scheduler.cc revision 13049
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(); 6212996Sgabeblack@google.com p->popListNode(); 6312959Sgabeblack@google.com p->ready(); 6412957Sgabeblack@google.com } 6512957Sgabeblack@google.com 6612985Sgabeblack@google.com for (auto ets: eventsToSchedule) 6712985Sgabeblack@google.com eq->schedule(ets.first, ets.second); 6812985Sgabeblack@google.com eventsToSchedule.clear(); 6912985Sgabeblack@google.com 7012961Sgabeblack@google.com if (_started) 7112961Sgabeblack@google.com eq->schedule(&maxTickEvent, maxTick); 7212961Sgabeblack@google.com 7312957Sgabeblack@google.com initReady = true; 7412957Sgabeblack@google.com} 7512957Sgabeblack@google.com 7612957Sgabeblack@google.comvoid 7712957Sgabeblack@google.comScheduler::reg(Process *p) 7812957Sgabeblack@google.com{ 7912957Sgabeblack@google.com if (initReady) { 8012957Sgabeblack@google.com // If we're past initialization, finalize static sensitivity. 8112957Sgabeblack@google.com p->finalize(); 8212957Sgabeblack@google.com // Mark the process as ready. 8312959Sgabeblack@google.com p->ready(); 8412957Sgabeblack@google.com } else { 8512957Sgabeblack@google.com // Otherwise, record that this process should be initialized once we 8612957Sgabeblack@google.com // get there. 8712957Sgabeblack@google.com initList.pushLast(p); 8812957Sgabeblack@google.com } 8912957Sgabeblack@google.com} 9012957Sgabeblack@google.com 9112957Sgabeblack@google.comvoid 9212957Sgabeblack@google.comScheduler::dontInitialize(Process *p) 9312957Sgabeblack@google.com{ 9412957Sgabeblack@google.com if (initReady) { 9512957Sgabeblack@google.com // Pop this process off of the ready list. 9612957Sgabeblack@google.com p->popListNode(); 9712957Sgabeblack@google.com } else { 9812957Sgabeblack@google.com // Push this process onto the list of processes which still need 9912957Sgabeblack@google.com // their static sensitivity to be finalized. That implicitly pops it 10012957Sgabeblack@google.com // off the list of processes to be initialized/marked ready. 10112957Sgabeblack@google.com toFinalize.pushLast(p); 10212957Sgabeblack@google.com } 10312953Sgabeblack@google.com} 10412953Sgabeblack@google.com 10512953Sgabeblack@google.comvoid 10612953Sgabeblack@google.comScheduler::yield() 10712953Sgabeblack@google.com{ 10812953Sgabeblack@google.com _current = readyList.getNext(); 10912953Sgabeblack@google.com if (!_current) { 11012953Sgabeblack@google.com // There are no more processes, so return control to evaluate. 11112953Sgabeblack@google.com Fiber::primaryFiber()->run(); 11212953Sgabeblack@google.com } else { 11312953Sgabeblack@google.com _current->popListNode(); 11412953Sgabeblack@google.com // Switch to whatever Fiber is supposed to run this process. All 11512953Sgabeblack@google.com // Fibers which aren't running should be parked at this line. 11612953Sgabeblack@google.com _current->fiber()->run(); 11712961Sgabeblack@google.com // If the current process needs to be manually started, start it. 11812961Sgabeblack@google.com if (_current && _current->needsStart()) 11912953Sgabeblack@google.com _current->run(); 12012953Sgabeblack@google.com } 12112995Sgabeblack@google.com if (_current && _current->excWrapper) { 12212995Sgabeblack@google.com // Make sure this isn't a method process. 12312995Sgabeblack@google.com assert(!_current->needsStart()); 12412995Sgabeblack@google.com auto ew = _current->excWrapper; 12512995Sgabeblack@google.com _current->excWrapper = nullptr; 12612995Sgabeblack@google.com ew->throw_it(); 12712995Sgabeblack@google.com } 12812953Sgabeblack@google.com} 12912953Sgabeblack@google.com 13012953Sgabeblack@google.comvoid 13112954Sgabeblack@google.comScheduler::ready(Process *p) 13212953Sgabeblack@google.com{ 13312954Sgabeblack@google.com // Clump methods together to minimize context switching. 