xnu-3789.51.2.tar.gz

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

/*
 * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The 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,
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 * Please see the License for the specific language governing rights and
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 */
#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();
}