pktfifo.hh revision 1214 
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), _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__
108