summaryrefslogtreecommitdiff
path: root/src/sim/eventq.hh
blob: c390d2155c8bd70e6823b17d6bdd85b49b63c26d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
/*
 * Copyright (c) 2000-2005 The Regents of The University of Michigan
 * Copyright (c) 2013 Advanced Micro Devices, Inc.
 * Copyright (c) 2013 Mark D. Hill and David A. Wood
 * 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.
 *
 * Authors: Steve Reinhardt
 *          Nathan Binkert
 */

/* @file
 * EventQueue interfaces
 */

#ifndef __SIM_EVENTQ_HH__
#define __SIM_EVENTQ_HH__

#include <algorithm>
#include <cassert>
#include <climits>
#include <iosfwd>
#include <memory>
#include <mutex>
#include <string>

#include "base/flags.hh"
#include "base/misc.hh"
#include "base/types.hh"
#include "debug/Event.hh"
#include "sim/serialize.hh"

class EventQueue;       // forward declaration
class BaseGlobalEvent;

//! Simulation Quantum for multiple eventq simulation.
//! The quantum value is the period length after which the queues
//! synchronize themselves with each other. This means that any
//! event to scheduled on Queue A which is generated by an event on
//! Queue B should be at least simQuantum ticks away in future.
extern Tick simQuantum;

//! Current number of allocated main event queues.
extern uint32_t numMainEventQueues;

//! Array for main event queues.
extern std::vector<EventQueue *> mainEventQueue;

#ifndef SWIG
//! The current event queue for the running thread. Access to this queue
//! does not require any locking from the thread.

extern __thread EventQueue *_curEventQueue;

#endif

//! Current mode of execution: parallel / serial
extern bool inParallelMode;

//! Function for returning eventq queue for the provided
//! index. The function allocates a new queue in case one
//! does not exist for the index, provided that the index
//! is with in bounds.
EventQueue *getEventQueue(uint32_t index);

inline EventQueue *curEventQueue() { return _curEventQueue; }
inline void curEventQueue(EventQueue *q) { _curEventQueue = q; }

/**
 * Common base class for Event and GlobalEvent, so they can share flag
 * and priority definitions and accessor functions.  This class should
 * not be used directly.
 */
class EventBase
{
  protected:   
    typedef unsigned short FlagsType;
    typedef ::Flags<FlagsType> Flags;

    static const FlagsType PublicRead    = 0x003f; // public readable flags
    static const FlagsType PublicWrite   = 0x001d; // public writable flags
    static const FlagsType Squashed      = 0x0001; // has been squashed
    static const FlagsType Scheduled     = 0x0002; // has been scheduled
    static const FlagsType AutoDelete    = 0x0004; // delete after dispatch
    static const FlagsType AutoSerialize = 0x0008; // must be serialized
    static const FlagsType IsExitEvent   = 0x0010; // special exit event
    static const FlagsType IsMainQueue   = 0x0020; // on main event queue
    static const FlagsType Initialized   = 0x7a40; // somewhat random bits
    static const FlagsType InitMask      = 0xffc0; // mask for init bits

  public:
    typedef int8_t Priority;

    /// 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.

    /// Minimum priority
    static const Priority Minimum_Pri =          SCHAR_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).
    static const Priority Debug_Enable_Pri =          -101;

    /// Breakpoints should happen before anything else (except
    /// enabling trace output), so we don't miss any action when
    /// debugging.
    static const Priority Debug_Break_Pri =           -100;

    /// 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.
    static const Priority CPU_Switch_Pri =             -31;

    /// For some reason "delayed" inter-cluster writebacks are
    /// scheduled before regular writebacks (which have default
    /// priority).  Steve?
    static const Priority Delayed_Writeback_Pri =       -1;

    /// Default is zero for historical reasons.
    static const Priority Default_Pri =                  0;

    /// DVFS update event leads to stats dump therefore given a lower priority
    /// to ensure all relevant states have been updated
    static const Priority DVFS_Update_Pri =             31;

    /// Serailization needs to occur before tick events also, so
    /// that a serialize/unserialize is identical to an on-line
    /// CPU switch.
    static const Priority Serialize_Pri =               32;

    /// CPU ticks must come after other associated CPU events
    /// (such as writebacks).
    static const Priority CPU_Tick_Pri =                50;

    /// Statistics events (dump, reset, etc.) come after
    /// everything else, but before exit.
    static const Priority Stat_Event_Pri =              90;

    /// Progress events come at the end.
    static const Priority Progress_Event_Pri =          95;

    /// If we want to exit on this cycle, it's the very last thing
    /// we do.
    static const Priority Sim_Exit_Pri =               100;

    /// Maximum priority
    static const Priority Maximum_Pri =          SCHAR_MAX;
};

