1/*
2 * Copyright (c) 2000-2005 The Regents of The University of Michigan
3 * Copyright (c) 2013 Advanced Micro Devices, Inc.
4 * Copyright (c) 2013 Mark D. Hill and David A. Wood
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions are
9 * met: redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer;
11 * redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution;
14 * neither the name of the copyright holders nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 *
30 * Authors: Steve Reinhardt
31 * Nathan Binkert
32 */
33
34/* @file
35 * EventQueue interfaces
36 */
37
38#ifndef __SIM_EVENTQ_HH__
39#define __SIM_EVENTQ_HH__
40
41#include <algorithm>
42#include <cassert>
43#include <climits>
44#include <iosfwd>
45#include <memory>
46#include <mutex>
47#include <string>
48
49#include "base/flags.hh"
50#include "base/types.hh"
51#include "debug/Event.hh"
52#include "sim/serialize.hh"
53
54class EventQueue; // forward declaration
55class BaseGlobalEvent;
56
57//! Simulation Quantum for multiple eventq simulation.
58//! The quantum value is the period length after which the queues
59//! synchronize themselves with each other. This means that any
60//! event to scheduled on Queue A which is generated by an event on
61//! Queue B should be at least simQuantum ticks away in future.
62extern Tick simQuantum;
63
64//! Current number of allocated main event queues.
65extern uint32_t numMainEventQueues;
66
67//! Array for main event queues.
68extern std::vector<EventQueue *> mainEventQueue;
69
70//! The current event queue for the running thread. Access to this queue
71//! does not require any locking from the thread.
72
73extern __thread EventQueue *_curEventQueue;
74
75//! Current mode of execution: parallel / serial
76extern bool inParallelMode;
77
78//! Function for returning eventq queue for the provided
79//! index. The function allocates a new queue in case one
80//! does not exist for the index, provided that the index
81//! is with in bounds.
82EventQueue *getEventQueue(uint32_t index);
83
84inline EventQueue *curEventQueue() { return _curEventQueue; }
85inline void curEventQueue(EventQueue *q) { _curEventQueue = q; }
86
87/**
88 * Common base class for Event and GlobalEvent, so they can share flag
89 * and priority definitions and accessor functions. This class should
90 * not be used directly.
91 */
92class EventBase
93{
94 protected:
95 typedef unsigned short FlagsType;
96 typedef ::Flags<FlagsType> Flags;
97
98 static const FlagsType PublicRead = 0x003f; // public readable flags
99 static const FlagsType PublicWrite = 0x001d; // public writable flags
100 static const FlagsType Squashed = 0x0001; // has been squashed
101 static const FlagsType Scheduled = 0x0002; // has been scheduled
102 static const FlagsType Managed = 0x0004; // Use life cycle manager
103 static const FlagsType AutoDelete = Managed; // delete after dispatch
104 /**
105 * This used to be AutoSerialize. This value can't be reused
106 * without changing the checkpoint version since the flag field
107 * gets serialized.
108 */
109 static const FlagsType Reserved0 = 0x0008;
110 static const FlagsType IsExitEvent = 0x0010; // special exit event
111 static const FlagsType IsMainQueue = 0x0020; // on main event queue
112 static const FlagsType Initialized = 0x7a40; // somewhat random bits
113 static const FlagsType InitMask = 0xffc0; // mask for init bits
114
115 public:
116 typedef int8_t Priority;
117
118 /// Event priorities, to provide tie-breakers for events scheduled
119 /// at the same cycle. Most events are scheduled at the default
120 /// priority; these values are used to control events that need to
121 /// be ordered within a cycle.
122
123 /// Minimum priority
124 static const Priority Minimum_Pri = SCHAR_MIN;
125
126 /// If we enable tracing on a particular cycle, do that as the
127 /// very first thing so we don't miss any of the events on
128 /// that cycle (even if we enter the debugger).
129 static const Priority Debug_Enable_Pri = -101;
130
131 /// Breakpoints should happen before anything else (except
132 /// enabling trace output), so we don't miss any action when
133 /// debugging.
134 static const Priority Debug_Break_Pri = -100;
135
136 /// CPU switches schedule the new CPU's tick event for the
137 /// same cycle (after unscheduling the old CPU's tick event).
138 /// The switch needs to come before any tick events to make
139 /// sure we don't tick both CPUs in the same cycle.
140 static const Priority CPU_Switch_Pri = -31;
141
142 /// For some reason "delayed" inter-cluster writebacks are
143 /// scheduled before regular writebacks (which have default
144 /// priority). Steve?
145 static const Priority Delayed_Writeback_Pri = -1;
146
147 /// Default is zero for historical reasons.
148 static const Priority Default_Pri = 0;
149
150 /// DVFS update event leads to stats dump therefore given a lower priority
151 /// to ensure all relevant states have been updated
152 static const Priority DVFS_Update_Pri = 31;
153
154 /// Serailization needs to occur before tick events also, so
155 /// that a serialize/unserialize is identical to an on-line
156 /// CPU switch.
157 static const Priority Serialize_Pri = 32;
158
159 /// CPU ticks must come after other associated CPU events
160 /// (such as writebacks).
161 static const Priority CPU_Tick_Pri = 50;
162
163 /// Statistics events (dump, reset, etc.) come after
164 /// everything else, but before exit.
165 static const Priority Stat_Event_Pri = 90;
166
167 /// Progress events come at the end.
168 static const Priority Progress_Event_Pri = 95;
169
170 /// If we want to exit on this cycle, it's the very last thing
171 /// we do.
172 static const Priority Sim_Exit_Pri = 100;
173
174 /// Maximum priority
175 static const Priority Maximum_Pri = SCHAR_MAX;
176};
177
178/*
179 * An item on an event queue. The action caused by a given
180 * event is specified by deriving a subclass and overriding the
181 * process() member function.
182 *
183 * Caution, the order of members is chosen to maximize data packing.
184 */
185class Event : public EventBase, public Serializable
186{
187 friend class EventQueue;
188
189 private:
190 // The event queue is now a linked list of linked lists. The
191 // 'nextBin' pointer is to find the bin, where a bin is defined as
192 // when+priority. All events in the same bin will be stored in a
193 // second linked list (a stack) maintained by the 'nextInBin'
194 // pointer. The list will be accessed in LIFO order. The end
195 // result is that the insert/removal in 'nextBin' is
196 // linear/constant, and the lookup/removal in 'nextInBin' is
197 // constant/constant. Hopefully this is a significant improvement
198 // over the current fully linear insertion.
