eventq.cc revision 9356
1/* 2 * Copyright (c) 2000-2005 The Regents of The University of Michigan 3 * Copyright (c) 2008 The Hewlett-Packard Development Company 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions are 8 * met: redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer; 10 * redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution; 13 * neither the name of the copyright holders nor the names of its 14 * contributors may be used to endorse or promote products derived from 15 * this software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 18 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 20 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 21 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 22 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 23 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 * 29 * Authors: Steve Reinhardt 30 * Nathan Binkert 31 * Steve Raasch 32 */ 33 34#include <cassert> 35#include <iostream> 36#include <string> 37#include <vector> 38 39#include "base/hashmap.hh" 40#include "base/misc.hh" 41#include "base/trace.hh" 42#include "cpu/smt.hh" 43#include "debug/Config.hh" 44#include "sim/core.hh" 45#include "sim/eventq_impl.hh" 46 47using namespace std; 48 49// 50// Main Event Queue 51// 52// Events on this queue are processed at the *beginning* of each 53// cycle, before the pipeline simulation is performed. 54// 55EventQueue mainEventQueue("Main Event Queue"); 56 57#ifndef NDEBUG 58Counter Event::instanceCounter = 0; 59#endif 60 61Event::~Event() 62{ 63 assert(!scheduled()); 64 flags = 0; 65} 66 67const std::string 68Event::name() const 69{ 70#ifndef NDEBUG 71 return csprintf("Event_%d", instance); 72#else 73 return csprintf("Event_%x", (uintptr_t)this); 74#endif 75} 76 77 78Event * 79Event::insertBefore(Event *event, Event *curr) 80{ 81 // Either way, event will be the top element in the 'in bin' list 82 // which is the pointer we need in order to look into the list, so 83 // we need to insert that into the bin list. 84 if (!curr || *event < *curr) { 85 // Insert the event before the current list since it is in the future. 86 event->nextBin = curr; 87 event->nextInBin = NULL; 88 } else { 89 // Since we're on the correct list, we need to point to the next list 90 event->nextBin = curr->nextBin; // curr->nextBin can now become stale 91 92 // Insert event at the top of the stack 93 event->nextInBin = curr; 94 } 95 96 return event; 97} 98 99void 100EventQueue::insert(Event *event) 101{ 102 // Deal with the head case 103 if (!head || *event <= *head) { 104 head = Event::insertBefore(event, head); 105 return; 106 } 107 108 // Figure out either which 'in bin' list we are on, or where a new list 109 // needs to be inserted 110 Event *prev = head; 111 Event *curr = head->nextBin; 112 while (curr && *curr < *event) { 113 prev = curr; 114 curr = curr->nextBin; 115 } 116 117 // Note: this operation may render all nextBin pointers on the 118 // prev 'in bin' list stale (except for the top one) 119 prev->nextBin = Event::insertBefore(event, curr); 120} 121 122Event * 123Event::removeItem(Event *event, Event *top) 124{ 125 Event *curr = top; 126 Event *next = top->nextInBin; 127 128 // if we removed the top item, we need to handle things specially 129 // and just remove the top item, fixing up the next bin pointer of 130 // the new top item 131 if (event == top) { 132 if (!next) 133 return top->nextBin; 134 next->nextBin = top->nextBin; 135 return next; 136 } 137 138 // Since we already checked the current element, we're going to 139 // keep checking event against the next element. 