/*
 * 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 EventBase, public Serializable
{
    friend class EventQueue;

  private:
    // The event queue is now a linked list of linked lists.  The
    // 'nextBin' pointer is to find the bin, where a bin is defined as
    // when+priority.  All events in the same bin will be stored in a
    // second linked list (a stack) maintained by the 'nextInBin'
    // pointer.  The list will be accessed in LIFO order.  The end
    // result is that the insert/removal in 'nextBin' is
    // linear/constant, and the lookup/removal in 'nextInBin' is
    // constant/constant.  Hopefully this is a significant improvement
    // over the current fully linear insertion.
    Event *nextBin;
    Event *nextInBin;

    static Event *insertBefore(Event *event, Event *curr);
    static Event *removeItem(Event *event, Event *last);

    Tick _when;         //!< timestamp when event should be processed
    Priority _priority; //!< event priority
    Flags flags;

#ifndef NDEBUG
    /// Global counter to generate unique IDs for Event instances
    static Counter instanceCounter;

    /// This event's unique ID.  We can also use pointer values for
    /// this but they're not consistent across runs making debugging
    /// more difficult.  Thus we use a global counter value when
    /// debugging.
    Counter instance;

    /// queue to which this event belongs (though it may or may not be
    /// scheduled on this queue yet)
    EventQueue *queue;
#endif

#ifdef EVENTQ_DEBUG
    Tick whenCreated;   //!< time created
    Tick whenScheduled; //!< time scheduled
#endif

    void
    setWhen(Tick when, EventQueue *q)
    {
        _when = when;
#ifndef NDEBUG
        queue = q;
#endif
#ifdef EVENTQ_DEBUG
        whenScheduled = curTick();
#endif
    }

    bool
    initialized() const
    {
        return this && (flags & InitMask) == Initialized;
    }

  protected:
    /// Accessor for flags.
    Flags
    getFlags() const
    {
        return flags & PublicRead;
    }

    bool
    isFlagSet(Flags _flags) const
    {
        assert(_flags.noneSet(~PublicRead));
        return flags.isSet(_flags);
    }

    /// Accessor for flags.
    void
    setFlags(Flags _flags)
    {
        assert(_flags.noneSet(~PublicWrite));
        flags.set(_flags);
    }

    void
    clearFlags(Flags _flags)
    {
        assert(_flags.noneSet(~PublicWrite));
        flags.clear(_flags);
    }

    void
    clearFlags()
    {
        flags.clear(PublicWrite);
    }

    // This function isn't really useful if TRACING_ON is not defined
    virtual void trace(const char *action);     //!< trace event activity

  public:

    /*
     * Event constructor
     * @param queue that the event gets scheduled on
     */
    Event(Priority p = Default_Pri, Flags f = 0)
        : nextBin(nullptr), nextInBin(nullptr), _when(0), _priority(p),
          flags(Initialized | f)
    {
        assert(f.noneSet(~PublicWrite));
#ifndef NDEBUG
        instance = ++instanceCounter;
        queue = NULL;
#endif
#ifdef EVENTQ_DEBUG
        whenCreated = curTick();
        whenScheduled = 0;
#endif
    }

    virtual ~Event();
    virtual const std::string name() const;

    /// 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 flags.isSet(Scheduled); }

    /// Squash the current event
    void squash() { flags.set(Squashed); }

    /// Check whether the event is squashed
    bool squashed() const { return flags.isSet(Squashed); }

    /// See if this is a SimExitEvent (without resorting to RTTI)
    bool isExitEvent() const { return flags.isSet(IsExitEvent); }

    /// Get the time that the event is scheduled
    Tick when() const { return _when; }

    /// Get the event priority
    Priority priority() const { return _priority; }

    //! If this is part of a GlobalEvent, return the pointer to the
    //! Global Event.  By default, there is no GlobalEvent, so return
    //! NULL.  (Overridden in GlobalEvent::BarrierEvent.)
    virtual BaseGlobalEvent *globalEvent() { return NULL; }

#ifndef SWIG
    virtual void serialize(std::ostream &os);
    virtual void unserialize(Checkpoint *cp, const std::string &section);

    //! This function is required to support restoring from checkpoints
    //! when running with multiple queues. Since we still have not thrashed
    //! out all the details on checkpointing, this function is most likely
    //! to be revisited in future.
    virtual void unserialize(Checkpoint *cp, const std::string &section,
                     EventQueue *eventq);
#endif
};

