scheduler.cc revision 13317:36c574a4036e
1/* 2 * Copyright 2018 Google, Inc. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are 6 * met: redistributions of source code must retain the above copyright 7 * notice, this list of conditions and the following disclaimer; 8 * redistributions in binary form must reproduce the above copyright 9 * notice, this list of conditions and the following disclaimer in the 10 * documentation and/or other materials provided with the distribution; 11 * neither the name of the copyright holders nor the names of its 12 * contributors may be used to endorse or promote products derived from 13 * this software without specific prior written permission. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 18 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 19 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 21 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 25 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 * 27 * Authors: Gabe Black 28 */ 29 30#include "systemc/core/scheduler.hh" 31 32#include "base/fiber.hh" 33#include "base/logging.hh" 34#include "sim/eventq.hh" 35#include "systemc/core/kernel.hh" 36#include "systemc/ext/core/messages.hh" 37#include "systemc/ext/core/sc_main.hh" 38#include "systemc/ext/utils/sc_report.hh" 39#include "systemc/ext/utils/sc_report_handler.hh" 40#include "systemc/utils/report.hh" 41#include "systemc/utils/tracefile.hh" 42 43namespace sc_gem5 44{ 45 46Scheduler::Scheduler() : 47 eq(nullptr), readyEvent(this, false, ReadyPriority), 48 pauseEvent(this, false, PausePriority), 49 stopEvent(this, false, StopPriority), 50 scMain(nullptr), _throwToScMain(nullptr), 51 starvationEvent(this, false, StarvationPriority), 52 _elaborationDone(false), _started(false), _stopNow(false), 53 _status(StatusOther), maxTickEvent(this, false, MaxTickPriority), 54 timeAdvancesEvent(this, false, TimeAdvancesPriority), _numCycles(0), 55 _changeStamp(0), _current(nullptr), initDone(false), runOnce(false) 56{} 57 58Scheduler::~Scheduler() 59{ 60 // Clear out everything that belongs to us to make sure nobody tries to 61 // clear themselves out after the scheduler goes away. 62 clear(); 63} 64 65void 66Scheduler::clear() 67{ 68 // Delta notifications. 69 while (!deltas.empty()) 70 deltas.front()->deschedule(); 71 72 // Timed notifications. 73 for (auto &tsp: timeSlots) { 74 TimeSlot *&ts = tsp.second; 75 while (!ts->events.empty()) 76 ts->events.front()->deschedule(); 77 deschedule(ts); 78 } 79 timeSlots.clear(); 80 81 // gem5 events. 82 if (readyEvent.scheduled()) 83 deschedule(&readyEvent); 84 if (pauseEvent.scheduled()) 85 deschedule(&pauseEvent); 86 if (stopEvent.scheduled()) 87 deschedule(&stopEvent); 88 if (starvationEvent.scheduled()) 89 deschedule(&starvationEvent); 90 if (maxTickEvent.scheduled()) 91 deschedule(&maxTickEvent); 92 if (timeAdvancesEvent.scheduled()) 93 deschedule(&timeAdvancesEvent); 94 95 Process *p; 96 while ((p = initList.getNext())) 97 p->popListNode(); 98 while ((p = readyListMethods.getNext())) 99 p->popListNode(); 100 while ((p = readyListThreads.getNext())) 101 p->popListNode(); 102 103 Channel *c; 104 while ((c = updateList.getNext())) 105 c->popListNode(); 106} 107 108void 109Scheduler::initPhase() 110{ 111 for (Process *p = initList.getNext(); p; p = initList.getNext()) { 112 p->popListNode(); 113 114 if (p->dontInitialize()) { 115 if (!p->hasStaticSensitivities() && !p->internal()) { 116 SC_REPORT_WARNING(sc_core::SC_ID_DISABLE_WILL_ORPHAN_PROCESS_, 117 p->name()); 118 } 119 } else { 120 p->ready(); 121 } 122 } 123 124 runUpdate(); 125 runDelta(); 126 127 for (auto ets: eventsToSchedule) 128 eq->schedule(ets.first, ets.second); 129 eventsToSchedule.clear(); 130 131 if (_started) { 132 if (!runToTime && starved()) 133 scheduleStarvationEvent(); 134 kernel->status(::sc_core::SC_RUNNING); 135 } 136 137 initDone = true; 138 139 status(StatusOther); 140 141 scheduleTimeAdvancesEvent(); 142} 143 144void 145Scheduler::reg(Process *p) 146{ 147 if (initDone) { 148 // If not marked as dontInitialize, mark as ready. 