scheduler.cc revision 13701:d84e5d2979a7
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/core/sc_main_fiber.hh" 37#include "systemc/ext/core/messages.hh" 38#include "systemc/ext/core/sc_main.hh" 39#include "systemc/ext/utils/sc_report.hh" 40#include "systemc/ext/utils/sc_report_handler.hh" 41#include "systemc/utils/report.hh" 42#include "systemc/utils/tracefile.hh" 43 44namespace sc_gem5 45{ 46 47Scheduler::Scheduler() : 48 eq(nullptr), readyEvent(this, false, ReadyPriority), 49 pauseEvent(this, false, PausePriority), 50 stopEvent(this, false, StopPriority), _throwUp(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 runUpdate(); 112 113 for (Process *p = initList.getNext(); p; p = initList.getNext()) { 114 p->popListNode(); 115 116 if (p->dontInitialize()) { 117 if (!p->hasStaticSensitivities() && !p->internal()) { 118 SC_REPORT_WARNING(sc_core::SC_ID_DISABLE_WILL_ORPHAN_PROCESS_, 119 p->name()); 120 } 121 } else { 122 p->ready(); 123 } 124 } 125 126 runDelta(); 127 128 for (auto ets: eventsToSchedule) 129 eq->schedule(ets.first, ets.second); 130 eventsToSchedule.clear(); 131 132 if (_started) { 133 if (!runToTime && starved()) 134 scheduleStarvationEvent(); 135 kernel->status(::sc_core::SC_RUNNING); 136 } 137 138 initDone = true; 139 140 status(StatusOther); 141 142 scheduleTimeAdvancesEvent(); 143} 144 145void 146Scheduler::reg(Process *p) 147{ 148 if (initDone) { 149 // If not marked as dontInitialize, mark as ready. 150 if (!p->dontInitialize()) 151 p->ready(); 152 } else { 153 // Otherwise, record that this process should be initialized once we 154 // get there. 155 initList.pushLast(p); 156 } 157} 158 159void 160Scheduler::yield() 161{ 162 // Pull a process from the active list. 163 _current = getNextReady(); 164 if (!_current) { 165 // There are no more processes, so return control to evaluate. 166 Fiber::primaryFiber()->run(); 167 } else { 168 _current->popListNode(); 169 _current->scheduled(false); 170 // Switch to whatever Fiber is supposed to run this process. All 171 // Fibers which aren't running should be parked at this line. 172 _current->fiber()->run(); 173 // If the current process needs to be manually started, start it. 174 if (_current && _current->needsStart()) { 175 _current->needsStart(false); 176 // If a process hasn't started yet, "resetting" it just starts it 177 // and signals its reset event. 178 if (_current->inReset()) 179 _current->resetEvent().notify(); 180 try { 181 _current->run(); 182 } catch (...) { 183 throwUp(); 184 } 185 } 186 } 187 if (_current && !_current->needsStart()) { 188 if (_current->excWrapper) { 189 auto ew = _current->excWrapper; 190 _current->excWrapper = nullptr; 191 ew->throw_it(); 192 } else if (_current->inReset()) { 193 _current->reset(false); 194 } 195 } 196} 197 198void 199Scheduler::ready(Process *p) 200{ 201 if (_stopNow) 202 return; 203 204 p->scheduled(true); 205 206 if (p->procKind() == ::sc_core::SC_METHOD_PROC_) 207 readyListMethods.pushLast(p); 208 else 209 readyListThreads.pushLast(p); 210 211 if (!inEvaluate()) 212 scheduleReadyEvent(); 213} 214 215void 216Scheduler::resume(Process *p) 217{ 218 if (initDone) 219 ready(p); 220 else 221 initList.pushLast(p); 222} 223 224bool 225listContains(ListNode *list, ListNode *target) 226{ 227 ListNode *n = list->nextListNode; 228 while (n != list) 229 if (n == target) 230 return true; 231 return false; 232} 233 234bool 235Scheduler::suspend(Process *p) 236{ 237 bool was_ready; 238 if (initDone) { 239 // After initialization, check if we're on a ready list. 240 was_ready = (p->nextListNode != nullptr); 241 p->popListNode(); 242 } else { 243 // Nothing is ready before init. 244 was_ready = false; 245 } 246 return was_ready; 247} 248 249void 250Scheduler::requestUpdate(Channel *c) 251{ 252 updateList.pushLast(c); 253 if (!inEvaluate()) 254 scheduleReadyEvent(); 255} 256 257void 258Scheduler::scheduleReadyEvent() 259{ 260 // Schedule the evaluate and update phases. 