eventq.cc revision 5774
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 "sim/core.hh" 44#include "sim/eventq.hh" 45 46using namespace std; 47 48// 49// Main Event Queue 50// 51// Events on this queue are processed at the *beginning* of each 52// cycle, before the pipeline simulation is performed. 53// 54EventQueue mainEventQueue("Main Event Queue"); 55 56#ifndef NDEBUG 57Counter Event::instanceCounter = 0; 58#endif 59 60Event::~Event() 61{ 62 assert(!scheduled()); 63} 64 65const std::string 66Event::name() const 67{ 68#ifndef NDEBUG 69 return csprintf("Event_%d", instance); 70#else 71 return csprintf("Event_%x", (uintptr_t)this); 72#endif 73} 74 75 76Event * 77Event::insertBefore(Event *event, Event *curr) 78{ 79 // Either way, event will be the top element in the 'in bin' list 80 // which is the pointer we need in order to look into the list, so 81 // we need to insert that into the bin list. 82 if (!curr || *event < *curr) { 83 // Insert the event before the current list since it is in the future. 84 event->nextBin = curr; 85 event->nextInBin = NULL; 86 } else { 87 // Since we're on the correct list, we need to point to the next list 88 event->nextBin = curr->nextBin; // curr->nextBin can now become stale 89 90 // Insert event at the top of the stack 91 event->nextInBin = curr; 92 } 93 94 return event; 95} 96 97void 98EventQueue::insert(Event *event) 99{ 100 // Deal with the head case 101 if (!head || *event <= *head) { 102 head = Event::insertBefore(event, head); 103 return; 104 } 105 106 // Figure out either which 'in bin' list we are on, or where a new list 107 // needs to be inserted 108 Event *prev = head; 109 Event *curr = head->nextBin; 110 while (curr && *curr < *event) { 111 prev = curr; 112 curr = curr->nextBin; 113 } 114 115 // Note: this operation may render all nextBin pointers on the 116 // prev 'in bin' list stale (except for the top one) 117 prev->nextBin = Event::insertBefore(event, curr); 118} 119 120Event * 121Event::removeItem(Event *event, Event *top) 122{ 123 Event *curr = top; 124 Event *next = top->nextInBin; 125 126 // if we removed the top item, we need to handle things specially 127 // and just remove the top item, fixing up the next bin pointer of 128 // the new top item 129 if (event == top) { 130 if (!next) 131 return top->nextBin; 132 next->nextBin = top->nextBin; 133 return next; 134 } 135 136 // Since we already checked the current element, we're going to 137 // keep checking event against the next element. 138 while (event != next) { 139 if (!next) 140 panic("event not found!"); 141 142 curr = next; 143 next = next->nextInBin; 144 } 145 146 // remove next from the 'in bin' list since it's what we're looking for 147 curr->nextInBin = next->nextInBin; 148 return top; 149} 150 151void 152EventQueue::remove(Event *event) 153{ 154 if (head == NULL) 155 panic("event not found!"); 156 157 // deal with an event on the head's 'in bin' list (event has the same 158 // time as the head) 159 if (*head == *event) { 160 head = Event::removeItem(event, head); 161 return; 162 } 163 164 // Find the 'in bin' list that this event belongs on 165 Event *prev = head; 166 Event *curr = head->nextBin; 167 while (curr && *curr < *event) { 168 prev = curr; 169 curr = curr->nextBin; 170 } 171 172 if (!curr || *curr != *event) 173 panic("event not found!"); 174 175 // curr points to the top item of the the correct 'in bin' list, when 176 // we remove an item, it returns the new top item (which may be 177 // unchanged) 178 prev->nextBin = Event::removeItem(event, curr); 179} 180 181Event * 182EventQueue::serviceOne() 183{ 184 Event *event = head; 185 Event *next = head->nextInBin; 186 event->flags.clear(Event::Scheduled); 187 188 if (next) { 189 // update the next bin pointer since it could be stale 190 next->nextBin = head->nextBin; 191 192 // pop the stack 193 head = next; 194 } else { 195 // this was the only element on the 'in bin' list, so get rid of 196 // the 'in bin' list and point to the next bin list 197 head = head->nextBin; 198 } 199 200 // handle action 201 if (!event->squashed()) { 202 event->process(); 203 if (event->isExitEvent()) { 204 assert(!event->flags.isSet(Event::AutoDelete)); // would be silly 205 return event; 206 } 207 } else { 208 event->flags.clear(Event::Squashed); 209 } 210 211 if (event->flags.isSet(Event::AutoDelete) && !event->scheduled()) 212 delete event; 213 214 return NULL; 215} 216 217void 218Event::serialize(std::ostream &os) 219{ 220 SERIALIZE_SCALAR(_when); 221 SERIALIZE_SCALAR(_priority); 222 short _flags = flags; 223 