pktfifo.hh revision 2665 
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
41class Checkpoint;
42class 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__
171