zfindresourceqinsertionpos.c

zilog的实时操作系统RZK,可以移植到多种处理器上

/*
* File				:	ZFindResourceQInsertionPos.c
*
* Description		:	This file contains definition of FindResourceQInsertionPos routine
*
* Copyright 2004 ZiLOG Inc.  ALL RIGHTS RESERVED.
*
* This file contains unpublished confidential and proprietary information
* of ZiLOG, Inc.
* NO PART OF THIS WORK MAY BE DUPLICATED, STORED, PUBLISHED OR DISCLOSED 
* IN ANY FORM WITHOUT THE PRIOR WRITTEN CONSENT OF ZiLOG, INC.
* This is not a license and no use of any kind of this work is authorized
* in the absence of a written license granted by ZiLOG, Inc. in ZiLOG's 
* sole discretion 
*/
#include "ZSysgen.h"
#include "ZTypes.h"
#include "ZThread.h"
#include "ZQueue.h"
#include "ZMessageQ.h"

#define pCurrentThread ((RZK_TCB_t *) hCurrentThread)

extern RZK_HANDLE_t hCurrentThread;

/* Function			:	FindResourceQInsertionPos
*
* Description		:	Finds the position for a new node to be inserted in the resource
*						queue depending on the priority of the thread. Returns a pointer
*						to the preceding element in the queue. The highest priority thread 
*						is always inserted in the first position.
* 
* Inputs			:	hControlblock - handle to the Control Block to be searched.
*
* Outputs			:	Insertion position in the queue.
*							
*
* Dependencies		:	None
*/
RZK_TCB_t * FindResourceQInsertionPos(RZK_MESSAGEQUEUE_t *hControlBlock)
{
	RZK_TCB_t * pInsertionPos = ( RZK_TCB_t *) hControlBlock;
	RZK_TCB_t * pTemp  = 	hControlBlock->pResNext;
	while ( pTemp != NULL)
	{
		if( pCurrentThread->cDispPriority <= pTemp->cDispPriority )
			return pInsertionPos;
		else
		{
			pInsertionPos = pTemp;
			pTemp = pTemp->pResNext;
		}
	}
	hControlBlock->pLastPosition = pCurrentThread;
	return pInsertionPos;
			
} /* End of FindResourceQInsertionPos */