#ifndef SWIG
inline bool
operator<(const Event &l, const Event &r)
{
    return l.when() < r.when() ||
        (l.when() == r.when() && l.priority() < r.priority());
}

inline bool
operator>(const Event &l, const Event &r)
{
    return l.when() > r.when() ||
        (l.when() == r.when() && l.priority() > r.priority());
}

inline bool
operator<=(const Event &l, const Event &r)
{
    return l.when() < r.when() ||
        (l.when() == r.when() && l.priority() <= r.priority());
}
inline bool
operator>=(const Event &l, const Event &r)
{
    return l.when() > r.when() ||
        (l.when() == r.when() && l.priority() >= r.priority());
}

inline bool
operator==(const Event &l, const Event &r)
{
    return l.when() == r.when() && l.priority() == r.priority();
}

inline bool
operator!=(const Event &l, const Event &r)
{
    return l.when() != r.when() || l.priority() != r.priority();
}
#endif

/**
 * Queue of events sorted in time order
 *
 * Events are scheduled (inserted into the event queue) using the
 * schedule() method. This method either inserts a <i>synchronous</i>
 * or <i>asynchronous</i> event.
 *
 * Synchronous events are scheduled using schedule() method with the
 * argument 'global' set to false (default). This should only be done
 * from a thread holding the event queue lock
 * (EventQueue::service_mutex). The lock is always held when an event
 * handler is called, it can therefore always insert events into its
 * own event queue unless it voluntarily releases the lock.
 *
 * Events can be scheduled across thread (and event queue borders) by
 * either scheduling asynchronous events or taking the target event
 * queue's lock. However, the lock should <i>never</i> be taken
 * directly since this is likely to cause deadlocks. Instead, code
 * that needs to schedule events in other event queues should
 * temporarily release its own queue and lock the new queue. This
 * prevents deadlocks since a single thread never owns more than one
 * event queue lock. This functionality is provided by the
 * ScopedMigration helper class. Note that temporarily migrating
 * between event queues can make the simulation non-deterministic, it
 * should therefore be limited to cases where that can be tolerated
 * (e.g., handling asynchronous IO or fast-forwarding in KVM).
 *
 * Asynchronous events can also be scheduled using the normal
 * schedule() method with the 'global' parameter set to true. Unlike
 * the previous queue migration strategy, this strategy is fully
 * deterministic. This causes the event to be inserted in a separate
 * queue of asynchronous events (async_queue), which is merged main
 * event queue at the end of each simulation quantum (by calling the
 * handleAsyncInsertions() method). Note that this implies that such
 * events must happen at least one simulation quantum into the future,
 * otherwise they risk being scheduled in the past by
 * handleAsyncInsertions().
 */
class EventQueue : public Serializable
{
  private:
    std::string objName;
    Event *head;
    Tick _curTick;

    //! Mutex to protect async queue.
    std::mutex async_queue_mutex;

    //! List of events added by other threads to this event queue.
    std::list<Event*> async_queue;

    /**
     * Lock protecting event handling.
     *
     * This lock is always taken when servicing events. It is assumed
     * that the thread scheduling new events (not asynchronous events
     * though) have taken this lock. This is normally done by
     * serviceOne() since new events are typically scheduled as a
     * response to an earlier event.
     *
     * This lock is intended to be used to temporarily steal an event
     * queue to support inter-thread communication when some
     * deterministic timing can be sacrificed for speed. For example,
     * the KVM CPU can use this support to access devices running in a
     * different thread.
     *
     * @see EventQueue::ScopedMigration.
     * @see EventQueue::ScopedRelease
     * @see EventQueue::lock()
     * @see EventQueue::unlock()
     */
    std::mutex service_mutex;

    //! Insert / remove event from the queue. Should only be called
    //! by thread operating this queue.
    void insert(Event *event);
    void remove(Event *event);

    //! Function for adding events to the async queue. The added events
    //! are added to main event queue later. Threads, other than the
    //! owning thread, should call this function instead of insert().
    void asyncInsert(Event *event);

    EventQueue(const EventQueue &);

  public:
#ifndef SWIG
    /**
     * Temporarily migrate execution to a different event queue.
     *
     * An instance of this class temporarily migrates execution to a
     * different event queue by releasing the current queue, locking
     * the new queue, and updating curEventQueue(). This can, for
     * example, be useful when performing IO across thread event
     * queues when timing is not crucial (e.g., during fast
     * forwarding).
     */
    class ScopedMigration
    {
      public:
        ScopedMigration(EventQueue *_new_eq)
            :  new_eq(*_new_eq), old_eq(*curEventQueue())
        {
            old_eq.unlock();
            new_eq.lock();
            curEventQueue(&new_eq);
        }

        ~ScopedMigration()
        {
            new_eq.unlock();
            old_eq.lock();
            curEventQueue(&old_eq);
        }

      private:
        EventQueue &new_eq;
        EventQueue &old_eq;
    };

    /**
     * Temporarily release the event queue service lock.
     *
     * There are cases where it is desirable to temporarily release
     * the event queue lock to prevent deadlocks. For example, when
     * waiting on the global barrier, we need to release the lock to
     * prevent deadlocks from happening when another thread tries to
     * temporarily take over the event queue waiting on the barrier.
     */
    class ScopedRelease
    {
      public:
        ScopedRelease(EventQueue *_eq)
            :  eq(*_eq)
        {
            eq.unlock();
        }