SERIALIZE_SCALAR(_flags); 224} 225 226void 227Event::unserialize(Checkpoint *cp, const string §ion) 228{ 229 if (scheduled()) 230 mainEventQueue.deschedule(this); 231 232 UNSERIALIZE_SCALAR(_when); 233 UNSERIALIZE_SCALAR(_priority); 234 235 // need to see if original event was in a scheduled, unsquashed 236 // state, but don't want to restore those flags in the current 237 // object itself (since they aren't immediately true) 238 short _flags; 239 UNSERIALIZE_SCALAR(_flags); 240 flags = _flags; 241 242 bool wasScheduled = flags.isSet(Scheduled) && !flags.isSet(Squashed); 243 flags.clear(Squashed | Scheduled); 244 245 if (wasScheduled) { 246 DPRINTF(Config, "rescheduling at %d\n", _when); 247 mainEventQueue.schedule(this, _when); 248 } 249} 250 251void 252EventQueue::serialize(ostream &os) 253{ 254 std::list<Event *> eventPtrs; 255 256 int numEvents = 0; 257 Event *nextBin = head; 258 while (nextBin) { 259 Event *nextInBin = nextBin; 260 261 while (nextInBin) { 262 if (nextInBin->flags.isSet(Event::AutoSerialize)) { 263 eventPtrs.push_back(nextInBin); 264 paramOut(os, csprintf("event%d", numEvents++), 265 nextInBin->name()); 266 } 267 nextInBin = nextInBin->nextInBin; 268 } 269 270 nextBin = nextBin->nextBin; 271 } 272 273 SERIALIZE_SCALAR(numEvents); 274 275 for (std::list<Event *>::iterator it = eventPtrs.begin(); 276 it != eventPtrs.end(); ++it) { 277 (*it)->nameOut(os); 278 (*it)->serialize(os); 279 } 280} 281 282void 283EventQueue::unserialize(Checkpoint *cp, const std::string §ion) 284{ 285 int numEvents; 286 UNSERIALIZE_SCALAR(numEvents); 287 288 std::string eventName; 289 for (int i = 0; i < numEvents; i++) { 290 // get the pointer value associated with the event 291 paramIn(cp, section, csprintf("event%d", i), eventName); 292 293 // create the event based on its pointer value 294 Serializable::create(cp, eventName); 295 } 296} 297 298void 299EventQueue::dump() const 300{ 301 cprintf("============================================================\n"); 302 cprintf("EventQueue Dump (cycle %d)\n", curTick); 303 cprintf("------------------------------------------------------------\n"); 304 305 if (empty()) 306 cprintf("<No Events>\n"); 307 else { 308 Event *nextBin = head; 309 while (nextBin) { 310 Event *nextInBin = nextBin; 311 while (nextInBin) { 312 nextInBin->dump(); 313 nextInBin = nextInBin->nextInBin; 314 } 315 316 nextBin = nextBin->nextBin; 317 } 318 } 319 320 cprintf("============================================================\n"); 321} 322 323bool 324EventQueue::debugVerify() const 325{ 326 m5::hash_map<long, bool> map; 327 328 Tick time = 0; 329 short priority = 0; 330 331 Event *nextBin = head; 332 while (nextBin) { 333 Event *nextInBin = nextBin; 334 while (nextInBin) { 335 if (nextInBin->when() < time) { 336 cprintf("time goes backwards!"); 337 nextInBin->dump(); 338 return false; 339 } else if (nextInBin->when() == time && 340 nextInBin->priority() < priority) { 341 cprintf("priority inverted!"); 342 nextInBin->dump(); 343 return false; 344 } 345 346 if (map[reinterpret_cast<long>(nextInBin)]) { 347 cprintf("Node already seen"); 348 nextInBin->dump(); 349 return false; 350 } 351 map[reinterpret_cast<long>(nextInBin)] = true; 352 353 time = nextInBin->when(); 354 priority = nextInBin->priority(); 355 356 nextInBin = nextInBin->nextInBin; 357 } 358 359 nextBin = nextBin->nextBin; 360 } 361 362 return true; 363} 364 365void 366dumpMainQueue() 367{ 368 mainEventQueue.dump(); 369} 370 371 372const char * 373Event::description() const 374{ 375 return "generic"; 376} 377 378void 379Event::trace(const char *action) 380{ 381 // This DPRINTF is unconditional because calls to this function 382 // are protected by an 'if (DTRACE(Event))' in the inlined Event 383 // methods. 384 // 385 // This is just a default implementation for derived classes where 386 // it's not worth doing anything special. If you want to put a 387 // more informative message in the trace, override this method on 388 // the particular subclass where you have the information that 389 // needs to be printed. 390 DPRINTFN("%s event %s @ %d\n", description(), action, when()); 391} 392 393void 394Event::dump() const 395{ 396 cprintf("Event %s (%s)\n", name(), description()); 397 cprintf("Flags: %#x\n", flags); 398#ifdef EVENTQ_DEBUG 399 cprintf("Created: %d\n", whenCreated); 400#endif 401 if (scheduled()) { 402#ifdef EVENTQ_DEBUG 403 cprintf("Scheduled at %d\n", whenScheduled); 404#endif 405 cprintf("Scheduled for %d, priority %d\n", when(), _priority); 406 } else { 407 cprintf("Not Scheduled\n"); 408 } 409} 410