os_mutex.c

MCB2300_ucgui_LCD320240.rar LPC2368的uc/gui的移植

*   						 mutex.
*
*   		   timeout  	 is an optional timeout period (in clock ticks).  If non-zero, your task will
*   						 wait for the resource up to the amount of time specified by this argument.
*   						 If you specify 0, however, your task will wait forever at the specified
*   						 mutex or, until the resource becomes available.
*
*   		   perr 		 is a pointer to where an error message will be deposited.  Possible error
*   						 messages are:
*   							OS_ERR_NONE 	   The call was successful and your task owns the mutex
*   							OS_ERR_TIMEOUT     The mutex was not available within the specified 'timeout'.
*   							OS_ERR_PEND_ABORT  The wait on the mutex was aborted.
*   							OS_ERR_EVENT_TYPE  If you didn't pass a pointer to a mutex
*   							OS_ERR_PEVENT_NULL 'pevent' is a NULL pointer
*   							OS_ERR_PEND_ISR    If you called this function from an ISR and the result
*   											   would lead to a suspension.
*   							OS_ERR_PIP_LOWER   If the priority of the task that owns the Mutex is
*   											   HIGHER (i.e. a lower number) than the PIP.  This error
*   											   indicates that you did not set the PIP higher (lower
*   											   number) than ALL the tasks that compete for the Mutex.
*   											   Unfortunately, this is something that could not be
*   											   detected when the Mutex is created because we don't know
*   											   what tasks will be using the Mutex.
*   							OS_ERR_PEND_LOCKED If you called this function when the scheduler is locked
*
* Returns    : none
*
* Note(s)    : 1) The task that owns the Mutex MUST NOT pend on any other event while it owns the mutex.
*
*   		   2) You MUST NOT change the priority of the task that owns the mutex
*********************************************************************************************************
*/
void OSMutexPend(OS_EVENT *pevent, INT16U timeout, INT8U *perr)
{
	INT8U      pip; 									   /* Priority Inheritance Priority (PIP)      */
	INT8U      mprio;   								   /* Mutex owner priority  				   */
	BOOLEAN    rdy; 									   /* Flag indicating task was ready		   */
	OS_TCB    *ptcb;
	OS_EVENT  *pevent2;
	INT8U      y;
	INT8U      pend_stat;
#if OS_CRITICAL_METHOD == 3 							   /* Allocate storage for CPU status register */
	OS_CPU_SR  cpu_sr = 0;
#endif



