2 * Copyright (c) 2000-2005 The Regents of The University of Michigan
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16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 * Authors: Steve Reinhardt
33 * EventQueue interfaces
36 #ifndef __SIM_EVENTQ_HH__
37 #define __SIM_EVENTQ_HH__
45 #include "base/flags.hh"
46 #include "base/misc.hh"
47 #include "base/types.hh"
48 #include "debug/Event.hh"
49 #include "sim/serialize.hh"
51 class EventQueue; // forward declaration
53 extern EventQueue mainEventQueue;
56 * An item on an event queue. The action caused by a given
57 * event is specified by deriving a subclass and overriding the
58 * process() member function.
60 * Caution, the order of members is chosen to maximize data packing.
62 class Event : public Serializable
64 friend class EventQueue;
67 typedef unsigned short FlagsType;
68 typedef ::Flags<FlagsType> Flags;
70 static const FlagsType PublicRead = 0x003f; // public readable flags
71 static const FlagsType PublicWrite = 0x001d; // public writable flags
72 static const FlagsType Squashed = 0x0001; // has been squashed
73 static const FlagsType Scheduled = 0x0002; // has been scheduled
74 static const FlagsType AutoDelete = 0x0004; // delete after dispatch
75 static const FlagsType AutoSerialize = 0x0008; // must be serialized
76 static const FlagsType IsExitEvent = 0x0010; // special exit event
77 static const FlagsType IsMainQueue = 0x0020; // on main event queue
78 static const FlagsType Initialized = 0x7a40; // somewhat random bits
79 static const FlagsType InitMask = 0xffc0; // mask for init bits
84 return this && (flags & InitMask) == Initialized;
88 typedef int8_t Priority;
91 // The event queue is now a linked list of linked lists. The
92 // 'nextBin' pointer is to find the bin, where a bin is defined as
93 // when+priority. All events in the same bin will be stored in a
94 // second linked list (a stack) maintained by the 'nextInBin'
95 // pointer. The list will be accessed in LIFO order. The end
96 // result is that the insert/removal in 'nextBin' is
97 // linear/constant, and the lookup/removal in 'nextInBin' is
98 // constant/constant. Hopefully this is a significant improvement
99 // over the current fully linear insertion.
103 static Event *insertBefore(Event *event, Event *curr);
104 static Event *removeItem(Event *event, Event *last);
106 Tick _when; //!< timestamp when event should be processed
107 Priority _priority; //!< event priority
111 /// Global counter to generate unique IDs for Event instances
112 static Counter instanceCounter;
114 /// This event's unique ID. We can also use pointer values for
115 /// this but they're not consistent across runs making debugging
116 /// more difficult. Thus we use a global counter value when
120 /// queue to which this event belongs (though it may or may not be
121 /// scheduled on this queue yet)
126 Tick whenCreated; //!< time created
127 Tick whenScheduled; //!< time scheduled
131 setWhen(Tick when, EventQueue *q)
138 whenScheduled = curTick();
143 /// Accessor for flags.
147 return flags & PublicRead;
151 isFlagSet(Flags _flags) const
153 assert(_flags.noneSet(~PublicRead));
154 return flags.isSet(_flags);
157 /// Accessor for flags.
159 setFlags(Flags _flags)
161 assert(_flags.noneSet(~PublicWrite));
166 clearFlags(Flags _flags)
168 assert(_flags.noneSet(~PublicWrite));
175 flags.clear(PublicWrite);
178 // This function isn't really useful if TRACING_ON is not defined
179 virtual void trace(const char *action); //!< trace event activity
182 /// Event priorities, to provide tie-breakers for events scheduled
183 /// at the same cycle. Most events are scheduled at the default
184 /// priority; these values are used to control events that need to
185 /// be ordered within a cycle.
188 static const Priority Minimum_Pri = SCHAR_MIN;
190 /// If we enable tracing on a particular cycle, do that as the
191 /// very first thing so we don't miss any of the events on
192 /// that cycle (even if we enter the debugger).
193 static const Priority Trace_Enable_Pri = -101;
195 /// Breakpoints should happen before anything else (except
196 /// enabling trace output), so we don't miss any action when
198 static const Priority Debug_Break_Pri = -100;
200 /// CPU switches schedule the new CPU's tick event for the
201 /// same cycle (after unscheduling the old CPU's tick event).
202 /// The switch needs to come before any tick events to make
203 /// sure we don't tick both CPUs in the same cycle.
204 static const Priority CPU_Switch_Pri = -31;
206 /// For some reason "delayed" inter-cluster writebacks are
207 /// scheduled before regular writebacks (which have default
208 /// priority). Steve?
209 static const Priority Delayed_Writeback_Pri = -1;
211 /// Default is zero for historical reasons.
212 static const Priority Default_Pri = 0;
214 /// Serailization needs to occur before tick events also, so
215 /// that a serialize/unserialize is identical to an on-line
217 static const Priority Serialize_Pri = 32;
219 /// CPU ticks must come after other associated CPU events
220 /// (such as writebacks).
221 static const Priority CPU_Tick_Pri = 50;
223 /// Statistics events (dump, reset, etc.) come after
224 /// everything else, but before exit.
225 static const Priority Stat_Event_Pri = 90;
227 /// Progress events come at the end.
228 static const Priority Progress_Event_Pri = 95;
230 /// If we want to exit on this cycle, it's the very last thing
232 static const Priority Sim_Exit_Pri = 100;
235 static const Priority Maximum_Pri = SCHAR_MAX;
239 * @param queue that the event gets scheduled on
241 Event(Priority p = Default_Pri, Flags f = 0)
242 : nextBin(NULL), nextInBin(NULL), _priority(p),
243 flags(Initialized | f)
245 assert(f.noneSet(~PublicWrite));
247 instance = ++instanceCounter;
251 whenCreated = curTick();
257 virtual const std::string name() const;
259 /// Return a C string describing the event. This string should
260 /// *not* be dynamically allocated; just a const char array
261 /// describing the event class.
