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/misc.hh"
51#include "base/types.hh"
52#include "debug/Event.hh"
53#include "sim/serialize.hh"
54
55class EventQueue; // forward declaration
56class BaseGlobalEvent;
57
58//! Simulation Quantum for multiple eventq simulation.
59//! The quantum value is the period length after which the queues
60//! synchronize themselves with each other. This means that any
61//! event to scheduled on Queue A which is generated by an event on
62//! Queue B should be at least simQuantum ticks away in future.
63extern Tick simQuantum;
64
65//! Current number of allocated main event queues.
66extern uint32_t numMainEventQueues;
67
68//! Array for main event queues.
69extern std::vector<EventQueue *> mainEventQueue;
70
71#ifndef SWIG
72//! The current event queue for the running thread. Access to this queue
73//! does not require any locking from the thread.
74
75extern __thread EventQueue *_curEventQueue;
76
77#endif
78
79//! Current mode of execution: parallel / serial
80extern bool inParallelMode;
81
82//! Function for returning eventq queue for the provided
83//! index. The function allocates a new queue in case one
84//! does not exist for the index, provided that the index
85//! is with in bounds.
86EventQueue *getEventQueue(uint32_t index);
87
88inline EventQueue *curEventQueue() { return _curEventQueue; }
89inline void curEventQueue(EventQueue *q) { _curEventQueue = q; }
90
91/**
92 * Common base class for Event and GlobalEvent, so they can share flag
93 * and priority definitions and accessor functions. This class should
94 * not be used directly.
95 */
96class EventBase
97{
98 protected:
99 typedef unsigned short FlagsType;
100 typedef ::Flags<FlagsType> Flags;
101
102 static const FlagsType PublicRead = 0x003f; // public readable flags
103 static const FlagsType PublicWrite = 0x001d; // public writable flags
104 static const FlagsType Squashed = 0x0001; // has been squashed
105 static const FlagsType Scheduled = 0x0002; // has been scheduled
106 static const FlagsType AutoDelete = 0x0004; // delete after dispatch
107 static const FlagsType AutoSerialize = 0x0008; // must be serialized
108 static const FlagsType IsExitEvent = 0x0010; // special exit event
109 static const FlagsType IsMainQueue = 0x0020; // on main event queue
110 static const FlagsType Initialized = 0x7a40; // somewhat random bits
111 static const FlagsType InitMask = 0xffc0; // mask for init bits
112
113 public:
114 typedef int8_t Priority;
115
116 /// Event priorities, to provide tie-breakers for events scheduled
117 /// at the same cycle. Most events are scheduled at the default
118 /// priority; these values are used to control events that need to
119 /// be ordered within a cycle.
120
121 /// Minimum priority
122 static const Priority Minimum_Pri = SCHAR_MIN;
123
124 /// If we enable tracing on a particular cycle, do that as the
125 /// very first thing so we don't miss any of the events on
126 /// that cycle (even if we enter the debugger).
127 static const Priority Debug_Enable_Pri = -101;
128
129 /// Breakpoints should happen before anything else (except
130 /// enabling trace output), so we don't miss any action when
131 /// debugging.
132 static const Priority Debug_Break_Pri = -100;
133
134 /// CPU switches schedule the new CPU's tick event for the
135 /// same cycle (after unscheduling the old CPU's tick event).
136 /// The switch needs to come before any tick events to make
137 /// sure we don't tick both CPUs in the same cycle.
138 static const Priority CPU_Switch_Pri = -31;
139
140 /// For some reason "delayed" inter-cluster writebacks are
141 /// scheduled before regular writebacks (which have default
142 /// priority). Steve?
143 static const Priority Delayed_Writeback_Pri = -1;
144
145 /// Default is zero for historical reasons.
146 static const Priority Default_Pri = 0;
147
148 /// DVFS update event leads to stats dump therefore given a lower priority
149 /// to ensure all relevant states have been updated
150 static const Priority DVFS_Update_Pri = 31;
151
152 /// Serailization needs to occur before tick events also, so
153 /// that a serialize/unserialize is identical to an on-line
154 /// CPU switch.
155 static const Priority Serialize_Pri = 32;
156
157 /// CPU ticks must come after other associated CPU events
158 /// (such as writebacks).
159 static const Priority CPU_Tick_Pri = 50;
160
161 /// Statistics events (dump, reset, etc.) come after
162 /// everything else, but before exit.
163 static const Priority Stat_Event_Pri = 90;
164
165 /// Progress events come at the end.
166 static const Priority Progress_Event_Pri = 95;
167
168 /// If we want to exit on this cycle, it's the very last thing
169 /// we do.
170 static const Priority Sim_Exit_Pri = 100;
171
172 /// Maximum priority
173 static const Priority Maximum_Pri = SCHAR_MAX;
174};
175
176/*
177 * An item on an event queue. The action caused by a given
178 * event is specified by deriving a subclass and overriding the
179 * process() member function.
180 *
181 * Caution, the order of members is chosen to maximize data packing.
182 */
183class Event : public EventBase, public Serializable
184{
185 friend class EventQueue;
186
187 private:
188 // The event queue is now a linked list of linked lists. The
189 // 'nextBin' pointer is to find the bin, where a bin is defined as
190 // when+priority. All events in the same bin will be stored in a
191 // second linked list (a stack) maintained by the 'nextInBin'
192 // pointer. The list will be accessed in LIFO order. The end
193 // result is that the insert/removal in 'nextBin' is
194 // linear/constant, and the lookup/removal in 'nextInBin' is
195 // constant/constant. Hopefully this is a significant improvement
196 // over the current fully linear insertion.
