eventq.hh revision 9356
1/* 2 * Copyright (c) 2000-2005 The Regents of The University of Michigan 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; 9 * redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution; 12 * neither the name of the copyright holders nor the names of its 13 * contributors may be used to endorse or promote products derived from 14 * this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * Authors: Steve Reinhardt 29 * Nathan Binkert 30 */ 31 32/* @file 33 * EventQueue interfaces 34 */ 35 36#ifndef __SIM_EVENTQ_HH__ 37#define __SIM_EVENTQ_HH__ 38 39#include <algorithm> 40#include <cassert> 41#include <climits> 42#include <iosfwd> 43#include <string> 44 45#include "base/flags.hh" 46#include "base/misc.hh" 47#include "base/types.hh" 48#include "debug/Event.hh" 49#include "sim/serialize.hh" 50 51class EventQueue; // forward declaration 52 53extern EventQueue mainEventQueue; 54 55/* 56 * An item on an event queue. The action caused by a given 57 * event is specified by deriving a subclass and overriding the 58 * process() member function. 59 * 60 * Caution, the order of members is chosen to maximize data packing. 61 */ 62class Event : public Serializable 63{ 64 friend class EventQueue; 65 66 protected: 67 typedef unsigned short FlagsType; 68 typedef ::Flags<FlagsType> Flags; 69 70 static const FlagsType PublicRead = 0x003f; // public readable flags 71 static const FlagsType PublicWrite = 0x001d; // public writable flags 72 static const FlagsType Squashed = 0x0001; // has been squashed 73 static const FlagsType Scheduled = 0x0002; // has been scheduled 74 static const FlagsType AutoDelete = 0x0004; // delete after dispatch 75 static const FlagsType AutoSerialize = 0x0008; // must be serialized 76 static const FlagsType IsExitEvent = 0x0010; // special exit event 77 static const FlagsType IsMainQueue = 0x0020; // on main event queue 78 static const FlagsType Initialized = 0x7a40; // somewhat random bits 79 static const FlagsType InitMask = 0xffc0; // mask for init bits 80 81 bool 82 initialized() const 83 { 84 return this && (flags & InitMask) == Initialized; 85 } 86 87 public: 88 typedef int8_t Priority; 89 90 private: 91 // The event queue is now a linked list of linked lists. The 92 // 'nextBin' pointer is to find the bin, where a bin is defined as 93 // when+priority. All events in the same bin will be stored in a 94 // second linked list (a stack) maintained by the 'nextInBin' 95 // pointer. The list will be accessed in LIFO order. The end 96 // result is that the insert/removal in 'nextBin' is 97 // linear/constant, and the lookup/removal in 'nextInBin' is 98 // constant/constant. Hopefully this is a significant improvement 99 // over the current fully linear insertion. 100 Event *nextBin; 101 Event *nextInBin; 102 103 static Event *insertBefore(Event *event, Event *curr); 104 static Event *removeItem(Event *event, Event *last); 105 106 Tick _when; //!< timestamp when event should be processed 107 Priority _priority; //!< event priority 108 Flags flags; 109 110#ifndef NDEBUG 111 /// Global counter to generate unique IDs for Event instances 112 static Counter instanceCounter; 113 114 /// This event's unique ID. We can also use pointer values for 115 /// this but they're not consistent across runs making debugging 116 /// more difficult. Thus we use a global counter value when 117 /// debugging. 118 Counter instance; 119 120 /// queue to which this event belongs (though it may or may not be 121 /// scheduled on this queue yet) 122 EventQueue *queue; 123#endif 124 125#ifdef EVENTQ_DEBUG 126 Tick whenCreated; //!< time created 127 Tick whenScheduled; //!< time scheduled 128#endif 129 130 void 131 setWhen(Tick when, EventQueue *q) 132 { 133 _when = when; 134#ifndef NDEBUG 135 queue = q; 136#endif 137#ifdef EVENTQ_DEBUG 138 whenScheduled = curTick(); 139#endif 140 } 141 142 protected: 143 /// Accessor for flags. 144 Flags 145 getFlags() const 146 { 147 return flags & PublicRead; 148 } 149 150 bool 151 isFlagSet(Flags _flags) const 152 { 153 assert(_flags.noneSet(~PublicRead)); 154 return flags.isSet(_flags); 155 } 156 157 /// Accessor for flags. 158 void 159 setFlags(Flags _flags) 160 { 161 assert(_flags.noneSet(~PublicWrite)); 162 flags.set(_flags); 163 } 164 165 void 166 clearFlags(Flags _flags) 167 { 168 assert(_flags.noneSet(~PublicWrite)); 169 flags.clear(_flags); 170 } 171 172 void 173 clearFlags() 174 { 175 flags.clear(PublicWrite); 176 } 177 178 // This function isn't really useful if TRACING_ON is not defined 179 virtual void trace(const char *action); //!< trace event activity 180 181 public: 182 /// Event priorities, to provide tie-breakers for events scheduled 183 /// at the same cycle. Most events are scheduled at the default 184 /// priority; these values are used to control events that need to 185 /// be ordered within a cycle. 