src/dev/net/pktfifo.hh

   1 /*
   2  * Copyright (c) 2004-2005 The Regents of The University of Michigan
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met: redistributions of source code must retain the above copyright
   8  * notice, this list of conditions and the following disclaimer;
   9  * redistributions in binary form must reproduce the above copyright
  10  * notice, this list of conditions and the following disclaimer in the
  11  * documentation and/or other materials provided with the distribution;
  12  * neither the name of the copyright holders nor the names of its
  13  * contributors may be used to endorse or promote products derived from
  14  * this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  19  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  20  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  *
  28  * Authors: Nathan Binkert
  29  */
  30
  31 #ifndef __DEV_NET_PKTFIFO_HH__
  32 #define __DEV_NET_PKTFIFO_HH__
  33
  34 #include <iosfwd>
  35 #include <list>
  36 #include <string>
  37
  38 #include "base/logging.hh"
  39 #include "dev/net/etherpkt.hh"
  40 #include "sim/serialize.hh"
  41
  42 class Checkpoint;
  43
  44 struct PacketFifoEntry
  45 {
  46     EthPacketPtr packet;
  47     uint64_t number;
  48     unsigned slack;
  49     int priv;
  50
  51     PacketFifoEntry()
  52     {
  53         clear();
  54     }
  55
  56     PacketFifoEntry(const PacketFifoEntry &s)
  57         : packet(s.packet), number(s.number), slack(s.slack), priv(s.priv)
  58     {
  59     }
  60
  61     PacketFifoEntry(EthPacketPtr p, uint64_t n)
  62         : packet(p), number(n), slack(0), priv(-1)
  63     {
  64     }
  65
  66     void clear()
  67     {
  68         packet = NULL;
  69         number = 0;
  70         slack = 0;
  71         priv = -1;
  72     }
  73
  74     void serialize(const std::string &base, CheckpointOut &cp) const;
  75     void unserialize(const std::string &base, CheckpointIn &cp);
  76 };
  77
  78 class PacketFifo
  79 {
  80   public:
  81
  82     typedef std::list<PacketFifoEntry> fifo_list;
  83     typedef fifo_list::iterator iterator;
  84     typedef fifo_list::const_iterator const_iterator;
  85
  86   protected:
  87     std::list<PacketFifoEntry> fifo;
  88     uint64_t _counter;
  89     unsigned _maxsize;
  90     unsigned _size;
  91     unsigned _reserved;
  92
  93   public:
  94     explicit PacketFifo(int max)
  95         : _counter(0), _maxsize(max), _size(0), _reserved(0) {}
  96     virtual ~PacketFifo() {}
  97
  98     unsigned packets() const { return fifo.size(); }
  99     unsigned maxsize() const { return _maxsize; }
 100     unsigned size() const { return _size; }
 101     unsigned reserved() const { return _reserved; }
 102     unsigned avail() const { return _maxsize - _size - _reserved; }
 103     bool empty() const { return size() <= 0; }
 104     bool full() const { return avail() <= 0; }
 105
 106     unsigned
 107     reserve(unsigned len = 0)
 108     {
 109         assert(avail() >= len);
 110         _reserved += len;
 111         return _reserved;
 112     }
 113
 114     iterator begin() { return fifo.begin(); }
 115     iterator end() { return fifo.end(); }
 116
 117     const_iterator begin() const { return fifo.begin(); }
 118     const_iterator end() const { return fifo.end(); }
 119
 120     EthPacketPtr front() { return fifo.begin()->packet; }
 121
 122     bool push(EthPacketPtr ptr)
 123     {
 124         assert(ptr->length);
 125         assert(_reserved <= ptr->length);
 126         if (avail() < ptr->length - _reserved)
 127             return false;
 128
 129         _size += ptr->length;
 130
 131         PacketFifoEntry entry;
 132         entry.packet = ptr;
 133         entry.number = _counter++;
 134         fifo.push_back(entry);
 135         _reserved = 0;
 136         return true;
 137     }
 138
 139     void pop()
 140     {
 141         if (empty())
 142             return;
 143
 144         iterator entry = fifo.begin();
 145         _size -= entry->packet->length;
 146         _size -= entry->slack;
 147         entry->packet = NULL;
 148         fifo.pop_front();
 149     }
 150
 151     void clear()
 152     {
 153         for (iterator i = begin(); i != end(); ++i)
 154             i->clear();
 155         fifo.clear();
 156         _size = 0;
 157         _reserved = 0;
 158     }
 159
 160     void remove(iterator i)
 161     {
 162         if (i != fifo.begin()) {
 163             iterator prev = i;
 164             --prev;
 165             assert(prev != fifo.end());
 166             prev->slack += i->packet->length;
 167             prev->slack += i->slack;
 168         } else {
 169             _size -= i->packet->length;
 170             _size -= i->slack;
 171         }
 172
 173         i->clear();
 174         fifo.erase(i);
 175     }
 176
 177     bool copyout(void *dest, unsigned offset, unsigned len);
 178
 179     int countPacketsBefore(const_iterator i) const
 180     {
 181         if (i == fifo.end())
 182             return 0;
 183         return i->number - fifo.begin()->number;
 184     }
 185
 186     int countPacketsAfter(const_iterator i) const
 187     {
 188         auto end = fifo.end();
 189         if (i == end)
 190             return 0;
 191         return (--end)->number - i->number;
 192     }
 193
 194     void check() const
 195     {
 196         unsigned total = 0;
 197         for (auto i = begin(); i != end(); ++i)
 198             total += i->packet->length + i->slack;
 199
 200         if (total != _size)
 201             panic("total (%d) is not == to size (%d)\n", total, _size);
 202     }
 203
 204 /**
 205  * Serialization stuff
 206  */
 207   public:
 208     void serialize(const std::string &base, CheckpointOut &cp) const;
 209     void unserialize(const std::string &base, CheckpointIn &cp);
 210 };
 211
 212 #endif // __DEV_NET_PKTFIFO_HH__