197 Event *nextBin;
198 Event *nextInBin;
199
200 static Event *insertBefore(Event *event, Event *curr);
201 static Event *removeItem(Event *event, Event *last);
202
203 Tick _when; //!< timestamp when event should be processed
204 Priority _priority; //!< event priority
205 Flags flags;
206
207#ifndef NDEBUG
208 /// Global counter to generate unique IDs for Event instances
209 static Counter instanceCounter;
210
211 /// This event's unique ID. We can also use pointer values for
212 /// this but they're not consistent across runs making debugging
213 /// more difficult. Thus we use a global counter value when
214 /// debugging.
215 Counter instance;
216
217 /// queue to which this event belongs (though it may or may not be
218 /// scheduled on this queue yet)
219 EventQueue *queue;
220#endif
221
222#ifdef EVENTQ_DEBUG
223 Tick whenCreated; //!< time created
224 Tick whenScheduled; //!< time scheduled
225#endif
226
227 void
228 setWhen(Tick when, EventQueue *q)
229 {
230 _when = when;
231#ifndef NDEBUG
232 queue = q;
233#endif
234#ifdef EVENTQ_DEBUG
235 whenScheduled = curTick();
236#endif
237 }
238
239 bool
240 initialized() const
241 {
242 return (flags & InitMask) == Initialized;
243 }
244
245 protected:
246 /// Accessor for flags.
247 Flags
248 getFlags() const
249 {
250 return flags & PublicRead;
251 }
252
253 bool
254 isFlagSet(Flags _flags) const
255 {
256 assert(_flags.noneSet(~PublicRead));
257 return flags.isSet(_flags);
258 }
259
260 /// Accessor for flags.
261 void
262 setFlags(Flags _flags)
263 {
264 assert(_flags.noneSet(~PublicWrite));
265 flags.set(_flags);
266 }
267
268 void
269 clearFlags(Flags _flags)
270 {
271 assert(_flags.noneSet(~PublicWrite));
272 flags.clear(_flags);
273 }
274
275 void
276 clearFlags()
277 {
278 flags.clear(PublicWrite);
279 }
280
281 // This function isn't really useful if TRACING_ON is not defined
282 virtual void trace(const char *action); //!< trace event activity
283
284 public:
285
286 /*
287 * Event constructor
288 * @param queue that the event gets scheduled on
289 */
290 Event(Priority p = Default_Pri, Flags f = 0)
291 : nextBin(nullptr), nextInBin(nullptr), _when(0), _priority(p),
292 flags(Initialized | f)
293 {
294 assert(f.noneSet(~PublicWrite));
295#ifndef NDEBUG
296 instance = ++instanceCounter;
297 queue = NULL;
298#endif
299#ifdef EVENTQ_DEBUG
300 whenCreated = curTick();
301 whenScheduled = 0;
302#endif
303 }
304
305 virtual ~Event();
306 virtual const std::string name() const;
307
308 /// Return a C string describing the event. This string should
309 /// *not* be dynamically allocated; just a const char array
310 /// describing the event class.
311 virtual const char *description() const;
312
313 /// Dump the current event data
314 void dump() const;
315
316 public:
317 /*
318 * This member function is invoked when the event is processed
319 * (occurs). There is no default implementation; each subclass
320 * must provide its own implementation. The event is not
321 * automatically deleted after it is processed (to allow for
322 * statically allocated event objects).
323 *
324 * If the AutoDestroy flag is set, the object is deleted once it
325 * is processed.
326 */
327 virtual void process() = 0;
328
329 /// Determine if the current event is scheduled
330 bool scheduled() const { return flags.isSet(Scheduled); }
331
332 /// Squash the current event
333 void squash() { flags.set(Squashed); }
334
335 /// Check whether the event is squashed
336 bool squashed() const { return flags.isSet(Squashed); }
337
338 /// See if this is a SimExitEvent (without resorting to RTTI)
339 bool isExitEvent() const { return flags.isSet(IsExitEvent); }
340
341 /// Get the time that the event is scheduled
342 Tick when() const { return _when; }
343
344 /// Get the event priority
345 Priority priority() const { return _priority; }
346
347 //! If this is part of a GlobalEvent, return the pointer to the
348 //! Global Event. By default, there is no GlobalEvent, so return
349 //! NULL. (Overridden in GlobalEvent::BarrierEvent.)
350 virtual BaseGlobalEvent *globalEvent() { return NULL; }
351
352#ifndef SWIG
353 void serialize(CheckpointOut &cp) const M5_ATTR_OVERRIDE;
354 void unserialize(CheckpointIn &cp) M5_ATTR_OVERRIDE;
| 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/misc.hh"
51#include "base/types.hh"
52#include "debug/Event.hh"
53#include "sim/serialize.hh"
54
55class EventQueue; // forward declaration
56class BaseGlobalEvent;
57
58//! Simulation Quantum for multiple eventq simulation.
59//! The quantum value is the period length after which the queues
60//! synchronize themselves with each other. This means that any
61//! event to scheduled on Queue A which is generated by an event on
62//! Queue B should be at least simQuantum ticks away in future.
63extern Tick simQuantum;
64
65//! Current number of allocated main event queues.
66extern uint32_t numMainEventQueues;
67
68//! Array for main event queues.
69extern std::vector<EventQueue *> mainEventQueue;
70
71#ifndef SWIG
72//! The current event queue for the running thread. Access to this queue
73//! does not require any locking from the thread.
74
75extern __thread EventQueue *_curEventQueue;
76
77#endif
78
79//! Current mode of execution: parallel / serial
80extern bool inParallelMode;
81
82//! Function for returning eventq queue for the provided
83//! index. The function allocates a new queue in case one
84//! does not exist for the index, provided that the index
85//! is with in bounds.
