Files
gem5/src/systemc/core/event.hh
Gabe Black 0cfce45800 systemc: Implement signal based resets.
The implementation is based on sc_event sensitivities.

Also of note is that the way reset works in the Accellera
implementation isn't consistent with the spec. That says that
wait(int n) is supposed to be equivalent to calling wait() n times,
assuming n is greater than 0.

Instead, Accellera stores that count and then doesn't wake up the
process until the count is 0, decrementing it otherwise.

That means that when the process is in reset, it won't actually reset
for those intermediate wait()s which it would if wait() was called
repeatedly. Also, oddly, when a reset becomes asserted, it will clear
the count to 0 explicitly. That may have been an attempt to make the
behavior of wait(int n) match the spec, but it doesn't handle cases
where the reset is already set when wait(int n) is called.

Change-Id: I92f8e9a128e6618af94dc048ce570a4436e17e4b
Reviewed-on: https://gem5-review.googlesource.com/c/13186
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
2018-10-16 00:35:50 +00:00

185 lines
5.1 KiB
C++

/*
* Copyright 2018 Google, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Authors: Gabe Black
*/
#ifndef __SYSTEMC_CORE_EVENT_HH__
#define __SYSTEMC_CORE_EVENT_HH__
#include <list>
#include <string>
#include <vector>
#include "sim/eventq.hh"
#include "systemc/core/list.hh"
#include "systemc/core/object.hh"
#include "systemc/core/process.hh"
#include "systemc/core/sched_event.hh"
#include "systemc/core/sensitivity.hh"
#include "systemc/ext/core/sc_prim.hh"
#include "systemc/ext/core/sc_time.hh"
namespace sc_core
{
class sc_event;
} // namespace sc_core
namespace sc_gem5
{
typedef std::vector<sc_core::sc_event *> Events;
class Sensitivity;
class Event
{
public:
Event(sc_core::sc_event *_sc_event);
Event(sc_core::sc_event *_sc_event, const char *_basename);
~Event();
sc_core::sc_event *sc_event() { return _sc_event; }
const std::string &name() const;
const std::string &basename() const;
bool inHierarchy() const;
sc_core::sc_object *getParentObject() const;
void notify(StaticSensitivities &senses);
void notify(DynamicSensitivities &senses);
void notify(ResetSensitivities &senses);
void notify();
void notify(const sc_core::sc_time &t);
void
notify(double d, sc_core::sc_time_unit &u)
{
notify(sc_core::sc_time(d, u));
}
void cancel();
bool triggered() const;
uint64_t triggeredStamp() const { return _triggeredStamp; }
static Event *
getFromScEvent(sc_core::sc_event *e)
{
return e->_gem5_event;
}
static const Event *
getFromScEvent(const sc_core::sc_event *e)
{
return e->_gem5_event;
}
void
addSensitivity(StaticSensitivity *s) const
{
// Insert static sensitivities in reverse order to match Accellera's
// implementation.
auto &senses = s->ofMethod() ? staticSenseMethod : staticSenseThread;
senses.insert(senses.begin(), s);
}
void
delSensitivity(StaticSensitivity *s) const
{
auto &senses = s->ofMethod() ? staticSenseMethod : staticSenseThread;
for (auto &t: senses) {
if (t == s) {
t = senses.back();
senses.pop_back();
break;
}
}
}
void
addSensitivity(DynamicSensitivity *s) const
{
auto &senses = s->ofMethod() ? dynamicSenseMethod : dynamicSenseThread;
senses.push_back(s);
}
void
delSensitivity(DynamicSensitivity *s) const
{
auto &senses = s->ofMethod() ? dynamicSenseMethod : dynamicSenseThread;
for (auto &t: senses) {
if (t == s) {
t = senses.back();
senses.pop_back();
break;
}
}
}
void
addSensitivity(ResetSensitivity *s) const
{
resetSense.push_back(s);
}
void
delSensitivity(ResetSensitivity *s) const
{
for (auto &t: resetSense) {
if (t == s) {
t = resetSense.back();
resetSense.pop_back();
break;
}
}
}
private:
sc_core::sc_event *_sc_event;
std::string _basename;
std::string _name;
bool _inHierarchy;
sc_core::sc_object *parent;
ScEvent delayedNotify;
mutable uint64_t _triggeredStamp;
mutable StaticSensitivities staticSenseMethod;
mutable StaticSensitivities staticSenseThread;
mutable DynamicSensitivities dynamicSenseMethod;
mutable DynamicSensitivities dynamicSenseThread;
mutable ResetSensitivities resetSense;
};
extern Events topLevelEvents;
extern Events allEvents;
EventsIt findEvent(const std::string &name);
} // namespace sc_gem5
#endif //__SYSTEMC_CORE_EVENT_HH__