186 187 /// Minimum priority 188 static const Priority Minimum_Pri = SCHAR_MIN; 189 190 /// If we enable tracing on a particular cycle, do that as the 191 /// very first thing so we don't miss any of the events on 192 /// that cycle (even if we enter the debugger). 193 static const Priority Trace_Enable_Pri = -101; 194 195 /// Breakpoints should happen before anything else (except 196 /// enabling trace output), so we don't miss any action when 197 /// debugging. 198 static const Priority Debug_Break_Pri = -100; 199 200 /// CPU switches schedule the new CPU's tick event for the 201 /// same cycle (after unscheduling the old CPU's tick event). 202 /// The switch needs to come before any tick events to make 203 /// sure we don't tick both CPUs in the same cycle. 204 static const Priority CPU_Switch_Pri = -31; 205 206 /// For some reason "delayed" inter-cluster writebacks are 207 /// scheduled before regular writebacks (which have default 208 /// priority). Steve? 209 static const Priority Delayed_Writeback_Pri = -1; 210 211 /// Default is zero for historical reasons. 212 static const Priority Default_Pri = 0; 213 214 /// Serailization needs to occur before tick events also, so 215 /// that a serialize/unserialize is identical to an on-line 216 /// CPU switch. 217 static const Priority Serialize_Pri = 32; 218 219 /// CPU ticks must come after other associated CPU events 220 /// (such as writebacks). 221 static const Priority CPU_Tick_Pri = 50; 222 223 /// Statistics events (dump, reset, etc.) come after 224 /// everything else, but before exit. 225 static const Priority Stat_Event_Pri = 90; 226 227 /// Progress events come at the end. 228 static const Priority Progress_Event_Pri = 95; 229 230 /// If we want to exit on this cycle, it's the very last thing 231 /// we do. 232 static const Priority Sim_Exit_Pri = 100; 233 234 /// Maximum priority 235 static const Priority Maximum_Pri = SCHAR_MAX; 236 237 /* 238 * Event constructor 239 * @param queue that the event gets scheduled on 240 */ 241 Event(Priority p = Default_Pri, Flags f = 0) 242 : nextBin(NULL), nextInBin(NULL), _priority(p), 243 flags(Initialized | f) 244 { 245 assert(f.noneSet(~PublicWrite)); 246#ifndef NDEBUG 247 instance = ++instanceCounter; 248 queue = NULL; 249#endif 250#ifdef EVENTQ_DEBUG 251 whenCreated = curTick(); 252 whenScheduled = 0; 253#endif 254 } 255 256 virtual ~Event(); 257 virtual const std::string name() const; 258 259 /// Return a C string describing the event. This string should 260 /// *not* be dynamically allocated; just a const char array 261 /// describing the event class. 262 virtual const char *description() const; 263 264 /// Dump the current event data 265 void dump() const; 266 267 public: 268 /* 269 * This member function is invoked when the event is processed 270 * (occurs). There is no default implementation; each subclass 271 * must provide its own implementation. The event is not 272 * automatically deleted after it is processed (to allow for 273 * statically allocated event objects). 274 * 275 * If the AutoDestroy flag is set, the object is deleted once it 276 * is processed. 277 */ 278 virtual void process() = 0; 279 280 /// Determine if the current event is scheduled 281 bool scheduled() const { return flags.isSet(Scheduled); } 282 283 /// Squash the current event 284 void squash() { flags.set(Squashed); } 285 286 /// Check whether the event is squashed 287 bool squashed() const { return flags.isSet(Squashed); } 288 289 /// See if this is a SimExitEvent (without resorting to RTTI) 290 bool isExitEvent() const { return flags.isSet(IsExitEvent); } 291 292 /// Get the time that the event is scheduled 293 Tick when() const { return _when; } 294 295 /// Get the event priority 296 Priority priority() const { return _priority; } 297 298#ifndef SWIG 299 struct priority_compare 300 : public std::binary_function<Event *, Event *, bool> 301 { 302 bool 303 operator()(const Event *l, const Event *r) const 304 { 305 return l->when() >= r->when() || l->priority() >= r->priority(); 306 } 307 }; 308 309 virtual void serialize(std::ostream &os); 310 virtual void unserialize(Checkpoint *cp, const std::string §ion); 311#endif 312}; 313 314#ifndef SWIG 315inline bool 316operator<(const Event &l, const Event &r) 317{ 318 return l.when() < r.when() || 319 (l.when() == r.when() && l.priority() < r.priority()); 320} 321 322inline bool 323operator>(const Event &l, const Event &r) 324{ 325 return l.when() > r.when() || 326 (l.when() == r.when() && l.priority() > r.priority()); 327} 328 329inline bool 330operator<=(const Event &l, const Event &r) 331{ 332 return l.when() < r.when() || 333 (l.when() == r.when() && l.priority() <= r.priority()); 334} 335inline bool 336operator>=(const Event &l, const Event &r) 337{ 338 return l.when() > r.when() || 339 (l.when() == r.when() && l.priority() >= r.priority()); 340} 341 342inline bool 343operator==(const Event &l, const Event &r) 344{ 345 return l.when() == r.when() && l.priority() == r.priority(); 346} 347 348inline bool 349operator!