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
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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::Managed) || 231 !event->flags.isSet(Event::IsMainQueue)); // would be silly 232 return event; 233 } 234 } else { 235 event->flags.clear(Event::Squashed); 236 } 237 238 event->release(); 239 240 return NULL; 241} 242 243void 244Event::serialize(CheckpointOut &cp) const 245{ 246 SERIALIZE_SCALAR(_when); 247 SERIALIZE_SCALAR(_priority); 248 short _flags = flags; 249 SERIALIZE_SCALAR(_flags); 250} 251 252void 253Event::unserialize(CheckpointIn &cp) 254{ 255 assert(!scheduled()); 256 257 UNSERIALIZE_SCALAR(_when); 258 UNSERIALIZE_SCALAR(_priority); 259 260 FlagsType _flags; 261 UNSERIALIZE_SCALAR(_flags); 262 263 // Old checkpoints had no concept of the Initialized flag 264 // so restoring from old checkpoints always fail. 265 // Events are initialized on construction but original code 266 // "flags = _flags" would just overwrite the initialization. 267 // So, read in the checkpoint flags, but then set the Initialized 268 // flag on top of it in order to avoid failures. 269 assert(initialized()); 270 flags = _flags; 271 flags.set(Initialized); 272 273 // need to see if original event was in a scheduled, unsquashed 274 // state, but don't want to restore those flags in the current 275 // object itself (since they aren't immediately true) 276 if (flags.isSet(Scheduled) && !flags.isSet(Squashed)) { 277 flags.clear(Squashed | Scheduled); 278 } else { 279 DPRINTF(Checkpoint, "Event '%s' need to be scheduled @%d\n", 280 name(), _when); 281 } 282} 283 284void 285EventQueue::checkpointReschedule(Event *event) 286{ 287 // It's safe to call insert() directly here since this method 288 // should only be called when restoring from a checkpoint (which 289 // happens before thread creation). 290 if (event->flags.isSet(Event::Scheduled)) 291 insert(event); 292} 293void 294EventQueue::dump() const 295{ 296 cprintf("============================================================\n"); 297 cprintf("EventQueue Dump (cycle %d)\n", curTick()); 298 cprintf("------------------------------------------------------------\n"); 299 300 if (empty()) 301 cprintf("<No Events>\n"); 302 else { 303 Event *nextBin = head; 304 while (nextBin) { 305 Event *nextInBin = nextBin; 306 while (nextInBin) { 307 nextInBin->dump(); 308 nextInBin = nextInBin->nextInBin; 309 } 310 311 nextBin = nextBin->nextBin; 312 } 313 } 314 315 cprintf("============================================================\n"); 316} 317 318bool 319EventQueue::debugVerify() const 320{ 321 std::unordered_map<long, bool> map; 322 323 Tick time = 0; 324 short priority = 0; 325 326 Event *nextBin = head; 327 while (nextBin) { 328 Event *nextInBin = nextBin; 329 while (nextInBin) { 330 if (nextInBin->when() < time) { 331 cprintf("time goes backwards!"); 332 nextInBin->dump(); 333 return false; 334 } else if (nextInBin->when() == time && 335 nextInBin->priority() < priority) { 336 cprintf("priority inverted!"); 337 nextInBin->dump(); 338 return false; 339 } 340 341 if (map[reinterpret_cast<long>(nextInBin)]) { 342 cprintf("Node already seen"); 343 nextInBin->dump(); 344 return false; 345 } 346 map[reinterpret_cast<long>(nextInBin)] = true; 347 348 time = nextInBin->when(); 349 priority = nextInBin->priority(); 350 351 nextInBin = nextInBin->nextInBin; 352 } 353 354 nextBin = nextBin->nextBin; 355 } 356 357 return true; 358} 359 360Event* 361EventQueue::replaceHead(Event* s) 362{ 363 Event* t = head; 364 head = s; 365 return t; 366} 367 368void 369dumpMainQueue() 370{ 371 for (uint32_t i = 0; i < numMainEventQueues; ++i) { 372 mainEventQueue[i]->dump(); 373 } 374} 375 376 377const char * 378Event::description() const 379{ 380 return "generic"; 381} 382 383void 384Event::trace(const char *action) 385{ 386 // This DPRINTF is unconditional because calls to this function 387 // are protected by an 'if (DTRACE(Event))' in the inlined Event 388 // methods. 389 // 390 // This is just a default implementation for derived classes where 391 // it's not worth doing anything special. If you want to put a 392 // more informative message in the trace, override this method on 393 // the particular subclass where you have the information that 394 // needs to be printed. 395 DPRINTFN("%s event %s @ %d\n", description(), action, when()); 396} 397 398void 399Event::dump() const 400{ 401 cprintf("Event %s (%s)\n", name(), description()); 402 cprintf("Flags: %#x\n", flags); 403#ifdef EVENTQ_DEBUG 404 cprintf("Created: %d\n", whenCreated); 405#endif 406 if (scheduled()) { 407#ifdef EVENTQ_DEBUG 408 cprintf("Scheduled at %d\n", whenScheduled); 409#endif 410 cprintf("Scheduled for %d, priority %d\n", when(), _priority); 411 } else { 412 cprintf("Not Scheduled\n"); 413 } 414} 415 416EventQueue::EventQueue(const string &n) 417 : objName(n), head(NULL), _curTick(0) 418{ 419} 420 421void 422EventQueue::asyncInsert(Event *event) 423{ 424 async_queue_mutex.lock(); 425 async_queue.push_back(event); 426 async_queue_mutex.unlock(); 427} 428 429void 430EventQueue::handleAsyncInsertions() 431{ 432 assert(this == curEventQueue()); 433 async_queue_mutex.lock(); 434 435 while (!async_queue.empty()) { 436 insert(async_queue.front()); 437 async_queue.pop_front(); 438 } 439 440 async_queue_mutex.unlock(); 441}
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