262 virtual const char *description() const;
264 /// Dump the current event data
269 * This member function is invoked when the event is processed
270 * (occurs). There is no default implementation; each subclass
271 * must provide its own implementation. The event is not
272 * automatically deleted after it is processed (to allow for
273 * statically allocated event objects).
275 * If the AutoDestroy flag is set, the object is deleted once it
278 virtual void process() = 0;
280 /// Determine if the current event is scheduled
281 bool scheduled() const { return flags.isSet(Scheduled); }
283 /// Squash the current event
284 void squash() { flags.set(Squashed); }
286 /// Check whether the event is squashed
287 bool squashed() const { return flags.isSet(Squashed); }
289 /// See if this is a SimExitEvent (without resorting to RTTI)
290 bool isExitEvent() const { return flags.isSet(IsExitEvent); }
292 /// Get the time that the event is scheduled
293 Tick when() const { return _when; }
295 /// Get the event priority
296 Priority priority() const { return _priority; }
299 virtual void serialize(std::ostream &os);
300 virtual void unserialize(Checkpoint *cp, const std::string §ion);
306 operator<(const Event &l, const Event &r)
308 return l.when() < r.when() ||
309 (l.when() == r.when() && l.priority() < r.priority());
313 operator>(const Event &l, const Event &r)
315 return l.when() > r.when() ||
316 (l.when() == r.when() && l.priority() > r.priority());
320 operator<=(const Event &l, const Event &r)
322 return l.when() < r.when() ||
323 (l.when() == r.when() && l.priority() <= r.priority());
326 operator>=(const Event &l, const Event &r)
328 return l.when() > r.when() ||
329 (l.when() == r.when() && l.priority() >= r.priority());
333 operator==(const Event &l, const Event &r)
335 return l.when() == r.when() && l.priority() == r.priority();
339 operator!=(const Event &l, const Event &r)
341 return l.when() != r.when() || l.priority() != r.priority();
346 * Queue of events sorted in time order
348 class EventQueue : public Serializable
355 void insert(Event *event);
356 void remove(Event *event);
358 EventQueue(const EventQueue &);
359 const EventQueue &operator=(const EventQueue &);
362 EventQueue(const std::string &n);
364 virtual const std::string name() const { return objName; }
366 // schedule the given event on this queue
367 void schedule(Event *event, Tick when);
368 void deschedule(Event *event);
369 void reschedule(Event *event, Tick when, bool always = false);
371 Tick nextTick() const { return head->when(); }
372 void setCurTick(Tick newVal) { _curTick = newVal; }
373 Tick getCurTick() { return _curTick; }
377 // process all events up to the given timestamp. we inline a
378 // quick test to see if there are any events to process; if so,
379 // call the internal out-of-line version to process them all.
381 serviceEvents(Tick when)
384 if (nextTick() > when)
388 * @todo this assert is a good bug catcher. I need to
389 * make it true again.
391 //assert(head->when() >= when && "event scheduled in the past");
398 // return true if no events are queued
399 bool empty() const { return head == NULL; }
403 bool debugVerify() const;
406 * function for replacing the head of the event queue, so that a
407 * different set of events can run without disturbing events that have
408 * already been scheduled. Already scheduled events can be processed
409 * by replacing the original head back.
410 * USING THIS FUNCTION CAN BE DANGEROUS TO THE HEALTH OF THE SIMULATOR.
411 * NOT RECOMMENDED FOR USE.
413 Event* replaceHead(Event* s);
416 virtual void serialize(std::ostream &os);
417 virtual void unserialize(Checkpoint *cp, const std::string §ion);
421 void dumpMainQueue();
427 /** A pointer to this object's event queue */
431 EventManager(EventManager &em) : eventq(em.eventq) {}
432 EventManager(EventManager *em) : eventq(em->eventq) {}
433 EventManager(EventQueue *eq) : eventq(eq) {}
442 schedule(Event &event, Tick when)
444 eventq->schedule(&event, when);
448 deschedule(Event &event)
450 eventq->deschedule(&event);
454 reschedule(Event &event, Tick when, bool always = false)
456 eventq->reschedule(&event, when, always);
460 schedule(Event *event, Tick when)
462 eventq->schedule(event, when);
466 deschedule(Event *event)
468 eventq->deschedule(event);
472 reschedule(Event *event, Tick when, bool always = false)
474 eventq->reschedule(event, when, always);
477 void setCurTick(Tick newVal) { eventq->setCurTick(newVal); }
480 template <class T, void (T::* F)()>
482 DelayFunction(EventQueue *eventq, Tick when, T *object)
484 class DelayEvent : public Event
491 : Event(Default_Pri, AutoDelete), object(o)
493 void process() { (object->*F)(); }
494 const char *description() const { return "delay"; }
497 eventq->schedule(new DelayEvent(object), when);
500 template <class T, void (T::* F)()>
501 class EventWrapper : public Event
507 EventWrapper(T *obj, bool del = false, Priority p = Default_Pri)
508 : Event(p), object(obj)
511 setFlags(AutoDelete);
514 EventWrapper(T &obj, bool del = false, Priority p = Default_Pri)
515 : Event(p), object(&obj)
518 setFlags(AutoDelete);
521 void process() { (object->*F)(); }
526 return object->name() + ".wrapped_event";
529 const char *description() const { return "EventWrapped"; }
533 #endif // __SIM_EVENTQ_HH__