| 1 | package de.uka.ipd.sdq.scheduler.strategy.impl; |
| 2 | |
| 3 | import scheduler.configuration.StarvationBoost; |
| 4 | import de.uka.ipd.sdq.scheduler.ISchedulableProcess; |
| 5 | import de.uka.ipd.sdq.scheduler.SchedulerModel; |
| 6 | import de.uka.ipd.sdq.scheduler.priority.IPriority; |
| 7 | import de.uka.ipd.sdq.scheduler.priority.IPriorityUpdateStrategy; |
| 8 | import de.uka.ipd.sdq.scheduler.priority.update.SetToBaseUpdate; |
| 9 | import de.uka.ipd.sdq.scheduler.processes.IActiveProcess; |
| 10 | import de.uka.ipd.sdq.scheduler.processes.impl.ProcessWithPriority; |
| 11 | import de.uka.ipd.sdq.scheduler.queueing.IQueueingStrategy; |
| 12 | import de.uka.ipd.sdq.scheduler.resources.IResourceInstance; |
| 13 | import de.uka.ipd.sdq.scheduler.resources.active.SimActiveResource; |
| 14 | import de.uka.ipd.sdq.scheduler.resources.active.SimResourceInstance; |
| 15 | |
| 16 | public class PreemptiveScheduler extends AbstractScheduler { |
| 17 | |
| 18 | private SchedulerModel model; |
| 19 | |
| 20 | public PreemptiveScheduler(SchedulerModel model, SimActiveResource resource, |
| 21 | IQueueingStrategy queueingStrategy, boolean in_front_after_waiting, |
| 22 | double scheduling_interval, StarvationBoost starvationBoost) { |
| 23 | super(resource, queueingStrategy, in_front_after_waiting, starvationBoost); |
| 24 | this.model = model; |
| 25 | this.scheduling_interval = scheduling_interval; |
| 26 | } |
| 27 | |
| 28 | |
| 29 | public void schedule(IResourceInstance instance) { |
| 30 | if (instance.isScheduling()) |
| 31 | return; |
| 32 | |
| 33 | // Balance the runqueue of this instance with the runqueues of other |
| 34 | // instances. This might change the state of the instance's runqueue. |
| 35 | // So, the next runnable process can only be determined after the |
| 36 | // balancing was finished. |
| 37 | queueing_strategy.activelyBalance(instance); |
| 38 | |
| 39 | // get the currently scheduled process for the instance. |
| 40 | ProcessWithPriority running_process = (ProcessWithPriority) instance |
| 41 | .getRunningProcess(); |
| 42 | |
| 43 | // Update the timing variables and priority of the process. Possibly |
| 44 | // pending events of the process are canceled. |
| 45 | toNow(running_process); |
| 46 | |
| 47 | if (running_process == null){ |
| 48 | } else if ( running_process.getTimeslice().isFinished()) { |
| 49 | unschedule(running_process, false, instance); |
| 50 | } else { |
| 51 | unschedule(running_process, true, instance); |
| 52 | } |
| 53 | scheduleNextProcess(instance); |
| 54 | scheduleNextEvent(instance); |
| 55 | } |
| 56 | |
| 57 | |
| 58 | private void scheduleNextProcess(ProcessWithPriority next_process, IResourceInstance instance) { |
| 59 | if (next_process != null) { |
| 60 | next_process.toNow(); |
| 61 | next_process.update(); |
| 62 | fromReadyToRunningOn(next_process, instance); |
| 63 | } |
| 64 | } |
| 65 | |
| 66 | private void scheduleNextProcess(IResourceInstance instance) { |
| 67 | lookForStarvingProcessesAndApplyStarvationBoost(instance); |
| 68 | |
| 69 | ProcessWithPriority next_process = (ProcessWithPriority) queueing_strategy.getNextProcessFor(instance); |
| 70 | scheduleNextProcess(next_process, instance); |
| 71 | } |
| 72 | |
| 73 | private void lookForStarvingProcessesAndApplyStarvationBoost(IResourceInstance instance) { |
| 74 | if(starvationBoost != null){ |
| 75 | for (IActiveProcess p : queueing_strategy.getStarvingProcesses(instance, starvationBoost.getStarvationLimit())){ |
| 76 | applyStarvationBoost((ProcessWithPriority)p); |
| 77 | } |
| 78 | |
