pktfifo.hh revision 1205 
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
39class Checkpoint;
40class 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) {}
50    virtual ~PacketFifo() {}
51
52    int maxsize() const { return _maxsize; }
53    int packets() const { return fifo.size(); }
54    int size() const { return _size + _reserved; }
55    int avail() const { return maxsize() - size(); }
56    bool empty() const { return size() == 0; }
57    bool full() const { return size() >= maxsize(); }
58
59    int reserve(int len = 0)
60    {
61        _reserved += len;
62        assert(avail() >= 0);
63        return _reserved;
64    }
65
66    bool push(PacketPtr ptr)
67    {
68        assert(_reserved <= ptr->length);
69        if (avail() < ptr->length - _reserved)
70            return false;
71
72        _size += ptr->length;
73        fifo.push_back(ptr);
74        _reserved = 0;
75        return true;
76    }
77
78    PacketPtr front() { return fifo.front(); }
79
80    void pop()
81    {
82        if (empty())
83            return;
84
85        _size -= fifo.front()->length;
86        fifo.front() = NULL;
87        fifo.pop_front();
88    }
89
90    void clear()
91    {
92        fifo.clear();
93        _size = 0;
94    }
95
96/**
97 * Serialization stuff
98 */
99  public:
100    void serialize(const std::string &base, std::ostream &os);
101    void unserialize(const std::string &base,
102                     Checkpoint *cp, const std::string &section);
103};
104
105#endif // __DEV_PKTFIFO_HH__
106