eventq.cc revision 10905
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/Config.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} 257 258void 259Event::unserializeEvent(CheckpointIn &cp, EventQueue *eventq) 260{ 261 if (scheduled()) 262 eventq->deschedule(this); 263 264 UNSERIALIZE_SCALAR(_when); 265 UNSERIALIZE_SCALAR(_priority); 266 267 short _flags; 268 UNSERIALIZE_SCALAR(_flags); 269 270 // Old checkpoints had no concept of the Initialized flag 271 // so restoring from old checkpoints always fail. 272 // Events are initialized on construction but original code 273 // "flags = _flags" would just overwrite the initialization. 274 // So, read in the checkpoint flags, but then set the Initialized 275 // flag on top of it in order to avoid failures. 276 assert(initialized()); 277 flags = _flags; 278 flags.set(Initialized); 279 280 // need to see if original event was in a scheduled, unsquashed 281 // state, but don't want to restore those flags in the current 282 // object itself (since they aren't immediately true) 283 bool wasScheduled = flags.isSet(Scheduled) && !flags.isSet(Squashed); 284 flags.clear(Squashed | Scheduled); 285 286 if (wasScheduled) { 287 DPRINTF(Config, "rescheduling at %d\n", _when); 288 eventq->schedule(this, _when); 289 } 290} 291 292void 293EventQueue::serialize(CheckpointOut &cp) const 294{ 295 std::list<Event *> eventPtrs; 296 297 int numEvents = 0; 298 Event *nextBin = head; 299 while (nextBin) { 300 Event *nextInBin = nextBin; 301 302 while (nextInBin) { 303 if (nextInBin->flags.isSet(Event::AutoSerialize)) { 304 eventPtrs.push_back(nextInBin); 305 paramOut(cp, csprintf("event%d", numEvents++), 306 nextInBin->name()); 307 } 308 nextInBin = nextInBin->nextInBin; 309 } 310 311 nextBin = nextBin->nextBin; 312 } 313 314 SERIALIZE_SCALAR(numEvents); 315 316 for (Event *ev : eventPtrs) 317 ev->serializeSection(cp, ev->name()); 318} 319 320void 321EventQueue::unserialize(CheckpointIn &cp) 322{ 323 int numEvents; 324 UNSERIALIZE_SCALAR(numEvents); 325 326 std::string eventName; 327 for (int i = 0; i < numEvents; i++) { 328 // get the pointer value associated with the event 329 paramIn(cp, csprintf("event%d", i), eventName); 330 331 // create the event based on its pointer value 332 Serializable::create(cp, eventName); 333 } 334} 335 336void 337EventQueue::dump() const 338{ 339 cprintf("============================================================\n"); 340 cprintf("EventQueue Dump (cycle %d)\n", curTick()); 341 cprintf("------------------------------------------------------------\n"); 342 343 if (empty()) 344 cprintf("<No Events>\n"); 345 else { 346 Event *nextBin = head; 347 while (nextBin) { 348 Event *nextInBin = nextBin; 349 while (nextInBin) { 350 nextInBin->dump(); 351 nextInBin = nextInBin->nextInBin; 352 } 353 354 nextBin = nextBin->nextBin; 355 } 356 } 357 358 cprintf("============================================================\n"); 359} 360 361bool 362EventQueue::debugVerify() const 363{ 364 m5::hash_map<long, bool> map; 365 366 Tick time = 0; 367 short priority = 0; 368 369 Event *nextBin = head; 370 while (nextBin) { 371 Event *nextInBin = nextBin; 372 while (nextInBin) { 373 if (nextInBin->when() < time) { 374 cprintf("time goes backwards!"); 375 nextInBin->dump(); 376 return false; 377 } else if (nextInBin->when() == time && 378 nextInBin->priority() < priority) { 379 cprintf("priority inverted!"); 380 nextInBin->dump(); 381 return false; 382 } 383 384 if (map[reinterpret_cast<long>(nextInBin)]) { 385 cprintf("Node already seen"); 386 nextInBin->dump(); 387 return false; 388 } 389 map[reinterpret_cast<long>(nextInBin)] = true; 390 391 time = nextInBin->when(); 392 priority = nextInBin->priority(); 393 394 nextInBin = nextInBin->nextInBin; 395 } 396 397 nextBin = nextBin->nextBin; 398 } 399 400 return true; 401} 402 403Event* 404EventQueue::replaceHead(Event* s) 405{ 406 Event* t = head; 407 head = s; 408 return t; 409} 410 411void 412dumpMainQueue() 413{ 414 for (uint32_t i = 0; i < numMainEventQueues; ++i) { 415 mainEventQueue[i]->dump(); 416 } 417} 418 419 420const char * 421Event::description() const 422{ 423 return "generic"; 424} 425 426void 427Event::trace(const char *action) 428{ 429 // This DPRINTF is unconditional because calls to this function 430 // are protected by an 'if (DTRACE(Event))' in the inlined Event 431 // methods. 432 // 433 // This is just a default implementation for derived classes where 434 // it's not worth doing anything special. If you want to put a 435 // more informative message in the trace, override this method on 436 // the particular subclass where you have the information that 437 // needs to be printed. 438 DPRINTFN("%s event %s @ %d\n", description(), action, when()); 439} 440 441void 442Event::dump() const 443{ 444 cprintf("Event %s (%s)\n", name(), description()); 445 cprintf("Flags: %#x\n", flags); 446#ifdef EVENTQ_DEBUG 447 cprintf("Created: %d\n", whenCreated); 448#endif 449 if (scheduled()) { 450#ifdef EVENTQ_DEBUG 451 cprintf("Scheduled at %d\n", whenScheduled); 452#endif 453 cprintf("Scheduled for %d, priority %d\n", when(), _priority); 454 } else { 455 cprintf("Not Scheduled\n"); 456 } 457} 458 459EventQueue::EventQueue(const string &n) 460 : objName(n), head(NULL), _curTick(0) 461{ 462} 463 464void 465EventQueue::asyncInsert(Event *event) 466{ 467 async_queue_mutex.lock(); 468 async_queue.push_back(event); 469 async_queue_mutex.unlock(); 470} 471 472void 473EventQueue::handleAsyncInsertions() 474{ 475 assert(this == curEventQueue()); 476 async_queue_mutex.lock(); 477 478 while (!async_queue.empty()) { 479 insert(async_queue.front()); 480 async_queue.pop_front(); 481 } 482 483 async_queue_mutex.unlock(); 484} 485