199 Event *nextBin;
200 Event *nextInBin;
201
202 static Event *insertBefore(Event *event, Event *curr);
203 static Event *removeItem(Event *event, Event *last);
204
205 Tick _when; //!< timestamp when event should be processed
206 Priority _priority; //!< event priority
207 Flags flags;
208
209#ifndef NDEBUG
210 /// Global counter to generate unique IDs for Event instances
211 static Counter instanceCounter;
212
213 /// This event's unique ID. We can also use pointer values for
214 /// this but they're not consistent across runs making debugging
215 /// more difficult. Thus we use a global counter value when
216 /// debugging.
217 Counter instance;
218
219 /// queue to which this event belongs (though it may or may not be
220 /// scheduled on this queue yet)
221 EventQueue *queue;
222#endif
223
224#ifdef EVENTQ_DEBUG
225 Tick whenCreated; //!< time created
226 Tick whenScheduled; //!< time scheduled
227#endif
228
229 void
230 setWhen(Tick when, EventQueue *q)
231 {
232 _when = when;
233#ifndef NDEBUG
234 queue = q;
235#endif
236#ifdef EVENTQ_DEBUG
237 whenScheduled = curTick();
238#endif
239 }
240
241 bool
242 initialized() const
243 {
244 return (flags & InitMask) == Initialized;
245 }
246
247 protected:
248 /// Accessor for flags.
249 Flags
250 getFlags() const
251 {
252 return flags & PublicRead;
253 }
254
255 bool
256 isFlagSet(Flags _flags) const
257 {
258 assert(_flags.noneSet(~PublicRead));
259 return flags.isSet(_flags);
260 }
261
262 /// Accessor for flags.
263 void
264 setFlags(Flags _flags)
265 {
266 assert(_flags.noneSet(~PublicWrite));
267 flags.set(_flags);
268 }
269
270 void
271 clearFlags(Flags _flags)
272 {
273 assert(_flags.noneSet(~PublicWrite));
274 flags.clear(_flags);
275 }
276
277 void
278 clearFlags()
279 {
280 flags.clear(PublicWrite);
281 }
282
283 // This function isn't really useful if TRACING_ON is not defined
284 virtual void trace(const char *action); //!< trace event activity
285
286 protected: /* Memory management */
287 /**
288 * @{
289 * Memory management hooks for events that have the Managed flag set
290 *
291 * Events can use automatic memory management by setting the
292 * Managed flag. The default implementation automatically deletes
293 * events once they have been removed from the event queue. This
294 * typically happens when events are descheduled or have been
295 * triggered and not rescheduled.
296 *
297 * The methods below may be overridden by events that need custom
298 * memory management. For example, events exported to Python need
299 * to impement reference counting to ensure that the Python
300 * implementation of the event is kept alive while it lives in the
301 * event queue.
302 *
303 * @note Memory managers are responsible for implementing
304 * reference counting (by overriding both acquireImpl() and
305 * releaseImpl()) or checking if an event is no longer scheduled
306 * in releaseImpl() before deallocating it.
307 */
308
309 /**
310 * Managed event scheduled and being held in the event queue.
311 */
312 void acquire()
313 {
314 if (flags.isSet(Event::Managed))
315 acquireImpl();
316 }
317
318 /**
319 * Managed event removed from the event queue.
320 */
321 void release() {
322 if (flags.isSet(Event::Managed))
323 releaseImpl();
324 }
325
326 virtual void acquireImpl() {}
327
328 virtual void releaseImpl() {
329 if (!scheduled())
330 delete this;
331 }
332
333 /** @} */
334
335 public:
336
337 /*
338 * Event constructor
339 * @param queue that the event gets scheduled on
340 */
341 Event(Priority p = Default_Pri, Flags f = 0)
342 : nextBin(nullptr), nextInBin(nullptr), _when(0), _priority(p),
343 flags(Initialized | f)
344 {
345 assert(f.noneSet(~PublicWrite));
346#ifndef NDEBUG
347 instance = ++instanceCounter;
348 queue = NULL;
349#endif
350#ifdef EVENTQ_DEBUG
351 whenCreated = curTick();
352 whenScheduled = 0;
353#endif
354 }
355
356 virtual ~Event();
357 virtual const std::string name() const;
358
359 /// Return a C string describing the event. This string should
360 /// *not* be dynamically allocated; just a const char array
361 /// describing the event class.
362 virtual const char *description() const;
363
364 /// Dump the current event data
365 void dump() const;
366
367 public:
368 /*
369 * This member function is invoked when the event is processed
370 * (occurs). There is no default implementation; each subclass
371 * must provide its own implementation. The event is not
372 * automatically deleted after it is processed (to allow for
373 * statically allocated event objects).
374 *
375 * If the AutoDestroy flag is set, the object is deleted once it
376 * is processed.
377 */
378 virtual void process() = 0;
379
380 /// Determine if the current event is scheduled
381 bool scheduled() const { return flags.isSet(Scheduled); }
382
383 /// Squash the current event
384 void squash() { flags.set(Squashed); }
385
386 /// Check whether the event is squashed
387 bool squashed() const { return flags.isSet(Squashed); }
388
389 /// See if this is a SimExitEvent (without resorting to RTTI)
390 bool isExitEvent() const { return flags.isSet(IsExitEvent); }
391
392 /// Check whether this event will auto-delete
393 bool isManaged() const { return flags.isSet(Managed); }
394 bool isAutoDelete() const { return isManaged(); }
395
396 /// Get the time that the event is scheduled
397 Tick when() const { return _when; }
398
399 /// Get the event priority
400 Priority priority() const { return _priority; }
401
402 //! If this is part of a GlobalEvent, return the pointer to the
403 //! Global Event. By default, there is no GlobalEvent, so return
404 //! NULL. (Overridden in GlobalEvent::BarrierEvent.)
