scheduler.cc revision 13061
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), 4913061Sgabeblack@google.com _numCycles(0), _current(nullptr), initReady(false), 5013061Sgabeblack@google.com runOnce(false) 5112954Sgabeblack@google.com{} 5212953Sgabeblack@google.com 5312953Sgabeblack@google.comvoid 5412957Sgabeblack@google.comScheduler::prepareForInit() 5512953Sgabeblack@google.com{ 5612957Sgabeblack@google.com for (Process *p = toFinalize.getNext(); p; p = toFinalize.getNext()) { 5712957Sgabeblack@google.com p->finalize(); 5812957Sgabeblack@google.com p->popListNode(); 5912957Sgabeblack@google.com } 6012957Sgabeblack@google.com 6112957Sgabeblack@google.com for (Process *p = initList.getNext(); p; p = initList.getNext()) { 6212957Sgabeblack@google.com p->finalize(); 6312996Sgabeblack@google.com p->popListNode(); 6412959Sgabeblack@google.com p->ready(); 6512957Sgabeblack@google.com } 6612957Sgabeblack@google.com 6712985Sgabeblack@google.com for (auto ets: eventsToSchedule) 6812985Sgabeblack@google.com eq->schedule(ets.first, ets.second); 6912985Sgabeblack@google.com eventsToSchedule.clear(); 7012985Sgabeblack@google.com 7112961Sgabeblack@google.com if (_started) 7212961Sgabeblack@google.com eq->schedule(&maxTickEvent, maxTick); 7312961Sgabeblack@google.com 7412957Sgabeblack@google.com initReady = true; 7512957Sgabeblack@google.com} 7612957Sgabeblack@google.com 7712957Sgabeblack@google.comvoid 7812957Sgabeblack@google.comScheduler::reg(Process *p) 7912957Sgabeblack@google.com{ 8012957Sgabeblack@google.com if (initReady) { 8112957Sgabeblack@google.com // If we're past initialization, finalize static sensitivity. 8212957Sgabeblack@google.com p->finalize(); 8312957Sgabeblack@google.com // Mark the process as ready. 8412959Sgabeblack@google.com p->ready(); 8512957Sgabeblack@google.com } else { 8612957Sgabeblack@google.com // Otherwise, record that this process should be initialized once we 8712957Sgabeblack@google.com // get there. 8812957Sgabeblack@google.com initList.pushLast(p); 8912957Sgabeblack@google.com } 9012957Sgabeblack@google.com} 9112957Sgabeblack@google.com 9212957Sgabeblack@google.comvoid 9312957Sgabeblack@google.comScheduler::dontInitialize(Process *p) 9412957Sgabeblack@google.com{ 9512957Sgabeblack@google.com if (initReady) { 9612957Sgabeblack@google.com // Pop this process off of the ready list. 9712957Sgabeblack@google.com p->popListNode(); 9812957Sgabeblack@google.com } else { 9912957Sgabeblack@google.com // Push this process onto the list of processes which still need 10012957Sgabeblack@google.com // their static sensitivity to be finalized. That implicitly pops it 10112957Sgabeblack@google.com // off the list of processes to be initialized/marked ready. 10212957Sgabeblack@google.com toFinalize.pushLast(p); 10312957Sgabeblack@google.com } 10412953Sgabeblack@google.com} 10512953Sgabeblack@google.com 10612953Sgabeblack@google.comvoid 10712953Sgabeblack@google.comScheduler::yield() 10812953Sgabeblack@google.com{ 10912953Sgabeblack@google.com _current = readyList.getNext(); 11012953Sgabeblack@google.com if (!_current) { 11112953Sgabeblack@google.com // There are no more processes, so return control to evaluate. 11212953Sgabeblack@google.com Fiber::primaryFiber()->run(); 11312953Sgabeblack@google.com } else { 11412953Sgabeblack@google.com _current->popListNode(); 11512953Sgabeblack@google.com // Switch to whatever Fiber is supposed to run this process. All 11612953Sgabeblack@google.com // Fibers which aren't running should be parked at this line. 11712953Sgabeblack@google.com _current->fiber()->run(); 11812961Sgabeblack@google.com // If the current process needs to be manually started, start it. 11912961Sgabeblack@google.com if (_current && _current->needsStart()) 12012953Sgabeblack@google.com _current->run(); 12112953Sgabeblack@google.com } 12212995Sgabeblack@google.com if (_current && _current->excWrapper) { 12312995Sgabeblack@google.com // Make sure this isn't a method process. 12412995Sgabeblack@google.com assert(!_current->needsStart()); 12512995Sgabeblack@google.com auto ew = _current->excWrapper; 12612995Sgabeblack@google.com _current->excWrapper = nullptr; 12712995Sgabeblack@google.com ew->throw_it(); 12812995Sgabeblack@google.com } 12912953Sgabeblack@google.com} 13012953Sgabeblack@google.com 13112953Sgabeblack@google.comvoid 13212954Sgabeblack@google.comScheduler::ready(Process *p) 13312953Sgabeblack@google.com{ 13412954Sgabeblack@google.com // Clump methods together to minimize context switching. 