140 while (event != next) { 141 if (!next) 142 panic("event not found!"); 143 144 curr = next; 145 next = next->nextInBin; 146 } 147 148 // remove next from the 'in bin' list since it's what we're looking for 149 curr->nextInBin = next->nextInBin; 150 return top; 151} 152 153void 154EventQueue::remove(Event *event) 155{ 156 if (head == NULL) 157 panic("event not found!"); 158 159 // deal with an event on the head's 'in bin' list (event has the same 160 // time as the head) 161 if (*head == *event) { 162 head = Event::removeItem(event, head); 163 return; 164 } 165 166 // Find the 'in bin' list that this event belongs on 167 Event *prev = head; 168 Event *curr = head->nextBin; 169 while (curr && *curr < *event) { 170 prev = curr; 171 curr = curr->nextBin; 172 } 173 174 if (!curr || *curr != *event) 175 panic("event not found!"); 176 177 // curr points to the top item of the the correct 'in bin' list, when 178 // we remove an item, it returns the new top item (which may be 179 // unchanged) 180 prev->nextBin = Event::removeItem(event, curr); 181} 182 183Event * 184EventQueue::serviceOne() 185{ 186 Event *event = head; 187 Event *next = head->nextInBin; 188 event->flags.clear(Event::Scheduled); 189 190 if (next) { 191 // update the next bin pointer since it could be stale 192 next->nextBin = head->nextBin; 193 194 // pop the stack 195 head = next; 196 } else { 197 // this was the only element on the 'in bin' list, so get rid of 198 // the 'in bin' list and point to the next bin list 199 head = head->nextBin; 200 } 201 202 // handle action 203 if (!event->squashed()) { 204 // forward current cycle to the time when this event occurs. 205 setCurTick(event->when()); 206 207 event->process(); 208 if (event->isExitEvent()) { 209 assert(!event->flags.isSet(Event::AutoDelete) || 210 !event->flags.isSet(Event::IsMainQueue)); // would be silly 211 return event; 212 } 213 } else { 214 event->flags.clear(Event::Squashed); 215 } 216 217 if (event->flags.isSet(Event::AutoDelete) && !event->scheduled()) 218 delete event; 219 220 return NULL; 221} 222 223void 224Event::serialize(std::ostream &os) 225{ 226 SERIALIZE_SCALAR(_when); 227 SERIALIZE_SCALAR(_priority); 228 short _flags = flags; 229 SERIALIZE_SCALAR(_flags); 230} 231 232void 233Event::unserialize(Checkpoint *cp, const string §ion) 234{ 235 if (scheduled()) 236 mainEventQueue.deschedule(this); 237 238 UNSERIALIZE_SCALAR(_when); 239 UNSERIALIZE_SCALAR(_priority); 240 241 short _flags; 242 UNSERIALIZE_SCALAR(_flags); 243 244 // Old checkpoints had no concept of the Initialized flag 245 // so restoring from old checkpoints always fail. 246 // Events are initialized on construction but original code 247 // "flags = _flags" would just overwrite the initialization. 248 // So, read in the checkpoint flags, but then set the Initialized 249 // flag on top of it in order to avoid failures. 250 assert(initialized()); 251 flags = _flags; 252 flags.set(Initialized); 253 254 // need to see if original event was in a scheduled, unsquashed 255 // state, but don't want to restore those flags in the current 256 // object itself (since they aren't immediately true) 257 bool wasScheduled = flags.isSet(Scheduled) && !flags.isSet(Squashed); 258 flags.clear(Squashed | Scheduled); 259 260 if (wasScheduled) { 261 DPRINTF(Config, "rescheduling at %d\n", _when); 262 mainEventQueue.schedule(this, _when); 263 } 264} 265 266void 267EventQueue::serialize(ostream &os) 268{ 269 std::list<Event *> eventPtrs; 270 271 int numEvents = 0; 272 Event *nextBin = head; 273 while (nextBin) { 274 Event *nextInBin = nextBin; 275 276 while (nextInBin) { 277 if (nextInBin->flags.isSet(Event::AutoSerialize)) { 278 eventPtrs.push_back(nextInBin); 279 paramOut(os, csprintf("event%d", numEvents++), 