| 79 | } |
| 80 | |
| 81 | } |
| 82 | |
| 83 | private void applyStarvationBoost(ProcessWithPriority p) { |
| 84 | p.setToStaticPriorityWithBonus(starvationBoost.getBoost()); |
| 85 | IPriorityUpdateStrategy priorityUpdateStrategy = new SetToBaseUpdate(starvationBoost.getDurationInTimeslices()); |
| 86 | p.setPriorityUpdateStrategy(priorityUpdateStrategy); |
| 87 | } |
| 88 | |
| 89 | |
| 90 | private void toNow(ProcessWithPriority process) { |
| 91 | if (process != null){ |
| 92 | process.toNow(); |
| 93 | } |
| 94 | } |
| 95 | |
| 96 | private void unschedule(ProcessWithPriority running_process, |
| 97 | boolean next_has_higher_priority, IResourceInstance current) { |
| 98 | if (running_process != null) { |
| 99 | if (running_process.getTimeslice().isFinished()){ |
| 100 | running_process.update(); |
| 101 | fromRunningToReady(running_process, current, false); |
| 102 | running_process.getTimeslice().fullReset(); |
| 103 | } else { |
| 104 | fromRunningToReady(running_process, current, next_has_higher_priority); |
| 105 | } |
| 106 | if (running_process.getRunQueue().getCurrentLoad() == 1){ |
| 107 | running_process.getRunQueue().resetStarvationInfo(); |
| 108 | } |
| 109 | } |
| 110 | } |
| 111 | |
| 112 | /** |
| 113 | * pOne > pTwo ? |
| 114 | * |
| 115 | * @param pTwo |
| 116 | * @return |
| 117 | */ |
| 118 | private boolean hasHigherPriority(ProcessWithPriority pOne, |
| 119 | ProcessWithPriority pTwo) { |
| 120 | if (pOne == null) |
| 121 | return false; |
| 122 | if (pTwo == null) |
| 123 | return true; |
| 124 | IPriority prio_one = pOne.getDynamicPriority(); |
| 125 | IPriority prio_two = pTwo.getDynamicPriority(); |
| 126 | return prio_one.greaterThan(prio_two); |
| 127 | } |
| 128 | |
| 129 | public void scheduleNextEvent(IResourceInstance instance) { |
| 130 | double time = model.getSimulationControl().getCurrentSimulationTime(); |
| 131 | ProcessWithPriority running = (ProcessWithPriority) instance |
| 132 | .getRunningProcess(); |
| 133 | if (running != null) { |
| 134 | running.toNow(); |
| 135 | double remainingTime = running.getTimeslice().getRemainingTime(); |
| 136 | double currentDemand = running.getCurrentDemand(); |
| 137 | if ( currentDemand < remainingTime ) |
| 138 | running.scheduleProceedEvent(this); |
| 139 | else |
| 140 | instance.scheduleSchedulingEvent(remainingTime); |
| 141 | } else { |
| 142 | if (!queueing_strategy.isIdle(instance)) |
| 143 | instance.scheduleSchedulingEvent(0); |
| 144 | else |
| 145 | instance.scheduleSchedulingEvent(scheduling_interval); |
| 146 | } |
| 147 | } |
| 148 | |
| 149 | |
| 150 | public boolean isIdle(IResourceInstance instance) { |
| 151 | return queueing_strategy.isIdle(instance); |
| 152 | } |
| 153 | |
| 154 | |
| 155 | public double getInterval() { |
| 156 | return scheduling_interval; |
| 157 | } |
| 158 | |
| 159 | @Override |
| 160 | public void terminateProcess(IActiveProcess process, IResourceInstance current) { |
| 161 | super.terminateProcess(process, current); |
| 162 | ISchedulableProcess sProcess = process.getSchedulableProcess(); |
| 163 | if (sProcess.isFinished() |
| 164 | // do NOT remove the originally defined processes as they |
| 165 | // serve as prototypes for all spawned processes. |
| 166 | && sProcess.getRootProcess() != sProcess){ |
| 167 | this.resource.unregisterProcess(process); |
| 168 | } |
| 169 | } |
| 170 | |
| 171 | |
| 172 | public int getQueueLengthFor(SimResourceInstance simResourceInstance) { |
| 173 | return this.queueing_strategy.getQueueLengthFor(simResourceInstance); |
| 174 | } |
| 175 | |
| 176 | |
| 177 | } |