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 "systemc/core/event.hh"
33#include "systemc/core/port.hh"
34#include "systemc/core/scheduler.hh"
35#include "systemc/ext/core/messages.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 && !_terminated) {
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 && !_terminated) {
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(sc_core::SC_ID_PROCESS_CONTROL_CORNER_CASE_,
124                message.c_str());
125    }
126
127    if (!_terminated)
128        _disabled = true;
129}
130
131void
132Process::enable(bool inc_kids)
133{
134
135    if (inc_kids)
136        forEachKid([](Process *p) { p->enable(true); });
137
138    if (!_terminated)
139        _disabled = false;
140}
141
142void
143Process::kill(bool inc_kids)
144{
145    if (::sc_core::sc_get_status() != ::sc_core::SC_RUNNING) {
146        SC_REPORT_ERROR(sc_core::SC_ID_KILL_PROCESS_WHILE_UNITIALIZED_,
147                name());
148    }
149
150    // Propogate the kill to our children no matter what happens to us.
151    if (inc_kids)
152        forEachKid([](Process *p) { p->kill(true); });
153
154    // If we're unwinding or terminated, ignore the kill request.
155    if (_isUnwinding || _terminated)
156        return;
157
158    // Update our state.
159    terminate();
160    _isUnwinding = true;
161
162    // Make sure this process isn't marked ready
163    popListNode();
164
165    // Inject the kill exception into this process if it's started.
166    if (!_needsStart)
167        injectException(killException);
168}
169
170void
171Process::reset(bool inc_kids)
172{
173    if (::sc_core::sc_get_status() != ::sc_core::SC_RUNNING) {
174        SC_REPORT_ERROR(sc_core::SC_ID_RESET_PROCESS_WHILE_NOT_RUNNING_,
175                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 already unwinding or terminated, ignore the reset request.
183    if (_isUnwinding || _terminated)
184        return;
185
186    // Clear suspended ready since we're about to run regardless.
187    _suspendedReady = false;
188
189    _resetEvent.notify();
190
191    if (_needsStart) {
192        scheduler.runNow(this);
193    } else {
194        _isUnwinding = true;
195        injectException(resetException);
196    }
197}
198
199void
200Process::throw_it(ExceptionWrapperBase &exc, bool inc_kids)
201{
202    if (::sc_core::sc_get_status() != ::sc_core::SC_RUNNING)
203        SC_REPORT_ERROR(sc_core::SC_ID_THROW_IT_WHILE_NOT_RUNNING_, name());
204
205    if (inc_kids)
206        forEachKid([&exc](Process *p) { p->throw_it(exc, true); });
207
208    if (_needsStart || _terminated ||
209            procKind() == ::sc_core::SC_METHOD_PROC_) {
210        SC_REPORT_WARNING(sc_core::SC_ID_THROW_IT_IGNORED_, name());
211        return;
212    }
213
214    injectException(exc);
215}
216
217void
218Process::injectException(ExceptionWrapperBase &exc)
219{
220    excWrapper = &exc;
221    scheduler.runNow(this);
222};
223
224void
225Process::syncResetOn(bool inc_kids)
226{
227    if (inc_kids)
228        forEachKid([](Process *p) { p->syncResetOn(true); });
229
230    _syncReset = true;
231}
232
233void
234Process::syncResetOff(bool inc_kids)
235{
236    if (inc_kids)
237        forEachKid([](Process *p) { p->syncResetOff(true); });
238
239    _syncReset = false;
240}
241
242void
243Process::signalReset(bool set, bool sync)
244{
245    if (set) {
246        waitCount(0);
247        if (sync) {
248            syncResetCount++;
249        } else {
250            asyncResetCount++;
251            cancelTimeout();
252            clearDynamic();
253            scheduler.runNext(this);
254        }
255    } else {
256        if (sync)
257            syncResetCount--;
258        else
259            asyncResetCount--;
260    }
261}
262
263void
264Process::run()
265{
266    bool reset;
267    do {
268        reset = false;
269        try {
270            func->call();
271        } catch(ScHalt) {
272            std::cout << "Terminating process " << name() << std::endl;
273        } catch(const ::sc_core::sc_unwind_exception &exc) {
274            reset = exc.is_reset();
275            _isUnwinding = false;
276        } catch (...) {
277            throw;
278        }
279    } while (reset);
280    needsStart(true);
281}
282
283void
284Process::addStatic(StaticSensitivity *s)
285{
286    staticSensitivities.push_back(s);
287}
288
289void
290Process::setDynamic(DynamicSensitivity *s)
291{
292    if (dynamicSensitivity) {
293        dynamicSensitivity->clear();
294        delete dynamicSensitivity;
295    }
296    dynamicSensitivity = s;
297}
298
299void
300Process::addReset(Reset *reset)
301{
302    resets.push_back(reset);
303}
304
305void
306Process::cancelTimeout()
307{
308    if (timeoutEvent.scheduled())
309        scheduler.deschedule(&timeoutEvent);
310}
311
312void
313Process::setTimeout(::sc_core::sc_time t)
314{
315    cancelTimeout();
316    scheduler.schedule(&timeoutEvent, t);
317}
318
319void
320Process::timeout()
321{
322    // A process is considered timed_out only if it was also waiting for an
323    // event but got a timeout instead.
