xnu-792.25.20.tar.gz

[apple/xnu.git] / iokit / Kernel / IOPMPowerSourceList.cpp

/*
 * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
#include <IOKit/pwr_mgt/IOPM.h>
#include <IOKit/pwr_mgt/IOPMPowerSourceList.h>
#include <IOKit/pwr_mgt/IOPMPowerSource.h>

#define super OSObject
OSDefineMetaClassAndStructors(IOPMPowerSourceList,OSObject)

//******************************************************************************
// init
//
//******************************************************************************
void IOPMPowerSourceList::initialize ( void )
{
    firstItem = NULL;
    length = 0;
}

//******************************************************************************
// addToList
//
//******************************************************************************

IOReturn IOPMPowerSourceList::addToList(IOPMPowerSource *newPowerSource)
{
    IOPMPowerSource * nextPowerSource;

    // Is new object already in the list?
    nextPowerSource = firstItem;
    while (  nextPowerSource != NULL ) 
    {
        if ( nextPowerSource == newPowerSource ) 
        {
            // yes, just return
            return IOPMNoErr;				
        }
        nextPowerSource = nextInList(nextPowerSource);
    }

    // add it to list
    newPowerSource->nextInList = firstItem;
    firstItem = newPowerSource;
    length++;
    return IOPMNoErr;
}


//******************************************************************************
// firstInList
//
//******************************************************************************

IOPMPowerSource * IOPMPowerSourceList::firstInList ( void )
{
    return firstItem;
}

//******************************************************************************
// nextInList
//
//******************************************************************************

IOPMPowerSource * IOPMPowerSourceList::nextInList(IOPMPowerSource *currentItem)
{
    if ( currentItem != NULL ) {
       return (currentItem->nextInList);
    }
    return NULL;
}

//******************************************************************************
// numberOfItems
//
//******************************************************************************

unsigned long IOPMPowerSourceList::numberOfItems ( void )
{
    return length;
}

//******************************************************************************
// removeFromList
//
// Find the item in the list, unlink it, and free it.
//******************************************************************************

IOReturn IOPMPowerSourceList::removeFromList ( IOPMPowerSource * theItem )
{
    IOPMPowerSource * item = firstItem;
    IOPMPowerSource * temp;

    if ( NULL == item) goto exit;
    
    if ( item  == theItem ) {
        firstItem = item->nextInList;
        length--;
        item->release();
        return IOPMNoErr;
    }
    while ( item->nextInList != NULL ) {
        if ( item->nextInList == theItem ) {
            temp = item->nextInList;
            item->nextInList = temp->nextInList;
            length--;
            temp->release();
            return IOPMNoErr;
        }
        item = item->nextInList;
    }

exit:
    return IOPMNoErr;
}


//******************************************************************************
// free
//
// Free all items in the list, and then free the list itself
//******************************************************************************

void IOPMPowerSourceList::free (void )
{
    IOPMPowerSource * next = firstItem;

    while ( next != NULL ) {
        firstItem = next->nextInList;
        length--;
        next->release();
        next = firstItem;        
    }
    super::free();
}