scheduler.cc revision 12987
112953Sgabeblack@google.com/* 212953Sgabeblack@google.com * Copyright 2018 Google, Inc. 312953Sgabeblack@google.com * 412953Sgabeblack@google.com * Redistribution and use in source and binary forms, with or without 512953Sgabeblack@google.com * modification, are permitted provided that the following conditions are 612953Sgabeblack@google.com * met: redistributions of source code must retain the above copyright 712953Sgabeblack@google.com * notice, this list of conditions and the following disclaimer; 812953Sgabeblack@google.com * redistributions in binary form must reproduce the above copyright 912953Sgabeblack@google.com * notice, this list of conditions and the following disclaimer in the 1012953Sgabeblack@google.com * documentation and/or other materials provided with the distribution; 1112953Sgabeblack@google.com * neither the name of the copyright holders nor the names of its 1212953Sgabeblack@google.com * contributors may be used to endorse or promote products derived from 1312953Sgabeblack@google.com * this software without specific prior written permission. 1412953Sgabeblack@google.com * 1512953Sgabeblack@google.com * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 1612953Sgabeblack@google.com * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 1712953Sgabeblack@google.com * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 1812953Sgabeblack@google.com * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 1912953Sgabeblack@google.com * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 2012953Sgabeblack@google.com * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 2112953Sgabeblack@google.com * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 2212953Sgabeblack@google.com * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 2312953Sgabeblack@google.com * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 2412953Sgabeblack@google.com * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 2512953Sgabeblack@google.com * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 2612953Sgabeblack@google.com * 2712953Sgabeblack@google.com * Authors: Gabe Black 2812953Sgabeblack@google.com */ 2912953Sgabeblack@google.com 3012953Sgabeblack@google.com#include "systemc/core/scheduler.hh" 3112953Sgabeblack@google.com 3212953Sgabeblack@google.com#include "base/fiber.hh" 3312954Sgabeblack@google.com#include "base/logging.hh" 3412954Sgabeblack@google.com#include "sim/eventq.hh" 3512982Sgabeblack@google.com#include "systemc/core/kernel.hh" 3612982Sgabeblack@google.com#include "systemc/ext/core/sc_main.hh" 3712953Sgabeblack@google.com 3812953Sgabeblack@google.comnamespace sc_gem5 3912953Sgabeblack@google.com{ 4012953Sgabeblack@google.com 4112954Sgabeblack@google.comScheduler::Scheduler() : 4212962Sgabeblack@google.com eq(nullptr), readyEvent(this, false, ReadyPriority), 4312961Sgabeblack@google.com pauseEvent(this, false, PausePriority), 4412961Sgabeblack@google.com stopEvent(this, false, StopPriority), 4512987Sgabeblack@google.com scMain(nullptr), 4612987Sgabeblack@google.com starvationEvent(this, false, StarvationPriority), 4712987Sgabeblack@google.com _started(false), _paused(false), _stopped(false), 4812961Sgabeblack@google.com maxTickEvent(this, false, MaxTickPriority), 4912957Sgabeblack@google.com _numCycles(0), _current(nullptr), initReady(false) 5012954Sgabeblack@google.com{} 5112953Sgabeblack@google.com 5212953Sgabeblack@google.comvoid 5312957Sgabeblack@google.comScheduler::prepareForInit() 5412953Sgabeblack@google.com{ 5512957Sgabeblack@google.com for (Process *p = toFinalize.getNext(); p; p = toFinalize.getNext()) { 5612957Sgabeblack@google.com p->finalize(); 5712957Sgabeblack@google.com p->popListNode(); 5812957Sgabeblack@google.com } 5912957Sgabeblack@google.com 6012957Sgabeblack@google.com for (Process *p = initList.getNext(); p; p = initList.getNext()) { 6112957Sgabeblack@google.com p->finalize(); 6212959Sgabeblack@google.com p->ready(); 6312957Sgabeblack@google.com } 6412957Sgabeblack@google.com 6512985Sgabeblack@google.com for (auto ets: eventsToSchedule) 6612985Sgabeblack@google.com eq->schedule(ets.first, ets.second); 6712985Sgabeblack@google.com eventsToSchedule.clear(); 6812985Sgabeblack@google.com 6912961Sgabeblack@google.com if (_started) 7012961Sgabeblack@google.com eq->schedule(&maxTickEvent, maxTick); 7112961Sgabeblack@google.com 7212957Sgabeblack@google.com initReady = true; 7312957Sgabeblack@google.com} 7412957Sgabeblack@google.com 7512957Sgabeblack@google.comvoid 7612957Sgabeblack@google.comScheduler::reg(Process *p) 7712957Sgabeblack@google.com{ 7812957Sgabeblack@google.com if (initReady) { 7912957Sgabeblack@google.com // If we're past initialization, finalize static sensitivity. 8012957Sgabeblack@google.com p->finalize(); 8112957Sgabeblack@google.com // Mark the process as ready. 8212959Sgabeblack@google.com p->ready(); 8312957Sgabeblack@google.com } else { 8412957Sgabeblack@google.com // Otherwise, record that this process should be initialized once we 8512957Sgabeblack@google.com // get there. 8612957Sgabeblack@google.com initList.pushLast(p); 8712957Sgabeblack@google.com } 8812957Sgabeblack@google.com} 8912957Sgabeblack@google.com 9012957Sgabeblack@google.comvoid 9112957Sgabeblack@google.comScheduler::dontInitialize(Process *p) 9212957Sgabeblack@google.com{ 9312957Sgabeblack@google.com if (initReady) { 9412957Sgabeblack@google.com // Pop this process off of the ready list. 9512957Sgabeblack@google.com p->popListNode(); 9612957Sgabeblack@google.com } else { 9712957Sgabeblack@google.com // Push this process onto the list of processes which still need 9812957Sgabeblack@google.com // their static sensitivity to be finalized. That implicitly pops it 9912957Sgabeblack@google.com // off the list of processes to be initialized/marked ready. 10012957Sgabeblack@google.com toFinalize.pushLast(p); 10112957Sgabeblack@google.com } 10212953Sgabeblack@google.com} 10312953Sgabeblack@google.com 10412953Sgabeblack@google.comvoid 10512953Sgabeblack@google.comScheduler::yield() 10612953Sgabeblack@google.com{ 10712953Sgabeblack@google.com _current = readyList.getNext(); 10812953Sgabeblack@google.com if (!_current) { 10912953Sgabeblack@google.com // There are no more processes, so return control to evaluate. 11012953Sgabeblack@google.com Fiber::primaryFiber()->run(); 11112953Sgabeblack@google.com } else { 11212953Sgabeblack@google.com _current->popListNode(); 11312953Sgabeblack@google.com // Switch to whatever Fiber is supposed to run this process. All 11412953Sgabeblack@google.com // Fibers which aren't running should be parked at this line. 11512953Sgabeblack@google.com _current->fiber()->run(); 11612961Sgabeblack@google.com // If the current process needs to be manually started, start it. 11712961Sgabeblack@google.com if (_current && _current->needsStart()) 11812953Sgabeblack@google.com _current->run(); 11912953Sgabeblack@google.com } 12012953Sgabeblack@google.com} 12112953Sgabeblack@google.com 12212953Sgabeblack@google.comvoid 12312954Sgabeblack@google.comScheduler::ready(Process *p) 12412953Sgabeblack@google.com{ 12512954Sgabeblack@google.com // Clump methods together to minimize context switching. 