86EventQueue *getEventQueue(uint32_t index);
87
88inline EventQueue *curEventQueue() { return _curEventQueue; }
89inline void curEventQueue(EventQueue *q) { _curEventQueue = q; }
90
91/**
92 * Common base class for Event and GlobalEvent, so they can share flag
93 * and priority definitions and accessor functions. This class should
94 * not be used directly.
95 */
96class EventBase
97{
98 protected:
99 typedef unsigned short FlagsType;
100 typedef ::Flags<FlagsType> Flags;
101
102 static const FlagsType PublicRead = 0x003f; // public readable flags
103 static const FlagsType PublicWrite = 0x001d; // public writable flags
104 static const FlagsType Squashed = 0x0001; // has been squashed
105 static const FlagsType Scheduled = 0x0002; // has been scheduled
106 static const FlagsType AutoDelete = 0x0004; // delete after dispatch
107 static const FlagsType AutoSerialize = 0x0008; // must be serialized
108 static const FlagsType IsExitEvent = 0x0010; // special exit event
109 static const FlagsType IsMainQueue = 0x0020; // on main event queue
110 static const FlagsType Initialized = 0x7a40; // somewhat random bits
111 static const FlagsType InitMask = 0xffc0; // mask for init bits
112
113 public:
114 typedef int8_t Priority;
115
116 /// Event priorities, to provide tie-breakers for events scheduled
117 /// at the same cycle. Most events are scheduled at the default
118 /// priority; these values are used to control events that need to
119 /// be ordered within a cycle.
120
121 /// Minimum priority
122 static const Priority Minimum_Pri = SCHAR_MIN;
123
124 /// If we enable tracing on a particular cycle, do that as the
125 /// very first thing so we don't miss any of the events on
126 /// that cycle (even if we enter the debugger).
127 static const Priority Debug_Enable_Pri = -101;
128
129 /// Breakpoints should happen before anything else (except
130 /// enabling trace output), so we don't miss any action when
131 /// debugging.
132 static const Priority Debug_Break_Pri = -100;
133
134 /// CPU switches schedule the new CPU's tick event for the
135 /// same cycle (after unscheduling the old CPU's tick event).
136 /// The switch needs to come before any tick events to make
137 /// sure we don't tick both CPUs in the same cycle.
138 static const Priority CPU_Switch_Pri = -31;
139
140 /// For some reason "delayed" inter-cluster writebacks are
141 /// scheduled before regular writebacks (which have default
142 /// priority). Steve?
143 static const Priority Delayed_Writeback_Pri = -1;
144
145 /// Default is zero for historical reasons.
146 static const Priority Default_Pri = 0;
147
148 /// DVFS update event leads to stats dump therefore given a lower priority
149 /// to ensure all relevant states have been updated
150 static const Priority DVFS_Update_Pri = 31;
151
152 /// Serailization needs to occur before tick events also, so
153 /// that a serialize/unserialize is identical to an on-line
154 /// CPU switch.
155 static const Priority Serialize_Pri = 32;
156
157 /// CPU ticks must come after other associated CPU events
158 /// (such as writebacks).
159 static const Priority CPU_Tick_Pri = 50;
160
161 /// Statistics events (dump, reset, etc.) come after
162 /// everything else, but before exit.
163 static const Priority Stat_Event_Pri = 90;
164
165 /// Progress events come at the end.
166 static const Priority Progress_Event_Pri = 95;
167
168 /// If we want to exit on this cycle, it's the very last thing
169 /// we do.
170 static const Priority Sim_Exit_Pri = 100;
171
172 /// Maximum priority
173 static const Priority Maximum_Pri = SCHAR_MAX;
174};
175
176/*
177 * An item on an event queue. The action caused by a given
178 * event is specified by deriving a subclass and overriding the
179 * process() member function.
180 *
181 * Caution, the order of members is chosen to maximize data packing.
182 */
183class Event : public EventBase, public Serializable
184{
185 friend class EventQueue;
186
187 private:
188 // The event queue is now a linked list of linked lists. The
189 // 'nextBin' pointer is to find the bin, where a bin is defined as
190 // when+priority. All events in the same bin will be stored in a
191 // second linked list (a stack) maintained by the 'nextInBin'
192 // pointer. The list will be accessed in LIFO order. The end
193 // result is that the insert/removal in 'nextBin' is
194 // linear/constant, and the lookup/removal in 'nextInBin' is
195 // constant/constant. Hopefully this is a significant improvement
196 // over the current fully linear insertion.
197 Event *nextBin;
198 Event *nextInBin;
199
200 static Event *insertBefore(Event *event, Event *curr);
201 static Event *removeItem(Event *event, Event *last);
202
203 Tick _when; //!< timestamp when event should be processed
204 Priority _priority; //!< event priority
205 Flags flags;
206
207#ifndef NDEBUG
208 /// Global counter to generate unique IDs for Event instances
209 static Counter instanceCounter;
210
211 /// This event's unique ID. We can also use pointer values for
212 /// this but they're not consistent across runs making debugging
213 /// more difficult. Thus we use a global counter value when
214 /// debugging.
215 Counter instance;
216
217 /// queue to which this event belongs (though it may or may not be
218 /// scheduled on this queue yet)
219 EventQueue *queue;
220#endif
221
222#ifdef EVENTQ_DEBUG
223 Tick whenCreated; //!< time created
224 Tick whenScheduled; //!< time scheduled
225#endif
226
227 void
228 setWhen(Tick when, EventQueue *q)
229 {
230 _when = when;
231#ifndef NDEBUG
232 queue = q;
233#endif
234#ifdef EVENTQ_DEBUG
235 whenScheduled = curTick();
236#endif
237 }
238
239 bool
240 initialized() const
241 {
242 return (flags & InitMask) == Initialized;
243 }
244
245 protected:
246 /// Accessor for flags.
