISALLOW_COPY_AND_ASSIGN(Cubic); |
79 }; | 86 }; |
80 | 87 |
81 } // namespace net | 88 } // namespace net |
82 | 89 |
83 #endif // NET_QUIC_CONGESTION_CONTROL_CUBIC_H_ | 90 #endif // NET_QUIC_CONGESTION_CONTROL_CUBIC_H_ |
OLD | NEW |