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 "systemc/core/process.hh"
31
32#include "base/logging.hh"
33#include "systemc/core/event.hh"
34#include "systemc/core/scheduler.hh"
35
36namespace sc_gem5
37{
38
39SensitivityTimeout::SensitivityTimeout(Process *p, ::sc_core::sc_time t) :
40 Sensitivity(p), timeoutEvent(this), time(t)
41{
42 Tick when = scheduler.getCurTick() + time.value();
43 scheduler.schedule(&timeoutEvent, when);
44}
45
46SensitivityTimeout::~SensitivityTimeout()
47{
48 if (timeoutEvent.scheduled())
49 scheduler.deschedule(&timeoutEvent);
50}
51
52void
53SensitivityTimeout::timeout()
54{
55 scheduler.eventHappened();
56 notify();
57}
58
59SensitivityEvent::SensitivityEvent(
60 Process *p, const ::sc_core::sc_event *e) : Sensitivity(p), event(e)
61{
62 Event::getFromScEvent(event)->addSensitivity(this);
63}
64
65SensitivityEvent::~SensitivityEvent()
66{
67 Event::getFromScEvent(event)->delSensitivity(this);
68}
69
70SensitivityEventAndList::SensitivityEventAndList(
71 Process *p, const ::sc_core::sc_event_and_list *list) :
72 Sensitivity(p), list(list), count(0)
73{
74 for (auto e: list->events)
75 Event::getFromScEvent(e)->addSensitivity(this);
76}
77
78SensitivityEventAndList::~SensitivityEventAndList()
79{
80 for (auto e: list->events)
81 Event::getFromScEvent(e)->delSensitivity(this);
82}
83
84void
85SensitivityEventAndList::notifyWork(Event *e)
86{
87 e->delSensitivity(this);
88 count++;
89 if (count == list->events.size())
90 process->satisfySensitivity(this);
91}
92
93SensitivityEventOrList::SensitivityEventOrList(
94 Process *p, const ::sc_core::sc_event_or_list *list) :
95 Sensitivity(p), list(list)
96{
97 for (auto e: list->events)
98 Event::getFromScEvent(e)->addSensitivity(this);
99}
100
101SensitivityEventOrList::~SensitivityEventOrList()
102{
103 for (auto e: list->events)
104 Event::getFromScEvent(e)->delSensitivity(this);
105}
106
107
108class UnwindExceptionReset : public ::sc_core::sc_unwind_exception
109{
110 public:
111 const char *what() const throw() override { return "RESET"; }
112 bool is_reset() const override { return true; }
113};
114
115class UnwindExceptionKill : public ::sc_core::sc_unwind_exception
116{
117 public:
118 const char *what() const throw() override { return "KILL"; }
119 bool is_reset() const override { return false; }
120};
121
122template <typename T>
123struct BuiltinExceptionWrapper : public ExceptionWrapperBase
124{
125 public:
126 T t;
127 void throw_it() override { throw t; }
128};
129
130BuiltinExceptionWrapper<UnwindExceptionReset> resetException;
131BuiltinExceptionWrapper<UnwindExceptionKill> killException;
132
133
134void
135Process::forEachKid(const std::function<void(Process *)> &work)
136{
137 for (auto &kid: get_child_objects()) {
138 Process *p_kid = dynamic_cast<Process *>(kid);
139 if (p_kid)
140 work(p_kid);
141 }
142}
143
144void
145Process::suspend(bool inc_kids)
146{
147 if (inc_kids)
148 forEachKid([](Process *p) { p->suspend(true); });
149
150 if (!_suspended) {
151 _suspended = true;
152 _suspendedReady = false;
153 }
154
155 if (procKind() != ::sc_core::SC_METHOD_PROC_ &&
156 scheduler.current() == this) {
157 scheduler.yield();
158 }
159}
160
161void
162Process::resume(bool inc_kids)
163{
164 if (inc_kids)
165 forEachKid([](Process *p) { p->resume(true); });
166
167 if (_suspended) {
168 _suspended = false;
169 if (_suspendedReady)
170 ready();
171 _suspendedReady = false;
172 }
173}
174
175void
176Process::disable(bool inc_kids)
177{
178 if (inc_kids)
179 forEachKid([](Process *p) { p->disable(true); });
180
181 _disabled = true;
182}
183
184void
185Process::enable(bool inc_kids)
186{
187
188 if (inc_kids)
189 forEachKid([](Process *p) { p->enable(true); });
190
191 _disabled = false;
192}
193
194void
195Process::kill(bool inc_kids)
196{
197 // Update our state.