247 Flags
248 getFlags() const
249 {
250 return flags & PublicRead;
251 }
252
253 bool
254 isFlagSet(Flags _flags) const
255 {
256 assert(_flags.noneSet(~PublicRead));
257 return flags.isSet(_flags);
258 }
259
260 /// Accessor for flags.
261 void
262 setFlags(Flags _flags)
263 {
264 assert(_flags.noneSet(~PublicWrite));
265 flags.set(_flags);
266 }
267
268 void
269 clearFlags(Flags _flags)
270 {
271 assert(_flags.noneSet(~PublicWrite));
272 flags.clear(_flags);
273 }
274
275 void
276 clearFlags()
277 {
278 flags.clear(PublicWrite);
279 }
280
281 // This function isn't really useful if TRACING_ON is not defined
282 virtual void trace(const char *action); //!< trace event activity
283
284 public:
285
286 /*
287 * Event constructor
288 * @param queue that the event gets scheduled on
289 */
290 Event(Priority p = Default_Pri, Flags f = 0)
291 : nextBin(nullptr), nextInBin(nullptr), _when(0), _priority(p),
292 flags(Initialized | f)
293 {
294 assert(f.noneSet(~PublicWrite));
295#ifndef NDEBUG
296 instance = ++instanceCounter;
297 queue = NULL;
298#endif
299#ifdef EVENTQ_DEBUG
300 whenCreated = curTick();
301 whenScheduled = 0;
302#endif
303 }
304
305 virtual ~Event();
306 virtual const std::string name() const;
307
308 /// Return a C string describing the event. This string should
309 /// *not* be dynamically allocated; just a const char array
310 /// describing the event class.
311 virtual const char *description() const;
312
313 /// Dump the current event data
314 void dump() const;
315
316 public:
317 /*
318 * This member function is invoked when the event is processed
319 * (occurs). There is no default implementation; each subclass
320 * must provide its own implementation. The event is not
321 * automatically deleted after it is processed (to allow for
322 * statically allocated event objects).
323 *
324 * If the AutoDestroy flag is set, the object is deleted once it
325 * is processed.
326 */
327 virtual void process() = 0;
328
329 /// Determine if the current event is scheduled
330 bool scheduled() const { return flags.isSet(Scheduled); }
331
332 /// Squash the current event
333 void squash() { flags.set(Squashed); }
334
335 /// Check whether the event is squashed
336 bool squashed() const { return flags.isSet(Squashed); }
337
338 /// See if this is a SimExitEvent (without resorting to RTTI)
339 bool isExitEvent() const { return flags.isSet(IsExitEvent); }
340
341 /// Get the time that the event is scheduled
342 Tick when() const { return _when; }
343
344 /// Get the event priority
345 Priority priority() const { return _priority; }
346
347 //! If this is part of a GlobalEvent, return the pointer to the
348 //! Global Event. By default, there is no GlobalEvent, so return
349 //! NULL. (Overridden in GlobalEvent::BarrierEvent.)
350 virtual BaseGlobalEvent *globalEvent() { return NULL; }
351
352#ifndef SWIG
353 void serialize(CheckpointOut &cp) const M5_ATTR_OVERRIDE;
354 void unserialize(CheckpointIn &cp) M5_ATTR_OVERRIDE;
|
355
356 //! This function is required to support restoring from checkpoints
357 //! when running with multiple queues. Since we still have not thrashed
358 //! out all the details on checkpointing, this function is most likely
359 //! to be revisited in future.
360 virtual void unserializeEvent(CheckpointIn &cp, EventQueue *eventq);
| |
361#endif
362};
363
364#ifndef SWIG
365inline bool
366operator<(const Event &l, const Event &r)
367{
368 return l.when() < r.when() ||
369 (l.when() == r.when() && l.priority() < r.priority());
370}
371
372inline bool
373operator>(const Event &l, const Event &r)
374{
375 return l.when() > r.when() ||
376 (l.when() == r.when() && l.priority() > r.priority());
377}
378
379inline bool
380operator<=(const Event &l, const Event &r)
381{
382 return l.when() < r.when() ||
383 (l.when() == r.when() && l.priority() <= r.priority());
384}
385inline bool
386operator>=(const Event &l, const Event &r)
387{
388 return l.when() > r.when() ||
389 (l.when() == r.when() && l.priority() >= r.priority());
390}
391
392inline bool
393operator==(const Event &l, const Event &r)
394{
395 return l.when() == r.when() && l.priority() == r.priority();
396}
397
398inline bool
399operator!=(const Event &l, const Event &r)
400{
401 return l.when() != r.when() || l.priority() != r.priority();
402}
403#endif
404
405/**
406 * Queue of events sorted in time order
407 *
408 * Events are scheduled (inserted into the event queue) using the
409 * schedule() method. This method either inserts a <i>synchronous</i>
410 * or <i>asynchronous</i> event.
411 *
412 * Synchronous events are scheduled using schedule() method with the
413 * argument 'global' set to false (default). This should only be done
414 * from a thread holding the event queue lock
415 * (EventQueue::service_mutex). The lock is always held when an event
416 * handler is called, it can therefore always insert events into its
417 * own event queue unless it voluntarily releases the lock.
418 *
419 * Events can be scheduled across thread (and event queue borders) by
420 * either scheduling asynchronous events or taking the target event
421 * queue's lock. However, the lock should <i>never</i> be taken
422 * directly since this is likely to cause deadlocks. Instead, code
423 * that needs to schedule events in other event queues should
424 * temporarily release its own queue and lock the new queue. This
425 * prevents deadlocks since a single thread never owns more than one
426 * event queue lock. This functionality is provided by the
427 * ScopedMigration helper class. Note that temporarily migrating
428 * between event queues can make the simulation non-deterministic, it
429 * should therefore be limited to cases where that can be tolerated
430 * (e.g., handling asynchronous IO or fast-forwarding in KVM).