149 if (!p->dontInitialize()) 150 p->ready(); 151 } else { 152 // Otherwise, record that this process should be initialized once we 153 // get there. 154 initList.pushLast(p); 155 } 156} 157 158void 159Scheduler::yield() 160{ 161 // Pull a process from the active list. 162 _current = getNextReady(); 163 if (!_current) { 164 // There are no more processes, so return control to evaluate. 165 Fiber::primaryFiber()->run(); 166 } else { 167 _current->popListNode(); 168 // Switch to whatever Fiber is supposed to run this process. All 169 // Fibers which aren't running should be parked at this line. 170 _current->fiber()->run(); 171 // If the current process needs to be manually started, start it. 172 if (_current && _current->needsStart()) { 173 _current->needsStart(false); 174 // If a process hasn't started yet, "resetting" it just starts it 175 // and signals its reset event. 176 if (_current->inReset()) 177 _current->resetEvent().notify(); 178 try { 179 _current->run(); 180 } catch (...) { 181 throwToScMain(); 182 } 183 } 184 } 185 if (_current && !_current->needsStart()) { 186 if (_current->excWrapper) { 187 auto ew = _current->excWrapper; 188 _current->excWrapper = nullptr; 189 ew->throw_it(); 190 } else if (_current->inReset()) { 191 _current->reset(false); 192 } 193 } 194} 195 196void 197Scheduler::ready(Process *p) 198{ 199 if (_stopNow) 200 return; 201 202 if (p->procKind() == ::sc_core::SC_METHOD_PROC_) 203 readyListMethods.pushLast(p); 204 else 205 readyListThreads.pushLast(p); 206 207 if (!inEvaluate()) 208 scheduleReadyEvent(); 209} 210 211void 212Scheduler::resume(Process *p) 213{ 214 if (initDone) 215 ready(p); 216 else 217 initList.pushLast(p); 218} 219 220bool 221listContains(ListNode *list, ListNode *target) 222{ 223 ListNode *n = list->nextListNode; 224 while (n != list) 225 if (n == target) 226 return true; 227 return false; 228} 229 230bool 231Scheduler::suspend(Process *p) 232{ 233 bool was_ready; 234 if (initDone) { 235 // After initialization, check if we're on a ready list. 236 was_ready = (p->nextListNode != nullptr); 237 p->popListNode(); 238 } else { 239 // Nothing is ready before init. 240 was_ready = false; 241 } 242 return was_ready; 243} 244 245void 246Scheduler::requestUpdate(Channel *c) 247{ 248 updateList.pushLast(c); 249 if (!inEvaluate()) 250 scheduleReadyEvent(); 251} 252 253void 254Scheduler::scheduleReadyEvent() 255{ 256 // Schedule the evaluate and update phases. 257 if (!readyEvent.scheduled()) { 258 schedule(&readyEvent); 259 if (starvationEvent.scheduled()) 260 deschedule(&starvationEvent); 261 } 262} 263 264void 265Scheduler::scheduleStarvationEvent() 266{ 267 if (!starvationEvent.scheduled()) { 268 schedule(&starvationEvent); 269 if (readyEvent.scheduled()) 270 deschedule(&readyEvent); 271 } 272} 273 274void 275Scheduler::runReady() 276{ 277 scheduleTimeAdvancesEvent(); 278 279 bool empty = readyListMethods.empty() && readyListThreads.empty(); 280 lastReadyTick = getCurTick(); 281 282 // The evaluation phase. 283 status(StatusEvaluate); 284 do { 285 yield(); 286 } while (getNextReady()); 287 _current = nullptr; 288 289 if (!empty) { 290 _numCycles++; 291 _changeStamp++; 292 } 293 294 if (_stopNow) { 295 status(StatusOther); 296 return; 297 } 298 299 runUpdate(); 300 if (!traceFiles.empty()) 301 trace(true); 302 runDelta(); 303 304 if (!runToTime && starved()) 305 scheduleStarvationEvent(); 306 307 if (runOnce) 308 schedulePause(); 309 310 status(StatusOther); 311} 312 313void 314Scheduler::runUpdate() 315{ 316 status(StatusUpdate); 317 318 try { 319 Channel *channel = updateList.getNext(); 320 while (channel) { 321 channel->popListNode(); 322 channel->update(); 323 channel = updateList.getNext(); 324 } 