sc_fifo.hh revision 13274:79ce1482d383 
1/*
2 * Copyright 2018 Google, Inc.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met: redistributions of source code must retain the above copyright
7 * notice, this list of conditions and the following disclaimer;
8 * redistributions in binary form must reproduce the above copyright
9 * notice, this list of conditions and the following disclaimer in the
10 * documentation and/or other materials provided with the distribution;
11 * neither the name of the copyright holders nor the names of its
12 * contributors may be used to endorse or promote products derived from
13 * this software without specific prior written permission.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
18 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
19 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
21 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
25 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 *
27 * Authors: Gabe Black
28 */
29
30#ifndef __SYSTEMC_EXT_CHANNEL_SC_FIFO_HH__
31#define __SYSTEMC_EXT_CHANNEL_SC_FIFO_HH__
32
33#include <list>
34#include <string>
35
36#include "../core/sc_module.hh" // for sc_gen_unique_name
37#include "../core/sc_prim.hh"
38#include "../utils/sc_report_handler.hh"
39#include "sc_fifo_in_if.hh"
40#include "sc_fifo_out_if.hh"
41
42namespace sc_core
43{
44
45class sc_port_base;
46class sc_event;
47
48template <class T>
49class sc_fifo : public sc_fifo_in_if<T>,
50                public sc_fifo_out_if<T>,
51                public sc_prim_channel
52{
53  public:
54    explicit sc_fifo(int size=16) :
55            sc_fifo_in_if<T>(), sc_fifo_out_if<T>(),
56            sc_prim_channel(sc_gen_unique_name("fifo")),
57            _size(size), _readsHappened(false), _reader(NULL), _writer(NULL)
58    {}
59    explicit sc_fifo(const char *name, int size=16) :
60            sc_fifo_in_if<T>(), sc_fifo_out_if<T>(),
61            sc_prim_channel(name), _size(size), _readsHappened(false),
62            _reader(NULL), _writer(NULL)
63    {}
64    virtual ~sc_fifo() {}
65
66    virtual void
67    register_port(sc_port_base &port, const char *iface_type_name)
68    {
69        std::string tn(iface_type_name);
70        if (tn == typeid(sc_fifo_in_if<T>).name() ||
71                tn == typeid(sc_fifo_blocking_in_if<T>).name()) {
72            if (_reader) {
73                SC_REPORT_ERROR(
74                        "(E104) sc_fifo<T> cannot have more than one reader",
75                        "");
76            }
77            _reader = &port;
78        } else if (tn == typeid(sc_fifo_out_if<T>).name() ||
79                tn == typeid(sc_fifo_blocking_out_if<T>).name()) {
80            if (_writer) {
81                SC_REPORT_ERROR(
82                        "(E105) sc_fifo<T> cannot have more than one writer",
83                        "");
84            }
85            _writer = &port;
86        } else {
87            SC_REPORT_ERROR("(E107) bind interface to port failed",
88                    "sc_fifo<T> port not recognized");
89        }
90    }
91
92    virtual void
93    read(T &t)
94    {
95        while (num_available() == 0)
96            sc_core::wait(_dataWriteEvent);
97        _readsHappened = true;
98        t = _entries.front();
99        _entries.pop_front();
100        request_update();
101    }
102    virtual T
103    read()
104    {
105        T t;
106        read(t);
107        return t;
108    }
109    virtual bool
110    nb_read(T &t)
111    {
112        if (num_available()) {
113            read(t);
114            return true;
115        } else {
116            return false;
117        }
118    }
119    operator T() { return read(); }
120
121    virtual void
122    write(const T &t)
123    {
124        while (num_free() == 0)
125            sc_core::wait(_dataReadEvent);
126        _pending.emplace_back(t);
127        request_update();
128    }
129    virtual bool
130    nb_write(const T &t)
131    {
132        if (num_free()) {
133            write(t);
134            return true;
135        } else {
136            return false;
137        }
138    }
139    sc_fifo<T> &
140    operator = (const T &t)
141    {
142        write(t);
143        return *this;
144    }
145
146    virtual const sc_event &
147    data_written_event() const
148    {
149        return _dataWriteEvent;
150    }
151    virtual const sc_event &
152    data_read_event() const
153    {
154        return _dataReadEvent;
155    }
156
157    virtual int num_available() const { return _entries.size(); }
158    virtual int
159    num_free() const
160    {
161        return _size - _entries.size() - _pending.size();
162    }
163
164    virtual void
165    print(std::ostream &os=std::cout) const
166    {
167        for (typename ::std::list<T>::iterator pos = _pending.begin();
168                pos != _pending.end(); pos++) {
169            os << *pos << ::std::endl;
170        }
171        for (typename ::std::list<T>::iterator pos = _entries.begin();
172                pos != _entries.end(); pos++) {
173            os << *pos << ::std::endl;
174        }
175    }
176    virtual void
177    dump(std::ostream &os=std::cout) const
178    {
179        os << "name = " << name() << std::endl;
180        int idx = 0;
181        for (typename ::std::list<T>::iterator pos = _pending.begin();
182                pos != _pending.end(); pos++) {
183            os << "value[" << idx++ << "] = " << *pos << ::std::endl;
184        }
185        for (typename ::std::list<T>::iterator pos = _entries.begin();
186                pos != _entries.end(); pos++) {
187            os << "value[" << idx++ << "] = " << *pos << ::std::endl;
188        }
189    }
190    virtual const char *kind() const { return "sc_fifo"; }
191
192  protected:
193    virtual void
194    update()
195    {
196        if (!_pending.empty()) {
197            _dataWriteEvent.notify(SC_ZERO_TIME);
198            _entries.insert(_entries.end(), _pending.begin(), _pending.end());
199            _pending.clear();
200        }
201        if (_readsHappened) {
202            _readsHappened = false;
203            _dataReadEvent.notify(SC_ZERO_TIME);
204        }
205    }
206
207  private:
208    // Disabled
209    sc_fifo(const sc_fifo<T> &) :
210            sc_fifo_in_if<T>(), sc_fifo_in_if<T>(), sc_prim_channel()
211    {}
212    sc_fifo &operator = (const sc_fifo<T> &) { return *this; }
213
214    sc_event _dataReadEvent;
215    sc_event _dataWriteEvent;
216
217    sc_port_base *_reader;
218    sc_port_base *_writer;
219
220    int _size;
221    mutable std::list<T> _entries;
222    mutable std::list<T> _pending;
223    bool _readsHappened;
224};
225
226template <class T>
227inline std::ostream &
228operator << (std::ostream &os, const sc_fifo<T> &f)
229{
230    f.print(os);
231    return os;
232}
233
234} // namespace sc_core
235
236#endif  //__SYSTEMC_EXT_CHANNEL_SC_FIFO_HH__
237