405 virtual BaseGlobalEvent *globalEvent() { return NULL; }
406
407 void serialize(CheckpointOut &cp) const override;
408 void unserialize(CheckpointIn &cp) override;
409};
410
411inline bool
412operator<(const Event &l, const Event &r)
413{
414 return l.when() < r.when() ||
415 (l.when() == r.when() && l.priority() < r.priority());
416}
417
418inline bool
419operator>(const Event &l, const Event &r)
420{
421 return l.when() > r.when() ||
422 (l.when() == r.when() && l.priority() > r.priority());
423}
424
425inline bool
426operator<=(const Event &l, const Event &r)
427{
428 return l.when() < r.when() ||
429 (l.when() == r.when() && l.priority() <= r.priority());
430}
431inline bool
432operator>=(const Event &l, const Event &r)
433{
434 return l.when() > r.when() ||
435 (l.when() == r.when() && l.priority() >= r.priority());
436}
437
438inline bool
439operator==(const Event &l, const Event &r)
440{
441 return l.when() == r.when() && l.priority() == r.priority();
442}
443
444inline bool
445operator!=(const Event &l, const Event &r)
446{
447 return l.when() != r.when() || l.priority() != r.priority();
448}
449
450/**
451 * Queue of events sorted in time order
452 *
453 * Events are scheduled (inserted into the event queue) using the
454 * schedule() method. This method either inserts a <i>synchronous</i>
455 * or <i>asynchronous</i> event.
456 *
457 * Synchronous events are scheduled using schedule() method with the
458 * argument 'global' set to false (default). This should only be done
459 * from a thread holding the event queue lock
460 * (EventQueue::service_mutex). The lock is always held when an event
461 * handler is called, it can therefore always insert events into its
462 * own event queue unless it voluntarily releases the lock.
463 *
464 * Events can be scheduled across thread (and event queue borders) by
465 * either scheduling asynchronous events or taking the target event
466 * queue's lock. However, the lock should <i>never</i> be taken
467 * directly since this is likely to cause deadlocks. Instead, code
468 * that needs to schedule events in other event queues should
469 * temporarily release its own queue and lock the new queue. This
470 * prevents deadlocks since a single thread never owns more than one
471 * event queue lock. This functionality is provided by the
472 * ScopedMigration helper class. Note that temporarily migrating
473 * between event queues can make the simulation non-deterministic, it
474 * should therefore be limited to cases where that can be tolerated
475 * (e.g., handling asynchronous IO or fast-forwarding in KVM).
476 *
477 * Asynchronous events can also be scheduled using the normal
478 * schedule() method with the 'global' parameter set to true. Unlike
479 * the previous queue migration strategy, this strategy is fully
480 * deterministic. This causes the event to be inserted in a separate
481 * queue of asynchronous events (async_queue), which is merged main
482 * event queue at the end of each simulation quantum (by calling the
483 * handleAsyncInsertions() method). Note that this implies that such
484 * events must happen at least one simulation quantum into the future,
485 * otherwise they risk being scheduled in the past by
486 * handleAsyncInsertions().
487 */
488class EventQueue
489{
490 private:
491 std::string objName;
492 Event *head;
493 Tick _curTick;
494
495 //! Mutex to protect async queue.
496 std::mutex async_queue_mutex;
497
498 //! List of events added by other threads to this event queue.
499 std::list<Event*> async_queue;
500
501 /**
502 * Lock protecting event handling.
503 *
504 * This lock is always taken when servicing events. It is assumed
505 * that the thread scheduling new events (not asynchronous events
506 * though) have taken this lock. This is normally done by
507 * serviceOne() since new events are typically scheduled as a
508 * response to an earlier event.
509 *
510 * This lock is intended to be used to temporarily steal an event
511 * queue to support inter-thread communication when some
512 * deterministic timing can be sacrificed for speed. For example,
513 * the KVM CPU can use this support to access devices running in a
514 * different thread.
515 *
516 * @see EventQueue::ScopedMigration.
517 * @see EventQueue::ScopedRelease
518 * @see EventQueue::lock()
519 * @see EventQueue::unlock()
520 */
521 std::mutex service_mutex;
522
523 //! Insert / remove event from the queue. Should only be called
524 //! by thread operating this queue.
525 void insert(Event *event);
526 void remove(Event *event);
527
528 //! Function for adding events to the async queue. The added events
529 //! are added to main event queue later. Threads, other than the
530 //! owning thread, should call this function instead of insert().
531 void asyncInsert(Event *event);
532
533 EventQueue(const EventQueue &);
534
535 public:
536 /**
537 * Temporarily migrate execution to a different event queue.
538 *
539 * An instance of this class temporarily migrates execution to a
540 * different event queue by releasing the current queue, locking
541 * the new queue, and updating curEventQueue(). This can, for
542 * example, be useful when performing IO across thread event
543 * queues when timing is not crucial (e.g., during fast
544 * forwarding).
545 *
546 * ScopedMigration does nothing if both eqs are the same
547 */
548 class ScopedMigration
549 {
550 public:
551 ScopedMigration(EventQueue *_new_eq, bool _doMigrate = true)
552 :new_eq(*_new_eq), old_eq(*curEventQueue()),
553 doMigrate((&new_eq != &old_eq)&&_doMigrate)
554 {
555 if (doMigrate){
556 old_eq.unlock();
557 new_eq.lock();
558 curEventQueue(&new_eq);
559 }
560 }
561
562 ~ScopedMigration()
563 {
564 if (doMigrate){
565 new_eq.unlock();
566 old_eq.lock();
567 curEventQueue(&old_eq);
568 }
569 }
570
571 private:
572 EventQueue &new_eq;
573 EventQueue &old_eq;
574 bool doMigrate;
575 };
576
577 /**
578 * Temporarily release the event queue service lock.
579 *
580 * There are cases where it is desirable to temporarily release
581 * the event queue lock to prevent deadlocks. For example, when
582 * waiting on the global barrier, we need to release the lock to
583 * prevent deadlocks from happening when another thread tries to
584 * temporarily take over the event queue waiting on the barrier.
585 */
586 class ScopedRelease
587 {
588 public:
589 ScopedRelease(EventQueue *_eq)
590 : eq(*_eq)
591 {
592 eq.unlock();
593 }
594
595 ~ScopedRelease()
596 {
597 eq.lock();
598 }
599
600 private:
601 EventQueue &eq;
602 };
603
604 EventQueue(const std::string &n);
605
606 virtual const std::string name() const { return objName; }
607 void name(const std::string &st) { objName = st; }
608
609 //! Schedule the given event on this queue. Safe to call from any
610 //! thread.
