setsemaphoreparameters.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.
*	  
*	File			:	RZKSetSemaphoreParameters
*
*	Author			:	Rohit S.P.
*	
*	Date Of Creation:	Sunday 13th April of 1999
*
*	Revision History :	23-01-01 Shreekanth.B ZIEL
*						RZKERR_CB_BUSY return encapsulated by #ifndef RZK_PERFORMANCE
*
*						18-09-2001 Mahadev K Cholachagudda, ZIEL
*						made to return an error if the value of The pSemaphoreParams member
*						uInitialCount ( pSemaphoreParams->uInitialCount ) is zero.
*						now returns RZKERR_INVALID_ARGUMENTS if uInitialCount is zero.
*
*	Modified By		:
*
*	Modification	:
*	Date
*
*	Purpose			:   To set the user specifed semaphore parameters to the semaphore structure.
*						control block to the user specified Semaphoreparams_t structure.
*
*	Inputs			:   hSemaphore - Specifies a handle to semaphore whose parameters 
*									are to be set.
*						pSemaphoreParams - Specifies a pointer to the semaphore 
*									parameter structure
*
*	Outputs			:	RZKERR_SUCCESS -If the parameters are successfully set.
*						RZKERR_INVALID_HANDLE - If the specified handle was invalid.
*						RZKERR_INVALID_ARGUMENTS - If the specified address of the structure was invalid.
*						RZKERR_OBJECT_IN_USE - Specifies that the object is in exclusively used.
*						RZKERR_CB_BUSY - Specifies that the control block is busy
*
*	Assumptions		:
*
*	Dependencies	:
*
*************************************************************/

#include "ZSysgen.h"
#include "ZTypes.h"
#include "ZThread.h"
#include "ZSemaphore.h"

#define pSemaphore ((RZK_SEMAPHORE_t *) hSemaphore)
extern RZK_THREADHANDLE_t hCurrentThread;

/** extern functions */
extern UINTRMASK RZKDisableInterrupts();
extern void RZKEnableInterrupts(UINTRMASK);

RZK_STATUS_t SetSemaphoreParameters
		( 
		RZK_SEMAPHOREHANDLE_t hSemaphore,
		RZK_SEMAPHOREPARAMS_t *pSemaphoreParams
		)

{
	/* Local Variable */
	RZK_STATE_t uState;
	/* check the validity of the arguments */
#ifdef RZK_DEBUG 
		
		if ((pSemaphore == NULL)||(pSemaphore -> uState == 0 )||
					(pSemaphore -> magic_num != MAGIC_NUM_SEMAPHORE ))
	 			return RZKERR_INVALID_HANDLE;

		if((pSemaphoreParams == NULL) || 
			(pSemaphoreParams -> uInitialCount == 0 )) /** 18-09-2001, Mahadev KC : refer revision history*/
				return RZKERR_INVALID_ARGUMENTS;	  

#endif /* RZK_DEBUG */
	

/* Check the threads which are pending on this semaphore */
		if((pSemaphore -> pResNext != NULL) || (pSemaphore->uInitialCount != pSemaphore->uDynamicCount))
				return RZKERR_OBJECT_IN_USE;


/* Check the created flag in uState member of the Semaphore control block.If it is reset return RZKERR_OBJECT_IN_USE error else reset the created flag of the uState member */
#ifndef RZK_PERFORMANCE					
		if(!(pSemaphore -> uState & OBJECT_CREATED))
				return RZKERR_CB_BUSY;
#endif

		uState = RZKDisablePreemption();
		pSemaphore -> uState &= ~(OBJECT_CREATED);
		pSemaphore->uInitialCount = pSemaphore->uDynamicCount = pSemaphoreParams -> uInitialCount;
		/* If the semaphore is changed from binary semaphore to counting semaphore , reset priority
		inheritance for this semaphore */
		if(pSemaphoreParams -> uInitialCount > 1)
			pSemaphore->uState &= ~OBJECT_PRIORITY_INHERITANCE;
		else if((pSemaphoreParams -> uInitialCount == 1) && (pSemaphore->uState & OBJECT_RECV_PRIORITY))
			pSemaphore->uState |= OBJECT_PRIORITY_INHERITANCE;

		/* Set the OBJECT_CREATED bit in uState field of Semaphore Control Block */
		pSemaphore -> uState |= OBJECT_CREATED;	
        RZKEnableInterrupts(uState);
		return RZKERR_SUCCESS;

}/* End of RZKSetSemaphoreParams */