eventq.cc revision 10906
1/* 2 * Copyright (c) 2000-2005 The Regents of The University of Michigan 3 * Copyright (c) 2008 The Hewlett-Packard Development Company 4 * Copyright (c) 2013 Advanced Micro Devices, Inc. 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 * Steve Raasch 33 */ 34 35#include <cassert> 36#include <iostream> 37#include <string> 38#include <vector> 39 40#include "base/hashmap.hh" 41#include "base/misc.hh" 42#include "base/trace.hh" 43#include "cpu/smt.hh" 44#include "debug/Checkpoint.hh" 45#include "sim/core.hh" 46#include "sim/eventq_impl.hh" 47 48using namespace std; 49 50Tick simQuantum = 0; 51 52// 53// Main Event Queues 54// 55// Events on these queues are processed at the *beginning* of each 56// cycle, before the pipeline simulation is performed. 57// 58uint32_t numMainEventQueues = 0; 59vector<EventQueue *> mainEventQueue; 60__thread EventQueue *_curEventQueue = NULL; 61bool inParallelMode = false; 62 63EventQueue * 64getEventQueue(uint32_t index) 65{ 66 while (numMainEventQueues <= index) { 67 numMainEventQueues++; 68 mainEventQueue.push_back( 69 new EventQueue(csprintf("MainEventQueue-%d", index))); 70 } 71 72 return mainEventQueue[index]; 73} 74 75#ifndef NDEBUG 76Counter Event::instanceCounter = 0; 77#endif 78 79Event::~Event() 80{ 81 assert(!scheduled()); 82 flags = 0; 83} 84 85const std::string 86Event::name() const 87{ 88#ifndef NDEBUG 89 return csprintf("Event_%d", instance); 90#else 91 return csprintf("Event_%x", (uintptr_t)this); 92#endif 93} 94 95 96Event * 97Event::insertBefore(Event *event, Event *curr) 98{ 99 // Either way, event will be the top element in the 'in bin' list 100 // which is the pointer we need in order to look into the list, so 101 // we need to insert that into the bin list. 102 if (!curr || *event < *curr) { 103 // Insert the event before the current list since it is in the future. 104 event->nextBin = curr; 105 event->nextInBin = NULL; 106 } else { 107 // Since we're on the correct list, we need to point to the next list 108 event->nextBin = curr->nextBin; // curr->nextBin can now become stale 109 110 // Insert event at the top of the stack 111 event->nextInBin = curr; 112 } 113 114 return event; 115} 116 117void 118EventQueue::insert(Event *event) 119{ 120 // Deal with the head case 121 if (!head || *event <= *head) { 122 head = Event::insertBefore(event, head); 123 return; 124 } 125 126 // Figure out either which 'in bin' list we are on, or where a new list 127 // needs to be inserted 128 Event *prev = head; 129 Event *curr = head->nextBin; 130 while (curr && *curr < *event) { 131 prev = curr; 132 curr = curr->nextBin; 133 } 134 135 // Note: this operation may render all nextBin pointers on the 136 // prev 'in bin' list stale (except for the top one) 137 prev->nextBin = Event::insertBefore(event, curr); 138} 139 140Event * 141Event::removeItem(Event *event, Event *top) 142{ 143 Event *curr = top; 144 Event *next = top->nextInBin; 145 146 // if we removed the top item, we need to handle things specially 147 // and just remove the top item, fixing up the next bin pointer of 148 // the new top item 149 if (event == top) { 150 if (!next) 151 return top->nextBin; 152 next->nextBin = top->nextBin; 153 return next; 154 } 155 156 // Since we already checked the current element, we're going to 157 // keep checking event against the next element. 