611 void schedule(Event *event, Tick when, bool global = false);
612
613 //! Deschedule the specified event. Should be called only from the
614 //! owning thread.
615 void deschedule(Event *event);
616
617 //! Reschedule the specified event. Should be called only from
618 //! the owning thread.
619 void reschedule(Event *event, Tick when, bool always = false);
620
621 Tick nextTick() const { return head->when(); }
622 void setCurTick(Tick newVal) { _curTick = newVal; }
623 Tick getCurTick() const { return _curTick; }
624 Event *getHead() const { return head; }
625
626 Event *serviceOne();
627
628 // process all events up to the given timestamp. we inline a
629 // quick test to see if there are any events to process; if so,
630 // call the internal out-of-line version to process them all.
631 void
632 serviceEvents(Tick when)
633 {
634 while (!empty()) {
635 if (nextTick() > when)
636 break;
637
638 /**
639 * @todo this assert is a good bug catcher. I need to
640 * make it true again.
641 */
642 //assert(head->when() >= when && "event scheduled in the past");
643 serviceOne();
644 }
645
646 setCurTick(when);
647 }
648
649 // return true if no events are queued
650 bool empty() const { return head == NULL; }
651
652 void dump() const;
653
654 bool debugVerify() const;
655
656 //! Function for moving events from the async_queue to the main queue.
657 void handleAsyncInsertions();
658
659 /**
660 * Function to signal that the event loop should be woken up because
661 * an event has been scheduled by an agent outside the gem5 event
662 * loop(s) whose event insertion may not have been noticed by gem5.
663 * This function isn't needed by the usual gem5 event loop but may
664 * be necessary in derived EventQueues which host gem5 onto other
665 * schedulers.
666 *
667 * @param when Time of a delayed wakeup (if known). This parameter
668 * can be used by an implementation to schedule a wakeup in the
669 * future if it is sure it will remain active until then.
670 * Or it can be ignored and the event queue can be woken up now.
671 */
672 virtual void wakeup(Tick when = (Tick)-1) { }
673
674 /**
675 * function for replacing the head of the event queue, so that a
676 * different set of events can run without disturbing events that have
677 * already been scheduled. Already scheduled events can be processed
678 * by replacing the original head back.
679 * USING THIS FUNCTION CAN BE DANGEROUS TO THE HEALTH OF THE SIMULATOR.
680 * NOT RECOMMENDED FOR USE.
681 */
682 Event* replaceHead(Event* s);
683
684 /**@{*/
685 /**
686 * Provide an interface for locking/unlocking the event queue.
687 *
688 * @warn Do NOT use these methods directly unless you really know
689 * what you are doing. Incorrect use can easily lead to simulator
690 * deadlocks.
691 *
692 * @see EventQueue::ScopedMigration.
693 * @see EventQueue::ScopedRelease
694 * @see EventQueue
695 */
696 void lock() { service_mutex.lock(); }
697 void unlock() { service_mutex.unlock(); }
698 /**@}*/
699
700 /**
701 * Reschedule an event after a checkpoint.
702 *
703 * Since events don't know which event queue they belong to,
704 * parent objects need to reschedule events themselves. This
705 * method conditionally schedules an event that has the Scheduled
706 * flag set. It should be called by parent objects after
707 * unserializing an object.
708 *
709 * @warn Only use this method after unserializing an Event.
710 */
711 void checkpointReschedule(Event *event);
712
713 virtual ~EventQueue() { }
714};
715
716void dumpMainQueue();
717
718class EventManager
719{
720 protected:
721 /** A pointer to this object's event queue */
722 EventQueue *eventq;
723
724 public:
725 EventManager(EventManager &em) : eventq(em.eventq) {}
726 EventManager(EventManager *em) : eventq(em->eventq) {}
727 EventManager(EventQueue *eq) : eventq(eq) {}
728
729 EventQueue *
730 eventQueue() const
731 {
732 return eventq;
733 }
734
735 void
736 schedule(Event &event, Tick when)
737 {
738 eventq->schedule(&event, when);
739 }
740
741 void
742 deschedule(Event &event)
743 {
744 eventq->deschedule(&event);
745 }
746
747 void
748 reschedule(Event &event, Tick when, bool always = false)
749 {
750 eventq->reschedule(&event, when, always);
751 }
752
753 void
754 schedule(Event *event, Tick when)
755 {
756 eventq->schedule(event, when);
757 }
758
759 void
760 deschedule(Event *event)
761 {
762 eventq->deschedule(event);
763 }
764
765 void
766 reschedule(Event *event, Tick when, bool always = false)
767 {
768 eventq->reschedule(event, when, always);
769 }
770
771 void wakeupEventQueue(Tick when = (Tick)-1)
772 {
773 eventq->wakeup(when);
774 }
775
776 void setCurTick(Tick newVal) { eventq->setCurTick(newVal); }
777};
778
779template <class T, void (T::* F)()>
780class EventWrapper : public Event
781{
782 private:
783 T *object;
784
785 public:
786 EventWrapper(T *obj, bool del = false, Priority p = Default_Pri)
787 : Event(p), object(obj)
788 {
789 if (del)
790 setFlags(AutoDelete);
791 }
792
793 EventWrapper(T &obj, bool del = false, Priority p = Default_Pri)
794 : Event(p), object(&obj)
795 {
796 if (del)
797 setFlags(AutoDelete);
798 }
799
800 void process() { (object->*F)(); }
801
802 const std::string
803 name() const
804 {
805 return object->name() + ".wrapped_event";
806 }
807
808 const char *description() const { return "EventWrapped"; }
809};
810
811class EventFunctionWrapper : public Event
812{
813 private:
814 std::function<void(void)> callback;
815 std::string _name;
816
817 public:
818 EventFunctionWrapper(const std::function<void(void)> &callback,
819 const std::string &name,
820 bool del = false,
821 Priority p = Default_Pri)
822 : Event(p), callback(callback), _name(name)
823 {
824 if (del)
825 setFlags(AutoDelete);
826 }
827
828 void process() { callback(); }
829
830 const std::string
831 name() const
832 {
833 return _name + ".wrapped_function_event";
834 }
835
836 const char *description() const { return "EventFunctionWrapped"; }
837};
838
839#endif // __SIM_EVENTQ_HH__
2 * Copyright (c) 2000-2005 The Regents of The University of Michigan
3 * Copyright (c) 2013 Advanced Micro Devices, Inc.