13512954Sgabeblack@google.com if (p->procKind() == ::sc_core::SC_METHOD_PROC_) 13612954Sgabeblack@google.com readyList.pushFirst(p); 13712954Sgabeblack@google.com else 13812954Sgabeblack@google.com readyList.pushLast(p); 13912953Sgabeblack@google.com 14012954Sgabeblack@google.com scheduleReadyEvent(); 14112954Sgabeblack@google.com} 14212954Sgabeblack@google.com 14312954Sgabeblack@google.comvoid 14412954Sgabeblack@google.comScheduler::requestUpdate(Channel *c) 14512954Sgabeblack@google.com{ 14612954Sgabeblack@google.com updateList.pushLast(c); 14713047Sgabeblack@google.com if (eq) 14813047Sgabeblack@google.com scheduleReadyEvent(); 14912954Sgabeblack@google.com} 15012954Sgabeblack@google.com 15112954Sgabeblack@google.comvoid 15212954Sgabeblack@google.comScheduler::scheduleReadyEvent() 15312954Sgabeblack@google.com{ 15412954Sgabeblack@google.com // Schedule the evaluate and update phases. 15512954Sgabeblack@google.com if (!readyEvent.scheduled()) { 15612954Sgabeblack@google.com panic_if(!eq, "Need to schedule ready, but no event manager.\n"); 15712954Sgabeblack@google.com eq->schedule(&readyEvent, eq->getCurTick()); 15812987Sgabeblack@google.com if (starvationEvent.scheduled()) 15912987Sgabeblack@google.com eq->deschedule(&starvationEvent); 16012987Sgabeblack@google.com } 16112987Sgabeblack@google.com} 16212987Sgabeblack@google.com 16312987Sgabeblack@google.comvoid 16412987Sgabeblack@google.comScheduler::scheduleStarvationEvent() 16512987Sgabeblack@google.com{ 16612987Sgabeblack@google.com if (!starvationEvent.scheduled()) { 16712987Sgabeblack@google.com panic_if(!eq, "Need to schedule starvation event, " 16812987Sgabeblack@google.com "but no event manager.\n"); 16912987Sgabeblack@google.com eq->schedule(&starvationEvent, eq->getCurTick()); 17012987Sgabeblack@google.com if (readyEvent.scheduled()) 17112987Sgabeblack@google.com eq->deschedule(&readyEvent); 17212954Sgabeblack@google.com } 17312954Sgabeblack@google.com} 17412954Sgabeblack@google.com 17512954Sgabeblack@google.comvoid 17612954Sgabeblack@google.comScheduler::runReady() 17712954Sgabeblack@google.com{ 17812954Sgabeblack@google.com bool empty = readyList.empty(); 17912954Sgabeblack@google.com 18012954Sgabeblack@google.com // The evaluation phase. 18112953Sgabeblack@google.com do { 18212953Sgabeblack@google.com yield(); 18312953Sgabeblack@google.com } while (!readyList.empty()); 18412954Sgabeblack@google.com 18512954Sgabeblack@google.com if (!empty) 18612954Sgabeblack@google.com _numCycles++; 18712954Sgabeblack@google.com 18812954Sgabeblack@google.com // The update phase. 18912954Sgabeblack@google.com update(); 19012954Sgabeblack@google.com 19112987Sgabeblack@google.com if (starved() && !runToTime) 19212987Sgabeblack@google.com scheduleStarvationEvent(); 19312987Sgabeblack@google.com 19412954Sgabeblack@google.com // The delta phase will happen naturally through the event queue. 19513061Sgabeblack@google.com 19613061Sgabeblack@google.com if (runOnce) { 19713061Sgabeblack@google.com eq->reschedule(&maxTickEvent, eq->getCurTick()); 19813061Sgabeblack@google.com runOnce = false; 19913061Sgabeblack@google.com } 20012953Sgabeblack@google.com} 20112953Sgabeblack@google.com 20212953Sgabeblack@google.comvoid 20312953Sgabeblack@google.comScheduler::update() 20412953Sgabeblack@google.com{ 20512954Sgabeblack@google.com Channel *channel = updateList.getNext(); 20612954Sgabeblack@google.com while (channel) { 20712954Sgabeblack@google.com channel->popListNode(); 20812954Sgabeblack@google.com channel->update(); 20912954Sgabeblack@google.com channel = updateList.getNext(); 21012954Sgabeblack@google.com } 21112953Sgabeblack@google.com} 21212953Sgabeblack@google.com 21312961Sgabeblack@google.comvoid 21412961Sgabeblack@google.comScheduler::pause() 21512961Sgabeblack@google.com{ 21612961Sgabeblack@google.com _paused = true; 21712982Sgabeblack@google.com kernel->status(::sc_core::SC_PAUSED); 21813061Sgabeblack@google.com runOnce = false; 21912961Sgabeblack@google.com scMain->run(); 22013049Sgabeblack@google.com 22113049Sgabeblack@google.com // If the ready event is supposed to run now, run it inline so that it 22213049Sgabeblack@google.com // preempts any delta notifications which were scheduled while we were 22313049Sgabeblack@google.com // paused. 