325 } catch (...) { 326 throwToScMain(); 327 } 328} 329 330void 331Scheduler::runDelta() 332{ 333 status(StatusDelta); 334 335 try { 336 while (!deltas.empty()) 337 deltas.back()->run(); 338 } catch (...) { 339 throwToScMain(); 340 } 341} 342 343void 344Scheduler::pause() 345{ 346 status(StatusPaused); 347 kernel->status(::sc_core::SC_PAUSED); 348 runOnce = false; 349 if (scMain && !scMain->finished()) 350 scMain->run(); 351} 352 353void 354Scheduler::stop() 355{ 356 status(StatusStopped); 357 kernel->stop(); 358 359 clear(); 360 361 runOnce = false; 362 if (scMain && !scMain->finished()) 363 scMain->run(); 364} 365 366void 367Scheduler::start(Tick max_tick, bool run_to_time) 368{ 369 // We should be running from sc_main. Keep track of that Fiber to return 370 // to later. 371 scMain = Fiber::currentFiber(); 372 373 _started = true; 374 status(StatusOther); 375 runToTime = run_to_time; 376 377 maxTick = max_tick; 378 lastReadyTick = getCurTick(); 379 380 if (initDone) { 381 if (!runToTime && starved()) 382 scheduleStarvationEvent(); 383 kernel->status(::sc_core::SC_RUNNING); 384 } 385 386 schedule(&maxTickEvent, maxTick); 387 scheduleTimeAdvancesEvent(); 388 389 // Return to gem5 to let it run events, etc. 390 Fiber::primaryFiber()->run(); 391 392 if (pauseEvent.scheduled()) 393 deschedule(&pauseEvent); 394 if (stopEvent.scheduled()) 395 deschedule(&stopEvent); 396 if (maxTickEvent.scheduled()) 397 deschedule(&maxTickEvent); 398 if (starvationEvent.scheduled()) 399 deschedule(&starvationEvent); 400 401 if (_throwToScMain) { 402 const ::sc_core::sc_report *to_throw = _throwToScMain; 403 _throwToScMain = nullptr; 404 throw *to_throw; 405 } 406} 407 408void 409Scheduler::oneCycle() 410{ 411 runOnce = true; 412 scheduleReadyEvent(); 413 start(::MaxTick, false); 414} 415 416void 417Scheduler::schedulePause() 418{ 419 if (pauseEvent.scheduled()) 420 return; 421 422 schedule(&pauseEvent); 423} 424 425void 426Scheduler::throwToScMain() 427{ 428 ::sc_core::sc_report report = reportifyException(); 429 _throwToScMain = &report; 430 status(StatusOther); 431 scMain->run(); 432} 433 434void 435Scheduler::scheduleStop(bool finish_delta) 436{ 437 if (stopEvent.scheduled()) 438 return; 439 440 if (!finish_delta) { 441 _stopNow = true; 442 // If we're not supposed to finish the delta cycle, flush all 443 // pending activity. 444 clear(); 445 } 446 schedule(&stopEvent); 447} 448 449void 450Scheduler::trace(bool delta) 451{ 452 for (auto tf: traceFiles) 453 tf->trace(delta); 454} 455 456Scheduler scheduler; 457 458namespace { 459 460void 461throwingReportHandler(const ::sc_core::sc_report &r, 462 const ::sc_core::sc_actions &) 463{ 464 throw r; 465} 466 467} // anonymous namespace 468 469const ::sc_core::sc_report 470reportifyException() 471{ 472 ::sc_core::sc_report_handler_proc old_handler = reportHandlerProc; 473 ::sc_core::sc_report_handler::set_handler(&throwingReportHandler); 474 475 try { 476 try { 477 // Rethrow the current exception so we can catch it and throw an 478 // sc_report instead if it's not a type we recognize/can handle. 479 throw; 480 } catch (const ::sc_core::sc_report &) { 481 // It's already a sc_report, so nothing to do. 482 throw; 483 } catch (const ::sc_core::sc_unwind_exception &) { 484 panic("Kill/reset exception escaped a Process::run()"); 485 } catch (const std::exception &e) { 486 SC_REPORT_ERROR( 487 sc_core::SC_ID_SIMULATION_UNCAUGHT_EXCEPTION_, e.what()); 488 } catch (const char *msg) { 489 SC_REPORT_ERROR( 490 sc_core::SC_ID_SIMULATION_UNCAUGHT_EXCEPTION_, msg); 491 } catch (...) { 492 SC_REPORT_ERROR( 493 sc_core::SC_ID_SIMULATION_UNCAUGHT_EXCEPTION_, 494 "UNKNOWN EXCEPTION"); 495 } 496 } catch (const ::sc_core::sc_report &r) { 497 ::sc_core::sc_report_handler::set_handler(old_handler); 498 return r; 499 } 500 panic("No exception thrown in reportifyException."); 501} 502 503} // namespace sc_gem5 504