4 * Copyright (c) 2013 Mark D. Hill and David A. Wood
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions are
9 * met: redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer;
11 * redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution;
14 * neither the name of the copyright holders nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 *
30 * Authors: Steve Reinhardt
31 * Nathan Binkert
32 */
33
34/* @file
35 * EventQueue interfaces
36 */
37
38#ifndef __SIM_EVENTQ_HH__
39#define __SIM_EVENTQ_HH__
40
41#include <algorithm>
42#include <cassert>
43#include <climits>
44#include <iosfwd>
45#include <memory>
46#include <mutex>
47#include <string>
48
49#include "base/flags.hh"
50#include "base/types.hh"
51#include "debug/Event.hh"
52#include "sim/serialize.hh"
53
54class EventQueue; // forward declaration
55class BaseGlobalEvent;
56
57//! Simulation Quantum for multiple eventq simulation.
58//! The quantum value is the period length after which the queues
59//! synchronize themselves with each other. This means that any
60//! event to scheduled on Queue A which is generated by an event on
61//! Queue B should be at least simQuantum ticks away in future.
62extern Tick simQuantum;
63
64//! Current number of allocated main event queues.
65extern uint32_t numMainEventQueues;
66
67//! Array for main event queues.
68extern std::vector<EventQueue *> mainEventQueue;
69
70//! The current event queue for the running thread. Access to this queue
71//! does not require any locking from the thread.
72
73extern __thread EventQueue *_curEventQueue;
74
75//! Current mode of execution: parallel / serial
76extern bool inParallelMode;
77
78//! Function for returning eventq queue for the provided
79//! index. The function allocates a new queue in case one
80//! does not exist for the index, provided that the index
81//! is with in bounds.
82EventQueue *getEventQueue(uint32_t index);
83
84inline EventQueue *curEventQueue() { return _curEventQueue; }
85inline void curEventQueue(EventQueue *q) { _curEventQueue = q; }
86
87/**
88 * Common base class for Event and GlobalEvent, so they can share flag
89 * and priority definitions and accessor functions. This class should
90 * not be used directly.
91 */
92class EventBase
93{
94 protected:
95 typedef unsigned short FlagsType;
96 typedef ::Flags<FlagsType> Flags;
97
98 static const FlagsType PublicRead = 0x003f; // public readable flags
99 static const FlagsType PublicWrite = 0x001d; // public writable flags
100 static const FlagsType Squashed = 0x0001; // has been squashed
101 static const FlagsType Scheduled = 0x0002; // has been scheduled
102 static const FlagsType Managed = 0x0004; // Use life cycle manager
103 static const FlagsType AutoDelete = Managed; // delete after dispatch
104 /**
105 * This used to be AutoSerialize. This value can't be reused
106 * without changing the checkpoint version since the flag field
107 * gets serialized.
108 */
109 static const FlagsType Reserved0 = 0x0008;
110 static const FlagsType IsExitEvent = 0x0010; // special exit event
111 static const FlagsType IsMainQueue = 0x0020; // on main event queue
112 static const FlagsType Initialized = 0x7a40; // somewhat random bits
113 static const FlagsType InitMask = 0xffc0; // mask for init bits
114
115 public:
116 typedef int8_t Priority;
117
118 /// Event priorities, to provide tie-breakers for events scheduled
119 /// at the same cycle. Most events are scheduled at the default
120 /// priority; these values are used to control events that need to
121 /// be ordered within a cycle.
122
123 /// Minimum priority
124 static const Priority Minimum_Pri = SCHAR_MIN;
125
126 /// If we enable tracing on a particular cycle, do that as the
127 /// very first thing so we don't miss any of the events on
128 /// that cycle (even if we enter the debugger).
129 static const Priority Debug_Enable_Pri = -101;
130
131 /// Breakpoints should happen before anything else (except
132 /// enabling trace output), so we don't miss any action when
133 /// debugging.
134 static const Priority Debug_Break_Pri = -100;
135
136 /// CPU switches schedule the new CPU's tick event for the
137 /// same cycle (after unscheduling the old CPU's tick event).
138 /// The switch needs to come before any tick events to make
139 /// sure we don't tick both CPUs in the same cycle.
140 static const Priority CPU_Switch_Pri = -31;
141
142 /// For some reason "delayed" inter-cluster writebacks are
143 /// scheduled before regular writebacks (which have default
144 /// priority). Steve?
145 static const Priority Delayed_Writeback_Pri = -1;
146
147 /// Default is zero for historical reasons.
148 static const Priority Default_Pri = 0;
149
150 /// DVFS update event leads to stats dump therefore given a lower priority
151 /// to ensure all relevant states have been updated
152 static const Priority DVFS_Update_Pri = 31;
153
154 /// Serailization needs to occur before tick events also, so
155 /// that a serialize/unserialize is identical to an on-line
156 /// CPU switch.
157 static const Priority Serialize_Pri = 32;
158
159 /// CPU ticks must come after other associated CPU events
160 /// (such as writebacks).
161 static const Priority CPU_Tick_Pri = 50;
162
163 /// Statistics events (dump, reset, etc.) come after
164 /// everything else, but before exit.
165 static const Priority Stat_Event_Pri = 90;
166
167 /// Progress events come at the end.
168 static const Priority Progress_Event_Pri = 95;
169
170 /// If we want to exit on this cycle, it's the very last thing
171 /// we do.
172 static const Priority Sim_Exit_Pri = 100;
173
174 /// Maximum priority
175 static const Priority Maximum_Pri = SCHAR_MAX;
176};
177
178/*
179 * An item on an event queue. The action caused by a given
180 * event is specified by deriving a subclass and overriding the
181 * process() member function.
182 *
183 * Caution, the order of members is chosen to maximize data packing.
184 */
185class Event : public EventBase, public Serializable
186{
187 friend class EventQueue;
188
189 private:
190 // The event queue is now a linked list of linked lists. The
191 // 'nextBin' pointer is to find the bin, where a bin is defined as
192 // when+priority. All events in the same bin will be stored in a
193 // second linked list (a stack) maintained by the 'nextInBin'
194 // pointer. The list will be accessed in LIFO order. The end
195 // result is that the insert/removal in 'nextBin' is
196 // linear/constant, and the lookup/removal in 'nextInBin' is
197 // constant/constant. Hopefully this is a significant improvement
198 // over the current fully linear insertion.
