resetqueue.c

zilog的实时操作系统RZK,可以移植到多种处理器上

/***************************************************
*	RZK	RTOS
*	Copyright (c)  1999,  ZiLOG.
*	Developed for ZiLOG by DACS,India.
*
*	Author			: Ram prasad B.E
*
*	Creation Date	: 13th of April,1999
*
*	Revision History :	23-01-01 Shreekanth.B ZIEL
*						RZKERR_CB_BUSY return encapsulated by #ifndef RZK_PERFORMANCE
*
*	Function		: RZKResetQueue
*
*	Purpose			: Removes all the messages queued up in this queue and resumes 
*					  all the threads waiting on this queue with appropriate status.
*					  The control block is reset to it's created state.
*
*	Inputs			: hMessageQueue  - handle to the message queue control block to reset

*	 
*	Outputs			: RZKERR_SUCCESS - If the message queue was successfully reset.
*					  RZKERR_CB_BUSY- If the message control block is being used exclusively by other thread.
*					  RZKERR_INVALID_HANDLE - If the hMessageQueue is invalid.

*
*	Dependencies	: None.
*	
*************************************************************************************************************/

#include "ZSysgen.h"
#include "ZTypes.h"
#include "ZThread.h"
#include "ZQueue.h" 
#include "ZMessageQ.h"
#include "ZScheduler.h"

#define pMessageQueue  ((RZK_MESSAGEQUEUE_t *) hMessageQueue)
extern RZK_THREADHANDLE_t hCurrentThread;

/** extern functions */
extern UINTRMASK RZKDisableInterrupts();
extern void RZKEnableInterrupts(UINTRMASK);
//extern void RZKScheduler();
//extern void UpdateThreadStatus( RZK_TCB_t * hThread,UINT errNum);
extern void InitializeCircularBuffer(RZK_MESSAGEQUEUE_t * );

RZK_STATUS_t ResetQueue
					(
						RZK_MESSAGEQHANDLE_t  hMessageQueue 
					)
{
	/* Local Variable */
	RZK_TCB_t *pTemp;
	RZK_STATE_t uState;
	
	/* validate the handle passed */
#ifdef RZK_DEBUG
		if((pMessageQueue==NULL) || ( pMessageQueue -> uState == 0 ) || 
			( pMessageQueue -> magic_num != MAGIC_NUM_MESSAGEQ ))
			return RZKERR_INVALID_HANDLE;
#endif

#ifndef RZK_PERFORMANCE
	if(!(pMessageQueue -> uState & OBJECT_CREATED))
		return RZKERR_CB_BUSY;
#endif

	/* Reset the created bit of uState */
	uState = RZKDisablePreemption();
	pMessageQueue -> uState &= ~(OBJECT_CREATED);
	
	pTemp = pMessageQueue->pResNext;
	/* check whether the threads which are waiting either to send or receive messages are in TimeQ2.If so remove it from TQ2 */
	while ( pTemp != NULL)
	{
		UpdateThreadStatus(pTemp,RZKERR_OBJECT_RESET);
		pTemp=pTemp->pResNext;
	}

	/* Set etWaitingQueue to MESSAGE_NONE */
	pMessageQueue -> etWaitingQueue = MESSAGE_NONE;

	InitializeCircularBuffer(pMessageQueue);
	/* Initialize uMessageSpaceLeft parameter */
	pMessageQueue->uMessageSpaceLeft = pMessageQueue->uQueueLength;

	/* Set the created flag of the uState */
	pMessageQueue->uState |= OBJECT_CREATED;

	RZKRestorePreemption(uState);
	return RZKERR_SUCCESS;
} /* end of RZKResetQueue */