/* This snippet demonstrates how to create a sleep queue entry under Think C */

#include "Power.h"

#include "SetUpa4.h"

pascal long MySleepQueueEntry(void);

SleepQRec gMySleepQStruct;

/*

  Here's where we install our sleep queue entry.  This is all

  by the book, as documented in Inside Mac volume VI.

*/

void InstallOurSleepQueueEntry()

{

    RememberA4();

    /* install our test routine in the sleep process queue */

    gMySleepQStruct.sleepQLink = 0;

    gMySleepQStruct.sleepQType = slpQType;

    gMySleepQStruct.sleepQProc = (ProcPtr) &MySleepQueueEntry;

    gMySleepQStruct.sleepQFlags = 0;

    SleepQInstall(&gMySleepQStruct);

}

/*  This routine can be called at any of four ways as indicated by D0.  

    When it's called, register A0 contains a pointer to our sleep queue record, 

    and register D0 contains a "what's happening" value:

    1 = sleep request (i.e. "Can I sleep?")

    2 = sleep demand (i.e. "You must sleep.")

    3 = wakeup demand (i.e. "You must wake up.")

    4 = sleep-request revocation (i.e. "I changed my mind about putting you to sleep.")

    Since Think C depends upon C calling conventions, you need special in-line

    assembly to handle this routine.

*/

pascal long MySleepQueueEntry(void)

{

    long        whatToDo;   /* passed to us in D0 */

    SleepQRec   *sqPtr;     /* passed to us in A0 */

    long        returnValue;

/* Important: These assembly instructions must be the first executable code

** in this routine, or you have the potential of changing D0 and/or A0 before

** you get a chance to save them.  Don't put any code before this asm statement!

*/

    asm {

            MOVE.L  D0, whatToDo

            MOVE.L  A0, sqPtr

    }

    SetUpA4();

    returnValue = 0;        /* 0 = okay whatever the system wants to do */

/* At this point, you'd do whatever you want to do at sleep time.

*/

    switch (whatToDo) {

        case sleepRequest:

            DebugStr("\pIn sleepRequest");

            break;

        case sleepDemand:

            DebugStr("\pIn sleepDemand");

            break;

        case sleepWakeUp:

            DebugStr("\pIn sleepWakeUp");

            break;

        case sleepRevoke:

            DebugStr("\pIn sleepRevoke");

            break;

    }

    RestoreA4();

/* Important: this asm statement must be the last executable code in this

** routine, or you won't return the proper value in D0.

*/

    asm {

            MOVE.L  returnValue, D0

    }

}