/*
* Title: CloudSim Toolkit
* Description: CloudSim (Cloud Simulation) Toolkit for Modeling and Simulation of Clouds
* Licence: GPL - http://www.gnu.org/copyleft/gpl.html
*
* Copyright (c) 2009-2012, The University of Melbourne, Australia
*/
package org.cloudbus.cloudsim;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.cloudbus.cloudsim.core.CloudSim;
/**
* VmAllocationPolicySimple is an VmAllocationPolicy that chooses, as the host for a VM, the host
* with less PEs in use. It is therefore a Worst Fit policy, allocating VMs into the
* host with most available PE.
*
* @author Rodrigo N. Calheiros
* @author Anton Beloglazov
* @since CloudSim Toolkit 1.0
*/
public class VmAllocationPolicySimple extends VmAllocationPolicy {
/** The map between each VM and its allocated host.
* The map key is a VM UID and the value is the allocated host for that VM. */
private Map<String, Host> vmTable;
/** The map between each VM and the number of Pes used.
* The map key is a VM UID and the value is the number of used Pes for that VM. */
private Map<String, Integer> usedPes;
/** The number of free Pes for each host from {@link #getHostList() }. */
private List<Integer> freePes;
/**
* Creates a new VmAllocationPolicySimple object.
*
* @param list the list of hosts
* @pre $none
* @post $none
*/
public VmAllocationPolicySimple(List<? extends Host> list) {
super(list);
setFreePes(new ArrayList<Integer>());
for (Host host : getHostList()) {
getFreePes().add(host.getNumberOfPes());
}
setVmTable(new HashMap<String, Host>());
setUsedPes(new HashMap<String, Integer>());
}
/**
* Allocates the host with less PEs in use for a given VM.
*
* @param vm {@inheritDoc}
* @return {@inheritDoc}
* @pre $none
* @post $none
*/
@Override
public boolean allocateHostForVm(Vm vm) {
int requiredPes = vm.getNumberOfPes();
boolean result = false;
int tries = 0;
List<Integer> freePesTmp = new ArrayList<Integer>();
for (Integer freePes : getFreePes()) {
freePesTmp.add(freePes);
}
if (!getVmTable().containsKey(vm.getUid())) { // if this vm was not created
do {// we still trying until we find a host or until we try all of them
int moreFree = Integer.MIN_VALUE;
int idx = -1;
// we want the host with less pes in use
for (int i = 0; i < freePesTmp.size(); i++) {
if (freePesTmp.get(i) > moreFree) {
moreFree = freePesTmp.get(i);
idx = i;
}
}
Host host = getHostList().get(idx);
result = host.vmCreate(vm);
if (result) { // if vm were succesfully created in the host
getVmTable().put(vm.getUid(), host);
getUsedPes().put(vm.getUid(), requiredPes);
getFreePes().set(idx, getFreePes().get(idx) - requiredPes);
result = true;
break;
} else {
freePesTmp.set(idx, Integer.MIN_VALUE);
}
tries++;
} while (!result && tries < getFreePes().size());
}
return result;
}
@Override
public void deallocateHostForVm(Vm vm) {
Host host = getVmTable().remove(vm.getUid());
int idx = getHostList().indexOf(host);
int pes = getUsedPes().remove(vm.getUid());
if (host != null) {
host.vmDestroy(vm);
getFreePes().set(idx, getFreePes().get(idx) + pes);
}
}
@Override
public Host getHost(Vm vm) {
return getVmTable().get(vm.getUid());
}
@Override
public Host getHost(int vmId, int userId) {
return getVmTable().get(Vm.getUid(userId, vmId));
}
/**
* Gets the vm table.
*
* @return the vm table
*/
public Map<String, Host> getVmTable() {
return vmTable;
}
/**
* Sets the vm table.
*
* @param vmTable the vm table
*/
protected void setVmTable(Map<String, Host> vmTable) {
this.vmTable = vmTable;
}
/**
* Gets the used pes.
*
* @return the used pes
*/
protected Map<String, Integer> getUsedPes() {
return usedPes;
}
/**
* Sets the used pes.
*
* @param usedPes the used pes
*/
protected void setUsedPes(Map<String, Integer> usedPes) {
this.usedPes = usedPes;
}
/**
* Gets the free pes.
*
* @return the free pes
*/
protected List<Integer> getFreePes() {
return freePes;
}
/**
* Sets the free pes.
*
* @param freePes the new free pes
*/
protected void setFreePes(List<Integer> freePes) {
this.freePes = freePes;
}
@Override
public List<Map<String, Object>> optimizeAllocation(List<? extends Vm> vmList) {
// TODO Auto-generated method stub
return null;
}
@Override
public boolean allocateHostForVm(Vm vm, Host host) {
if (host.vmCreate(vm)) { // if vm has been succesfully created in the host
getVmTable().put(vm.getUid(), host);
int requiredPes = vm.getNumberOfPes();
int idx = getHostList().indexOf(host);
getUsedPes().put(vm.getUid(), requiredPes);
getFreePes().set(idx, getFreePes().get(idx) - requiredPes);
Log.formatLine(
"%.2f: VM #" + vm.getId() + " has been allocated to the host #" + host.getId(),
CloudSim.clock());
return true;
}
return false;
}
}