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/port.hh"
35#include "systemc/core/scheduler.hh"
36#include "systemc/ext/core/sc_join.hh"
37#include "systemc/ext/core/sc_main.hh"
38#include "systemc/ext/core/sc_process_handle.hh"
39#include "systemc/ext/utils/sc_report_handler.hh"
40
41namespace sc_gem5
42{
43
44class UnwindExceptionReset : public ::sc_core::sc_unwind_exception
45{
46 public:
47 UnwindExceptionReset() { _isReset = true; }
48};
49
50class UnwindExceptionKill : public ::sc_core::sc_unwind_exception
51{
52 public:
53 UnwindExceptionKill() {}
54};
55
56template <typename T>
57struct BuiltinExceptionWrapper : public ExceptionWrapperBase
58{
59 public:
60 T t;
61 void throw_it() override { throw t; }
62};
63
64BuiltinExceptionWrapper<UnwindExceptionReset> resetException;
65BuiltinExceptionWrapper<UnwindExceptionKill> killException;
66
67
68void
69Process::forEachKid(const std::function<void(Process *)> &work)
70{
71 for (auto &kid: get_child_objects()) {
72 Process *p_kid = dynamic_cast<Process *>(kid);
73 if (p_kid)
74 work(p_kid);
75 }
76}
77
78void
79Process::suspend(bool inc_kids)
80{
81 if (inc_kids)
82 forEachKid([](Process *p) { p->suspend(true); });
83
84 if (!_suspended) {
85 _suspended = true;
86 _suspendedReady = scheduler.suspend(this);
87
88 if (procKind() != ::sc_core::SC_METHOD_PROC_ &&
89 scheduler.current() == this) {
90 // This isn't in the spec, but Accellera says that a thread that
91 // self suspends should be marked ready immediately when it's
92 // resumed.
93 _suspendedReady = true;
94 scheduler.yield();
95 }
96 }
97}
98
99void
100Process::resume(bool inc_kids)
101{
102 if (inc_kids)
103 forEachKid([](Process *p) { p->resume(true); });
104
105 if (_suspended) {
106 _suspended = false;
107 if (_suspendedReady)
108 scheduler.resume(this);
109 _suspendedReady = false;
110 }
111}
112
113void
114Process::disable(bool inc_kids)
115{
116 if (inc_kids)
117 forEachKid([](Process *p) { p->disable(true); });
118
119 if (!::sc_core::sc_allow_process_control_corners &&
120 timeoutEvent.scheduled()) {
121 std::string message("attempt to disable a thread with timeout wait: ");
122 message += name();
123 SC_REPORT_ERROR("Undefined process control interaction",
124 message.c_str());
125 }
126
127 _disabled = true;
128}
129
130void
131Process::enable(bool inc_kids)
132{
133
134 if (inc_kids)
135 forEachKid([](Process *p) { p->enable(true); });
136
137 _disabled = false;
138}
139
140void
141Process::kill(bool inc_kids)
142{
143 if (::sc_core::sc_get_status() != ::sc_core::SC_RUNNING) {
144 SC_REPORT_ERROR(
145 "(E572) a process may not be killed before it is initialized",
146 name());
147 }
148
149 // Propogate the kill to our children no matter what happens to us.
150 if (inc_kids)
151 forEachKid([](Process *p) { p->kill(true); });
152
153 // If we're in the middle of unwinding, ignore the kill request.
154 if (_isUnwinding)
155 return;
156
157 // Update our state.
158 terminate();
159 _isUnwinding = true;
160
161 // Make sure this process isn't marked ready
162 popListNode();
163
164 // Inject the kill exception into this process if it's started.
165 if (!_needsStart)
166 injectException(killException);
167}
168
169void
170Process::reset(bool inc_kids)
171{
172 if (::sc_core::sc_get_status() != ::sc_core::SC_RUNNING) {
173 SC_REPORT_ERROR(
174 "(E573) a process may not be asynchronously reset while"
175 "the simulation is not running", name());
176 }
177
178 // Propogate the reset to our children no matter what happens to us.
179 if (inc_kids)
180 forEachKid([](Process *p) { p->reset(true); });
181
182 // If we're in the middle of unwinding, ignore the reset request.
