- (void) receiveSleepNote: (NSNotification*) note

{

    NSLog(@"receiveSleepNote: %@", [note name]);

}

- (void) receiveWakeNote: (NSNotification*) note

{

    NSLog(@"receiveWakeNote: %@", [note name]);

}

- (void) fileNotifications

{

    //These notifications are filed on NSWorkspace's notification center, not the default

    // notification center. You will not receive sleep/wake notifications if you file

    //with the default notification center.

    [[[NSWorkspace sharedWorkspace] notificationCenter] addObserver: self

            selector: @selector(receiveSleepNote:)

            name: NSWorkspaceWillSleepNotification object: NULL];

    [[[NSWorkspace sharedWorkspace] notificationCenter] addObserver: self

            selector: @selector(receiveWakeNote:)

            name: NSWorkspaceDidWakeNotification object: NULL];

}

...

#import <IOKit/pwr_mgt/IOPMLib.h>

...

// kIOPMAssertionTypeNoDisplaySleep prevents display sleep,

// kIOPMAssertionTypeNoIdleSleep prevents idle sleep

//reasonForActivity is a descriptive string used by the system whenever it needs

//  to tell the user why the system is not sleeping. For example,

//  "Mail Compacting Mailboxes" would be a useful string.

//  NOTE: IOPMAssertionCreateWithName limits the string to 128 characters.

CFStringRef* reasonForActivity= CFSTR("Describe Activity Type");

IOPMAssertionID assertionID;

IOReturn success = IOPMAssertionCreateWithName(kIOPMAssertionTypeNoDisplaySleep,

                                    kIOPMAssertionLevelOn, reasonForActivity, &assertionID);

if (success == kIOReturnSuccess)

{

    //Add the work you need to do without

    //  the system sleeping here.

    success = IOPMAssertionRelease(assertionID);

    //The system will be able to sleep again.

}

...

#include <ctype.h>

#include <stdlib.h>

#include <stdio.h>

#include <mach/mach_port.h>

#include <mach/mach_interface.h>

#include <mach/mach_init.h>

#include <IOKit/pwr_mgt/IOPMLib.h>

#include <IOKit/IOMessage.h>

io_connect_t  root_port; // a reference to the Root Power Domain IOService

void

MySleepCallBack( void * refCon, io_service_t service, natural_t messageType, void * messageArgument )

{

    printf( "messageType %08lx, arg %08lx\n",

        (long unsigned int)messageType,

        (long unsigned int)messageArgument );

    switch ( messageType )

    {

        case kIOMessageCanSystemSleep:

            /* Idle sleep is about to kick in. This message will not be sent for forced sleep.

                Applications have a chance to prevent sleep by calling IOCancelPowerChange.

                Most applications should not prevent idle sleep.

                Power Management waits up to 30 seconds for you to either allow or deny idle

                sleep. If you don't acknowledge this power change by calling either

                IOAllowPowerChange or IOCancelPowerChange, the system will wait 30

                seconds then go to sleep.

            */

            //Uncomment to cancel idle sleep

            //IOCancelPowerChange( root_port, (long)messageArgument );

            // we will allow idle sleep

            IOAllowPowerChange( root_port, (long)messageArgument );

            break;

        case kIOMessageSystemWillSleep:

            /* The system WILL go to sleep. If you do not call IOAllowPowerChange or

                IOCancelPowerChange to acknowledge this message, sleep will be

                delayed by 30 seconds.

                NOTE: If you call IOCancelPowerChange to deny sleep it returns

                kIOReturnSuccess, however the system WILL still go to sleep.

            */

            IOAllowPowerChange( root_port, (long)messageArgument );

            break;

        case kIOMessageSystemWillPowerOn:

            //System has started the wake up process...

            break;

        case kIOMessageSystemHasPoweredOn:

            //System has finished waking up...

        break;

        default:

            break;

    }

}

int main( int argc, char **argv )

{

    // notification port allocated by IORegisterForSystemPower

    IONotificationPortRef  notifyPortRef;

    // notifier object, used to deregister later

    io_object_t            notifierObject;

   // this parameter is passed to the callback

    void*                  refCon;

    // register to receive system sleep notifications

    root_port = IORegisterForSystemPower( refCon, &notifyPortRef, MySleepCallBack, &notifierObject );

    if ( root_port == 0 )

    {

        printf("IORegisterForSystemPower failed\n");

        return 1;

    }

    // add the notification port to the application runloop

    CFRunLoopAddSource( CFRunLoopGetCurrent(),

            IONotificationPortGetRunLoopSource(notifyPortRef), kCFRunLoopCommonModes );

    /* Start the run loop to receive sleep notifications. Don't call CFRunLoopRun if this code

        is running on the main thread of a Cocoa or Carbon application. Cocoa and Carbon

        manage the main thread's run loop for you as part of their event handling

        mechanisms.

    */

    CFRunLoopRun();

    //Not reached, CFRunLoopRun doesn't return in this case.

    return (0);

}

...

    // we no longer want sleep notifications:

    // remove the sleep notification port from the application runloop

    CFRunLoopRemoveSource( CFRunLoopGetCurrent(),

                           IONotificationPortGetRunLoopSource(notifyPortRef),

                           kCFRunLoopCommonModes );

    // deregister for system sleep notifications

    IODeregisterForSystemPower( &notifierObject );

    // IORegisterForSystemPower implicitly opens the Root Power Domain IOService

    // so we close it here

    IOServiceClose( root_port );

    // destroy the notification port allocated by IORegisterForSystemPower

    IONotificationPortDestroy( notifyPortRef );

...