process.cc revision 13307:e30fee54d354 
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            procKind() == ::sc_core::SC_METHOD_PROC_) {
211        SC_REPORT_WARNING("(W556) throw_it on method/non-running process "
212                "is being ignored ", name());
213        return;
214    }
215
216    injectException(exc);
217}
218
219void
220Process::injectException(ExceptionWrapperBase &exc)
221{
222    excWrapper = &exc;
223    scheduler.runNow(this);
224};
225
226void
227Process::syncResetOn(bool inc_kids)
228{
229    if (inc_kids)
230        forEachKid([](Process *p) { p->syncResetOn(true); });
231
232    _syncReset = true;
233}
234
235void
236Process::syncResetOff(bool inc_kids)
237{
238    if (inc_kids)
239        forEachKid([](Process *p) { p->syncResetOff(true); });
240
241    _syncReset = false;
242}
243
244void
245Process::signalReset(bool set, bool sync)
246{
247    if (set) {
248        waitCount(0);
249        if (sync) {
250            syncResetCount++;
251        } else {
252            asyncResetCount++;
253            cancelTimeout();
254            clearDynamic();
255            scheduler.runNext(this);
256        }
257    } else {
258        if (sync)
259            syncResetCount--;
260        else
261            asyncResetCount--;
262    }
263}
264
265void
266Process::run()
267{
268    bool reset;
269    do {
270        reset = false;
271        try {
272            func->call();
273        } catch(ScHalt) {
274            std::cout << "Terminating process " << name() << std::endl;
275        } catch(const ::sc_core::sc_unwind_exception &exc) {
276            reset = exc.is_reset();
277            _isUnwinding = false;
278        } catch (...) {
279            throw;
280        }
281    } while (reset);
282    needsStart(true);
283}
284
285void
286Process::addStatic(StaticSensitivity *s)
287{
288    staticSensitivities.push_back(s);
289}
290
291void
292Process::setDynamic(DynamicSensitivity *s)
293{
294    if (dynamicSensitivity) {
295        dynamicSensitivity->clear();
296        delete dynamicSensitivity;
297    }
298    dynamicSensitivity = s;
299}
300
301void
302Process::addReset(Reset *reset)
303{
304    resets.push_back(reset);
305}
306
307void
308Process::cancelTimeout()
309{
310    if (timeoutEvent.scheduled())
311        scheduler.deschedule(&timeoutEvent);
312}
313
314void
315Process::setTimeout(::sc_core::sc_time t)
316{
317    cancelTimeout();
318    scheduler.schedule(&timeoutEvent, t);
319}
320
321void
322Process::timeout()
323{
324    // A process is considered timed_out only if it was also waiting for an
325    // event but got a timeout instead.
326    _timedOut = (dynamicSensitivity != nullptr);
327
328    setDynamic(nullptr);
329    if (disabled())
330        return;
331
332    ready();
333}
334
335void
336Process::satisfySensitivity(Sensitivity *s)
337{
338    if (_waitCount) {
339        _waitCount--;
340        return;
341    }
342
343    // If there's a dynamic sensitivity and this wasn't it, ignore.
344    if ((dynamicSensitivity || timeoutEvent.scheduled()) &&
345            dynamicSensitivity != s) {
346        return;
347    }
348
349    _timedOut = false;
350    // This sensitivity should already be cleared by this point, or the event
351    // which triggered it will take care of it.
352    delete dynamicSensitivity;
353    dynamicSensitivity = nullptr;
354    cancelTimeout();
355    ready();
356}
357
358void
359Process::ready()
360{
361    if (disabled())
362        return;
363    if (suspended())
364        _suspendedReady = true;
365    else
366        scheduler.ready(this);
367}
368
369void
370Process::lastReport(::sc_core::sc_report *report)
371{
372    if (report) {
373        _lastReport = std::unique_ptr<::sc_core::sc_report>(
374                new ::sc_core::sc_report(*report));
375    } else {
376        _lastReport = nullptr;
377    }
378}
379
380::sc_core::sc_report *Process::lastReport() const { return _lastReport.get(); }
381
382Process::Process(const char *name, ProcessFuncWrapper *func, bool internal) :
383    ::sc_core::sc_process_b(name), excWrapper(nullptr),
384    timeoutEvent([this]() { this->timeout(); }),
385    func(func), _internal(internal), _timedOut(false), _dontInitialize(false),
386    _needsStart(true), _isUnwinding(false), _terminated(false),
387    _suspended(false), _disabled(false), _syncReset(false), syncResetCount(0),
388    asyncResetCount(0), _waitCount(0), refCount(0),
389    stackSize(::Fiber::DefaultStackSize), dynamicSensitivity(nullptr)
390{
391    _dynamic =
392            (::sc_core::sc_get_status() >
393             ::sc_core::SC_BEFORE_END_OF_ELABORATION);
394    _newest = this;
395}
396
397void
398Process::terminate()
399{
400    _terminated = true;
401    _suspendedReady = false;
402    _suspended = false;
403    _syncReset = false;
404    clearDynamic();
405    cancelTimeout();
406    for (auto s: staticSensitivities) {
407        s->clear();
408        delete s;
409    }
410    staticSensitivities.clear();
411
412    _terminatedEvent.notify();
413
414    for (auto jw: joinWaiters)
415        jw->signal();
416    joinWaiters.clear();
417}
418
419Process *Process::_newest;
420
421void
422throw_it_wrapper(Process *p, ExceptionWrapperBase &exc, bool inc_kids)
423{
424    p->throw_it(exc, inc_kids);
425}
426
427void
428newReset(const sc_core::sc_port_base *pb, Process *p, bool s, bool v)
429{
430    Port *port = Port::fromPort(pb);
431    port->addReset(new Reset(p, s, v));
432}
433
434void
435newReset(const sc_core::sc_signal_in_if<bool> *sig, Process *p, bool s, bool v)
436{
437    Reset *reset = new Reset(p, s, v);
438    if (!reset->install(sig))
439        delete reset;
440}
441
442} // namespace sc_gem5
443