199 Event *nextBin;
200 Event *nextInBin;
201
202 static Event *insertBefore(Event *event, Event *curr);
203 static Event *removeItem(Event *event, Event *last);
204
205 Tick _when; //!< timestamp when event should be processed
206 Priority _priority; //!< event priority
207 Flags flags;
208
209#ifndef NDEBUG
210 /// Global counter to generate unique IDs for Event instances
211 static Counter instanceCounter;
212
213 /// This event's unique ID. We can also use pointer values for
214 /// this but they're not consistent across runs making debugging
215 /// more difficult. Thus we use a global counter value when
216 /// debugging.
217 Counter instance;
218
219 /// queue to which this event belongs (though it may or may not be
220 /// scheduled on this queue yet)
221 EventQueue *queue;
222#endif
223
224#ifdef EVENTQ_DEBUG
225 Tick whenCreated; //!< time created
226 Tick whenScheduled; //!< time scheduled
227#endif
228
229 void
230 setWhen(Tick when, EventQueue *q)
231 {
232 _when = when;
233#ifndef NDEBUG
234 queue = q;
235#endif
236#ifdef EVENTQ_DEBUG
237 whenScheduled = curTick();
238#endif
239 }
240
241 bool
242 initialized() const
243 {
244 return (flags & InitMask) == Initialized;
245 }
246
247 protected:
248 /// Accessor for flags.
249 Flags
250 getFlags() const
251 {
252 return flags & PublicRead;
253 }
254
255 bool
256 isFlagSet(Flags _flags) const
257 {
258 assert(_flags.noneSet(~PublicRead));
259 return flags.isSet(_flags);
260 }
261
262 /// Accessor for flags.
263 void
264 setFlags(Flags _flags)
265 {
266 assert(_flags.noneSet(~PublicWrite));
267 flags.set(_flags);
268 }
269
270 void
271 clearFlags(Flags _flags)
272 {
273 assert(_flags.noneSet(~PublicWrite));
274 flags.clear(_flags);
275 }
276
277 void
278 clearFlags()
279 {
280 flags.clear(PublicWrite);
281 }
282
283 // This function isn't really useful if TRACING_ON is not defined
284 virtual void trace(const char *action); //!< trace event activity
285
286 protected: /* Memory management */
287 /**
288 * @{
289 * Memory management hooks for events that have the Managed flag set
290 *
291 * Events can use automatic memory management by setting the
292 * Managed flag. The default implementation automatically deletes
293 * events once they have been removed from the event queue. This
294 * typically happens when events are descheduled or have been
295 * triggered and not rescheduled.
296 *
297 * The methods below may be overridden by events that need custom
298 * memory management. For example, events exported to Python need
299 * to impement reference counting to ensure that the Python
300 * implementation of the event is kept alive while it lives in the
301 * event queue.
302 *
303 * @note Memory managers are responsible for implementing
304 * reference counting (by overriding both acquireImpl() and
305 * releaseImpl()) or checking if an event is no longer scheduled
306 * in releaseImpl() before deallocating it.
307 */
308
309 /**
310 * Managed event scheduled and being held in the event queue.
311 */
312 void acquire()
313 {
314 if (flags.isSet(Event::Managed))
315 acquireImpl();
316 }
317
318 /**
319 * Managed event removed from the event queue.
320 */
321 void release() {
322 if (flags.isSet(Event::Managed))
323 releaseImpl();
324 }
325
326 virtual void acquireImpl() {}
327
328 virtual void releaseImpl() {
329 if (!scheduled())
330 delete this;
331 }
332
333 /** @} */
334
335 public:
336
337 /*
338 * Event constructor
339 * @param queue that the event gets scheduled on
340 */
341 Event(Priority p = Default_Pri, Flags f = 0)
342 : nextBin(nullptr), nextInBin(nullptr), _when(0), _priority(p),
343 flags(Initialized | f)
344 {
345 assert(f.noneSet(~PublicWrite));
346#ifndef NDEBUG
347 instance = ++instanceCounter;
348 queue = NULL;
349#endif
350#ifdef EVENTQ_DEBUG
351 whenCreated = curTick();
352 whenScheduled = 0;
353#endif
354 }
355
356 virtual ~Event();
357 virtual const std::string name() const;
358
359 /// Return a C string describing the event. This string should
360 /// *not* be dynamically allocated; just a const char array
361 /// describing the event class.
362 virtual const char *description() const;
363
364 /// Dump the current event data
365 void dump() const;
366
367 public:
368 /*
369 * This member function is invoked when the event is processed
370 * (occurs). There is no default implementation; each subclass
371 * must provide its own implementation. The event is not
372 * automatically deleted after it is processed (to allow for
373 * statically allocated event objects).
374 *
375 * If the AutoDestroy flag is set, the object is deleted once it
376 * is processed.
377 */
378 virtual void process() = 0;
379
380 /// Determine if the current event is scheduled
381 bool scheduled() const { return flags.isSet(Scheduled); }
382
383 /// Squash the current event
384 void squash() { flags.set(Squashed); }
385
386 /// Check whether the event is squashed
387 bool squashed() const { return flags.isSet(Squashed); }
388
389 /// See if this is a SimExitEvent (without resorting to RTTI)
390 bool isExitEvent() const { return flags.isSet(IsExitEvent); }
391
392 /// Check whether this event will auto-delete
393 bool isManaged() const { return flags.isSet(Managed); }
394 bool isAutoDelete() const { return isManaged(); }
395
396 /// Get the time that the event is scheduled
397 Tick when() const { return _when; }
398
399 /// Get the event priority
400 Priority priority() const { return _priority; }
401
402 //! If this is part of a GlobalEvent, return the pointer to the
403 //! Global Event. By default, there is no GlobalEvent, so return
404 //! NULL. (Overridden in GlobalEvent::BarrierEvent.)
