net/tools/quic/test_tools/packet_dropping_test_writer.h

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef NET_TOOLS_QUIC_TEST_TOOLS_PACKET_DROPPING_TEST_WRITER_H_
   6 #define NET_TOOLS_QUIC_TEST_TOOLS_PACKET_DROPPING_TEST_WRITER_H_
   7
   8 #include <list>
   9 #include <string>
  10
  11 #include "base/basictypes.h"
  12 #include "base/logging.h"
  13 #include "base/memory/scoped_ptr.h"
  14 #include "base/synchronization/lock.h"
  15 #include "net/quic/quic_alarm.h"
  16 #include "net/quic/test_tools/quic_test_utils.h"
  17 #include "net/tools/quic/quic_epoll_clock.h"
  18 #include "net/tools/quic/quic_packet_writer_wrapper.h"
  19 #include "net/tools/quic/test_tools/quic_test_client.h"
  20 #include "net/tools/quic/test_tools/quic_test_utils.h"
  21
  22 namespace net {
  23 namespace tools {
  24 namespace test {
  25
  26 // Simulates a connection that drops packets a configured percentage of the time
  27 // and has a blocked socket a configured percentage of the time.  Also provides
  28 // the options to delay packets and reorder packets if delay is enabled.
  29 class PacketDroppingTestWriter : public QuicPacketWriterWrapper {
  30  public:
  31   class Delegate {
  32    public:
  33     virtual ~Delegate() {}
  34     virtual void OnPacketSent(WriteResult result) = 0;
  35     virtual void OnCanWrite() = 0;
  36   };
  37
  38   PacketDroppingTestWriter();
  39
  40   ~PacketDroppingTestWriter() override;
  41
  42   // Must be called before blocking, reordering or delaying (loss is OK). May be
  43   // called after connecting if the helper is not available before.
  44   // |on_can_write| will be triggered when fake-unblocking; ownership will be
  45   // assumed.
  46   void Initialize(QuicConnectionHelperInterface* helper,
  47                   Delegate* on_can_write);
  48
  49   // QuicPacketWriter methods:
  50   WriteResult WritePacket(const char* buffer,
  51                           size_t buf_len,
  52                           const IPAddressNumber& self_address,
  53                           const IPEndPoint& peer_address) override;
  54
  55   bool IsWriteBlocked() const override;
  56
  57   void SetWritable() override;
  58
  59   // Writes out any packet which should have been sent by now
  60   // to the contained writer and returns the time
  61   // for the next delayed packet to be written.
  62   QuicTime ReleaseOldPackets();
  63
  64   void OnCanWrite();
  65
  66   // The percent of time a packet is simulated as being lost.
  67   void set_fake_packet_loss_percentage(int32 fake_packet_loss_percentage) {
  68     base::AutoLock locked(config_mutex_);
  69     fake_packet_loss_percentage_ = fake_packet_loss_percentage;
  70   }
  71
  72   // The percent of time WritePacket will block and set WriteResult's status
  73   // to WRITE_STATUS_BLOCKED.
  74   void set_fake_blocked_socket_percentage(
  75       int32 fake_blocked_socket_percentage) {
  76     DCHECK(clock_);
  77     base::AutoLock locked(config_mutex_);
  78     fake_blocked_socket_percentage_  = fake_blocked_socket_percentage;
  79   }
  80
  81   // The percent of time a packet is simulated as being reordered.
  82   void set_fake_reorder_percentage(int32 fake_packet_reorder_percentage) {
  83     DCHECK(clock_);
  84     base::AutoLock locked(config_mutex_);
  85     DCHECK(!fake_packet_delay_.IsZero());
  86     fake_packet_reorder_percentage_ = fake_packet_reorder_percentage;
  87   }
  88
  89   // The delay before writing this packet.
  90   void set_fake_packet_delay(QuicTime::Delta fake_packet_delay) {
  91     DCHECK(clock_);
  92     base::AutoLock locked(config_mutex_);
  93     fake_packet_delay_  = fake_packet_delay;
  94   }
  95
  96   // The maximum bandwidth and buffer size of the connection.  When these are
  97   // set, packets will be delayed until a connection with that bandwidth would
  98   // transmit it.  Once the |buffer_size| is reached, all new packets are
  99   // dropped.
 100   void set_max_bandwidth_and_buffer_size(QuicBandwidth fake_bandwidth,
 101                                          QuicByteCount buffer_size) {
 102     DCHECK(clock_);
 103     base::AutoLock locked(config_mutex_);
 104     fake_bandwidth_ = fake_bandwidth;
 105     buffer_size_ = buffer_size;
 106   }
 107
 108   // Useful for reproducing very flaky issues.
 109   void set_seed(uint64 seed) {
 110     simple_random_.set_seed(seed);
 111   }
 112
 113  private:
 114   // Writes out the next packet to the contained writer and returns the time
 115   // for the next delayed packet to be written.
 116   QuicTime ReleaseNextPacket();
 117
 118   // A single packet which will be sent at the supplied send_time.
 119   struct DelayedWrite {
 120    public:
 121     DelayedWrite(const char* buffer,
 122                  size_t buf_len,
 123                  const IPAddressNumber& self_address,
 124                  const IPEndPoint& peer_address,
 125                  QuicTime send_time);
 126     ~DelayedWrite();
 127
 128     std::string buffer;
 129     const IPAddressNumber self_address;
 130     const IPEndPoint peer_address;
 131     QuicTime send_time;
 132   };
 133
 134   typedef std::list<DelayedWrite> DelayedPacketList;
 135
 136   const QuicClock* clock_;
 137   scoped_ptr<QuicAlarm> write_unblocked_alarm_;
 138   scoped_ptr<QuicAlarm> delay_alarm_;
 139   scoped_ptr<Delegate> on_can_write_;
 140   net::test::SimpleRandom simple_random_;
 141   // Stored packets delayed by fake packet delay or bandwidth restrictions.
 142   DelayedPacketList delayed_packets_;
 143   QuicByteCount cur_buffer_size_;
 144
 145   base::Lock config_mutex_;
 146   int32 fake_packet_loss_percentage_;
 147   int32 fake_blocked_socket_percentage_;
 148   int32 fake_packet_reorder_percentage_;
 149   QuicTime::Delta fake_packet_delay_;
 150   QuicBandwidth fake_bandwidth_;
 151   QuicByteCount buffer_size_;
 152
 153   DISALLOW_COPY_AND_ASSIGN(PacketDroppingTestWriter);
 154 };
 155
 156 }  // namespace test
 157 }  // namespace tools
 158 }  // namespace net
 159
 160 #endif  // NET_TOOLS_QUIC_TEST_TOOLS_PACKET_DROPPING_TEST_WRITER_H_