/* $Xorg: sched.h,v 1.3 2000/08/17 19:47:46 cpqbld Exp $ */
/**** module sched.h ****/
/******************************************************************************

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******************************************************************************

	sched.h -- DDXIE machine independent scheduler definitions

	Robert NC Shelley -- AGE Logic, Inc.  May 1993

******************************************************************************/
/* $XFree86: xc/programs/Xserver/XIE/mixie/include/sched.h,v 1.4 2001/01/17 22:13:07 dawes Exp $ */

#ifndef _XIEH_SCHED
#define _XIEH_SCHED

/* scheduler interface
 */
struct _petex;
typedef bandMsk	(*xieBandProc)(floDefPtr flo, struct _petex *pet);
typedef struct _schedvec {
  xieBoolProc	execute;
  xieBandProc	runnable;
} schedVecRec;

/* call scheduler to execute until out of data;
 * returns Bool: true if flo still active
 */
#define Execute(flo,import_pet) \
		(*flo->schedVec->execute)(flo,import_pet)

/* detect execution suspension/resumption
 * returns Bool: true if scheduler has exited to core X since last checked
 * (useful for determining if fresh lookups are needed for core X resources)
 */
#define Resumed(flo,pet) \
		(pet->schedCnt == flo->floTex->exitCnt ? FALSE \
                 : ((pet->schedCnt = flo->floTex->exitCnt), TRUE))

/* toggle the band's ready bit if "available >= threshold" status has changed
 * and return the updated ready mask;
 * if the ready bit doesn't toggle, return NO_BANDS
 */
#define CheckSrcReady(bnd,bmsk) \
		(bnd->receptor->ready & (bmsk) \
		 ? (bnd->available < bnd->threshold \
		    ? (bnd->receptor->ready &= ~(bmsk)) : NO_BANDS) \
		 : (bnd->available >= bnd->threshold \
		    ? (bnd->receptor->ready |=  (bmsk)) : NO_BANDS))

/* try to schedule the specified element based on new data arriving for:
 * 			receptorPtr rcp, bandPtr bnd, and bandMsk bmsk
 * nothing is returned, but pet->scheduled indicates which bands are runnable
 */
#define Schedule(flo,pet,rcp,bnd,bmsk) \
		{ bandMsk r = CheckSrcReady(bnd,bmsk) & rcp->attend; \
		  if(r && !pet->scheduled) { \
		    if(!pet->inSync) { \
		      if(!pet->bandSync || r == (rcp->active & rcp->attend)) {\
		        pet->scheduled |= r; \
			InsertMember(pet, &flo->floTex->schedHead); \
		      } \
		    } else if((r = (*flo->schedVec->runnable)(flo,pet)) != 0) { \
		      pet->scheduled = r; \
		      InsertMember(pet,&flo->floTex->schedHead); \
		} } }
#endif /* end _XIEH_SCHED */