dev/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_PKTFIFO_HH__
  30 #define __DEV_PKTFIFO_HH__
  31
  32 #include <iosfwd>
  33 #include <list>
  34 #include <string>
  35
  36 #include "dev/etherpkt.hh"
  37 #include "sim/serialize.hh"
  38
  39 class Checkpoint;
  40 class PacketFifo
  41 {
  42   public:
  43     typedef std::list<PacketPtr> fifo_list;
  44     typedef fifo_list::iterator iterator;
  45
  46   protected:
  47     std::list<PacketPtr> fifo;
  48     int _maxsize;
  49     int _size;
  50     int _reserved;
  51
  52   public:
  53     explicit PacketFifo(int max) : _maxsize(max), _size(0), _reserved(0) {}
  54     virtual ~PacketFifo() {}
  55
  56     int packets() const { return fifo.size(); }
  57     int maxsize() const { return _maxsize; }
  58     int size() const { return _size; }
  59     int reserved() const { return _reserved; }
  60     int avail() const { return _maxsize - _size - _reserved; }
  61     bool empty() const { return size() <= 0; }
  62     bool full() const { return avail() <= 0; }
  63
  64     int reserve(int len = 0)
  65     {
  66         _reserved += len;
  67         assert(avail() >= 0);
  68         return _reserved;
  69     }
  70
  71     iterator begin() { return fifo.begin(); }
  72     iterator end() { return fifo.end(); }
  73
  74     PacketPtr front() { return fifo.front(); }
  75
  76     bool push(PacketPtr ptr)
  77     {
  78         assert(ptr->length);
  79         assert(_reserved <= ptr->length);
  80         assert(ptr->slack == 0);
  81         if (avail() < ptr->length - _reserved)
  82             return false;
  83
  84         _size += ptr->length;
  85         fifo.push_back(ptr);
  86         _reserved = 0;
  87         return true;
  88     }
  89
  90     void pop()
  91     {
  92         if (empty())
  93             return;
  94
  95         PacketPtr &packet = fifo.front();
  96         _size -= packet->length;
  97         _size -= packet->slack;
  98         packet->slack = 0;
  99         packet = NULL;
 100         fifo.pop_front();
 101     }
 102
 103     void clear()
 104     {
 105         for (iterator i = begin(); i != end(); ++i)
 106             (*i)->slack = 0;
 107         fifo.clear();
 108         _size = 0;
 109         _reserved = 0;
 110     }
 111
 112     void remove(iterator i)
 113     {
 114         PacketPtr &packet = *i;
 115         if (i != fifo.begin()) {
 116             iterator prev = i;
 117             --prev;
 118             assert(prev != fifo.end());
 119             (*prev)->slack += packet->length;
 120         } else {
 121             _size -= packet->length;
 122             _size -= packet->slack;
 123         }
 124
 125         packet->slack = 0;
 126         packet = NULL;
 127         fifo.erase(i);
 128     }
 129
 130     bool copyout(void *dest, int offset, int len);
 131
 132     int countPacketsBefore(iterator end)
 133     {
 134         iterator i = fifo.begin();
 135         int count = 0;
 136
 137         while (i != end) {
 138             ++count;
 139             ++i;
 140         }
 141
 142         return count;
 143     }
 144
 145     int countPacketsAfter(iterator i)
 146     {
 147         iterator end = fifo.end();
 148         int count = 0;
 149
 150         while (i != end) {
 151             ++count;
 152             ++i;
 153         }
 154
 155         return count;
 156     }
 157
 158
 159 /**
 160  * Serialization stuff
 161  */
 162   public:
 163     void serialize(const std::string &base, std::ostream &os);
 164     void unserialize(const std::string &base,
 165                      Checkpoint *cp, const std::string &section);
 166 };
 167
 168 #endif // __DEV_PKTFIFO_HH__