pktfifo.hh revision 2010 
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
39class Checkpoint;
40class 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/**
131 * Serialization stuff
132 */
133  public:
134    void serialize(const std::string &base, std::ostream &os);
135    void unserialize(const std::string &base,
136                     Checkpoint *cp, const std::string &section);
137};
138
139#endif // __DEV_PKTFIFO_HH__
140