431 *
432 * Asynchronous events can also be scheduled using the normal
433 * schedule() method with the 'global' parameter set to true. Unlike
434 * the previous queue migration strategy, this strategy is fully
435 * deterministic. This causes the event to be inserted in a separate
436 * queue of asynchronous events (async_queue), which is merged main
437 * event queue at the end of each simulation quantum (by calling the
438 * handleAsyncInsertions() method). Note that this implies that such
439 * events must happen at least one simulation quantum into the future,
440 * otherwise they risk being scheduled in the past by
441 * handleAsyncInsertions().
442 */
443class EventQueue : public Serializable
444{
445 private:
446 std::string objName;
447 Event *head;
448 Tick _curTick;
449
450 //! Mutex to protect async queue.
451 std::mutex async_queue_mutex;
452
453 //! List of events added by other threads to this event queue.
454 std::list<Event*> async_queue;
455
456 /**
457 * Lock protecting event handling.
458 *
459 * This lock is always taken when servicing events. It is assumed
460 * that the thread scheduling new events (not asynchronous events
461 * though) have taken this lock. This is normally done by
462 * serviceOne() since new events are typically scheduled as a
463 * response to an earlier event.
464 *
465 * This lock is intended to be used to temporarily steal an event
466 * queue to support inter-thread communication when some
467 * deterministic timing can be sacrificed for speed. For example,
468 * the KVM CPU can use this support to access devices running in a
469 * different thread.
470 *
471 * @see EventQueue::ScopedMigration.
472 * @see EventQueue::ScopedRelease
473 * @see EventQueue::lock()
474 * @see EventQueue::unlock()
475 */
476 std::mutex service_mutex;
477
478 //! Insert / remove event from the queue. Should only be called
479 //! by thread operating this queue.
480 void insert(Event *event);
481 void remove(Event *event);
482
483 //! Function for adding events to the async queue. The added events
484 //! are added to main event queue later. Threads, other than the
485 //! owning thread, should call this function instead of insert().
486 void asyncInsert(Event *event);
487
488 EventQueue(const EventQueue &);
489
490 public:
491#ifndef SWIG
492 /**
493 * Temporarily migrate execution to a different event queue.
494 *
495 * An instance of this class temporarily migrates execution to a
496 * different event queue by releasing the current queue, locking
497 * the new queue, and updating curEventQueue(). This can, for
498 * example, be useful when performing IO across thread event
499 * queues when timing is not crucial (e.g., during fast
500 * forwarding).
501 */
502 class ScopedMigration
503 {
504 public:
505 ScopedMigration(EventQueue *_new_eq)
506 : new_eq(*_new_eq), old_eq(*curEventQueue())
507 {
508 old_eq.unlock();
509 new_eq.lock();
510 curEventQueue(&new_eq);
511 }
512
513 ~ScopedMigration()
514 {
515 new_eq.unlock();
516 old_eq.lock();
517 curEventQueue(&old_eq);
518 }
519
520 private:
521 EventQueue &new_eq;
522 EventQueue &old_eq;
523 };
524
525 /**
526 * Temporarily release the event queue service lock.
527 *
528 * There are cases where it is desirable to temporarily release
529 * the event queue lock to prevent deadlocks. For example, when
530 * waiting on the global barrier, we need to release the lock to
531 * prevent deadlocks from happening when another thread tries to
532 * temporarily take over the event queue waiting on the barrier.
533 */
534 class ScopedRelease
535 {
536 public:
537 ScopedRelease(EventQueue *_eq)
538 : eq(*_eq)
539 {
540 eq.unlock();
541 }
542
543 ~ScopedRelease()
544 {
545 eq.lock();
546 }
547
548 private:
549 EventQueue &eq;
550 };
551#endif
552
553 EventQueue(const std::string &n);
554
555 virtual const std::string name() const { return objName; }
556 void name(const std::string &st) { objName = st; }
557
558 //! Schedule the given event on this queue. Safe to call from any
559 //! thread.
560 void schedule(Event *event, Tick when, bool global = false);
561
562 //! Deschedule the specified event. Should be called only from the
563 //! owning thread.
564 void deschedule(Event *event);
565
566 //! Reschedule the specified event. Should be called only from
567 //! the owning thread.
568 void reschedule(Event *event, Tick when, bool always = false);
569
570 Tick nextTick() const { return head->when(); }
571 void setCurTick(Tick newVal) { _curTick = newVal; }
572 Tick getCurTick() { return _curTick; }
573
574 Event *serviceOne();
575
576 // process all events up to the given timestamp. we inline a
577 // quick test to see if there are any events to process; if so,
578 // call the internal out-of-line version to process them all.
579 void
580 serviceEvents(Tick when)
581 {
582 while (!empty()) {
583 if (nextTick() > when)
584 break;
585
586 /**
587 * @todo this assert is a good bug catcher. I need to
588 * make it true again.
589 */
590 //assert(head->when() >= when && "event scheduled in the past");
591 serviceOne();
592 }
593
594 setCurTick(when);
595 }
596
597 // return true if no events are queued
598 bool empty() const { return head == NULL; }
599
600 void dump() const;
601
602 bool debugVerify() const;
603
604 //! Function for moving events from the async_queue to the main queue.
605 void handleAsyncInsertions();
606
607 /**
608 * Function to signal that the event loop should be woken up because
609 * an event has been scheduled by an agent outside the gem5 event
610 * loop(s) whose event insertion may not have been noticed by gem5.