158 while (event != next) { 159 if (!next) 160 panic("event not found!"); 161 162 curr = next; 163 next = next->nextInBin; 164 } 165 166 // remove next from the 'in bin' list since it's what we're looking for 167 curr->nextInBin = next->nextInBin; 168 return top; 169} 170 171void 172EventQueue::remove(Event *event) 173{ 174 if (head == NULL) 175 panic("event not found!"); 176 177 assert(event->queue == this); 178 179 // deal with an event on the head's 'in bin' list (event has the same 180 // time as the head) 181 if (*head == *event) { 182 head = Event::removeItem(event, head); 183 return; 184 } 185 186 // Find the 'in bin' list that this event belongs on 187 Event *prev = head; 188 Event *curr = head->nextBin; 189 while (curr && *curr < *event) { 190 prev = curr; 191 curr = curr->nextBin; 192 } 193 194 if (!curr || *curr != *event) 195 panic("event not found!"); 196 197 // curr points to the top item of the the correct 'in bin' list, when 198 // we remove an item, it returns the new top item (which may be 199 // unchanged) 200 prev->nextBin = Event::removeItem(event, curr); 201} 202 203Event * 204EventQueue::serviceOne() 205{ 206 std::lock_guard<EventQueue> lock(*this); 207 Event *event = head; 208 Event *next = head->nextInBin; 209 event->flags.clear(Event::Scheduled); 210 211 if (next) { 212 // update the next bin pointer since it could be stale 213 next->nextBin = head->nextBin; 214 215 // pop the stack 216 head = next; 217 } else { 218 // this was the only element on the 'in bin' list, so get rid of 219 // the 'in bin' list and point to the next bin list 220 head = head->nextBin; 221 } 222 223 // handle action 224 if (!event->squashed()) { 225 // forward current cycle to the time when this event occurs. 226 setCurTick(event->when()); 227 228 event->process(); 229 if (event->isExitEvent()) { 230 assert(!event->flags.isSet(Event::AutoDelete) || 231 !event->flags.isSet(Event::IsMainQueue)); // would be silly 232 return event; 233 } 234 } else { 235 event->flags.clear(Event::Squashed); 236 } 237 238 if (event->flags.isSet(Event::AutoDelete) && !event->scheduled()) 239 delete event; 240 241 return NULL; 242} 243 244void 245Event::serialize(CheckpointOut &cp) const 246{ 247 SERIALIZE_SCALAR(_when); 248 SERIALIZE_SCALAR(_priority); 249 short _flags = flags; 250 SERIALIZE_SCALAR(_flags); 251} 252 253void 254Event::unserialize(CheckpointIn &cp) 255{ 256 assert(!scheduled()); 257 258 UNSERIALIZE_SCALAR(_when); 259 UNSERIALIZE_SCALAR(_priority); 260 261 FlagsType _flags; 262 UNSERIALIZE_SCALAR(_flags); 263 264 // Old checkpoints had no concept of the Initialized flag 265 // so restoring from old checkpoints always fail. 266 // Events are initialized on construction but original code 267 // "flags = _flags" would just overwrite the initialization. 268 // So, read in the checkpoint flags, but then set the Initialized 269 // flag on top of it in order to avoid failures. 270 assert(initialized()); 271 flags = _flags; 272 flags.set(Initialized); 273 274 // need to see if original event was in a scheduled, unsquashed 275 // state, but don't want to restore those flags in the current 276 // object itself (since they aren't immediately true) 277 if (flags.isSet(Scheduled) && !flags.isSet(Squashed)) { 278 flags.clear(Squashed | Scheduled); 279 } else { 280 DPRINTF(Checkpoint, "Event '%s' need to be scheduled @%d\n", 281 name(), _when); 282 } 283} 284 285void 286EventQueue::serialize(CheckpointOut &cp) const 287{ 288 std::list<Event *> eventPtrs; 289 290 int numEvents = 0; 291 Event *nextBin = head; 292 while (nextBin) { 293 Event *nextInBin = nextBin; 294 295 while (nextInBin) { 296 if (nextInBin->flags.isSet(Event::AutoSerialize)) { 297 eventPtrs.push_back(nextInBin); 298 paramOut(cp, csprintf("event%d", numEvents++), 299 nextInBin->name()); 300 } 301 nextInBin = nextInBin->nextInBin; 302 } 303 304 nextBin = nextBin->nextBin; 305 } 306 307 SERIALIZE_SCALAR(numEvents); 308 309 for (Event *ev : eventPtrs) 310 ev->serializeSection(cp, ev->name()); 311} 312 313void 314EventQueue::unserialize(CheckpointIn &cp) 315{ 316 int numEvents; 317 UNSERIALIZE_SCALAR(numEvents); 318 319 std::string eventName; 320 for (int i = 0; i < numEvents; i++) { 321 // get the pointer value associated with the event 322 paramIn(cp, csprintf("event%d", i), eventName); 323 324 // create the event based on its pointer value 325 Serializable *obj(Serializable::create(cp, eventName)); 326 Event *event(dynamic_cast<Event *>(obj)); 327 fatal_if(!event, 328 "Event queue unserialized something that wasn't an event.