ATATimerEventSource.cpp   [plain text]

/*
 * Copyright (c) 2001-2008 Apple 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@
 */
/*
 * ATATimerEventSource.cpp
 *
 *	implements a timer event source that can be checked from behind the 
 *  workloop for a timeout event.
 */
 
#include <sys/cdefs.h>

__BEGIN_DECLS
#include <kern/thread_call.h>
__END_DECLS

#include <IOKit/assert.h>
#include <IOKit/system.h>

#include <IOKit/IOLib.h>
#include <IOKit/IOTimerEventSource.h>
#include <IOKit/IOWorkLoop.h>
#include "ATATimerEventSource.h"


#define super IOTimerEventSource
OSDefineMetaClassAndStructors(ATATimerEventSource, IOTimerEventSource)
OSMetaClassDefineReservedUnused(ATATimerEventSource, 0);
OSMetaClassDefineReservedUnused(ATATimerEventSource, 1);
OSMetaClassDefineReservedUnused(ATATimerEventSource, 2);
OSMetaClassDefineReservedUnused(ATATimerEventSource, 3);
OSMetaClassDefineReservedUnused(ATATimerEventSource, 4);
OSMetaClassDefineReservedUnused(ATATimerEventSource, 5);
OSMetaClassDefineReservedUnused(ATATimerEventSource, 6);
OSMetaClassDefineReservedUnused(ATATimerEventSource, 7);

// the interesting part of the function.
bool 
ATATimerEventSource::hasTimedOut( void )
{
	return (hasExpired == kTimedOutTrue);
}


// Timeout handler function. This function is called by the kernel when
// the timeout interval expires.
//
void ATATimerEventSource::myTimeout(void *self)
{
    ATATimerEventSource *me = (ATATimerEventSource *) self;
	
	OSCompareAndSwap( kTimedOutFalse, kTimedOutTrue, &(me->hasExpired) );
	
	// pasted from superclass's static handler.
 
	if (me->enabled) 
	{
        Action doit = (Action) me->action;

        if (doit) 
		{
            me->closeGate();
            (*doit)(me->owner, me);
            me->openGate();
        }
    }
}

void ATATimerEventSource::setTimeoutFunc()
{
    calloutEntry = (void *) thread_call_allocate((thread_call_func_t) myTimeout,
                                                 (thread_call_param_t) this);
}

bool ATATimerEventSource::init(OSObject *inOwner, Action inAction)
{
    if ( !super::init( (OSObject *)inOwner, (Action) inAction) )
        return false;

	hasExpired = kTimedOutFalse;
	
    return true;
}


ATATimerEventSource *
ATATimerEventSource::ataTimerEventSource(OSObject *inOwner, Action inAction)
{
    ATATimerEventSource *me = new ATATimerEventSource;

    if (me && !me->init(inOwner, inAction)) {
        me->free();
        return 0;
    }

    return me;
}
void ATATimerEventSource::cancelTimeout()
{
	hasExpired = kTimedOutFalse;
	super::cancelTimeout();
}

void ATATimerEventSource::enable()
{
	hasExpired = kTimedOutFalse;
    super::enable();
}

void ATATimerEventSource::disable()
{
	hasExpired = kTimedOutFalse;

    super::disable();
}

IOReturn ATATimerEventSource::wakeAtTime(UnsignedWide inAbstime)
{
	hasExpired = kTimedOutFalse;
#if ABSOLUTETIME_SCALAR_TYPE
	UInt64	abstime = (UInt64)inAbstime.hi << 32 | (UInt64)inAbstime.lo;
    return super::wakeAtTime( abstime );
#else
	return super::wakeAtTime(inAbstime);
#endif	/* ABSOLUTETIME_SCALAR_TYPE */
}