sc_signal.cc revision 13278:a059617d0d44 
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#include <sstream>
31
32#include "systemc/core/scheduler.hh"
33#include "systemc/ext/channel/sc_signal.hh"
34#include "systemc/ext/core/sc_main.hh"
35
36namespace sc_gem5
37{
38
39ScSignalBase::ScSignalBase(const char *name) :
40    sc_core::sc_prim_channel(name), _changeStamp(~0ULL),
41    _gem5WriterPort(nullptr)
42{}
43
44ScSignalBase::~ScSignalBase() {}
45
46const sc_core::sc_event &
47ScSignalBase::defaultEvent() const
48{
49    return valueChangedEvent();
50}
51
52const sc_core::sc_event &
53ScSignalBase::valueChangedEvent() const
54{
55    return _valueChangedEvent;
56}
57
58bool
59ScSignalBase::event() const
60{
61    return _changeStamp == getChangeStamp();
62}
63
64void
65ScSignalBase::_signalChange()
66{
67    _changeStamp = getChangeStamp();
68    _valueChangedEvent.notify(sc_core::SC_ZERO_TIME);
69}
70
71namespace
72{
73
74void
75reportSignalError(ScSignalBase *sig, sc_core::sc_object *first,
76        sc_core::sc_object *second, bool delta_conflict=false)
77{
78    std::ostringstream ss;
79    ss << "\n signal " << "`" << sig->name() << "' (" << sig->kind() << ")";
80    ss << "\n first driver `" << first->name() << "' (" <<
81        first->kind() << ")";
82    ss << "\n second driver `" << second->name() << "' (" <<
83        second->kind() << ")";
84    if (delta_conflict) {
85        ss << "\n conflicting write in delta cycle " <<
86            sc_core::sc_delta_count();
87    }
88    SC_REPORT_ERROR(
89            "(E115) sc_signal<T> cannot have more than one driver",
90            ss.str().c_str());
91}
92
93} // anonymous namespace
94
95WriteChecker<sc_core::SC_ONE_WRITER>::WriteChecker(ScSignalBase *_sig) :
96    sig(_sig), firstPort(nullptr), proc(nullptr), writeStamp(~0ULL)
97{}
98
99void
100WriteChecker<sc_core::SC_ONE_WRITER>::checkPort(sc_core::sc_port_base &port,
101        std::string iface_type_name, std::string out_name)
102{
103    if (iface_type_name == out_name) {
104        if (firstPort)
105            reportSignalError(sig, firstPort, &port);
106        firstPort = &port;
107    }
108}
109
110void
111WriteChecker<sc_core::SC_ONE_WRITER>::checkWriter()
112{
113    Process *p = scheduler.current();
114    if (!p)
115        return;
116    uint64_t stamp = getChangeStamp();
117    if (proc && proc != p)
118        reportSignalError(sig, proc, p);
119    proc = p;
120    writeStamp = stamp;
121}
122
123WriteChecker<sc_core::SC_MANY_WRITERS>::WriteChecker(ScSignalBase *_sig) :
124    sig(_sig), proc(nullptr), writeStamp(~0ULL)
125{}
126
127void
128WriteChecker<sc_core::SC_MANY_WRITERS>::checkPort(sc_core::sc_port_base &port,
129        std::string iface_type_name, std::string out_name)
130{
131    return;
132}
133
134void
135WriteChecker<sc_core::SC_MANY_WRITERS>::checkWriter()
136{
137    Process *p = scheduler.current();
138    if (!p)
139        return;
140    uint64_t stamp = getChangeStamp();
141    if (writeStamp == stamp && proc && proc != p)
142        reportSignalError(sig, proc, p, writeStamp == stamp);
143    proc = p;
144    writeStamp = stamp;
145}
146
147ScSignalBaseBinary::ScSignalBaseBinary(const char *_name) :
148    ScSignalBase(_name), _posStamp(~0ULL), _negStamp(~0ULL)
149{}
150
151const sc_core::sc_event &
152ScSignalBaseBinary::posedgeEvent() const
153{
154    return _posedgeEvent;
155}
156
157const sc_core::sc_event &
158ScSignalBaseBinary::negedgeEvent() const
159{
160    return _negedgeEvent;
161}
162
163bool
164ScSignalBaseBinary::posedge() const
165{
166    return _posStamp == getChangeStamp();
167}
168bool
169
170ScSignalBaseBinary::negedge() const
171{
172    return _negStamp == getChangeStamp();
173}
174
175} // namespace sc_gem5
176