13412954Sgabeblack@google.com if (p->procKind() == ::sc_core::SC_METHOD_PROC_) 13512954Sgabeblack@google.com readyList.pushFirst(p); 13612954Sgabeblack@google.com else 13712954Sgabeblack@google.com readyList.pushLast(p); 13812953Sgabeblack@google.com 13912954Sgabeblack@google.com scheduleReadyEvent(); 14012954Sgabeblack@google.com} 14112954Sgabeblack@google.com 14212954Sgabeblack@google.comvoid 14312954Sgabeblack@google.comScheduler::requestUpdate(Channel *c) 14412954Sgabeblack@google.com{ 14512954Sgabeblack@google.com updateList.pushLast(c); 14613047Sgabeblack@google.com if (eq) 14713047Sgabeblack@google.com scheduleReadyEvent(); 14812954Sgabeblack@google.com} 14912954Sgabeblack@google.com 15012954Sgabeblack@google.comvoid 15112954Sgabeblack@google.comScheduler::scheduleReadyEvent() 15212954Sgabeblack@google.com{ 15312954Sgabeblack@google.com // Schedule the evaluate and update phases. 15412954Sgabeblack@google.com if (!readyEvent.scheduled()) { 15512954Sgabeblack@google.com panic_if(!eq, "Need to schedule ready, but no event manager.\n"); 15612954Sgabeblack@google.com eq->schedule(&readyEvent, eq->getCurTick()); 15712987Sgabeblack@google.com if (starvationEvent.scheduled()) 15812987Sgabeblack@google.com eq->deschedule(&starvationEvent); 15912987Sgabeblack@google.com } 16012987Sgabeblack@google.com} 16112987Sgabeblack@google.com 16212987Sgabeblack@google.comvoid 16312987Sgabeblack@google.comScheduler::scheduleStarvationEvent() 16412987Sgabeblack@google.com{ 16512987Sgabeblack@google.com if (!starvationEvent.scheduled()) { 16612987Sgabeblack@google.com panic_if(!eq, "Need to schedule starvation event, " 16712987Sgabeblack@google.com "but no event manager.\n"); 16812987Sgabeblack@google.com eq->schedule(&starvationEvent, eq->getCurTick()); 16912987Sgabeblack@google.com if (readyEvent.scheduled()) 17012987Sgabeblack@google.com eq->deschedule(&readyEvent); 17112954Sgabeblack@google.com } 17212954Sgabeblack@google.com} 17312954Sgabeblack@google.com 17412954Sgabeblack@google.comvoid 17512954Sgabeblack@google.comScheduler::runReady() 17612954Sgabeblack@google.com{ 17712954Sgabeblack@google.com bool empty = readyList.empty(); 17812954Sgabeblack@google.com 17912954Sgabeblack@google.com // The evaluation phase. 18012953Sgabeblack@google.com do { 18112953Sgabeblack@google.com yield(); 18212953Sgabeblack@google.com } while (!readyList.empty()); 18312954Sgabeblack@google.com 18412954Sgabeblack@google.com if (!empty) 18512954Sgabeblack@google.com _numCycles++; 18612954Sgabeblack@google.com 18712954Sgabeblack@google.com // The update phase. 18812954Sgabeblack@google.com update(); 18912954Sgabeblack@google.com 19012987Sgabeblack@google.com if (starved() && !runToTime) 19112987Sgabeblack@google.com scheduleStarvationEvent(); 19212987Sgabeblack@google.com 19312954Sgabeblack@google.com // The delta phase will happen naturally through the event queue. 19412953Sgabeblack@google.com} 19512953Sgabeblack@google.com 19612953Sgabeblack@google.comvoid 19712953Sgabeblack@google.comScheduler::update() 19812953Sgabeblack@google.com{ 19912954Sgabeblack@google.com Channel *channel = updateList.getNext(); 20012954Sgabeblack@google.com while (channel) { 20112954Sgabeblack@google.com channel->popListNode(); 20212954Sgabeblack@google.com channel->update(); 20312954Sgabeblack@google.com channel = updateList.getNext(); 20412954Sgabeblack@google.com } 20512953Sgabeblack@google.com} 20612953Sgabeblack@google.com 20712961Sgabeblack@google.comvoid 20812961Sgabeblack@google.comScheduler::pause() 20912961Sgabeblack@google.com{ 21012961Sgabeblack@google.com _paused = true; 21112982Sgabeblack@google.com kernel->status(::sc_core::SC_PAUSED); 21212961Sgabeblack@google.com scMain->run(); 21313049Sgabeblack@google.com 21413049Sgabeblack@google.com // If the ready event is supposed to run now, run it inline so that it 21513049Sgabeblack@google.com // preempts any delta notifications which were scheduled while we were 21613049Sgabeblack@google.com // paused. 