        ~ScopedRelease()
        {
            eq.lock();
        }

      private:
        EventQueue &eq;
    };
#endif

    EventQueue(const std::string &n);

    virtual const std::string name() const { return objName; }
    void name(const std::string &st) { objName = st; }

    //! Schedule the given event on this queue. Safe to call from any
    //! thread.
    void schedule(Event *event, Tick when, bool global = false);

    //! Deschedule the specified event. Should be called only from the
    //! owning thread.
    void deschedule(Event *event);

    //! Reschedule the specified event. Should be called only from
    //! the owning thread.
    void reschedule(Event *event, Tick when, bool always = false);

    Tick nextTick() const { return head->when(); }
    void setCurTick(Tick newVal) { _curTick = newVal; }
    Tick getCurTick() { return _curTick; }

    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)
    {
        while (!empty()) {
            if (nextTick() > when)
                break;

            /**
             * @todo this assert is a good bug catcher.  I need to
             * make it true again.
             */
            //assert(head->when() >= when && "event scheduled in the past");
            serviceOne();
        }

        setCurTick(when);
    }

    // return true if no events are queued
    bool empty() const { return head == NULL; }

    void dump() const;

    bool debugVerify() const;

    //! Function for moving events from the async_queue to the main queue.
    void handleAsyncInsertions();

    /**
     *  function for replacing the head of the event queue, so that a
     *  different set of events can run without disturbing events that have
     *  already been scheduled. Already scheduled events can be processed
     *  by replacing the original head back.
     *  USING THIS FUNCTION CAN BE DANGEROUS TO THE HEALTH OF THE SIMULATOR.
     *  NOT RECOMMENDED FOR USE.
     */
    Event* replaceHead(Event* s);

    /**@{*/
    /**
     * Provide an interface for locking/unlocking the event queue.
     *
     * @warn Do NOT use these methods directly unless you really know
     * what you are doing. Incorrect use can easily lead to simulator
     * deadlocks.
     *
     * @see EventQueue::ScopedMigration.
     * @see EventQueue::ScopedRelease
     * @see EventQueue
     */
    void lock() { service_mutex.lock(); }
    void unlock() { service_mutex.unlock(); }
    /**@}*/

#ifndef SWIG
    virtual void serialize(std::ostream &os);
    virtual void unserialize(Checkpoint *cp, const std::string &section);
#endif
};

void dumpMainQueue();

#ifndef SWIG
class EventManager
{
  protected:
    /** A pointer to this object's event queue */
    EventQueue *eventq;

  public:
    EventManager(EventManager &em) : eventq(em.eventq) {}
    EventManager(EventManager *em) : eventq(em->eventq) {}
    EventManager(EventQueue *eq) : eventq(eq) {}

    EventQueue *
    eventQueue() const
    {
        return eventq;
    }

    void
    schedule(Event &event, Tick when)
    {
        eventq->schedule(&event, when);
    }

    void
    deschedule(Event &event)
    {
        eventq->deschedule(&event);
    }

    void
    reschedule(Event &event, Tick when, bool always = false)
    {
        eventq->reschedule(&event, when, always);
    }

    void
    schedule(Event *event, Tick when)
    {
        eventq->schedule(event, when);
    }

    void
    deschedule(Event *event)
    {
        eventq->deschedule(event);
    }

    void
    reschedule(Event *event, Tick when, bool always = false)
    {
        eventq->reschedule(event, when, always);
    }

    void setCurTick(Tick newVal) { eventq->setCurTick(newVal); }
};

template <class T, void (T::* F)()>
void
DelayFunction(EventQueue *eventq, Tick when, T *object)
{
    class DelayEvent : public Event
    {
      private:
        T *object;

      public:
        DelayEvent(T *o)
            : Event(Default_Pri, AutoDelete), object(o)
        { }
        void process() { (object->*F)(); }
        const char *description() const { return "delay"; }
    };

    eventq->schedule(new DelayEvent(object), when);
}

template <class T, void (T::* F)()>
class EventWrapper : public Event
{
  private:
    T *object;

  public:
    EventWrapper(T *obj, bool del = false, Priority p = Default_Pri)
        : Event(p), object(obj)
    {
        if (del)
            setFlags(AutoDelete);
    }

    EventWrapper(T &obj, bool del = false, Priority p = Default_Pri)
        : Event(p), object(&obj)
    {
        if (del)
            setFlags(AutoDelete);
    }

    void process() { (object->*F)(); }

    const std::string
    name() const
    {
        return object->name() + ".wrapped_event";
    }

    const char *description() const { return "EventWrapped"; }
};
#endif

#endif // __SIM_EVENTQ_HH__