src/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  * Authors: Nathan Binkert
  29  */
  30
  31 #ifndef __DEV_PKTFIFO_HH__
  32 #define __DEV_PKTFIFO_HH__
  33
  34 #include <iosfwd>
  35 #include <list>
  36 #include <string>
  37
  38 #include "dev/etherpkt.hh"
  39 #include "sim/serialize.hh"
  40
  41 class Checkpoint;
  42 class PacketFifo
  43 {
  44   public:
  45     typedef std::list<EthPacketPtr> fifo_list;
  46     typedef fifo_list::iterator iterator;
  47
  48   protected:
  49     std::list<EthPacketPtr> fifo;
  50     int _maxsize;
  51     int _size;
  52     int _reserved;
  53
  54   public:
  55     explicit PacketFifo(int max) : _maxsize(max), _size(0), _reserved(0) {}
  56     virtual ~PacketFifo() {}
  57
  58     int packets() const { return fifo.size(); }
  59     int maxsize() const { return _maxsize; }
  60     int size() const { return _size; }
  61     int reserved() const { return _reserved; }
  62     int avail() const { return _maxsize - _size - _reserved; }
  63     bool empty() const { return size() <= 0; }
  64     bool full() const { return avail() <= 0; }
  65
  66     int reserve(int len = 0)
  67     {
  68         _reserved += len;
  69         assert(avail() >= 0);
  70         return _reserved;
  71     }
  72
  73     iterator begin() { return fifo.begin(); }
  74     iterator end() { return fifo.end(); }
  75
  76     EthPacketPtr front() { return fifo.front(); }
  77
  78     bool push(EthPacketPtr ptr)
  79     {
  80         assert(ptr->length);
  81         assert(_reserved <= ptr->length);
  82         assert(ptr->slack == 0);
  83         if (avail() < ptr->length - _reserved)
  84             return false;
  85
  86         _size += ptr->length;
  87         fifo.push_back(ptr);
  88         _reserved = 0;
  89         return true;
  90     }
  91
  92     void pop()
  93     {
  94         if (empty())
  95             return;
  96
  97         EthPacketPtr &packet = fifo.front();
  98         _size -= packet->length;
  99         _size -= packet->slack;
 100         packet->slack = 0;
 101         packet = NULL;
 102         fifo.pop_front();
 103     }
 104
 105     void clear()
 106     {
 107         for (iterator i = begin(); i != end(); ++i)
 108             (*i)->slack = 0;
 109         fifo.clear();
 110         _size = 0;
 111         _reserved = 0;
 112     }
 113
 114     void remove(iterator i)
 115     {
 116         EthPacketPtr &packet = *i;
 117         if (i != fifo.begin()) {
 118             iterator prev = i;
 119             --prev;
 120             assert(prev != fifo.end());
 121             (*prev)->slack += packet->length;
 122         } else {
 123             _size -= packet->length;
 124             _size -= packet->slack;
 125         }
 126
 127         packet->slack = 0;
 128         packet = NULL;
 129         fifo.erase(i);
 130     }
 131
 132     bool copyout(void *dest, int offset, int len);
 133
 134     int countPacketsBefore(iterator end)
 135     {
 136         iterator i = fifo.begin();
 137         int count = 0;
 138
 139         while (i != end) {
 140             ++count;
 141             ++i;
 142         }
 143
 144         return count;
 145     }
 146
 147     int countPacketsAfter(iterator i)
 148     {
 149         iterator end = fifo.end();
 150         int count = 0;
 151
 152         while (i != end) {
 153             ++count;
 154             ++i;
 155         }
 156
 157         return count;
 158     }
 159
 160
 161 /**
 162  * Serialization stuff
 163  */
 164   public:
 165     void serialize(const std::string &base, std::ostream &os);
 166     void unserialize(const std::string &base,
 167                      Checkpoint *cp, const std::string &section);
 168 };
 169
 170 #endif // __DEV_PKTFIFO_HH__