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
  29 #ifndef __DEV_NET_PKTFIFO_HH__
  30 #define __DEV_NET_PKTFIFO_HH__
  31
  32 #include <iosfwd>
  33 #include <list>
  34 #include <string>
  35
  36 #include "base/logging.hh"
  37 #include "dev/net/etherpkt.hh"
  38 #include "sim/serialize.hh"
  39
  40 class Checkpoint;
  41
  42 struct PacketFifoEntry
  43 {
  44     EthPacketPtr packet;
  45     uint64_t number;
  46     unsigned slack;
  47     int priv;
  48
  49     PacketFifoEntry()
  50     {
  51         clear();
  52     }
  53
  54     PacketFifoEntry(const PacketFifoEntry &s)
  55         : packet(s.packet), number(s.number), slack(s.slack), priv(s.priv)
  56     {
  57     }
  58
  59     PacketFifoEntry(EthPacketPtr p, uint64_t n)
  60         : packet(p), number(n), slack(0), priv(-1)
  61     {
  62     }
  63
  64     void clear()
  65     {
  66         packet = NULL;
  67         number = 0;
  68         slack = 0;
  69         priv = -1;
  70     }
  71
  72     void serialize(const std::string &base, CheckpointOut &cp) const;
  73     void unserialize(const std::string &base, CheckpointIn &cp);
  74 };
  75
  76 class PacketFifo
  77 {
  78   public:
  79
  80     typedef std::list<PacketFifoEntry> fifo_list;
  81     typedef fifo_list::iterator iterator;
  82     typedef fifo_list::const_iterator const_iterator;
  83
  84   protected:
  85     std::list<PacketFifoEntry> fifo;
  86     uint64_t _counter;
  87     unsigned _maxsize;
  88     unsigned _size;
  89     unsigned _reserved;
  90
  91   public:
  92     explicit PacketFifo(int max)
  93         : _counter(0), _maxsize(max), _size(0), _reserved(0) {}
  94     virtual ~PacketFifo() {}
  95
  96     unsigned packets() const { return fifo.size(); }
  97     unsigned maxsize() const { return _maxsize; }
  98     unsigned size() const { return _size; }
  99     unsigned reserved() const { return _reserved; }
 100     unsigned avail() const { return _maxsize - _size - _reserved; }
 101     bool empty() const { return size() <= 0; }
 102     bool full() const { return avail() <= 0; }
 103
 104     unsigned
 105     reserve(unsigned len = 0)
 106     {
 107         assert(avail() >= len);
 108         _reserved += len;
 109         return _reserved;
 110     }
 111
 112     iterator begin() { return fifo.begin(); }
 113     iterator end() { return fifo.end(); }
 114
 115     const_iterator begin() const { return fifo.begin(); }
 116     const_iterator end() const { return fifo.end(); }
 117
 118     EthPacketPtr front() { return fifo.begin()->packet; }
 119
 120     bool push(EthPacketPtr ptr)
 121     {
 122         assert(ptr->length);
 123         assert(_reserved <= ptr->length);
 124         if (avail() < ptr->length - _reserved)
 125             return false;
 126
 127         _size += ptr->length;
 128
 129         PacketFifoEntry entry;
 130         entry.packet = ptr;
 131         entry.number = _counter++;
 132         fifo.push_back(entry);
 133         _reserved = 0;
 134         return true;
 135     }
 136
 137     void pop()
 138     {
 139         if (empty())
 140             return;
 141
 142         iterator entry = fifo.begin();
 143         _size -= entry->packet->length;
 144         _size -= entry->slack;
 145         entry->packet = NULL;
 146         fifo.pop_front();
 147     }
 148
 149     void clear()
 150     {
 151         for (iterator i = begin(); i != end(); ++i)
 152             i->clear();
 153         fifo.clear();
 154         _size = 0;
 155         _reserved = 0;
 156     }
 157
 158     void remove(iterator i)
 159     {
 160         if (i != fifo.begin()) {
 161             iterator prev = i;
 162             --prev;
 163             assert(prev != fifo.end());
 164             prev->slack += i->packet->length;
 165             prev->slack += i->slack;
 166         } else {
 167             _size -= i->packet->length;
 168             _size -= i->slack;
 169         }
 170
 171         i->clear();
 172         fifo.erase(i);
 173     }
 174
 175     bool copyout(void *dest, unsigned offset, unsigned len);
 176
 177     int countPacketsBefore(const_iterator i) const
 178     {
 179         if (i == fifo.end())
 180             return 0;
 181         return i->number - fifo.begin()->number;
 182     }
 183
 184     int countPacketsAfter(const_iterator i) const
 185     {
 186         auto end = fifo.end();
 187         if (i == end)
 188             return 0;
 189         return (--end)->number - i->number;
 190     }
 191
 192     void check() const
 193     {
 194         unsigned total = 0;
 195         for (auto i = begin(); i != end(); ++i)
 196             total += i->packet->length + i->slack;
 197
 198         if (total != _size)
 199             panic("total (%d) is not == to size (%d)\n", total, _size);
 200     }
 201
 202 /**
 203  * Serialization stuff
 204  */
 205   public:
 206     void serialize(const std::string &base, CheckpointOut &cp) const;
 207     void unserialize(const std::string &base, CheckpointIn &cp);
 208 };
 209
 210 #endif // __DEV_NET_PKTFIFO_HH__