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eventq: Clean up the Event class so that it uses fewer bytes. This

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will hopefullly allow it to fit in a cache line.
This commit is contained in:
Nathan Binkert 2008-07-10 21:35:42 -07:00
parent 7a83c50a59
commit 93517dd90c
3 changed files with 101 additions and 99 deletions
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27
src/sim/eventq.cc
View file

@ -30,18 +30,16 @@
* Steve Raasch
*/
#include <assert.h>
#include <cassert>
#include <iostream>
#include <string>
#include <vector>
#include "cpu/smt.hh"
#include "base/misc.hh"
#include "sim/eventq.hh"
#include "base/trace.hh"
#include "cpu/smt.hh"
#include "sim/core.hh"
#include "sim/eventq.hh"
using namespace std;
@ -203,7 +201,7 @@ EventQueue::unserialize(Checkpoint *cp, const std::string &section)
}
void
EventQueue::dump()
EventQueue::dump() const
{
cprintf("============================================================\n");
cprintf("EventQueue Dump (cycle %d)\n", curTick);
@ -235,7 +233,6 @@ Event::description() const
return "generic";
}
#if TRACING_ON
void
Event::trace(const char *action)
{
@ -250,23 +247,21 @@ Event::trace(const char *action)
// needs to be printed.
DPRINTFN("%s event %s @ %d\n", description(), action, when());
}
#endif
void
Event::dump()
Event::dump() const
{
cprintf("Event (%s)\n", description());
cprintf("Event %s (%s)\n", name(), description());
cprintf("Flags: %#x\n", _flags);
#if TRACING_ON
cprintf("Created: %d\n", when_created);
#ifdef EVENTQ_DEBUG
cprintf("Created: %d\n", whenCreated);
#endif
if (scheduled()) {
#if TRACING_ON
cprintf("Scheduled at %d\n", when_scheduled);
#ifdef EVENTQ_DEBUG
cprintf("Scheduled at %d\n", whenScheduled);
#endif
cprintf("Scheduled for %d, priority %d\n", when(), _priority);
}
else {
} else {
cprintf("Not Scheduled\n");
}
}

