/*
* $Id$
*
* Copyright (C) 2003-2014 JNode.org
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; If not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
package org.jnode.vm;
import org.jnode.system.resource.IOResource;
import org.jnode.system.resource.Resource;
import org.jnode.system.resource.ResourceNotFreeException;
import org.jnode.system.resource.ResourceOwner;
import org.jnode.util.NumberUtils;
/**
* Default implementation of IOResource.
*
* @author Ewout Prangsma (epr@users.sourceforge.net)
*/
final class IOResourceImpl extends Region implements IOResource {
/**
* The first port of this resource
*/
private int startPort;
/**
* The length of the port region
*/
private int length;
/**
* Has this resource been released?
*/
private boolean released;
/**
* The list of active IOResource's
*/
private static Region resources;
/**
* Create a new instance
*
* @param owner
* @param startPort
* @param length
*/
private IOResourceImpl(ResourceOwner owner, int startPort, int length) {
super(owner);
this.startPort = startPort;
this.length = length;
this.released = false;
}
/**
* Claim a range of IO ports
*
* @param owner
* @param startPort
* @param length
* @return The claimed resource
* @throws ResourceNotFreeException
*/
protected static synchronized IOResource claimIOResource(ResourceOwner owner, int startPort, int length)
throws ResourceNotFreeException {
final IOResourceImpl res = new IOResourceImpl(owner, startPort, length);
if (isFree(resources, res)) {
resources = add(resources, res);
return res;
} else {
final Object curOwner = get(resources, res).getOwner();
throw new ResourceNotFreeException("port " + NumberUtils.hex(startPort) + '-' +
NumberUtils.hex(startPort + length - 1) + " is owned by " + curOwner);
}
}
/**
* Returns the length.
*
* @return int
*/
public int getLength() {
return length;
}
/**
* Returns the startPort.
*
* @return int
*/
public int getStartPort() {
return startPort;
}
public int inPortByte(int portNr) {
testPort(portNr, 1);
return Unsafe.inPortByte(portNr);
}
public int inPortWord(int portNr) {
testPort(portNr, 2);
return Unsafe.inPortWord(portNr);
}
public int inPortDword(int portNr) {
testPort(portNr, 4);
return Unsafe.inPortDword(portNr);
}
public void outPortByte(int portNr, int value) {
testPort(portNr, 1);
Unsafe.outPortByte(portNr, value);
}
public void outPortWord(int portNr, int value) {
testPort(portNr, 2);
Unsafe.outPortWord(portNr, value);
}
public void outPortDword(int portNr, int value) {
testPort(portNr, 4);
Unsafe.outPortDword(portNr, value);
}
/**
* Compare to regions.
*
* @param otherRegion
* @return a negative integer, zero, or a positive integer as
* this object is less than, equal to, or greater than the
* specified region. If the regions overlap, 0 is returned.
*/
public int compareTo(Region otherRegion) {
final IOResourceImpl other = (IOResourceImpl) otherRegion;
if (this.startPort + this.length <= other.startPort) {
return -1;
} else if (this.startPort >= other.startPort + other.length) {
return 1;
} else {
return 0;
}
}
/**
* Give up this resource. After this method has been called, the resource
* cannot be used anymore.
*/
public void release() {
if (!this.released) {
this.released = true;
synchronized (getClass()) {
resources = remove(resources, this);
}
}
}
/**
* Gets the parent resource if any.
*
* @return The parent resource, or null if this resource has no parent.
*/
public Resource getParent() {
return null;
}
private void testPort(int portNr, int size) {
if (released) {
throw new IndexOutOfBoundsException("Resource is released");
}
if ((portNr < startPort) || ((portNr + size) > (startPort + length))) {
throw new IndexOutOfBoundsException();
}
}
}