process.cc revision 12962:004cc9133bd6 
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    if (_dynamic)
342        finalize();
343    else
344        scheduler.reg(this);
345}
346
347Process *Process::_newest;
348
349void
350throw_it_wrapper(Process *p, ExceptionWrapperBase &exc, bool inc_kids)
351{
352    p->throw_it(exc, inc_kids);
353}
354
355} // namespace sc_gem5
356