process.cc revision 13310:160fb526ab4d 
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    // 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(
204                "(E574) throw_it not allowed unless simulation is running ",
205                name());
206    }
207
208    if (inc_kids)
209        forEachKid([&exc](Process *p) { p->throw_it(exc, true); });
210
211    if (_needsStart || _terminated ||
212            procKind() == ::sc_core::SC_METHOD_PROC_) {
213        SC_REPORT_WARNING("(W556) throw_it on method/non-running process "
214                "is being ignored ", name());
215        return;
216    }
217
218    injectException(exc);
219}
220
221void
222Process::injectException(ExceptionWrapperBase &exc)
223{
224    excWrapper = &exc;
225    scheduler.runNow(this);
226};
227
228void
229Process::syncResetOn(bool inc_kids)
230{
231    if (inc_kids)
232        forEachKid([](Process *p) { p->syncResetOn(true); });
233
234    _syncReset = true;
235}
236
237void
238Process::syncResetOff(bool inc_kids)
239{
240    if (inc_kids)
241        forEachKid([](Process *p) { p->syncResetOff(true); });
242
243    _syncReset = false;
244}
245
246void
247Process::signalReset(bool set, bool sync)
248{
249    if (set) {
250        waitCount(0);
251        if (sync) {
252            syncResetCount++;
253        } else {
254            asyncResetCount++;
255            cancelTimeout();
256            clearDynamic();
257            scheduler.runNext(this);
258        }
259    } else {
260        if (sync)
261            syncResetCount--;
262        else
263            asyncResetCount--;
264    }
265}
266
267void
268Process::run()
269{
270    bool reset;
271    do {
272        reset = false;
273        try {
274            func->call();
275        } catch(ScHalt) {
276            std::cout << "Terminating process " << name() << std::endl;
277        } catch(const ::sc_core::sc_unwind_exception &exc) {
278            reset = exc.is_reset();
279            _isUnwinding = false;
280        } catch (...) {
281            throw;
282        }
283    } while (reset);
284    needsStart(true);
285}
286
287void
288Process::addStatic(StaticSensitivity *s)
289{
290    staticSensitivities.push_back(s);
291}
292
293void
294Process::setDynamic(DynamicSensitivity *s)
295{
296    if (dynamicSensitivity) {
297        dynamicSensitivity->clear();
298        delete dynamicSensitivity;
299    }
300    dynamicSensitivity = s;
301}
302
303void
304Process::addReset(Reset *reset)
305{
306    resets.push_back(reset);
307}
308
309void
310Process::cancelTimeout()
311{
312    if (timeoutEvent.scheduled())
313        scheduler.deschedule(&timeoutEvent);
314}
315
316void
317Process::setTimeout(::sc_core::sc_time t)
318{
319    cancelTimeout();
320    scheduler.schedule(&timeoutEvent, t);
321}
322
323void
324Process::timeout()
325{
326    // A process is considered timed_out only if it was also waiting for an
327    // event but got a timeout instead.
328    _timedOut = (dynamicSensitivity != nullptr);
329
330    setDynamic(nullptr);
331    if (disabled())
332        return;
333
334    ready();
335}
336
337void
338Process::satisfySensitivity(Sensitivity *s)
339{
340    if (_waitCount) {
341        _waitCount--;
342        return;
343    }
344
345    // If there's a dynamic sensitivity and this wasn't it, ignore.
346    if ((dynamicSensitivity || timeoutEvent.scheduled()) &&
347            dynamicSensitivity != s) {
348        return;
349    }
350
351    _timedOut = false;
352    // This sensitivity should already be cleared by this point, or the event
353    // which triggered it will take care of it.
354    delete dynamicSensitivity;
355    dynamicSensitivity = nullptr;
356    cancelTimeout();
357    ready();
358}
359
360void
361Process::ready()
362{
363    if (disabled())
364        return;
365    if (suspended())
366        _suspendedReady = true;
367    else
368        scheduler.ready(this);
369}
370
371void
372Process::lastReport(::sc_core::sc_report *report)
373{
374    if (report) {
375        _lastReport = std::unique_ptr<::sc_core::sc_report>(
376                new ::sc_core::sc_report(*report));
377    } else {
378        _lastReport = nullptr;
379    }
380}
381
382::sc_core::sc_report *Process::lastReport() const { return _lastReport.get(); }
383
384Process::Process(const char *name, ProcessFuncWrapper *func, bool internal) :
385    ::sc_core::sc_process_b(name), excWrapper(nullptr),
386    timeoutEvent([this]() { this->timeout(); }),
387    func(func), _internal(internal), _timedOut(false), _dontInitialize(false),
388    _needsStart(true), _isUnwinding(false), _terminated(false),
389    _suspended(false), _disabled(false), _syncReset(false), syncResetCount(0),
390    asyncResetCount(0), _waitCount(0), refCount(0),
391    stackSize(::Fiber::DefaultStackSize), dynamicSensitivity(nullptr)
392{
393    _dynamic =
394            (::sc_core::sc_get_status() >
395             ::sc_core::SC_BEFORE_END_OF_ELABORATION);
396    _newest = this;
397}
398
399void
400Process::terminate()
401{
402    _terminated = true;
403    _suspendedReady = false;
404    _suspended = false;
405    _syncReset = false;
406    clearDynamic();
407    cancelTimeout();
408    for (auto s: staticSensitivities) {
409        s->clear();
410        delete s;
411    }
412    staticSensitivities.clear();
413
414    _terminatedEvent.notify();
415
416    for (auto jw: joinWaiters)
417        jw->signal();
418    joinWaiters.clear();
419}
420
421Process *Process::_newest;
422
423void
424throw_it_wrapper(Process *p, ExceptionWrapperBase &exc, bool inc_kids)
425{
426    p->throw_it(exc, inc_kids);
427}
428
429void
430newReset(const sc_core::sc_port_base *pb, Process *p, bool s, bool v)
431{
432    Port *port = Port::fromPort(pb);
433    port->addReset(new Reset(p, s, v));
434}
435
436void
437newReset(const sc_core::sc_signal_in_if<bool> *sig, Process *p, bool s, bool v)
438{
439    Reset *reset = new Reset(p, s, v);
440    if (!reset->install(sig))
441        delete reset;
442}
443
444} // namespace sc_gem5
445