gem5/sim/eventq.hh
Nathan Binkert a1259a4fcf Add a simple event wrapper class that takes a class pointer
and member function and will schedule it for the future.

--HG--
extra : convert_revision : f5c5a8df0839e1e10716850c2086862c4a5bc499
2004-02-20 15:24:21 -05:00

396 lines
10 KiB
C++

/*
* Copyright (c) 2003 The Regents of The University of Michigan
* All rights reserved.
*
* 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.
*/
/* @file
* EventQueue interfaces
*/
#ifndef __EVENTQ_HH__
#define __EVENTQ_HH__
#include <assert.h>
#include <algorithm>
#include <map>
#include <string>
#include <vector>
#include "sim/host.hh" // for Tick
#include "base/fast_alloc.hh"
#include "sim/serialize.hh"
#include "base/trace.hh"
class EventQueue; // forward declaration
/*
* An item on an event queue. The action caused by a given
* event is specified by deriving a subclass and overriding the
* process() member function.
*/
class Event : public Serializable, public FastAlloc
{
friend class EventQueue;
private:
/// queue to which this event belongs (though it may or may not be
/// scheduled on this queue yet)
EventQueue *queue;
Event *next;
Tick _when; //!< timestamp when event should be processed
int _priority; //!< event priority
char _flags;
protected:
enum Flags {
None = 0x0,
Squashed = 0x1,
Scheduled = 0x2,
AutoDelete = 0x4,
AutoSerialize = 0x8
};
bool getFlags(Flags f) const { return (_flags & f) == f; }
void setFlags(Flags f) { _flags |= f; }
void clearFlags(Flags f) { _flags &= ~f; }
protected:
EventQueue *theQueue() const { return queue; }
#if TRACING_ON
Tick when_created; //!< Keep track of creation time For debugging
Tick when_scheduled; //!< Keep track of creation time For debugging
virtual void trace(const char *action); //!< trace event activity
#else
void trace(const char *) {}
#endif
unsigned annotated_value;
public:
/// Event priorities, to provide tie-breakers for events scheduled
/// at the same cycle. Most events are scheduled at the default
/// priority; these values are used to control events that need to
/// be ordered within a cycle.
enum Priority {
/// Breakpoints should happen before anything else, so we
/// don't miss any action when debugging.
Debug_Break_Pri = -100,
/// For some reason "delayed" inter-cluster writebacks are
/// scheduled before regular writebacks (which have default
/// priority). Steve?
Delayed_Writeback_Pri = -1,
/// Default is zero for historical reasons.
Default_Pri = 0,
/// CPU switches schedule the new CPU's tick event for the
/// same cycle (after unscheduling the old CPU's tick event).
/// The switch needs to come before any tick events to make
/// sure we don't tick both CPUs in the same cycle.
CPU_Switch_Pri = 31,
/// Serailization needs to occur before tick events also, so
/// that a serialize/unserialize is identical to an on-line
/// CPU switch.
Serialize_Pri = 32,
/// CPU ticks must come after other associated CPU events
/// (such as writebacks).
CPU_Tick_Pri = 50,
/// Statistics events (dump, reset, etc.) come after
/// everything else, but before exit.
Stat_Event_Pri = 90,
/// If we want to exit on this cycle, it's the very last thing
/// we do.
Sim_Exit_Pri = 100
};
/*
* Event constructor
* @param queue that the event gets scheduled on
*/
Event(EventQueue *q, Priority p = Default_Pri)
: queue(q), next(NULL), _priority(p), _flags(None),
#if TRACING_ON
when_created(curTick), when_scheduled(0),
#endif
annotated_value(0)
{
}
~Event() {}
virtual const std::string name() const {
return csprintf("Event_%x", (uintptr_t)this);
}
/// Determine if the current event is scheduled
bool scheduled() const { return getFlags(Scheduled); }
/// Schedule the event with the current priority or default priority
void schedule(Tick t);
/// Reschedule the event with the current priority
void reschedule(Tick t);
/// Remove the event from the current schedule
void deschedule();
/// Return a C string describing the event. This string should
/// *not* be dynamically allocated; just a const char array
/// describing the event class.
virtual const char *description();
/// Dump the current event data
void dump();
/*
* This member function is invoked when the event is processed
* (occurs). There is no default implementation; each subclass
