pktfifo.hh revision 10905 
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
84  protected:
85    std::list<PacketFifoEntry> fifo;
86    uint64_t _counter;
87    unsigned _maxsize;
88    unsigned _size;
89    unsigned _reserved;
90
91  public:
92    explicit PacketFifo(int max)
93        : _counter(0), _maxsize(max), _size(0), _reserved(0) {}
94    virtual ~PacketFifo() {}
95
96    unsigned packets() const { return fifo.size(); }
97    unsigned maxsize() const { return _maxsize; }
98    unsigned size() const { return _size; }
99    unsigned reserved() const { return _reserved; }
100    unsigned avail() const { return _maxsize - _size - _reserved; }
101    bool empty() const { return size() <= 0; }
102    bool full() const { return avail() <= 0; }
103
104    unsigned
105    reserve(unsigned len = 0)
106    {
107        _reserved += len;
108        assert(avail() >= 0);
109        return _reserved;
110    }
111
112    iterator begin() { return fifo.begin(); }
113    iterator end() { return fifo.end(); }
114
115    EthPacketPtr front() { return fifo.begin()->packet; }
116
117    bool push(EthPacketPtr ptr)
118    {
119        assert(ptr->length);
120        assert(_reserved <= ptr->length);
121        if (avail() < ptr->length - _reserved)
122            return false;
123
124        _size += ptr->length;
125
126        PacketFifoEntry entry;
127        entry.packet = ptr;
128        entry.number = _counter++;
129        fifo.push_back(entry);
130        _reserved = 0;
131        return true;
132    }
133
134    void pop()
135    {
136        if (empty())
137            return;
138
139        iterator entry = fifo.begin();
140        _size -= entry->packet->length;
141        _size -= entry->slack;
142        entry->packet = NULL;
143        fifo.pop_front();
144    }
145
146    void clear()
147    {
148        for (iterator i = begin(); i != end(); ++i)
149            i->clear();
150        fifo.clear();
151        _size = 0;
152        _reserved = 0;
153    }
154
155    void remove(iterator i)
156    {
157        if (i != fifo.begin()) {
158            iterator prev = i;
159            --prev;
160            assert(prev != fifo.end());
161            prev->slack += i->packet->length;
162            prev->slack += i->slack;
163        } else {
164            _size -= i->packet->length;
165            _size -= i->slack;
166        }
167
168        i->clear();
169        fifo.erase(i);
170    }
171
172    bool copyout(void *dest, unsigned offset, unsigned len);
173
174    int countPacketsBefore(iterator i)
175    {
176        if (i == fifo.end())
177            return 0;
178        return i->number - fifo.begin()->number;
179    }
180
181    int countPacketsAfter(iterator i)
182    {
183        iterator end = fifo.end();
184        if (i == end)
185            return 0;
186        return (--end)->number - i->number;
187    }
188
189    void check()
190    {
191        unsigned total = 0;
192        for (iterator i = begin(); i != end(); ++i)
193            total += i->packet->length + i->slack;
194
195        if (total != _size)
196            panic("total (%d) is not == to size (%d)\n", total, _size);
197    }
198
199/**
200 * Serialization stuff
201 */
202  public:
203    void serialize(const std::string &base, CheckpointOut &cp) const;
204    void unserialize(const std::string &base, CheckpointIn &cp);
205};
206
207#endif // __DEV_PKTFIFO_HH__
208