dev/pktfifo.hh

   1 /*
   2  * Copyright (c) 2002-2004 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   protected:
  43     std::list<PacketPtr> fifo;
  44     int _maxsize;
  45     int _size;
  46     int _reserved;
  47
  48   public:
  49     explicit PacketFifo(int max) : _maxsize(max), _size(0), _reserved(0) {}
  50     virtual ~PacketFifo() {}
  51
  52     int packets() const { return fifo.size(); }
  53     int maxsize() const { return _maxsize; }
  54     int size() const { return _size; }
  55     int reserved() const { return _reserved; }
  56     int avail() const { return _maxsize - _size - _reserved; }
  57     bool empty() const { return size() <= 0; }
  58     bool full() const { return avail() <= 0; }
  59
  60     int reserve(int len = 0)
  61     {
  62         _reserved += len;
  63         assert(avail() >= 0);
  64         return _reserved;
  65     }
  66
  67     bool push(PacketPtr ptr)
  68     {
  69         assert(_reserved <= ptr->length);
  70         if (avail() < ptr->length - _reserved)
  71             return false;
  72
  73         _size += ptr->length;
  74         fifo.push_back(ptr);
  75         _reserved = 0;
  76         return true;
  77     }
  78
  79     PacketPtr front() { return fifo.front(); }
  80
  81     void pop()
  82     {
  83         if (empty())
  84             return;
  85
  86         _size -= fifo.front()->length;
  87         fifo.front() = NULL;
  88         fifo.pop_front();
  89     }
  90
  91     void clear()
  92     {
  93         fifo.clear();
  94         _size = 0;
  95         _reserved = 0;
  96     }
  97
  98 /**
  99  * Serialization stuff
 100  */
 101   public:
 102     void serialize(const std::string &base, std::ostream &os);
 103     void unserialize(const std::string &base,
 104                      Checkpoint *cp, const std::string &section);
 105 };
 106
 107 #endif // __DEV_PKTFIFO_HH__