198 _terminated = true;
199 _isUnwinding = true;
200
201 // Propogate the kill to our children no matter what happens to us.
202 if (inc_kids)
203 forEachKid([](Process *p) { p->kill(true); });
204
205 // If we're in the middle of unwinding, ignore the kill request.
206 if (_isUnwinding)
207 return;
208
209 // Inject the kill exception into this process.
210 injectException(killException);
211
212 _terminatedEvent.notify();
213}
214
215void
216Process::reset(bool inc_kids)
217{
218 // Update our state.
219 _isUnwinding = true;
220
221 // Propogate the reset to our children no matter what happens to us.
222 if (inc_kids)
223 forEachKid([](Process *p) { p->reset(true); });
224
225 // If we're in the middle of unwinding, ignore the reset request.
226 if (_isUnwinding)
227 return;
228
229 // Inject the reset exception into this process.
230 injectException(resetException);
231
232 _resetEvent.notify();
233}
234
235void
236Process::throw_it(ExceptionWrapperBase &exc, bool inc_kids)
237{
238 if (inc_kids)
239 forEachKid([&exc](Process *p) { p->throw_it(exc, true); });
240}
241
242void
243Process::injectException(ExceptionWrapperBase &exc)
244{
245 excWrapper = &exc;
246 // Let this process preempt us.
247};
248
249void
250Process::syncResetOn(bool inc_kids)
251{
252 if (inc_kids)
253 forEachKid([](Process *p) { p->syncResetOn(true); });
254
255 _syncReset = true;
256}
257
258void
259Process::syncResetOff(bool inc_kids)
260{
261 if (inc_kids)
262 forEachKid([](Process *p) { p->syncResetOff(true); });
263
264 _syncReset = false;
265}
266
267void
268Process::dontInitialize()
269{
270 scheduler.dontInitialize(this);
271}
272
273void
274Process::finalize()
275{
276 for (auto &s: pendingStaticSensitivities) {
277 s->finalize(staticSensitivities);
278 delete s;
279 s = nullptr;
280 }
281 pendingStaticSensitivities.clear();
282};
283
284void
285Process::run()
286{
287 bool reset;
288 do {
289 reset = false;
290 try {
291 func->call();
292 } catch(::sc_core::sc_unwind_exception exc) {
293 reset = exc.is_reset();
294 }
295 } while (reset);
296 _terminated = true;
297}
298
299void
300Process::addStatic(PendingSensitivity *s)
301{
302 pendingStaticSensitivities.push_back(s);
303}
304
305void
306Process::setDynamic(Sensitivity *s)
307{
308 delete dynamicSensitivity;
309 dynamicSensitivity = s;
310}
311
312void
313Process::satisfySensitivity(Sensitivity *s)
314{
315 // If there's a dynamic sensitivity and this wasn't it, ignore.
316 if (dynamicSensitivity && dynamicSensitivity != s)
317 return;
318
319 setDynamic(nullptr);
320 ready();
321}
322
323void
324Process::ready()
325{
326 if (suspended())
327 _suspendedReady = true;
328 else
329 scheduler.ready(this);
330}
331
332Process::Process(const char *name, ProcessFuncWrapper *func,
333 bool _dynamic, bool needs_start) :
334 ::sc_core::sc_object(name), excWrapper(nullptr), func(func),
335 _needsStart(needs_start), _dynamic(_dynamic), _isUnwinding(false),
336 _terminated(false), _suspended(false), _disabled(false),
337 _syncReset(false), refCount(0), stackSize(::Fiber::DefaultStackSize),
338 dynamicSensitivity(nullptr)
339{
340 _newest = this;
341}
342
343Process *Process::_newest;
344
345void
346throw_it_wrapper(Process *p, ExceptionWrapperBase &exc, bool inc_kids)
347{
348 p->throw_it(exc, inc_kids);
349}
350
351} // namespace sc_gem5