183 if (_isUnwinding)
184 return;
185
186
187 _resetEvent.notify();
188
189 if (_needsStart) {
190 scheduler.runNow(this);
191 } else {
192 _isUnwinding = true;
193 injectException(resetException);
194 }
195}
196
197void
198Process::throw_it(ExceptionWrapperBase &exc, bool inc_kids)
199{
200 if (::sc_core::sc_get_status() != ::sc_core::SC_RUNNING) {
201 SC_REPORT_ERROR(
202 "(E574) throw_it not allowed unless simulation is running ",
203 name());
204 }
205
206 if (inc_kids)
207 forEachKid([&exc](Process *p) { p->throw_it(exc, true); });
208
209 if (_needsStart || _terminated)
210 return;
211
212 injectException(exc);
213}
214
215void
216Process::injectException(ExceptionWrapperBase &exc)
217{
218 excWrapper = &exc;
219 scheduler.runNow(this);
220};
221
222void
223Process::syncResetOn(bool inc_kids)
224{
225 if (inc_kids)
226 forEachKid([](Process *p) { p->syncResetOn(true); });
227
228 _syncReset = true;
229}
230
231void
232Process::syncResetOff(bool inc_kids)
233{
234 if (inc_kids)
235 forEachKid([](Process *p) { p->syncResetOff(true); });
236
237 _syncReset = false;
238}
239
240void
241Process::signalReset(bool set, bool sync)
242{
243 if (set) {
244 waitCount(0);
245 if (sync) {
246 syncResetCount++;
247 } else {
248 asyncResetCount++;
249 cancelTimeout();
250 clearDynamic();
251 scheduler.runNext(this);
252 }
253 } else {
254 if (sync)
255 syncResetCount--;
256 else
257 asyncResetCount--;
258 }
259}
260
261void
262Process::run()
263{
264 bool reset;
265 do {
266 reset = false;
267 try {
268 func->call();
269 } catch(ScHalt) {
270 std::cout << "Terminating process " << name() << std::endl;
271 } catch(const ::sc_core::sc_unwind_exception &exc) {
272 reset = exc.is_reset();
273 _isUnwinding = false;
274 } catch (...) {
275 throw;
276 }
277 } while (reset);
278 needsStart(true);
279}
280
281void
282Process::addStatic(StaticSensitivity *s)
283{
284 staticSensitivities.push_back(s);
285}
286
287void
288Process::setDynamic(DynamicSensitivity *s)
289{
290 if (dynamicSensitivity) {
291 dynamicSensitivity->clear();
292 delete dynamicSensitivity;
293 }
294 dynamicSensitivity = s;
295}
296
297void
298Process::addReset(Reset *reset)
299{
300 resets.push_back(reset);
301}
302
303void
304Process::cancelTimeout()
305{
306 if (timeoutEvent.scheduled())
307 scheduler.deschedule(&timeoutEvent);
308}
309
310void
311Process::setTimeout(::sc_core::sc_time t)
312{
313 cancelTimeout();
314 scheduler.schedule(&timeoutEvent, t);
315}
316
317void
318Process::timeout()
319{
320 // A process is considered timed_out only if it was also waiting for an
321 // event but got a timeout instead.
322 _timedOut = (dynamicSensitivity != nullptr);
323
324 setDynamic(nullptr);
325 if (disabled())
326 return;
327
328 ready();
329}
330
331void
332Process::satisfySensitivity(Sensitivity *s)
333{
334 if (_waitCount) {
335 _waitCount--;
336 return;
337 }
338
339 // If there's a dynamic sensitivity and this wasn't it, ignore.
340 if ((dynamicSensitivity || timeoutEvent.scheduled()) &&
341 dynamicSensitivity != s) {
342 return;
343 }
344
345 _timedOut = false;
346 // This sensitivity should already be cleared by this point, or the event
347 // which triggered it will take care of it.
348 delete dynamicSensitivity;
349 dynamicSensitivity = nullptr;
350 cancelTimeout();
351 ready();
352}
353
354void
355Process::ready()
356{
357 if (disabled())
358 return;
359 if (suspended())
360 _suspendedReady = true;
361 else
362 scheduler.ready(this);
363}
364
365void
366Process::lastReport(::sc_core::sc_report *report)
367{
368 if (report) {
369 _lastReport = std::unique_ptr<::sc_core::sc_report>(
370 new ::sc_core::sc_report(*report));
371 } else {
372 _lastReport = nullptr;
373 }
374}
375
376::sc_core::sc_report *Process::lastReport() const { return _lastReport.get(); }
377
378Process::Process(const char *name, ProcessFuncWrapper *func, bool internal) :
379 ::sc_core::sc_process_b(name), excWrapper(nullptr),
380 timeoutEvent([this]() { this->timeout(); }),
381 func(func), _internal(internal), _timedOut(false), _dontInitialize(false),
382 _needsStart(true), _isUnwinding(false), _terminated(false),
383 _suspended(false), _disabled(false), _syncReset(false), syncResetCount(0),
384 asyncResetCount(0), _waitCount(0), refCount(0),
385 stackSize(::Fiber::DefaultStackSize), dynamicSensitivity(nullptr)
386{
387 _dynamic =
388 (::sc_core::sc_get_status() >
389 ::sc_core::SC_BEFORE_END_OF_ELABORATION);
390 _newest = this;
391}
392
393void
394Process::terminate()
395{
396 _terminated = true;
397 _suspendedReady = false;
398 _suspended = false;
399 _syncReset = false;
400 clearDynamic();
401 cancelTimeout();
402 for (auto s: staticSensitivities) {
403 s->clear();
404 delete s;
405 }
406 staticSensitivities.clear();
407
408 _terminatedEvent.notify();
409
410 for (auto jw: joinWaiters)
411 jw->signal();
412 joinWaiters.clear();
413}
414
415Process *Process::_newest;
416
417void
418throw_it_wrapper(Process *p, ExceptionWrapperBase &exc, bool inc_kids)
419{
420 p->throw_it(exc, inc_kids);
421}
422
423void
424newReset(const sc_core::sc_port_base *pb, Process *p, bool s, bool v)
425{
426 Port *port = Port::fromPort(pb);
427 port->addReset(new Reset(p, s, v));
428}
429
430void
431newReset(const sc_core::sc_signal_in_if<bool> *sig, Process *p, bool s, bool v)
432{
433 Reset *reset = new Reset(p, s, v);
434 if (!reset->install(sig))
435 delete reset;
436}
437
438} // namespace sc_gem5