* must provide its own implementation. The event is not
* automatically deleted after it is processed (to allow for
* statically allocated event objects).
*
* If the AutoDestroy flag is set, the object is deleted once it
* is processed.
*/
virtual void process() = 0;
void annotate(unsigned value) { annotated_value = value; };
unsigned annotation() { return annotated_value; }
/// Squash the current event
void squash() { setFlags(Squashed); }
/// Check whether the event is squashed
bool squashed() { return getFlags(Squashed); }
/// Get the time that the event is scheduled
Tick when() const { return _when; }
/// Get the event priority
int priority() const { return _priority; }
struct priority_compare :
public std::binary_function<Event *, Event *, bool>
{
bool operator()(const Event *l, const Event *r) const {
return l->when() >= r->when() || l->priority() >= r->priority();
}
};
virtual void serialize(std::ostream &os);
virtual void unserialize(Checkpoint *cp, const std::string &section);
};
template <class T, void (T::* F)()>
void
DelayFunction(Tick when, T *object)
{
class DelayEvent : public Event
{
private:
T *object;
public:
DelayEvent(Tick when, T *o)
: Event(&mainEventQueue), object(o)
{ setFlags(AutoDestroy); schedule(when); }
void process() { (object->*F)(); }
const char *description() { return "delay"; }
};
new DelayEvent(when, object);
}
template <class T, void (T::* F)()>
class EventWrapper : public Event
{
private:
T *object;
public:
EventWrapper(T *obj, EventQueue *q = &mainEventQueue,
Priority p = Default_Pri)
: Event(q, p), object(obj)
{}
void process() { (object->*F)(); }
};
/*
* Queue of events sorted in time order
*/
class EventQueue : public Serializable
{
protected:
std::string objName;
private:
Event *head;
void insert(Event *event);
void remove(Event *event);
public:
// constructor
EventQueue(const std::string &n)
: objName(n), head(NULL)
{}
virtual const std::string name() const { return objName; }
// schedule the given event on this queue
void schedule(Event *ev);
void deschedule(Event *ev);
void reschedule(Event *ev);
Tick nextTick() { return head->when(); }
void serviceOne();
// process all events up to the given timestamp. we inline a
// quick test to see if there are any events to process; if so,
// call the internal out-of-line version to process them all.
void serviceEvents(Tick when) {
while (!empty()) {
if (nextTick() > when)
break;
assert(head->when() >= when && "event scheduled in the past");
serviceOne();
}
}
// default: process all events up to 'now' (curTick)
void serviceEvents() { serviceEvents(curTick); }
// return true if no events are queued
bool empty() { return head == NULL; }
void dump();
Tick nextEventTime() { return empty() ? curTick : head->when(); }
virtual void serialize(std::ostream &os);
virtual void unserialize(Checkpoint *cp, const std::string &section);
};
//////////////////////
//
// inline functions
//
// can't put these inside declaration due to circular dependence
// between Event and EventQueue classes.
//
//////////////////////
// schedule at specified time (place on event queue specified via
// constructor)
inline void
Event::schedule(Tick t)
{
assert(!scheduled());
setFlags(Scheduled);
#if TRACING_ON
when_scheduled = curTick;
#endif
_when = t;
queue->schedule(this);
}
inline void
Event::deschedule()
{
assert(scheduled());
clearFlags(Squashed);
clearFlags(Scheduled);
queue->deschedule(this);
}
inline void
Event::reschedule(Tick t)
{
assert(scheduled());
clearFlags(Squashed);
#if TRACING_ON
when_scheduled = curTick;
#endif
_when = t;
queue->reschedule(this);
}
inline void
EventQueue::schedule(Event *event)
{
insert(event);
if (DTRACE(Event))
event->trace("scheduled");
}
inline void
EventQueue::deschedule(Event *event)
{
remove(event);
if (DTRACE(Event))
event->trace("descheduled");
}
inline void
EventQueue::reschedule(Event *event)
{
remove(event);
insert(event);
if (DTRACE(Event))
event->trace("rescheduled");
}
//////////////////////
//
// Main Event Queue
//
// Events on this queue are processed at the *beginning* of each
// cycle, before the pipeline simulation is performed.
//
// defined in eventq.cc
//
//////////////////////
extern EventQueue mainEventQueue;
#endif // __EVENTQ_HH__