12612954Sgabeblack@google.com if (p->procKind() == ::sc_core::SC_METHOD_PROC_) 12712954Sgabeblack@google.com readyList.pushFirst(p); 12812954Sgabeblack@google.com else 12912954Sgabeblack@google.com readyList.pushLast(p); 13012953Sgabeblack@google.com 13112954Sgabeblack@google.com scheduleReadyEvent(); 13212954Sgabeblack@google.com} 13312954Sgabeblack@google.com 13412954Sgabeblack@google.comvoid 13512954Sgabeblack@google.comScheduler::requestUpdate(Channel *c) 13612954Sgabeblack@google.com{ 13712954Sgabeblack@google.com updateList.pushLast(c); 13812954Sgabeblack@google.com scheduleReadyEvent(); 13912954Sgabeblack@google.com} 14012954Sgabeblack@google.com 14112954Sgabeblack@google.comvoid 14212954Sgabeblack@google.comScheduler::scheduleReadyEvent() 14312954Sgabeblack@google.com{ 14412954Sgabeblack@google.com // Schedule the evaluate and update phases. 14512954Sgabeblack@google.com if (!readyEvent.scheduled()) { 14612954Sgabeblack@google.com panic_if(!eq, "Need to schedule ready, but no event manager.\n"); 14712954Sgabeblack@google.com eq->schedule(&readyEvent, eq->getCurTick()); 14812987Sgabeblack@google.com if (starvationEvent.scheduled()) 14912987Sgabeblack@google.com eq->deschedule(&starvationEvent); 15012987Sgabeblack@google.com } 15112987Sgabeblack@google.com} 15212987Sgabeblack@google.com 15312987Sgabeblack@google.comvoid 15412987Sgabeblack@google.comScheduler::scheduleStarvationEvent() 15512987Sgabeblack@google.com{ 15612987Sgabeblack@google.com if (!starvationEvent.scheduled()) { 15712987Sgabeblack@google.com panic_if(!eq, "Need to schedule starvation event, " 15812987Sgabeblack@google.com "but no event manager.\n"); 15912987Sgabeblack@google.com eq->schedule(&starvationEvent, eq->getCurTick()); 16012987Sgabeblack@google.com if (readyEvent.scheduled()) 16112987Sgabeblack@google.com eq->deschedule(&readyEvent); 16212954Sgabeblack@google.com } 16312954Sgabeblack@google.com} 16412954Sgabeblack@google.com 16512954Sgabeblack@google.comvoid 16612954Sgabeblack@google.comScheduler::runReady() 16712954Sgabeblack@google.com{ 16812954Sgabeblack@google.com bool empty = readyList.empty(); 16912954Sgabeblack@google.com 17012954Sgabeblack@google.com // The evaluation phase. 17112953Sgabeblack@google.com do { 17212953Sgabeblack@google.com yield(); 17312953Sgabeblack@google.com } while (!readyList.empty()); 17412954Sgabeblack@google.com 17512954Sgabeblack@google.com if (!empty) 17612954Sgabeblack@google.com _numCycles++; 17712954Sgabeblack@google.com 17812954Sgabeblack@google.com // The update phase. 17912954Sgabeblack@google.com update(); 18012954Sgabeblack@google.com 18112987Sgabeblack@google.com if (starved() && !runToTime) 18212987Sgabeblack@google.com scheduleStarvationEvent(); 18312987Sgabeblack@google.com 18412954Sgabeblack@google.com // The delta phase will happen naturally through the event queue. 18512953Sgabeblack@google.com} 18612953Sgabeblack@google.com 18712953Sgabeblack@google.comvoid 18812953Sgabeblack@google.comScheduler::update() 18912953Sgabeblack@google.com{ 19012954Sgabeblack@google.com Channel *channel = updateList.getNext(); 19112954Sgabeblack@google.com while (channel) { 19212954Sgabeblack@google.com channel->popListNode(); 19312954Sgabeblack@google.com channel->update(); 19412954Sgabeblack@google.com channel = updateList.getNext(); 19512954Sgabeblack@google.com } 19612953Sgabeblack@google.com} 19712953Sgabeblack@google.com 19812961Sgabeblack@google.comvoid 19912961Sgabeblack@google.comScheduler::pause() 20012961Sgabeblack@google.com{ 20112961Sgabeblack@google.com _paused = true; 20212982Sgabeblack@google.com kernel->status(::sc_core::SC_PAUSED); 20312961Sgabeblack@google.com scMain->run(); 