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