pktfifo.hh revision 11294 
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_NET_PKTFIFO_HH__
32#define __DEV_NET_PKTFIFO_HH__
33
34#include <iosfwd>
35#include <list>
36#include <string>
37
38#include "base/misc.hh"
39#include "dev/net/etherpkt.hh"
40#include "sim/serialize.hh"
41
42class Checkpoint;
43
44struct PacketFifoEntry
45{
46    EthPacketPtr packet;
47    uint64_t number;
48    unsigned slack;
49    int priv;
50
51    PacketFifoEntry()
52    {
53        clear();
54    }
55
56    PacketFifoEntry(const PacketFifoEntry &s)
57        : packet(s.packet), number(s.number), slack(s.slack), priv(s.priv)
58    {
59    }
60
61    PacketFifoEntry(EthPacketPtr p, uint64_t n)
62        : packet(p), number(n), slack(0), priv(-1)
63    {
64    }
65
66    void clear()
67    {
68        packet = NULL;
69        number = 0;
70        slack = 0;
71        priv = -1;
72    }
73
74    void serialize(const std::string &base, CheckpointOut &cp) const;
75    void unserialize(const std::string &base, CheckpointIn &cp);
76};
77
78class PacketFifo
79{
80  public:
81
82    typedef std::list<PacketFifoEntry> fifo_list;
83    typedef fifo_list::iterator iterator;
84    typedef fifo_list::const_iterator const_iterator;
85
86  protected:
87    std::list<PacketFifoEntry> fifo;
88    uint64_t _counter;
89    unsigned _maxsize;
90    unsigned _size;
91    unsigned _reserved;
92
93  public:
94    explicit PacketFifo(int max)
95        : _counter(0), _maxsize(max), _size(0), _reserved(0) {}
96    virtual ~PacketFifo() {}
97
98    unsigned packets() const { return fifo.size(); }
99    unsigned maxsize() const { return _maxsize; }
100    unsigned size() const { return _size; }
101    unsigned reserved() const { return _reserved; }
102    unsigned avail() const { return _maxsize - _size - _reserved; }
103    bool empty() const { return size() <= 0; }
104    bool full() const { return avail() <= 0; }
105
106    unsigned
107    reserve(unsigned len = 0)
108    {
109        assert(avail() >= len);
110        _reserved += len;
111        return _reserved;
112    }
113
114    iterator begin() { return fifo.begin(); }
115    iterator end() { return fifo.end(); }
116
117    const_iterator begin() const { return fifo.begin(); }
118    const_iterator end() const { return fifo.end(); }
119
120    EthPacketPtr front() { return fifo.begin()->packet; }
121
122    bool push(EthPacketPtr ptr)
123    {
124        assert(ptr->length);
125        assert(_reserved <= ptr->length);
126        if (avail() < ptr->length - _reserved)
127            return false;
128
129        _size += ptr->length;
130
131        PacketFifoEntry entry;
132        entry.packet = ptr;
133        entry.number = _counter++;
134        fifo.push_back(entry);
135        _reserved = 0;
136        return true;
137    }
138
139    void pop()
140    {
141        if (empty())
142            return;
143
144        iterator entry = fifo.begin();
145        _size -= entry->packet->length;
146        _size -= entry->slack;
147        entry->packet = NULL;
148        fifo.pop_front();
149    }
150
151    void clear()
152    {
153        for (iterator i = begin(); i != end(); ++i)
154            i->clear();
155        fifo.clear();
156        _size = 0;
157        _reserved = 0;
158    }
159
160    void remove(iterator i)
161    {
162        if (i != fifo.begin()) {
163            iterator prev = i;
164            --prev;
165            assert(prev != fifo.end());
166            prev->slack += i->packet->length;
167            prev->slack += i->slack;
168        } else {
169            _size -= i->packet->length;
170            _size -= i->slack;
171        }
172
173        i->clear();
174        fifo.erase(i);
175    }
176
177    bool copyout(void *dest, unsigned offset, unsigned len);
178
179    int countPacketsBefore(const_iterator i) const
180    {
181        if (i == fifo.end())
182            return 0;
183        return i->number - fifo.begin()->number;
184    }
185
186    int countPacketsAfter(const_iterator i) const
187    {
188        auto end = fifo.end();
189        if (i == end)
190            return 0;
191        return (--end)->number - i->number;
192    }
193
194    void check() const
195    {
196        unsigned total = 0;
197        for (auto i = begin(); i != end(); ++i)
198            total += i->packet->length + i->slack;
199
200        if (total != _size)
201            panic("total (%d) is not == to size (%d)\n", total, _size);
202    }
203
204/**
205 * Serialization stuff
206 */
207  public:
208    void serialize(const std::string &base, CheckpointOut &cp) const;
209    void unserialize(const std::string &base, CheckpointIn &cp);
210};
211
212#endif // __DEV_NET_PKTFIFO_HH__
213