405 virtual BaseGlobalEvent *globalEvent() { return NULL; }
406
407 void serialize(CheckpointOut &cp) const override;
408 void unserialize(CheckpointIn &cp) override;
409};
410
411inline bool
412operator<(const Event &l, const Event &r)
413{
414 return l.when() < r.when() ||
415 (l.when() == r.when() && l.priority() < r.priority());
416}
417
418inline bool
419operator>(const Event &l, const Event &r)
420{
421 return l.when() > r.when() ||
422 (l.when() == r.when() && l.priority() > r.priority());
423}
424
425inline bool
426operator<=(const Event &l, const Event &r)
427{
428 return l.when() < r.when() ||
429 (l.when() == r.when() && l.priority() <= r.priority());
430}
431inline bool
432operator>=(const Event &l, const Event &r)
433{
434 return l.when() > r.when() ||
435 (l.when() == r.when() && l.priority() >= r.priority());
436}
437
438inline bool
439operator==(const Event &l, const Event &r)
440{
441 return l.when() == r.when() && l.priority() == r.priority();
442}
443
444inline bool
445operator!=(const Event &l, const Event &r)
446{
447 return l.when() != r.when() || l.priority() != r.priority();
448}
449
450/**
451 * Queue of events sorted in time order
452 *
453 * Events are scheduled (inserted into the event queue) using the
454 * schedule() method. This method either inserts a <i>synchronous</i>
455 * or <i>asynchronous</i> event.
456 *
457 * Synchronous events are scheduled using schedule() method with the
458 * argument 'global' set to false (default). This should only be done
459 * from a thread holding the event queue lock
460 * (EventQueue::service_mutex). The lock is always held when an event
461 * handler is called, it can therefore always insert events into its
462 * own event queue unless it voluntarily releases the lock.
463 *
464 * Events can be scheduled across thread (and event queue borders) by
465 * either scheduling asynchronous events or taking the target event
466 * queue's lock. However, the lock should <i>never</i> be taken
467 * directly since this is likely to cause deadlocks. Instead, code
468 * that needs to schedule events in other event queues should
469 * temporarily release its own queue and lock the new queue. This
470 * prevents deadlocks since a single thread never owns more than one
471 * event queue lock. This functionality is provided by the
472 * ScopedMigration helper class. Note that temporarily migrating
473 * between event queues can make the simulation non-deterministic, it
474 * should therefore be limited to cases where that can be tolerated
475 * (e.g., handling asynchronous IO or fast-forwarding in KVM).
476 *
477 * Asynchronous events can also be scheduled using the normal
478 * schedule() method with the 'global' parameter set to true. Unlike
479 * the previous queue migration strategy, this strategy is fully
480 * deterministic. This causes the event to be inserted in a separate
481 * queue of asynchronous events (async_queue), which is merged main
482 * event queue at the end of each simulation quantum (by calling the
483 * handleAsyncInsertions() method). Note that this implies that such
484 * events must happen at least one simulation quantum into the future,
485 * otherwise they risk being scheduled in the past by
486 * handleAsyncInsertions().
487 */
488class EventQueue
489{
490 private:
491 std::string objName;
492 Event *head;
493 Tick _curTick;
494
495 //! Mutex to protect async queue.
496 std::mutex async_queue_mutex;
497
498 //! List of events added by other threads to this event queue.
499 std::list<Event*> async_queue;
500
501 /**
502 * Lock protecting event handling.
503 *
504 * This lock is always taken when servicing events. It is assumed
505 * that the thread scheduling new events (not asynchronous events
506 * though) have taken this lock. This is normally done by
507 * serviceOne() since new events are typically scheduled as a
508 * response to an earlier event.
509 *
510 * This lock is intended to be used to temporarily steal an event
511 * queue to support inter-thread communication when some
512 * deterministic timing can be sacrificed for speed. For example,
513 * the KVM CPU can use this support to access devices running in a
514 * different thread.
515 *
516 * @see EventQueue::ScopedMigration.
517 * @see EventQueue::ScopedRelease
518 * @see EventQueue::lock()
519 * @see EventQueue::unlock()
520 */
521 std::mutex service_mutex;
522
523 //! Insert / remove event from the queue. Should only be called
524 //! by thread operating this queue.
525 void insert(Event *event);
526 void remove(Event *event);
527
528 //! Function for adding events to the async queue. The added events
529 //! are added to main event queue later. Threads, other than the
530 //! owning thread, should call this function instead of insert().
531 void asyncInsert(Event *event);
532
533 EventQueue(const EventQueue &);
534
535 public:
536 /**
537 * Temporarily migrate execution to a different event queue.
538 *
539 * An instance of this class temporarily migrates execution to a
540 * different event queue by releasing the current queue, locking
541 * the new queue, and updating curEventQueue(). This can, for
542 * example, be useful when performing IO across thread event
543 * queues when timing is not crucial (e.g., during fast
544 * forwarding).
545 *
546 * ScopedMigration does nothing if both eqs are the same
547 */
548 class ScopedMigration
549 {
550 public:
551 ScopedMigration(EventQueue *_new_eq, bool _doMigrate = true)
552 :new_eq(*_new_eq), old_eq(*curEventQueue()),
553 doMigrate((&new_eq != &old_eq)&&_doMigrate)
554 {
555 if (doMigrate){
556 old_eq.unlock();
557 new_eq.lock();
558 curEventQueue(&new_eq);
559 }
560 }
561
562 ~ScopedMigration()
563 {
564 if (doMigrate){
565 new_eq.unlock();
566 old_eq.lock();
567 curEventQueue(&old_eq);
568 }
569 }
570
571 private:
572 EventQueue &new_eq;
573 EventQueue &old_eq;
574 bool doMigrate;
575 };
576
577 /**
578 * Temporarily release the event queue service lock.
579 *
580 * There are cases where it is desirable to temporarily release
581 * the event queue lock to prevent deadlocks. For example, when
582 * waiting on the global barrier, we need to release the lock to
583 * prevent deadlocks from happening when another thread tries to
584 * temporarily take over the event queue waiting on the barrier.
585 */
586 class ScopedRelease
587 {
588 public:
589 ScopedRelease(EventQueue *_eq)
590 : eq(*_eq)
591 {
592 eq.unlock();
593 }
594
595 ~ScopedRelease()
596 {
597 eq.lock();
598 }
599
600 private:
601 EventQueue &eq;
602 };
603
604 EventQueue(const std::string &n);
605
606 virtual const std::string name() const { return objName; }
607 void name(const std::string &st) { objName = st; }
608
609 //! Schedule the given event on this queue. Safe to call from any
610 //! thread.