=(const Event &l, const Event &r) 350{ 351 return l.when() != r.when() || l.priority() != r.priority(); 352} 353#endif 354 355/* 356 * Queue of events sorted in time order 357 */ 358class EventQueue : public Serializable 359{ 360 private: 361 std::string objName; 362 Event *head; 363 Tick _curTick; 364 365 void insert(Event *event); 366 void remove(Event *event); 367 368 EventQueue(const EventQueue &); 369 const EventQueue &operator=(const EventQueue &); 370 371 public: 372 EventQueue(const std::string &n); 373 374 virtual const std::string name() const { return objName; } 375 376 // schedule the given event on this queue 377 void schedule(Event *event, Tick when); 378 void deschedule(Event *event); 379 void reschedule(Event *event, Tick when, bool always = false); 380 381 Tick nextTick() const { return head->when(); } 382 void setCurTick(Tick newVal) { _curTick = newVal; } 383 Tick getCurTick() { return _curTick; } 384 385 Event *serviceOne(); 386 387 // process all events up to the given timestamp. we inline a 388 // quick test to see if there are any events to process; if so, 389 // call the internal out-of-line version to process them all. 390 void 391 serviceEvents(Tick when) 392 { 393 while (!empty()) { 394 if (nextTick() > when) 395 break; 396 397 /** 398 * @todo this assert is a good bug catcher. I need to 399 * make it true again. 400 */ 401 //assert(head->when() >= when && "event scheduled in the past"); 402 serviceOne(); 403 } 404 405 setCurTick(when); 406 } 407 408 // return true if no events are queued 409 bool empty() const { return head == NULL; } 410 411 void dump() const; 412 413 bool debugVerify() const; 414 415 /** 416 * function for replacing the head of the event queue, so that a 417 * different set of events can run without disturbing events that have 418 * already been scheduled. Already scheduled events can be processed 419 * by replacing the original head back. 420 * USING THIS FUNCTION CAN BE DANGEROUS TO THE HEALTH OF THE SIMULATOR. 421 * NOT RECOMMENDED FOR USE. 422 */ 423 Event* replaceHead(Event* s); 424 425#ifndef SWIG 426 virtual void serialize(std::ostream &os); 427 virtual void unserialize(Checkpoint *cp, const std::string §ion); 428#endif 429}; 430 431#ifndef SWIG 432class EventManager 433{ 434 protected: 435 /** A pointer to this object's event queue */ 436 EventQueue *eventq; 437 438 public: 439 EventManager(EventManager &em) : eventq(em.eventq) {} 440 EventManager(EventManager *em) : eventq(em->eventq) {} 441 EventManager(EventQueue *eq) : eventq(eq) {} 442 443 EventQueue * 444 eventQueue() const 445 { 446 return eventq; 447 } 448 449 void 450 schedule(Event &event, Tick when) 451 { 452 eventq->schedule(&event, when); 453 } 454 455 void 456 deschedule(Event &event) 457 { 458 eventq->deschedule(&event); 459 } 460 461 void 462 reschedule(Event &event, Tick when, bool always = false) 463 { 464 eventq->reschedule(&event, when, always); 465 } 466 467 void 468 schedule(Event *event, Tick when) 469 { 470 eventq->schedule(event, when); 471 } 472 473 void 474 deschedule(Event *event) 475 { 476 eventq->deschedule(event); 477 } 478 479 void 480 reschedule(Event *event, Tick when, bool always = false) 481 { 482 eventq->reschedule(event, when, always); 483 } 484 485 void setCurTick(Tick newVal) { eventq->setCurTick(newVal); } 486}; 487 488template <class T, void (T::* F)()> 489void 490DelayFunction(EventQueue *eventq, Tick when, T *object) 491{ 492 class DelayEvent : public Event 493 { 494 private: 495 T *object; 496 497 public: 498 DelayEvent(T *o) 499 : Event(Default_Pri, AutoDelete), object(o) 500 { } 501 void process() { (object->*F)(); } 502 const char *description() const { return "delay"; } 503 }; 504 505 eventq->schedule(new DelayEvent(object), when); 506} 507 508template <class T, void (T::* F)()> 509class EventWrapper : public Event 510{ 511 private: 512 T *object; 513 514 public: 515 EventWrapper(T *obj, bool del = false, Priority p = Default_Pri) 516 : Event(p), object(obj) 517 { 518 if (del) 519 setFlags(AutoDelete); 520 } 521 522 EventWrapper(T &obj, bool del = false, Priority p = Default_Pri) 523 : Event(p), object(&obj) 524 { 525 if (del) 526 setFlags(AutoDelete); 527 } 528 529 void process() { (object->*F)(); } 530 531 const std::string 532 name() const 533 { 534 return object->name() + ".wrapped_event"; 535 } 536 537 const char *description() const { return "EventWrapped"; } 538}; 539#endif 540 541#endif // __SIM_EVENTQ_HH__ 542