611 * This function isn't needed by the usual gem5 event loop but may
612 * be necessary in derived EventQueues which host gem5 onto other
613 * schedulers.
614 *
615 * @param when Time of a delayed wakeup (if known). This parameter
616 * can be used by an implementation to schedule a wakeup in the
617 * future if it is sure it will remain active until then.
618 * Or it can be ignored and the event queue can be woken up now.
619 */
620 virtual void wakeup(Tick when = (Tick)-1) { }
621
622 /**
623 * function for replacing the head of the event queue, so that a
624 * different set of events can run without disturbing events that have
625 * already been scheduled. Already scheduled events can be processed
626 * by replacing the original head back.
627 * USING THIS FUNCTION CAN BE DANGEROUS TO THE HEALTH OF THE SIMULATOR.
628 * NOT RECOMMENDED FOR USE.
629 */
630 Event* replaceHead(Event* s);
631
632 /**@{*/
633 /**
634 * Provide an interface for locking/unlocking the event queue.
635 *
636 * @warn Do NOT use these methods directly unless you really know
637 * what you are doing. Incorrect use can easily lead to simulator
638 * deadlocks.
639 *
640 * @see EventQueue::ScopedMigration.
641 * @see EventQueue::ScopedRelease
642 * @see EventQueue
643 */
644 void lock() { service_mutex.lock(); }
645 void unlock() { service_mutex.unlock(); }
646 /**@}*/
647
648#ifndef SWIG
649 void serialize(CheckpointOut &cp) const M5_ATTR_OVERRIDE;
650 void unserialize(CheckpointIn &cp) M5_ATTR_OVERRIDE;
651#endif
652
| 355#endif
356};
357
358#ifndef SWIG
359inline bool
360operator<(const Event &l, const Event &r)
361{
362 return l.when() < r.when() ||
363 (l.when() == r.when() && l.priority() < r.priority());
364}
365
366inline bool
367operator>(const Event &l, const Event &r)
368{
369 return l.when() > r.when() ||
370 (l.when() == r.when() && l.priority() > r.priority());
371}
372
373inline bool
374operator<=(const Event &l, const Event &r)
375{
376 return l.when() < r.when() ||
377 (l.when() == r.when() && l.priority() <= r.priority());
378}
379inline bool
380operator>=(const Event &l, const Event &r)
381{
382 return l.when() > r.when() ||
383 (l.when() == r.when() && l.priority() >= r.priority());
384}
385
386inline bool
387operator==(const Event &l, const Event &r)
388{
389 return l.when() == r.when() && l.priority() == r.priority();
390}
391
392inline bool
393operator!=(const Event &l, const Event &r)
394{
395 return l.when() != r.when() || l.priority() != r.priority();
396}
397#endif
398
399/**
400 * Queue of events sorted in time order
401 *
402 * Events are scheduled (inserted into the event queue) using the
403 * schedule() method. This method either inserts a <i>synchronous</i>
404 * or <i>asynchronous</i> event.
405 *
406 * Synchronous events are scheduled using schedule() method with the
407 * argument 'global' set to false (default). This should only be done
408 * from a thread holding the event queue lock
409 * (EventQueue::service_mutex). The lock is always held when an event
410 * handler is called, it can therefore always insert events into its
411 * own event queue unless it voluntarily releases the lock.
412 *
413 * Events can be scheduled across thread (and event queue borders) by
414 * either scheduling asynchronous events or taking the target event
415 * queue's lock. However, the lock should <i>never</i> be taken
416 * directly since this is likely to cause deadlocks. Instead, code
417 * that needs to schedule events in other event queues should
418 * temporarily release its own queue and lock the new queue. This
419 * prevents deadlocks since a single thread never owns more than one
420 * event queue lock. This functionality is provided by the
421 * ScopedMigration helper class. Note that temporarily migrating
422 * between event queues can make the simulation non-deterministic, it
423 * should therefore be limited to cases where that can be tolerated
424 * (e.g., handling asynchronous IO or fast-forwarding in KVM).
425 *
426 * Asynchronous events can also be scheduled using the normal
427 * schedule() method with the 'global' parameter set to true. Unlike
428 * the previous queue migration strategy, this strategy is fully
429 * deterministic. This causes the event to be inserted in a separate
430 * queue of asynchronous events (async_queue), which is merged main
431 * event queue at the end of each simulation quantum (by calling the
432 * handleAsyncInsertions() method). Note that this implies that such
433 * events must happen at least one simulation quantum into the future,
434 * otherwise they risk being scheduled in the past by
435 * handleAsyncInsertions().
436 */
437class EventQueue : public Serializable
438{
439 private:
440 std::string objName;
441 Event *head;
442 Tick _curTick;
443
444 //! Mutex to protect async queue.
445 std::mutex async_queue_mutex;
446
447 //! List of events added by other threads to this event queue.
448 std::list<Event*> async_queue;
449
450 /**
451 * Lock protecting event handling.
452 *
453 * This lock is always taken when servicing events. It is assumed
454 * that the thread scheduling new events (not asynchronous events
455 * though) have taken this lock. This is normally done by
456 * serviceOne() since new events are typically scheduled as a
457 * response to an earlier event.
458 *
459 * This lock is intended to be used to temporarily steal an event
460 * queue to support inter-thread communication when some
461 * deterministic timing can be sacrificed for speed. For example,
462 * the KVM CPU can use this support to access devices running in a
463 * different thread.
464 *
465 * @see EventQueue::ScopedMigration.
466 * @see EventQueue::ScopedRelease
467 * @see EventQueue::lock()
468 * @see EventQueue::unlock()
469 */
470 std::mutex service_mutex;
471
472 //! Insert / remove event from the queue. Should only be called
473 //! by thread operating this queue.