280 nextInBin->name()); 281 } 282 nextInBin = nextInBin->nextInBin; 283 } 284 285 nextBin = nextBin->nextBin; 286 } 287 288 SERIALIZE_SCALAR(numEvents); 289 290 for (std::list<Event *>::iterator it = eventPtrs.begin(); 291 it != eventPtrs.end(); ++it) { 292 (*it)->nameOut(os); 293 (*it)->serialize(os); 294 } 295} 296 297void 298EventQueue::unserialize(Checkpoint *cp, const std::string §ion) 299{ 300 int numEvents; 301 UNSERIALIZE_SCALAR(numEvents); 302 303 std::string eventName; 304 for (int i = 0; i < numEvents; i++) { 305 // get the pointer value associated with the event 306 paramIn(cp, section, csprintf("event%d", i), eventName); 307 308 // create the event based on its pointer value 309 Serializable::create(cp, eventName); 310 } 311} 312 313void 314EventQueue::dump() const 315{ 316 cprintf("============================================================\n"); 317 cprintf("EventQueue Dump (cycle %d)\n", curTick()); 318 cprintf("------------------------------------------------------------\n"); 319 320 if (empty()) 321 cprintf("<No Events>\n"); 322 else { 323 Event *nextBin = head; 324 while (nextBin) { 325 Event *nextInBin = nextBin; 326 while (nextInBin) { 327 nextInBin->dump(); 328 nextInBin = nextInBin->nextInBin; 329 } 330 331 nextBin = nextBin->nextBin; 332 } 333 } 334 335 cprintf("============================================================\n"); 336} 337 338bool 339EventQueue::debugVerify() const 340{ 341 m5::hash_map<long, bool> map; 342 343 Tick time = 0; 344 short priority = 0; 345 346 Event *nextBin = head; 347 while (nextBin) { 348 Event *nextInBin = nextBin; 349 while (nextInBin) { 350 if (nextInBin->when() < time) { 351 cprintf("time goes backwards!"); 352 nextInBin->dump(); 353 return false; 354 } else if (nextInBin->when() == time && 355 nextInBin->priority() < priority) { 356 cprintf("priority inverted!"); 357 nextInBin->dump(); 358 return false; 359 } 360 361 if (map[reinterpret_cast<long>(nextInBin)]) { 362 cprintf("Node already seen"); 363 nextInBin->dump(); 364 return false; 365 } 366 map[reinterpret_cast<long>(nextInBin)] = true; 367 368 time = nextInBin->when(); 369 priority = nextInBin->priority(); 370 371 nextInBin = nextInBin->nextInBin; 372 } 373 374 nextBin = nextBin->nextBin; 375 } 376 377 return true; 378} 379 380Event* 381EventQueue::replaceHead(Event* s) 382{ 383 Event* t = head; 384 head = s; 385 return t; 386} 387 388void 389dumpMainQueue() 390{ 391 mainEventQueue.dump(); 392} 393 394 395const char * 396Event::description() const 397{ 398 return "generic"; 399} 400 401void 402Event::trace(const char *action) 403{ 404 // This DPRINTF is unconditional because calls to this function 405 // are protected by an 'if (DTRACE(Event))' in the inlined Event 406 // methods. 407 // 408 // This is just a default implementation for derived classes where 409 // it's not worth doing anything special. If you want to put a 410 // more informative message in the trace, override this method on 411 // the particular subclass where you have the information that 412 // needs to be printed. 413 DPRINTFN("%s event %s @ %d\n", description(), action, when()); 414} 415 416void 417Event::dump() const 418{ 419 cprintf("Event %s (%s)\n", name(), description()); 420 cprintf("Flags: %#x\n", flags); 421#ifdef EVENTQ_DEBUG 422 cprintf("Created: %d\n", whenCreated); 423#endif 424 if (scheduled()) { 425#ifdef EVENTQ_DEBUG 426 cprintf("Scheduled at %d\n", whenScheduled); 427#endif 428 cprintf("Scheduled for %d, priority %d\n", when(), _priority); 429 } else { 430 cprintf("Not Scheduled\n"); 431 } 432} 433 434EventQueue::EventQueue(const string &n) 435 : objName(n), head(NULL), _curTick(0) 436{} 437