20412961Sgabeblack@google.com} 20512961Sgabeblack@google.com 20612961Sgabeblack@google.comvoid 20712961Sgabeblack@google.comScheduler::stop() 20812961Sgabeblack@google.com{ 20912961Sgabeblack@google.com _stopped = true; 21012982Sgabeblack@google.com kernel->stop(); 21112961Sgabeblack@google.com scMain->run(); 21212961Sgabeblack@google.com} 21312961Sgabeblack@google.com 21412961Sgabeblack@google.comvoid 21512961Sgabeblack@google.comScheduler::start(Tick max_tick, bool run_to_time) 21612961Sgabeblack@google.com{ 21712961Sgabeblack@google.com // We should be running from sc_main. Keep track of that Fiber to return 21812961Sgabeblack@google.com // to later. 21912961Sgabeblack@google.com scMain = Fiber::currentFiber(); 22012961Sgabeblack@google.com 22112961Sgabeblack@google.com _started = true; 22212961Sgabeblack@google.com _paused = false; 22312961Sgabeblack@google.com _stopped = false; 22412987Sgabeblack@google.com runToTime = run_to_time; 22512961Sgabeblack@google.com 22612961Sgabeblack@google.com maxTick = max_tick; 22712961Sgabeblack@google.com 22812987Sgabeblack@google.com if (starved() && !runToTime) 22912987Sgabeblack@google.com return; 23012987Sgabeblack@google.com 23112982Sgabeblack@google.com if (initReady) { 23212982Sgabeblack@google.com kernel->status(::sc_core::SC_RUNNING); 23312961Sgabeblack@google.com eq->schedule(&maxTickEvent, maxTick); 23412982Sgabeblack@google.com } 23512961Sgabeblack@google.com 23612961Sgabeblack@google.com // Return to gem5 to let it run events, etc. 23712961Sgabeblack@google.com Fiber::primaryFiber()->run(); 23812961Sgabeblack@google.com 23912961Sgabeblack@google.com if (pauseEvent.scheduled()) 24012961Sgabeblack@google.com eq->deschedule(&pauseEvent); 24112961Sgabeblack@google.com if (stopEvent.scheduled()) 24212961Sgabeblack@google.com eq->deschedule(&stopEvent); 24312961Sgabeblack@google.com if (maxTickEvent.scheduled()) 24412961Sgabeblack@google.com eq->deschedule(&maxTickEvent); 24512987Sgabeblack@google.com if (starvationEvent.scheduled()) 24612987Sgabeblack@google.com eq->deschedule(&starvationEvent); 24712961Sgabeblack@google.com} 24812961Sgabeblack@google.com 24912961Sgabeblack@google.comvoid 25012961Sgabeblack@google.comScheduler::schedulePause() 25112961Sgabeblack@google.com{ 25212961Sgabeblack@google.com if (pauseEvent.scheduled()) 25312961Sgabeblack@google.com return; 25412961Sgabeblack@google.com 25512961Sgabeblack@google.com eq->schedule(&pauseEvent, eq->getCurTick()); 25612961Sgabeblack@google.com} 25712961Sgabeblack@google.com 25812961Sgabeblack@google.comvoid 25912961Sgabeblack@google.comScheduler::scheduleStop(bool finish_delta) 26012961Sgabeblack@google.com{ 26112961Sgabeblack@google.com if (stopEvent.scheduled()) 26212961Sgabeblack@google.com return; 26312961Sgabeblack@google.com 26412961Sgabeblack@google.com if (!finish_delta) { 26512961Sgabeblack@google.com // If we're not supposed to finish the delta cycle, flush the list 26612961Sgabeblack@google.com // of ready processes and scheduled updates. 26712961Sgabeblack@google.com Process *p; 26812961Sgabeblack@google.com while ((p = readyList.getNext())) 26912961Sgabeblack@google.com p->popListNode(); 27012961Sgabeblack@google.com Channel *c; 27112961Sgabeblack@google.com while ((c = updateList.getNext())) 27212961Sgabeblack@google.com c->popListNode(); 27312961Sgabeblack@google.com } 27412961Sgabeblack@google.com eq->schedule(&stopEvent, eq->getCurTick()); 27512961Sgabeblack@google.com} 27612961Sgabeblack@google.com 27712953Sgabeblack@google.comScheduler scheduler; 27812953Sgabeblack@google.com 27912953Sgabeblack@google.com} // namespace sc_gem5 280