21713049Sgabeblack@google.com if (readyEvent.scheduled()) { 21813049Sgabeblack@google.com eq->deschedule(&readyEvent); 21913049Sgabeblack@google.com runReady(); 22013049Sgabeblack@google.com } 22112961Sgabeblack@google.com} 22212961Sgabeblack@google.com 22312961Sgabeblack@google.comvoid 22412961Sgabeblack@google.comScheduler::stop() 22512961Sgabeblack@google.com{ 22612961Sgabeblack@google.com _stopped = true; 22712982Sgabeblack@google.com kernel->stop(); 22812961Sgabeblack@google.com scMain->run(); 22912961Sgabeblack@google.com} 23012961Sgabeblack@google.com 23112961Sgabeblack@google.comvoid 23212961Sgabeblack@google.comScheduler::start(Tick max_tick, bool run_to_time) 23312961Sgabeblack@google.com{ 23412961Sgabeblack@google.com // We should be running from sc_main. Keep track of that Fiber to return 23512961Sgabeblack@google.com // to later. 23612961Sgabeblack@google.com scMain = Fiber::currentFiber(); 23712961Sgabeblack@google.com 23812961Sgabeblack@google.com _started = true; 23912961Sgabeblack@google.com _paused = false; 24012961Sgabeblack@google.com _stopped = false; 24112987Sgabeblack@google.com runToTime = run_to_time; 24212961Sgabeblack@google.com 24312961Sgabeblack@google.com maxTick = max_tick; 24412961Sgabeblack@google.com 24512987Sgabeblack@google.com if (starved() && !runToTime) 24612987Sgabeblack@google.com return; 24712987Sgabeblack@google.com 24812982Sgabeblack@google.com if (initReady) { 24912982Sgabeblack@google.com kernel->status(::sc_core::SC_RUNNING); 25012961Sgabeblack@google.com eq->schedule(&maxTickEvent, maxTick); 25112982Sgabeblack@google.com } 25212961Sgabeblack@google.com 25312961Sgabeblack@google.com // Return to gem5 to let it run events, etc. 25412961Sgabeblack@google.com Fiber::primaryFiber()->run(); 25512961Sgabeblack@google.com 25612961Sgabeblack@google.com if (pauseEvent.scheduled()) 25712961Sgabeblack@google.com eq->deschedule(&pauseEvent); 25812961Sgabeblack@google.com if (stopEvent.scheduled()) 25912961Sgabeblack@google.com eq->deschedule(&stopEvent); 26012961Sgabeblack@google.com if (maxTickEvent.scheduled()) 26112961Sgabeblack@google.com eq->deschedule(&maxTickEvent); 26212987Sgabeblack@google.com if (starvationEvent.scheduled()) 26312987Sgabeblack@google.com eq->deschedule(&starvationEvent); 26412961Sgabeblack@google.com} 26512961Sgabeblack@google.com 26612961Sgabeblack@google.comvoid 26712961Sgabeblack@google.comScheduler::schedulePause() 26812961Sgabeblack@google.com{ 26912961Sgabeblack@google.com if (pauseEvent.scheduled()) 27012961Sgabeblack@google.com return; 27112961Sgabeblack@google.com 27212961Sgabeblack@google.com eq->schedule(&pauseEvent, eq->getCurTick()); 27312961Sgabeblack@google.com} 27412961Sgabeblack@google.com 27512961Sgabeblack@google.comvoid 27612961Sgabeblack@google.comScheduler::scheduleStop(bool finish_delta) 27712961Sgabeblack@google.com{ 27812961Sgabeblack@google.com if (stopEvent.scheduled()) 27912961Sgabeblack@google.com return; 28012961Sgabeblack@google.com 28112961Sgabeblack@google.com if (!finish_delta) { 28212961Sgabeblack@google.com // If we're not supposed to finish the delta cycle, flush the list 28312961Sgabeblack@google.com // of ready processes and scheduled updates. 28412961Sgabeblack@google.com Process *p; 28512961Sgabeblack@google.com while ((p = readyList.getNext())) 28612961Sgabeblack@google.com p->popListNode(); 28712961Sgabeblack@google.com Channel *c; 28812961Sgabeblack@google.com while ((c = updateList.getNext())) 28912961Sgabeblack@google.com c->popListNode(); 29012961Sgabeblack@google.com } 29112961Sgabeblack@google.com eq->schedule(&stopEvent, eq->getCurTick()); 29212961Sgabeblack@google.com} 29312961Sgabeblack@google.com 29412953Sgabeblack@google.comScheduler scheduler; 29512953Sgabeblack@google.com 29612953Sgabeblack@google.com} // namespace sc_gem5 297