611 void schedule(Event *event, Tick when, bool global = false);
612
613 //! Deschedule the specified event. Should be called only from the
614 //! owning thread.
615 void deschedule(Event *event);
616
617 //! Reschedule the specified event. Should be called only from
618 //! the owning thread.
619 void reschedule(Event *event, Tick when, bool always = false);
620
621 Tick nextTick() const { return head->when(); }
622 void setCurTick(Tick newVal) { _curTick = newVal; }
623 Tick getCurTick() const { return _curTick; }
624 Event *getHead() const { return head; }
625
626 Event *serviceOne();
627
628 // process all events up to the given timestamp. we inline a
629 // quick test to see if there are any events to process; if so,
630 // call the internal out-of-line version to process them all.
631 void
632 serviceEvents(Tick when)
633 {
634 while (!empty()) {
635 if (nextTick() > when)
636 break;
637
638 /**
639 * @todo this assert is a good bug catcher. I need to
640 * make it true again.
641 */
642 //assert(head->when() >= when && "event scheduled in the past");
643 serviceOne();
644 }
645
646 setCurTick(when);
647 }
648
649 // return true if no events are queued
650 bool empty() const { return head == NULL; }
651
652 void dump() const;
653
654 bool debugVerify() const;
655
656 //! Function for moving events from the async_queue to the main queue.
657 void handleAsyncInsertions();
658
659 /**
660 * Function to signal that the event loop should be woken up because
661 * an event has been scheduled by an agent outside the gem5 event
662 * loop(s) whose event insertion may not have been noticed by gem5.
663 * This function isn't needed by the usual gem5 event loop but may
664 * be necessary in derived EventQueues which host gem5 onto other
665 * schedulers.
666 *
667 * @param when Time of a delayed wakeup (if known). This parameter
668 * can be used by an implementation to schedule a wakeup in the
669 * future if it is sure it will remain active until then.
670 * Or it can be ignored and the event queue can be woken up now.
671 */
672 virtual void wakeup(Tick when = (Tick)-1) { }
673
674 /**
675 * function for replacing the head of the event queue, so that a
676 * different set of events can run without disturbing events that have
677 * already been scheduled. Already scheduled events can be processed
678 * by replacing the original head back.
679 * USING THIS FUNCTION CAN BE DANGEROUS TO THE HEALTH OF THE SIMULATOR.
680 * NOT RECOMMENDED FOR USE.
681 */
682 Event* replaceHead(Event* s);
683
684 /**@{*/
685 /**
686 * Provide an interface for locking/unlocking the event queue.
687 *
688 * @warn Do NOT use these methods directly unless you really know
689 * what you are doing. Incorrect use can easily lead to simulator
690 * deadlocks.
691 *
692 * @see EventQueue::ScopedMigration.
693 * @see EventQueue::ScopedRelease
694 * @see EventQueue
695 */
696 void lock() { service_mutex.lock(); }
697 void unlock() { service_mutex.unlock(); }
698 /**@}*/
699
700 /**
701 * Reschedule an event after a checkpoint.
702 *
703 * Since events don't know which event queue they belong to,
704 * parent objects need to reschedule events themselves. This
705 * method conditionally schedules an event that has the Scheduled
706 * flag set. It should be called by parent objects after
707 * unserializing an object.
708 *
709 * @warn Only use this method after unserializing an Event.
710 */
711 void checkpointReschedule(Event *event);
712
713 virtual ~EventQueue() { }
714};
715
716void dumpMainQueue();
717
718class EventManager
719{
720 protected:
721 /** A pointer to this object's event queue */
722 EventQueue *eventq;
723
724 public:
725 EventManager(EventManager &em) : eventq(em.eventq) {}
726 EventManager(EventManager *em) : eventq(em->eventq) {}
727 EventManager(EventQueue *eq) : eventq(eq) {}
728
729 EventQueue *
730 eventQueue() const
731 {
732 return eventq;
733 }
734
735 void
736 schedule(Event &event, Tick when)
737 {
738 eventq->schedule(&event, when);
739 }
740
741 void
742 deschedule(Event &event)
743 {
744 eventq->deschedule(&event);
745 }
746
747 void
748 reschedule(Event &event, Tick when, bool always = false)
749 {
750 eventq->reschedule(&event, when, always);
751 }
752
753 void
754 schedule(Event *event, Tick when)
755 {
756 eventq->schedule(event, when);
757 }
758
759 void
760 deschedule(Event *event)
761 {
762 eventq->deschedule(event);
763 }
764
765 void
766 reschedule(Event *event, Tick when, bool always = false)
767 {
768 eventq->reschedule(event, when, always);
769 }
770
771 void wakeupEventQueue(Tick when = (Tick)-1)
772 {
773 eventq->wakeup(when);
774 }
775
776 void setCurTick(Tick newVal) { eventq->setCurTick(newVal); }
777};
778
779template <class T, void (T::* F)()>
780class EventWrapper : public Event
781{
782 private:
783 T *object;
784
785 public:
786 EventWrapper(T *obj, bool del = false, Priority p = Default_Pri)
787 : Event(p), object(obj)
788 {
789 if (del)
790 setFlags(AutoDelete);
791 }
792
793 EventWrapper(T &obj, bool del = false, Priority p = Default_Pri)
794 : Event(p), object(&obj)
795 {
796 if (del)
797 setFlags(AutoDelete);
798 }
799
800 void process() { (object->*F)(); }
801
802 const std::string
803 name() const
804 {
805 return object->name() + ".wrapped_event";
806 }
807
808 const char *description() const { return "EventWrapped"; }
809};
810
811class EventFunctionWrapper : public Event
812{
813 private:
814 std::function<void(void)> callback;
815 std::string _name;
816
817 public:
818 EventFunctionWrapper(const std::function<void(void)> &callback,
819 const std::string &name,
820 bool del = false,
821 Priority p = Default_Pri)
822 : Event(p), callback(callback), _name(name)
823 {
824 if (del)
825 setFlags(AutoDelete);
826 }
827
828 void process() { callback(); }
829
830 const std::string
831 name() const
832 {
833 return _name + ".wrapped_function_event";
834 }
835
836 const char *description() const { return "EventFunctionWrapped"; }
837};
838
839#endif // __SIM_EVENTQ_HH__