474 void insert(Event *event);
475 void remove(Event *event);
476
477 //! Function for adding events to the async queue. The added events
478 //! are added to main event queue later. Threads, other than the
479 //! owning thread, should call this function instead of insert().
480 void asyncInsert(Event *event);
481
482 EventQueue(const EventQueue &);
483
484 public:
485#ifndef SWIG
486 /**
487 * Temporarily migrate execution to a different event queue.
488 *
489 * An instance of this class temporarily migrates execution to a
490 * different event queue by releasing the current queue, locking
491 * the new queue, and updating curEventQueue(). This can, for
492 * example, be useful when performing IO across thread event
493 * queues when timing is not crucial (e.g., during fast
494 * forwarding).
495 */
496 class ScopedMigration
497 {
498 public:
499 ScopedMigration(EventQueue *_new_eq)
500 : new_eq(*_new_eq), old_eq(*curEventQueue())
501 {
502 old_eq.unlock();
503 new_eq.lock();
504 curEventQueue(&new_eq);
505 }
506
507 ~ScopedMigration()
508 {
509 new_eq.unlock();
510 old_eq.lock();
511 curEventQueue(&old_eq);
512 }
513
514 private:
515 EventQueue &new_eq;
516 EventQueue &old_eq;
517 };
518
519 /**
520 * Temporarily release the event queue service lock.
521 *
522 * There are cases where it is desirable to temporarily release
523 * the event queue lock to prevent deadlocks. For example, when
524 * waiting on the global barrier, we need to release the lock to
525 * prevent deadlocks from happening when another thread tries to
526 * temporarily take over the event queue waiting on the barrier.
527 */
528 class ScopedRelease
529 {
530 public:
531 ScopedRelease(EventQueue *_eq)
532 : eq(*_eq)
533 {
534 eq.unlock();
535 }
536
537 ~ScopedRelease()
538 {
539 eq.lock();
540 }
541
542 private:
543 EventQueue &eq;
544 };
545#endif
546
547 EventQueue(const std::string &n);
548
549 virtual const std::string name() const { return objName; }
550 void name(const std::string &st) { objName = st; }
551
552 //! Schedule the given event on this queue. Safe to call from any
553 //! thread.
554 void schedule(Event *event, Tick when, bool global = false);
555
556 //! Deschedule the specified event. Should be called only from the
557 //! owning thread.
558 void deschedule(Event *event);
559
560 //! Reschedule the specified event. Should be called only from
561 //! the owning thread.
562 void reschedule(Event *event, Tick when, bool always = false);
563
564 Tick nextTick() const { return head->when(); }
565 void setCurTick(Tick newVal) { _curTick = newVal; }
566 Tick getCurTick() { return _curTick; }
567
568 Event *serviceOne();
569
570 // process all events up to the given timestamp. we inline a
571 // quick test to see if there are any events to process; if so,
572 // call the internal out-of-line version to process them all.
573 void
574 serviceEvents(Tick when)
575 {
576 while (!empty()) {
577 if (nextTick() > when)
578 break;
579
580 /**
581 * @todo this assert is a good bug catcher. I need to
582 * make it true again.
583 */
584 //assert(head->when() >= when && "event scheduled in the past");
585 serviceOne();
586 }
587
588 setCurTick(when);
589 }
590
591 // return true if no events are queued
592 bool empty() const { return head == NULL; }
593
594 void dump() const;
595
596 bool debugVerify() const;
597
598 //! Function for moving events from the async_queue to the main queue.
599 void handleAsyncInsertions();
600
601 /**
602 * Function to signal that the event loop should be woken up because
603 * an event has been scheduled by an agent outside the gem5 event
604 * loop(s) whose event insertion may not have been noticed by gem5.
605 * This function isn't needed by the usual gem5 event loop but may
606 * be necessary in derived EventQueues which host gem5 onto other
607 * schedulers.
608 *
609 * @param when Time of a delayed wakeup (if known). This parameter
610 * can be used by an implementation to schedule a wakeup in the
611 * future if it is sure it will remain active until then.
612 * Or it can be ignored and the event queue can be woken up now.
613 */
614 virtual void wakeup(Tick when = (Tick)-1) { }
615
616 /**
617 * function for replacing the head of the event queue, so that a
618 * different set of events can run without disturbing events that have
619 * already been scheduled. Already scheduled events can be processed
620 * by replacing the original head back.
621 * USING THIS FUNCTION CAN BE DANGEROUS TO THE HEALTH OF THE SIMULATOR.
622 * NOT RECOMMENDED FOR USE.
623 */
624 Event* replaceHead(Event* s);
625
626 /**@{*/
627 /**
628 * Provide an interface for locking/unlocking the event queue.
629 *
630 * @warn Do NOT use these methods directly unless you really know
631 * what you are doing. Incorrect use can easily lead to simulator
632 * deadlocks.
633 *
634 * @see EventQueue::ScopedMigration.
635 * @see EventQueue::ScopedRelease
636 * @see EventQueue
637 */
638 void lock() { service_mutex.lock(); }
639 void unlock() { service_mutex.unlock(); }
640 /**@}*/
641
642#ifndef SWIG
643 void serialize(CheckpointOut &cp) const M5_ATTR_OVERRIDE;
644 void unserialize(CheckpointIn &cp) M5_ATTR_OVERRIDE;
645#endif
646
|
| 647 /**
648 * Reschedule an event after a checkpoint.
649 *
650 * Since events don't know which event queue they belong to,
651 * parent objects need to reschedule events themselves. This
652 * method conditionally schedules an event that has the Scheduled
653 * flag set. It should be called by parent objects after
654 * unserializing an object.
