| 1 | package de.uka.ipd.sdq.scheduler.loaddistribution.balancers; |
| 2 | |
| 3 | import java.util.List; |
| 4 | |
| 5 | import de.uka.ipd.sdq.scheduler.processes.IActiveProcess; |
| 6 | import de.uka.ipd.sdq.scheduler.processes.impl.PreemptiveProcess; |
| 7 | import de.uka.ipd.sdq.scheduler.resources.IResourceInstance; |
| 8 | |
| 9 | /** |
| 10 | * Moves one process to each idle resource, if possible. |
| 11 | * |
| 12 | * @author jens.happe |
| 13 | * |
| 14 | */ |
| 15 | public class OneToIdleBalancer extends AbstractLoadBalancer { |
| 16 | |
| 17 | private int upperBound = 1; |
| 18 | |
| 19 | private int lowerBound = 1; |
| 20 | |
| 21 | public OneToIdleBalancer(double balance_interval, boolean prio_increasing, |
| 22 | boolean queue_ascending) { |
| 23 | super(balance_interval, prio_increasing, queue_ascending); |
| 24 | } |
| 25 | |
| 26 | public void activelyBalance(IResourceInstance instance) { |
| 27 | // double now = simulator.time(); |
| 28 | // if ((now - last_balanced.get(instance)) > balancing_interval) { |
| 29 | // balanceAsReceiver(instance); |
| 30 | // last_balanced.put(instance, now); |
| 31 | // } |
| 32 | } |
| 33 | |
| 34 | public void onFork(IResourceInstance instance) { |
| 35 | balanceAsSender(instance); |
| 36 | } |
| 37 | |
| 38 | public void onSleep(IResourceInstance instance) { |
| 39 | balanceAsReceiver(instance); |
| 40 | } |
| 41 | |
| 42 | public void onTerminate(IResourceInstance instance) { |
| 43 | balanceAsReceiver(instance); |
| 44 | } |
| 45 | |
| 46 | public void onWake(IResourceInstance instance) { |
| 47 | balanceAsSender(instance); |
| 48 | } |
| 49 | |
| 50 | private void balanceAsSender(IResourceInstance instance) { |
| 51 | if (load(instance) > upperBound) { |
| 52 | balance(instance, getReceiver()); |
| 53 | } |
| 54 | } |
| 55 | |
| 56 | private void balanceAsReceiver(IResourceInstance instance) { |
| 57 | if (load(instance) < lowerBound) { |
| 58 | balance(getSender(), instance); |
| 59 | } |
| 60 | } |
| 61 | |
| 62 | private IResourceInstance getSender() { |
| 63 | IResourceInstance result = null; |
| 64 | for (IResourceInstance ri : queue_holder.getResourceInstances()) { |
| 65 | if (result == null || load(ri) > load(result)) { |
| 66 | result = ri; |
| 67 | } |
| 68 | } |
| 69 | if (load(result) > upperBound) { |
| 70 | return result; |
| 71 | } else { |
| 72 | return null; |
| 73 | } |
| 74 | } |
| 75 | |
| 76 | private IResourceInstance getReceiver() { |
| 77 | IResourceInstance result = null; |
| 78 | for (IResourceInstance ri : queue_holder.getResourceInstances()) { |
| 79 | if (result == null || load(ri) < load(result)) { |
| 80 | result = ri; |
| 81 | } |
| 82 | } |
| 83 | if (load(result) < lowerBound) { |
| 84 | return result; |
| 85 | } else { |
| 86 | return null; |
| 87 | } |
| 88 | } |
| 89 | |
| 90 | private void balance(IResourceInstance sender, IResourceInstance receiver) { |
| 91 | if (sender != null && receiver != null) { |
| 92 | if (!sender.equals(receiver)) { |
| 93 | List<IActiveProcess> processList = queue_holder.getRunQueueFor( |
| 94 | sender).identifyMovableProcesses(receiver, |
| 95 | prio_increasing, queue_ascending, 1); |
| 96 | |
| 97 | if (processList.size() > 0) { |
| 98 | fakeThreadLoadBalancing(processList.get(0), sender, |
| 99 | receiver); |
| 100 | } |
| 101 | } |
| 102 | } |
| 103 | } |
| 104 | |
| 105 | /** |
| 106 | * From the beautiful method name, the careful reader might have guessed |
| 107 | * that things get a bit, well, messy at this point. Fact is, that Windows |
| 108 | * (or Java ?) balances threads differently from processes by simply |
| 109 | * changing the association between light weight processes and (user level) |
| 110 | * threads. That makes things a bit difficult as heavy weight and light |
| 111 | * weight processes as well as threads would have to be reflected in the |
| 112 | * model. |
| 113 | * |
| 114 | * Sorry for anyone responsible fixing this, but I hope this comment helps. |
| 115 | * Further discussion can be found in class 'SimResourceInstance' at |
| 116 | * variable 'last_running_process'. |
| 117 | * |
| 118 | * @param process |
| 119 | * moved process |
| 120 | * @param sender |
| 121 | * sending resource instance |
| 122 | * @param receiver |
| 123 | * receiving resource instance |
| 124 | */ |
| 125 | private void fakeThreadLoadBalancing(IActiveProcess process, |
| 126 | IResourceInstance sender, IResourceInstance receiver) { |
| 127 | if (receiver.getLastRunningProcess() != null) { |
| 128 | PreemptiveProcess p = (PreemptiveProcess) receiver.getLastRunningProcess(); |
| 129 | |
| 130 | // here we assume that the waiting process is in fact a thread that |
| 131 | // belongs to the same process as the thread (process) to move. |
| 132 | // the following assigns the waiting thread to the resource of |
| 133 | // the sender. This fakes the switch of LWPs. |
| 134 | if (p.isWaiting()) { |
| 135 | p.setLastInstance(process.getLastInstance()); |
| 136 | p.setIdealInstance(process.getIdealInstance()); |
| 137 | } |
| 138 | } |
| 139 | queue_holder.move(process, sender, receiver); |
| 140 | } |
| 141 | } |