eventq.cc revision 11320
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 <unordered_map> 39#include <vector> 40 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::checkpointReschedule(Event *event) 287{ 288 // It's safe to call insert() directly here since this method 289 // should only be called when restoring from a checkpoint (which 290 // happens before thread creation). 291 if (event->flags.isSet(Event::Scheduled)) 292 insert(event); 293} 294void 295EventQueue::dump() const 296{ 297 cprintf("============================================================\n"); 298 cprintf("EventQueue Dump (cycle %d)\n", curTick()); 299 cprintf("------------------------------------------------------------\n"); 300 301 if (empty()) 302 cprintf("<No Events>\n"); 303 else { 304 Event *nextBin = head; 305 while (nextBin) { 306 Event *nextInBin = nextBin; 307 while (nextInBin) { 308 nextInBin->dump(); 309 nextInBin = nextInBin->nextInBin; 310 } 311 312 nextBin = nextBin->nextBin; 313 } 314 } 315 316 cprintf("============================================================\n"); 317} 318 319bool 320EventQueue::debugVerify() const 321{ 322 std::unordered_map<long, bool> map; 323 324 Tick time = 0; 325 short priority = 0; 326 327 Event *nextBin = head; 328 while (nextBin) { 329 Event *nextInBin = nextBin; 330 while (nextInBin) { 331 if (nextInBin->when() < time) { 332 cprintf("time goes backwards!"); 333 nextInBin->dump(); 334 return false; 335 } else if (nextInBin->when() == time && 336 nextInBin->priority() < priority) { 337 cprintf("priority inverted!"); 338 nextInBin->dump(); 339 return false; 340 } 341 342 if (map[reinterpret_cast<long>(nextInBin)]) { 343 cprintf("Node already seen"); 344 nextInBin->dump(); 345 return false; 346 } 347 map[reinterpret_cast<long>(nextInBin)] = true; 348 349 time = nextInBin->when(); 350 priority = nextInBin->priority(); 351 352 nextInBin = nextInBin->nextInBin; 353 } 354 355 nextBin = nextBin->nextBin; 356 } 357 358 return true; 359} 360 361Event* 362EventQueue::replaceHead(Event* s) 363{ 364 Event* t = head; 365 head = s; 366 return t; 367} 368 369void 370dumpMainQueue() 371{ 372 for (uint32_t i = 0; i < numMainEventQueues; ++i) { 373 mainEventQueue[i]->dump(); 374 } 375} 376 377 378const char * 379Event::description() const 380{ 381 return "generic"; 382} 383 384void 385Event::trace(const char *action) 386{ 387 // This DPRINTF is unconditional because calls to this function 388 // are protected by an 'if (DTRACE(Event))' in the inlined Event 389 // methods. 390 // 391 // This is just a default implementation for derived classes where 392 // it's not worth doing anything special. If you want to put a 393 // more informative message in the trace, override this method on 394 // the particular subclass where you have the information that 395 // needs to be printed. 396 DPRINTFN("%s event %s @ %d\n", description(), action, when()); 397} 398 399void 400Event::dump() const 401{ 402 cprintf("Event %s (%s)\n", name(), description()); 403 cprintf("Flags: %#x\n", flags); 404#ifdef EVENTQ_DEBUG 405 cprintf("Created: %d\n", whenCreated); 406#endif 407 if (scheduled()) { 408#ifdef EVENTQ_DEBUG 409 cprintf("Scheduled at %d\n", whenScheduled); 410#endif 411 cprintf("Scheduled for %d, priority %d\n", when(), _priority); 412 } else { 413 cprintf("Not Scheduled\n"); 414 } 415} 416 417EventQueue::EventQueue(const string &n) 418 : objName(n), head(NULL), _curTick(0) 419{ 420} 421 422void 423EventQueue::asyncInsert(Event *event) 424{ 425 async_queue_mutex.lock(); 426 async_queue.push_back(event); 427 async_queue_mutex.unlock(); 428} 429 430void 431EventQueue::handleAsyncInsertions() 432{ 433 assert(this == curEventQueue()); 434 async_queue_mutex.lock(); 435 436 while (!async_queue.empty()) { 437 insert(async_queue.front()); 438 async_queue.pop_front(); 439 } 440 441 async_queue_mutex.unlock(); 442} 443