655 *
656 * @warn Only use this method after unserializing an Event.
657 */
658 void checkpointReschedule(Event *event);
659
|
653 virtual ~EventQueue() { }
654};
655
656void dumpMainQueue();
657
658#ifndef SWIG
659class EventManager
660{
661 protected:
662 /** A pointer to this object's event queue */
663 EventQueue *eventq;
664
665 public:
666 EventManager(EventManager &em) : eventq(em.eventq) {}
667 EventManager(EventManager *em) : eventq(em->eventq) {}
668 EventManager(EventQueue *eq) : eventq(eq) {}
669
670 EventQueue *
671 eventQueue() const
672 {
673 return eventq;
674 }
675
676 void
677 schedule(Event &event, Tick when)
678 {
679 eventq->schedule(&event, when);
680 }
681
682 void
683 deschedule(Event &event)
684 {
685 eventq->deschedule(&event);
686 }
687
688 void
689 reschedule(Event &event, Tick when, bool always = false)
690 {
691 eventq->reschedule(&event, when, always);
692 }
693
694 void
695 schedule(Event *event, Tick when)
696 {
697 eventq->schedule(event, when);
698 }
699
700 void
701 deschedule(Event *event)
702 {
703 eventq->deschedule(event);
704 }
705
706 void
707 reschedule(Event *event, Tick when, bool always = false)
708 {
709 eventq->reschedule(event, when, always);
710 }
711
712 void wakeupEventQueue(Tick when = (Tick)-1)
713 {
714 eventq->wakeup(when);
715 }
716
717 void setCurTick(Tick newVal) { eventq->setCurTick(newVal); }
718};
719
720template <class T, void (T::* F)()>
721void
722DelayFunction(EventQueue *eventq, Tick when, T *object)
723{
724 class DelayEvent : public Event
725 {
726 private:
727 T *object;
728
729 public:
730 DelayEvent(T *o)
731 : Event(Default_Pri, AutoDelete), object(o)
732 { }
733 void process() { (object->*F)(); }
734 const char *description() const { return "delay"; }
735 };
736
737 eventq->schedule(new DelayEvent(object), when);
738}
739
740template <class T, void (T::* F)()>
741class EventWrapper : public Event
742{
743 private:
744 T *object;
745
746 public:
747 EventWrapper(T *obj, bool del = false, Priority p = Default_Pri)
748 : Event(p), object(obj)
749 {
750 if (del)
751 setFlags(AutoDelete);
752 }
753
754 EventWrapper(T &obj, bool del = false, Priority p = Default_Pri)
755 : Event(p), object(&obj)
756 {
757 if (del)
758 setFlags(AutoDelete);
759 }
760
761 void process() { (object->*F)(); }
762
763 const std::string
764 name() const
765 {
766 return object->name() + ".wrapped_event";
767 }
768
769 const char *description() const { return "EventWrapped"; }
770};
771#endif
772
773#endif // __SIM_EVENTQ_HH__
| 660 virtual ~EventQueue() { }
661};
662
663void dumpMainQueue();
664
665#ifndef SWIG
666class EventManager
667{
668 protected:
669 /** A pointer to this object's event queue */
670 EventQueue *eventq;
671
672 public:
673 EventManager(EventManager &em) : eventq(em.eventq) {}
674 EventManager(EventManager *em) : eventq(em->eventq) {}
675 EventManager(EventQueue *eq) : eventq(eq) {}
676
677 EventQueue *
678 eventQueue() const
679 {
680 return eventq;
681 }
682
683 void
684 schedule(Event &event, Tick when)
685 {
686 eventq->schedule(&event, when);
687 }
688
689 void
690 deschedule(Event &event)
691 {
692 eventq->deschedule(&event);
693 }
694
695 void
696 reschedule(Event &event, Tick when, bool always = false)
697 {
698 eventq->reschedule(&event, when, always);
699 }
700
701 void
702 schedule(Event *event, Tick when)
703 {
704 eventq->schedule(event, when);
705 }
706
707 void
708 deschedule(Event *event)
709 {
710 eventq->deschedule(event);
711 }
712
713 void
714 reschedule(Event *event, Tick when, bool always = false)
715 {
716 eventq->reschedule(event, when, always);
717 }
718
719 void wakeupEventQueue(Tick when = (Tick)-1)
720 {
721 eventq->wakeup(when);
722 }
723
724 void setCurTick(Tick newVal) { eventq->setCurTick(newVal); }
725};
726
727template <class T, void (T::* F)()>
728void
729DelayFunction(EventQueue *eventq, Tick when, T *object)
730{
731 class DelayEvent : public Event
732 {
733 private:
734 T *object;
735
736 public:
737 DelayEvent(T *o)
738 : Event(Default_Pri, AutoDelete), object(o)
739 { }
740 void process() { (object->*F)(); }
741 const char *description() const { return "delay"; }
742 };
743
744 eventq->schedule(new DelayEvent(object), when);
745}
746
747template <class T, void (T::* F)()>
748class EventWrapper : public Event
749{
750 private:
751 T *object;
752
753 public:
754 EventWrapper(T *obj, bool del = false, Priority p = Default_Pri)
755 : Event(p), object(obj)
756 {
757 if (del)
758 setFlags(AutoDelete);
759 }
760
761 EventWrapper(T &obj, bool del = false, Priority p = Default_Pri)
762 : Event(p), object(&obj)
763 {
764 if (del)
765 setFlags(AutoDelete);
766 }
767
768 void process() { (object->*F)(); }
769
770 const std::string
771 name() const
772 {
773 return object->name() + ".wrapped_event";
774 }
775
776 const char *description() const { return "EventWrapped"; }
777};
778#endif
779
780#endif // __SIM_EVENTQ_HH__
|