pktfifo.hh revision 11006 
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;
42
43struct PacketFifoEntry
44{
45    EthPacketPtr packet;
46    uint64_t number;
47    unsigned slack;
48    int priv;
49
50    PacketFifoEntry()
51    {
52        clear();
53    }
54
55    PacketFifoEntry(const PacketFifoEntry &s)
56        : packet(s.packet), number(s.number), slack(s.slack), priv(s.priv)
57    {
58    }
59
60    PacketFifoEntry(EthPacketPtr p, uint64_t n)
61        : packet(p), number(n), slack(0), priv(-1)
62    {
63    }
64
65    void clear()
66    {
67        packet = NULL;
68        number = 0;
69        slack = 0;
70        priv = -1;
71    }
72
73    void serialize(const std::string &base, CheckpointOut &cp) const;
74    void unserialize(const std::string &base, CheckpointIn &cp);
75};
76
77class PacketFifo
78{
79  public:
80
81    typedef std::list<PacketFifoEntry> fifo_list;
82    typedef fifo_list::iterator iterator;
83    typedef fifo_list::const_iterator const_iterator;
84
85  protected:
86    std::list<PacketFifoEntry> fifo;
87    uint64_t _counter;
88    unsigned _maxsize;
89    unsigned _size;
90    unsigned _reserved;
91
92  public:
93    explicit PacketFifo(int max)
94        : _counter(0), _maxsize(max), _size(0), _reserved(0) {}
95    virtual ~PacketFifo() {}
96
97    unsigned packets() const { return fifo.size(); }
98    unsigned maxsize() const { return _maxsize; }
99    unsigned size() const { return _size; }
100    unsigned reserved() const { return _reserved; }
101    unsigned avail() const { return _maxsize - _size - _reserved; }
102    bool empty() const { return size() <= 0; }
103    bool full() const { return avail() <= 0; }
104
105    unsigned
106    reserve(unsigned len = 0)
107    {
108        _reserved += len;
109        assert(avail() >= 0);
110        return _reserved;
111    }
112
113    iterator begin() { return fifo.begin(); }
114    iterator end() { return fifo.end(); }
115
116    const_iterator begin() const { return fifo.begin(); }
117    const_iterator end() const { return fifo.end(); }
118
119    EthPacketPtr front() { return fifo.begin()->packet; }
120
121    bool push(EthPacketPtr ptr)
122    {
123        assert(ptr->length);
124        assert(_reserved <= ptr->length);
125        if (avail() < ptr->length - _reserved)
126            return false;
127
128        _size += ptr->length;
129
130        PacketFifoEntry entry;
131        entry.packet = ptr;
132        entry.number = _counter++;
133        fifo.push_back(entry);
134        _reserved = 0;
135        return true;
136    }
137
138    void pop()
139    {
140        if (empty())
141            return;
142
143        iterator entry = fifo.begin();
144        _size -= entry->packet->length;
145        _size -= entry->slack;
146        entry->packet = NULL;
147        fifo.pop_front();
148    }
149
150    void clear()
151    {
152        for (iterator i = begin(); i != end(); ++i)
153            i->clear();
154        fifo.clear();
155        _size = 0;
156        _reserved = 0;
157    }
158
159    void remove(iterator i)
160    {
161        if (i != fifo.begin()) {
162            iterator prev = i;
163            --prev;
164            assert(prev != fifo.end());
165            prev->slack += i->packet->length;
166            prev->slack += i->slack;
167        } else {
168            _size -= i->packet->length;
169            _size -= i->slack;
170        }
171
172        i->clear();
173        fifo.erase(i);
174    }
175
176    bool copyout(void *dest, unsigned offset, unsigned len);
177
178    int countPacketsBefore(const_iterator i) const
179    {
180        if (i == fifo.end())
181            return 0;
182        return i->number - fifo.begin()->number;
183    }
184
185    int countPacketsAfter(const_iterator i) const
186    {
187        auto end = fifo.end();
188        if (i == end)
189            return 0;
190        return (--end)->number - i->number;
191    }
192
193    void check() const
194    {
195        unsigned total = 0;
196        for (auto i = begin(); i != end(); ++i)
197            total += i->packet->length + i->slack;
198
199        if (total != _size)
200            panic("total (%d) is not == to size (%d)\n", total, _size);
201    }
202
203/**
204 * Serialization stuff
205 */
206  public:
207    void serialize(const std::string &base, CheckpointOut &cp) const;
208    void unserialize(const std::string &base, CheckpointIn &cp);
209};
210
211#endif // __DEV_PKTFIFO_HH__
212