324    _timedOut = (dynamicSensitivity != nullptr);
325
326    setDynamic(nullptr);
327    if (disabled())
328        return;
329
330    ready();
331}
332
333void
334Process::satisfySensitivity(Sensitivity *s)
335{
336    if (_waitCount) {
337        _waitCount--;
338        return;
339    }
340
341    // If there's a dynamic sensitivity and this wasn't it, ignore.
342    if ((dynamicSensitivity || timeoutEvent.scheduled()) &&
343            dynamicSensitivity != s) {
344        return;
345    }
346
347    _timedOut = false;
348    // This sensitivity should already be cleared by this point, or the event
349    // which triggered it will take care of it.
350    delete dynamicSensitivity;
351    dynamicSensitivity = nullptr;
352    cancelTimeout();
353    ready();
354}
355
356void
357Process::ready()
358{
359    if (disabled())
360        return;
361    if (suspended())
362        _suspendedReady = true;
363    else if (!scheduled())
364        scheduler.ready(this);
365}
366
367void
368Process::lastReport(::sc_core::sc_report *report)
369{
370    if (report) {
371        _lastReport = std::unique_ptr<::sc_core::sc_report>(
372                new ::sc_core::sc_report(*report));
373    } else {
374        _lastReport = nullptr;
375    }
376}
377
378::sc_core::sc_report *Process::lastReport() const { return _lastReport.get(); }
379
380Process::Process(const char *name, ProcessFuncWrapper *func, bool internal) :
381    ::sc_core::sc_process_b(name), excWrapper(nullptr),
382    timeoutEvent([this]() { this->timeout(); }),
383    func(func), _internal(internal), _timedOut(false), _dontInitialize(false),
384    _needsStart(true), _isUnwinding(false), _terminated(false),
385    _scheduled(false), _suspended(false), _disabled(false),
386    _syncReset(false), syncResetCount(0), asyncResetCount(0), _waitCount(0),
387    refCount(0), stackSize(::Fiber::DefaultStackSize),
388    dynamicSensitivity(nullptr)
389{
390    _dynamic =
391            (::sc_core::sc_get_status() >
392             ::sc_core::SC_BEFORE_END_OF_ELABORATION);
393    _newest = this;
394}
395
396void
397Process::terminate()
398{
399    _terminated = true;
400    _suspendedReady = false;
401    _suspended = false;
402    _syncReset = false;
403    clearDynamic();
404    cancelTimeout();
405    for (auto s: staticSensitivities) {
406        s->clear();
407        delete s;
408    }
409    staticSensitivities.clear();
410
411    _terminatedEvent.notify();
412
413    for (auto jw: joinWaiters)
414        jw->signal();
415    joinWaiters.clear();
416}
417
418Process *Process::_newest;
419
420void
421throw_it_wrapper(Process *p, ExceptionWrapperBase &exc, bool inc_kids)
422{
423    p->throw_it(exc, inc_kids);
424}
425
426void
427newReset(const sc_core::sc_port_base *pb, Process *p, bool s, bool v)
428{
429    Port *port = Port::fromPort(pb);
430    port->addReset(new Reset(p, s, v));
431}
432
433void
434newReset(const sc_core::sc_signal_in_if<bool> *sig, Process *p, bool s, bool v)
435{
436    Reset *reset = new Reset(p, s, v);
437    if (!reset->install(sig))
438        delete reset;
439}
440
441} // namespace sc_gem5
442