22413049Sgabeblack@google.com if (readyEvent.scheduled()) { 22513049Sgabeblack@google.com eq->deschedule(&readyEvent); 22613049Sgabeblack@google.com runReady(); 22713049Sgabeblack@google.com } 22812961Sgabeblack@google.com} 22912961Sgabeblack@google.com 23012961Sgabeblack@google.comvoid 23112961Sgabeblack@google.comScheduler::stop() 23212961Sgabeblack@google.com{ 23312961Sgabeblack@google.com _stopped = true; 23412982Sgabeblack@google.com kernel->stop(); 23513061Sgabeblack@google.com runOnce = false; 23612961Sgabeblack@google.com scMain->run(); 23712961Sgabeblack@google.com} 23812961Sgabeblack@google.com 23912961Sgabeblack@google.comvoid 24012961Sgabeblack@google.comScheduler::start(Tick max_tick, bool run_to_time) 24112961Sgabeblack@google.com{ 24212961Sgabeblack@google.com // We should be running from sc_main. Keep track of that Fiber to return 24312961Sgabeblack@google.com // to later. 24412961Sgabeblack@google.com scMain = Fiber::currentFiber(); 24512961Sgabeblack@google.com 24612961Sgabeblack@google.com _started = true; 24712961Sgabeblack@google.com _paused = false; 24812961Sgabeblack@google.com _stopped = false; 24912987Sgabeblack@google.com runToTime = run_to_time; 25012961Sgabeblack@google.com 25112961Sgabeblack@google.com maxTick = max_tick; 25212961Sgabeblack@google.com 25312987Sgabeblack@google.com if (starved() && !runToTime) 25412987Sgabeblack@google.com return; 25512987Sgabeblack@google.com 25612982Sgabeblack@google.com if (initReady) { 25712982Sgabeblack@google.com kernel->status(::sc_core::SC_RUNNING); 25812961Sgabeblack@google.com eq->schedule(&maxTickEvent, maxTick); 25912982Sgabeblack@google.com } 26012961Sgabeblack@google.com 26112961Sgabeblack@google.com // Return to gem5 to let it run events, etc. 26212961Sgabeblack@google.com Fiber::primaryFiber()->run(); 26312961Sgabeblack@google.com 26412961Sgabeblack@google.com if (pauseEvent.scheduled()) 26512961Sgabeblack@google.com eq->deschedule(&pauseEvent); 26612961Sgabeblack@google.com if (stopEvent.scheduled()) 26712961Sgabeblack@google.com eq->deschedule(&stopEvent); 26812961Sgabeblack@google.com if (maxTickEvent.scheduled()) 26912961Sgabeblack@google.com eq->deschedule(&maxTickEvent); 27012987Sgabeblack@google.com if (starvationEvent.scheduled()) 27112987Sgabeblack@google.com eq->deschedule(&starvationEvent); 27212961Sgabeblack@google.com} 27312961Sgabeblack@google.com 27412961Sgabeblack@google.comvoid 27513061Sgabeblack@google.comScheduler::oneCycle() 27613061Sgabeblack@google.com{ 27713061Sgabeblack@google.com runOnce = true; 27813061Sgabeblack@google.com start(::MaxTick, false); 27913061Sgabeblack@google.com} 28013061Sgabeblack@google.com 28113061Sgabeblack@google.comvoid 28212961Sgabeblack@google.comScheduler::schedulePause() 28312961Sgabeblack@google.com{ 28412961Sgabeblack@google.com if (pauseEvent.scheduled()) 28512961Sgabeblack@google.com return; 28612961Sgabeblack@google.com 28712961Sgabeblack@google.com eq->schedule(&pauseEvent, eq->getCurTick()); 28812961Sgabeblack@google.com} 28912961Sgabeblack@google.com 29012961Sgabeblack@google.comvoid 29112961Sgabeblack@google.comScheduler::scheduleStop(bool finish_delta) 29212961Sgabeblack@google.com{ 29312961Sgabeblack@google.com if (stopEvent.scheduled()) 29412961Sgabeblack@google.com return; 29512961Sgabeblack@google.com 29612961Sgabeblack@google.com if (!finish_delta) { 29712961Sgabeblack@google.com // If we're not supposed to finish the delta cycle, flush the list 29812961Sgabeblack@google.com // of ready processes and scheduled updates. 29912961Sgabeblack@google.com Process *p; 30012961Sgabeblack@google.com while ((p = readyList.getNext())) 30112961Sgabeblack@google.com p->popListNode(); 30212961Sgabeblack@google.com Channel *c; 30312961Sgabeblack@google.com while ((c = updateList.getNext())) 30412961Sgabeblack@google.com c->popListNode(); 30512961Sgabeblack@google.com } 30612961Sgabeblack@google.com eq->schedule(&stopEvent, eq->getCurTick()); 30712961Sgabeblack@google.com} 30812961Sgabeblack@google.com 30912953Sgabeblack@google.comScheduler scheduler; 31012953Sgabeblack@google.com 31112953Sgabeblack@google.com} // namespace sc_gem5 312