261 if (!readyEvent.scheduled()) { 262 schedule(&readyEvent); 263 if (starvationEvent.scheduled()) 264 deschedule(&starvationEvent); 265 } 266} 267 268void 269Scheduler::scheduleStarvationEvent() 270{ 271 if (!starvationEvent.scheduled()) { 272 schedule(&starvationEvent); 273 if (readyEvent.scheduled()) 274 deschedule(&readyEvent); 275 } 276} 277 278void 279Scheduler::runReady() 280{ 281 scheduleTimeAdvancesEvent(); 282 283 bool empty = readyListMethods.empty() && readyListThreads.empty(); 284 lastReadyTick = getCurTick(); 285 286 // The evaluation phase. 287 status(StatusEvaluate); 288 do { 289 yield(); 290 } while (getNextReady()); 291 _current = nullptr; 292 293 if (!empty) { 294 _numCycles++; 295 _changeStamp++; 296 } 297 298 if (_stopNow) { 299 status(StatusOther); 300 return; 301 } 302 303 runUpdate(); 304 if (!traceFiles.empty()) 305 trace(true); 306 runDelta(); 307 308 if (!runToTime && starved()) 309 scheduleStarvationEvent(); 310 311 if (runOnce) 312 schedulePause(); 313 314 status(StatusOther); 315} 316 317void 318Scheduler::runUpdate() 319{ 320 status(StatusUpdate); 321 322 try { 323 Channel *channel = updateList.getNext(); 324 while (channel) { 325 channel->popListNode(); 326 channel->update(); 327 channel = updateList.getNext(); 328 } 329 } catch (...) { 330 throwUp(); 331 } 332} 333 334void 335Scheduler::runDelta() 336{ 337 status(StatusDelta); 338 339 try { 340 while (!deltas.empty()) 341 deltas.back()->run(); 342 } catch (...) { 343 throwUp(); 344 } 345} 346 347void 348Scheduler::pause() 349{ 350 status(StatusPaused); 351 kernel->status(::sc_core::SC_PAUSED); 352 runOnce = false; 353 if (scMainFiber.called() && !scMainFiber.finished()) 354 scMainFiber.run(); 355} 356 357void 358Scheduler::stop() 359{ 360 status(StatusStopped); 361 kernel->stop(); 362 363 clear(); 364 365 runOnce = false; 366 if (scMainFiber.called() && !scMainFiber.finished()) 367 scMainFiber.run(); 368} 369 370void 371Scheduler::start(Tick max_tick, bool run_to_time) 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 (_throwUp) { 402 const ::sc_core::sc_report *to_throw = _throwUp; 403 _throwUp = 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::throwUp() 427{ 428 if (scMainFiber.called() && !scMainFiber.finished()) { 429 ::sc_core::sc_report report = reportifyException(); 430 _throwUp = &report; 431 status(StatusOther); 432 scMainFiber.run(); 433 } else { 434 reportHandlerProc(reportifyException(), 435 ::sc_core::sc_report_handler::get_catch_actions()); 436 } 437} 438 439void 440Scheduler::scheduleStop(bool finish_delta) 441{ 442 if (stopEvent.scheduled()) 443 return; 444 445 if (!finish_delta) { 446 _stopNow = true; 447 // If we're not supposed to finish the delta cycle, flush all 448 // pending activity. 449 clear(); 450 } 451 schedule(&stopEvent); 452} 453 454void 455Scheduler::trace(bool delta) 456{ 457 for (auto tf: traceFiles) 458 tf->trace(delta); 459} 460 461Scheduler scheduler; 462Process *getCurrentProcess() { return scheduler.current(); } 463 464namespace { 465 466void 467throwingReportHandler(const ::sc_core::sc_report &r, 468 const ::sc_core::sc_actions &) 469{ 470 throw r; 471} 472 473} // anonymous namespace 474 475const ::sc_core::sc_report 476reportifyException() 477{ 478 ::sc_core::sc_report_handler_proc old_handler = reportHandlerProc; 479 ::sc_core::sc_report_handler::set_handler(&throwingReportHandler); 480 481 try { 482 try { 483 // Rethrow the current exception so we can catch it and throw an 484 // sc_report instead if it's not a type we recognize/can handle. 485 throw; 486 } catch (const ::sc_core::sc_report &) { 487 // It's already a sc_report, so nothing to do. 488 throw; 489 } catch (const ::sc_core::sc_unwind_exception &) { 490 panic("Kill/reset exception escaped a Process::run()"); 491 } catch (const std::exception &e) { 492 SC_REPORT_ERROR( 493 sc_core::SC_ID_SIMULATION_UNCAUGHT_EXCEPTION_, e.what()); 494 } catch (const char *msg) { 495 SC_REPORT_ERROR( 496 sc_core::SC_ID_SIMULATION_UNCAUGHT_EXCEPTION_, msg); 497 } catch (...) { 498 SC_REPORT_ERROR( 499 sc_core::SC_ID_SIMULATION_UNCAUGHT_EXCEPTION_, 500 "UNKNOWN EXCEPTION"); 501 } 502 } catch (const ::sc_core::sc_report &r) { 503 ::sc_core::sc_report_handler::set_handler(old_handler); 504 return r; 505 } 506 panic("No exception thrown in reportifyException."); 507} 508 509} // namespace sc_gem5 510