171
src/sim/eventq.hh
View file

@ -36,19 +36,17 @@
#ifndef __SIM_EVENTQ_HH__
#define __SIM_EVENTQ_HH__
#include <assert.h>
#include <algorithm>
#include <cassert>
#include <map>
#include <string>
#include <vector>
#include "sim/host.hh" // for Tick
#include "base/fast_alloc.hh"
#include "base/misc.hh"
#include "base/trace.hh"
#include "sim/serialize.hh"
#include "sim/host.hh"
class EventQueue; // forward declaration
@ -64,17 +62,27 @@ class EventQueue; // forward declaration
//////////////////////
extern EventQueue mainEventQueue;
/*
* 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.
*
* Caution, the order of members is chosen to maximize data packing.
*/
class Event : public Serializable, public FastAlloc
{
friend class EventQueue;
private:
Event *next;
/// queue to which this event belongs (though it may or may not be
/// scheduled on this queue yet)
EventQueue *_queue;
Tick _when; //!< timestamp when event should be processed
short _priority; //!< event priority
short _flags;
#ifndef NDEBUG
/// Global counter to generate unique IDs for Event instances
@ -84,19 +92,13 @@ class Event : public Serializable, public FastAlloc
/// this but they're not consistent across runs making debugging
/// more difficult. Thus we use a global counter value when
/// debugging.
Counter instanceId;
#endif // NDEBUG
/// 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;
Counter instance;
#endif
#ifdef DEBUG_EVENTQ
Tick whenCreated; //!< time created
Tick whenScheduled; //!< time scheduled
#endif
protected:
enum Flags {
None = 0x0,
@ -112,26 +114,20 @@ class Event : public Serializable, public FastAlloc
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
EventQueue *queue() const { return _queue; }
// This function isn't really useful if TRACING_ON is not defined
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 {
/// Minimum priority
Minimum_Pri = SHRT_MIN,
/// If we enable tracing on a particular cycle, do that as the
/// very first thing so we don't miss any of the events on
/// that cycle (even if we enter the debugger).
@ -174,7 +170,10 @@ class Event : public Serializable, public FastAlloc
/// If we want to exit on this cycle, it's the very last thing
/// we do.
Sim_Exit_Pri = 100
Sim_Exit_Pri = 100,
/// Maximum priority
Maximum_Pri = SHRT_MAX
};
/*
@ -182,27 +181,53 @@ class Event : public Serializable, public FastAlloc
* @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)
: next(NULL), _queue(q), _priority(p), _flags(None)
{
#ifndef NDEBUG
instanceId = ++instanceCounter;
instance = ++instanceCounter;
#endif
#ifdef EVENTQ_DEBUG
whenCreated = curTick;
whenScheduled = 0;
#endif
}
~Event() {}
virtual
~Event()
{
}
virtual const std::string name() const {
virtual const std::string
name() const
{
#ifndef NDEBUG
return csprintf("Event_%d", instanceId);
return csprintf("Event_%d", instance);
#else
return csprintf("Event_%x", (uintptr_t)this);
#endif
}
/// 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() const;
/// Dump the current event data
void dump() const;
public:
/*
* 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;
/// Determine if the current event is scheduled
bool scheduled() const { return getFlags(Scheduled); }
@ -216,37 +241,14 @@ class Event : public Serializable, public FastAlloc
/// 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() const;
/// 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); }
bool squashed() const { return getFlags(Squashed); }
/// See if this is a SimExitEvent (without resorting to RTTI)
bool isExitEvent() { return getFlags(IsExitEvent); }
bool isExitEvent() const { return getFlags(IsExitEvent); }
/// Get the time that the event is scheduled
Tick when() const { return _when; }
@ -254,10 +256,12 @@ class Event : public Serializable, public FastAlloc
/// Get the event priority
int priority() const { return _priority; }
struct priority_compare :
public std::binary_function<Event *, Event *, bool>
struct priority_compare
: public std::binary_function<Event *, Event *, bool>
{
bool operator()(const Event *l, const Event *r) const {
bool
operator()(const Event *l, const Event *r) const
{
return l->when() >= r->when() || l->priority() >= r->priority();
}
};
@ -343,13 +347,15 @@ class EventQueue : public Serializable
void deschedule(Event *ev);
void reschedule(Event *ev);
Tick nextTick() { return head->when(); }
Tick nextTick() const { return head->when(); }
Event *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) {
void
serviceEvents(Tick when)
{
while (!empty()) {
if (nextTick() > when)
break;
@ -367,9 +373,9 @@ class EventQueue : public Serializable
void serviceEvents() { serviceEvents(curTick); }
// return true if no events are queued
bool empty() { return head == NULL; }
bool empty() const { return head == NULL; }
void dump();
void dump() const;
Tick nextEventTime() { return empty() ? curTick : head->when(); }
@ -393,15 +399,14 @@ inline void
Event::schedule(Tick t)
{
assert(!scheduled());
// if (t < curTick)
// warn("t is less than curTick, ensure you don't want cycles");
assert(t >= curTick);
setFlags(Scheduled);
#if TRACING_ON
when_scheduled = curTick;
#ifdef DEBUG_EVENTQ
whenScheduled = curTick;
#endif
_when = t;
queue->schedule(this);
_queue->schedule(this);
}
inline void
@ -411,25 +416,26 @@ Event::deschedule()
clearFlags(Squashed);
clearFlags(Scheduled);
queue->deschedule(this);
_queue->deschedule(this);
}
inline void
Event::reschedule(Tick t, bool always)
{
assert(scheduled() || always);
assert(t >= curTick);
#if TRACING_ON
when_scheduled = curTick;
#ifdef DEBUG_EVENTQ
whenScheduled = curTick;
#endif
_when = t;
if (scheduled()) {
clearFlags(Squashed);
queue->reschedule(this);
_queue->reschedule(this);
} else {
setFlags(Scheduled);
queue->schedule(this);
_queue->schedule(this);
}
}
@ -447,6 +453,9 @@ EventQueue::deschedule(Event *event)
remove(event);
if (DTRACE(Event))
event->trace("descheduled");
if (event->getFlags(Event::AutoDelete))
delete event;
}
inline void
@ -458,6 +467,4 @@ EventQueue::reschedule(Event *event)
event->trace("rescheduled");
}
#endif // __SIM_EVENTQ_HH__

2
src/sim/sim_events.cc
View file

@ -49,7 +49,7 @@ SimLoopExitEvent::process()
// if this got scheduled on a different queue (e.g. the committed
// instruction queue) then make a corresponding event on the main
// queue.
if (theQueue() != &mainEventQueue) {
if (queue() != &mainEventQueue) {
exitSimLoop(cause, code);
delete this;
}