\n"); 329 330 checkpointReschedule(event); 331 } 332} 333 334void 335EventQueue::checkpointReschedule(Event *event) 336{ 337 // It's safe to call insert() directly here since this method 338 // should only be called when restoring from a checkpoint (which 339 // happens before thread creation). 340 if (event->flags.isSet(Event::Scheduled)) 341 insert(event); 342} 343void 344EventQueue::dump() const 345{ 346 cprintf("============================================================\n"); 347 cprintf("EventQueue Dump (cycle %d)\n", curTick()); 348 cprintf("------------------------------------------------------------\n"); 349 350 if (empty()) 351 cprintf("<No Events>\n"); 352 else { 353 Event *nextBin = head; 354 while (nextBin) { 355 Event *nextInBin = nextBin; 356 while (nextInBin) { 357 nextInBin->dump(); 358 nextInBin = nextInBin->nextInBin; 359 } 360 361 nextBin = nextBin->nextBin; 362 } 363 } 364 365 cprintf("============================================================\n"); 366} 367 368bool 369EventQueue::debugVerify() const 370{ 371 m5::hash_map<long, bool> map; 372 373 Tick time = 0; 374 short priority = 0; 375 376 Event *nextBin = head; 377 while (nextBin) { 378 Event *nextInBin = nextBin; 379 while (nextInBin) { 380 if (nextInBin->when() < time) { 381 cprintf("time goes backwards!"); 382 nextInBin->dump(); 383 return false; 384 } else if (nextInBin->when() == time && 385 nextInBin->priority() < priority) { 386 cprintf("priority inverted!"); 387 nextInBin->dump(); 388 return false; 389 } 390 391 if (map[reinterpret_cast<long>(nextInBin)]) { 392 cprintf("Node already seen"); 393 nextInBin->dump(); 394 return false; 395 } 396 map[reinterpret_cast<long>(nextInBin)] = true; 397 398 time = nextInBin->when(); 399 priority = nextInBin->priority(); 400 401 nextInBin = nextInBin->nextInBin; 402 } 403 404 nextBin = nextBin->nextBin; 405 } 406 407 return true; 408} 409 410Event* 411EventQueue::replaceHead(Event* s) 412{ 413 Event* t = head; 414 head = s; 415 return t; 416} 417 418void 419dumpMainQueue() 420{ 421 for (uint32_t i = 0; i < numMainEventQueues; ++i) { 422 mainEventQueue[i]->dump(); 423 } 424} 425 426 427const char * 428Event::description() const 429{ 430 return "generic"; 431} 432 433void 434Event::trace(const char *action) 435{ 436 // This DPRINTF is unconditional because calls to this function 437 // are protected by an 'if (DTRACE(Event))' in the inlined Event 438 // methods. 439 // 440 // This is just a default implementation for derived classes where 441 // it's not worth doing anything special. If you want to put a 442 // more informative message in the trace, override this method on 443 // the particular subclass where you have the information that 444 // needs to be printed. 445 DPRINTFN("%s event %s @ %d\n", description(), action, when()); 446} 447 448void 449Event::dump() const 450{ 451 cprintf("Event %s (%s)\n", name(), description()); 452 cprintf("Flags: %#x\n", flags); 453#ifdef EVENTQ_DEBUG 454 cprintf("Created: %d\n", whenCreated); 455#endif 456 if (scheduled()) { 457#ifdef EVENTQ_DEBUG 458 cprintf("Scheduled at %d\n", whenScheduled); 459#endif 460 cprintf("Scheduled for %d, priority %d\n", when(), _priority); 461 } else { 462 cprintf("Not Scheduled\n"); 463 } 464} 465 466EventQueue::EventQueue(const string &n) 467 : objName(n), head(NULL), _curTick(0) 468{ 469} 470 471void 472EventQueue::asyncInsert(Event *event) 473{ 474 async_queue_mutex.lock(); 475 async_queue.push_back(event); 476 async_queue_mutex.unlock(); 477} 478 479void 480EventQueue::handleAsyncInsertions() 481{ 482 assert(this == curEventQueue()); 483 async_queue_mutex.lock(); 484 485 while (!async_queue.empty()) { 486 insert(async_queue.front()); 487 async_queue.pop_front(); 488 } 489 490 async_queue_mutex.unlock(); 491} 492