#if OS_ARG_CHK_EN > 0
	if (perr == (INT8U *) 0)
	{
		/* Validate 'perr'  						*/
		return;
	}
	if (pevent == (OS_EVENT *) 0)
	{
		/* Validate 'pevent'						*/
		*perr = OS_ERR_PEVENT_NULL;
		return;
	}
#endif
	if (pevent->OSEventType != OS_EVENT_TYPE_MUTEX)
	{
		/* Validate event block type				*/
		*perr = OS_ERR_EVENT_TYPE;
		return;
	}
	if (OSIntNesting > 0)
	{
		/* See if called from ISR ...   			*/
		*perr = OS_ERR_PEND_ISR;						   /* ... can't PEND from an ISR               */
		return;
	}
	if (OSLockNesting > 0)
	{
		/* See if called with scheduler locked ...  */
		*perr = OS_ERR_PEND_LOCKED; 					   /* ... can't PEND when locked               */
		return;
	}
	OS_ENTER_CRITICAL();								
	pip = (INT8U) (pevent->OSEventCnt >> 8);				/* Get PIP from mutex   					*/
	/* Is Mutex available?  					*/
	if ((INT8U) (pevent->OSEventCnt & OS_MUTEX_KEEP_LOWER_8) == OS_MUTEX_AVAILABLE)
	{
		pevent->OSEventCnt &= OS_MUTEX_KEEP_UPPER_8;	   /* Yes, Acquire the resource 			   */
		pevent->OSEventCnt |= OSTCBCur->OSTCBPrio;  	   /*      Save priority of owning task 	   */
		pevent->OSEventPtr = (void *) OSTCBCur; 		   /*      Point to owning task's OS_TCB       */
		if (OSTCBCur->OSTCBPrio <= pip)
		{
			/*  	PIP 'must' have a SMALLER prio ...  */
			OS_EXIT_CRITICAL(); 						   /*      ... than current task!   		   */
			*perr = OS_ERR_PIP_LOWER;
		}
		else
		{
			OS_EXIT_CRITICAL();
			*perr = OS_ERR_NONE;
		}
		return;
	}
	mprio = (INT8U) (pevent->OSEventCnt & OS_MUTEX_KEEP_LOWER_8);  /* No, Get priority of mutex owner   */
	ptcb = (OS_TCB *) (pevent->OSEventPtr); 					  /*	 Point to TCB of mutex owner   */
	if (ptcb->OSTCBPrio > pip)
	{
		/*     Need to promote prio of owner?*/
		if (mprio > OSTCBCur->OSTCBPrio)
		{
			y = ptcb->OSTCBY;
			if ((OSRdyTbl[y] & ptcb->OSTCBBitX) != 0)
			{
				/*     See if mutex owner is ready   */
				OSRdyTbl[y] &= ~ptcb->OSTCBBitX;				  /*	 Yes, Remove owner from Rdy ...*/
				if (OSRdyTbl[y] == 0)
				{
					/*  		... list at current prio */
					OSRdyGrp &= ~ptcb->OSTCBBitY;
				}
				rdy = OS_TRUE;
			}
			else
			{
				pevent2 = ptcb->OSTCBEventPtr;
				if (pevent2 != (OS_EVENT *) 0)
				{
					/* Remove from event wait list  	 */
					if ((pevent2->OSEventTbl[ptcb->OSTCBY] &= ~ptcb->OSTCBBitX) == 0)
					{
						pevent2->OSEventGrp &= ~ptcb->OSTCBBitY;
					}
				}
				rdy = OS_FALSE; 						   /* No									   */
			}
			ptcb->OSTCBPrio = pip;  					   /* Change owner task prio to PIP 		   */
#if OS_LOWEST_PRIO <= 63
			ptcb->OSTCBY = (INT8U) (ptcb->OSTCBPrio >> 3);
			ptcb->OSTCBX = (INT8U) (ptcb->OSTCBPrio & 0x07);
			ptcb->OSTCBBitY = (INT8U) (1 << ptcb->OSTCBY);
			ptcb->OSTCBBitX = (INT8U) (1 << ptcb->OSTCBX);
#else
			ptcb->OSTCBY = (INT8U) ((ptcb->OSTCBPrio >> 4) & 0xFF);
			ptcb->OSTCBX = (INT8U) (ptcb->OSTCBPrio & 0x0F);
			ptcb->OSTCBBitY = (INT16U) (1 << ptcb->OSTCBY);
			ptcb->OSTCBBitX = (INT16U) (1 << ptcb->OSTCBX);
#endif
			if (rdy == OS_TRUE)
			{
				/* If task was ready at owner's priority ...*/
				OSRdyGrp |= ptcb->OSTCBBitY; /* ... make it ready at new priority.  	 */
				OSRdyTbl[ptcb->OSTCBY] |= ptcb->OSTCBBitX;
			}
			else
			{
				pevent2 = ptcb->OSTCBEventPtr;
				if (pevent2 != (OS_EVENT *) 0)
				{
					/* Add to event wait list   				*/
					pevent2->OSEventGrp |= ptcb->OSTCBBitY;
					pevent2->OSEventTbl[ptcb->OSTCBY] |= ptcb->OSTCBBitX;
				}
			}
			OSTCBPrioTbl[pip] = ptcb;
		}
	}
	OSTCBCur->OSTCBStat |= OS_STAT_MUTEX;   	  /* Mutex not available, pend current task 	   */
	OSTCBCur->OSTCBStatPend = OS_STAT_PEND_OK;
	OSTCBCur->OSTCBDly = timeout;   			/* Store timeout in current task's TCB           */
	OS_EventTaskWait(pevent);   					  /* Suspend task until event or timeout occurs    */
	OS_EXIT_CRITICAL();
	OS_Sched(); 									  /* Find next highest priority task ready  	   */
	OS_ENTER_CRITICAL();
	if (OSTCBCur->OSTCBStatPend != OS_STAT_PEND_OK)
	{
		/* See if we timed out during the pend  		 */
		pend_stat = OSTCBCur->OSTCBStatPend;
		OS_EventTOAbort(pevent);
		OS_EXIT_CRITICAL();
		switch (pend_stat)
		{
			case OS_STAT_PEND_TO:
			default:
				*perr = OS_ERR_TIMEOUT; 			 /* Indicate that we didn't get mutex within TO   */
				break;

			case OS_STAT_PEND_ABORT:
				*perr = OS_ERR_PEND_ABORT;  		 /* Indicate that we aborted getting mutex  	  */
				break;
		}
		return;
	}
	OSTCBCur->OSTCBEventPtr = (OS_EVENT *) 0;
	OS_EXIT_CRITICAL();
	*perr = OS_ERR_NONE;
}
/*$PAGE*/
/*
*********************************************************************************************************
*   							   POST TO A MUTUAL EXCLUSION SEMAPHORE
*
* Description: This function signals a mutual exclusion semaphore
*
* Arguments  : pevent   		   is a pointer to the event control block associated with the desired
*   							   mutex.
*
* Returns    : OS_ERR_NONE  		   The call was successful and the mutex was signaled.
*   		   OS_ERR_EVENT_TYPE	   If you didn't pass a pointer to a mutex
*   		   OS_ERR_PEVENT_NULL      'pevent' is a NULL pointer
*   		   OS_ERR_POST_ISR  	   Attempted to post from an ISR (not valid for MUTEXes)
*   		   OS_ERR_NOT_MUTEX_OWNER  The task that did the post is NOT the owner of the MUTEX.
*   		   OS_ERR_PIP_LOWER 	   If the priority of the new task that owns the Mutex is
*   								   HIGHER (i.e. a lower number) than the PIP.  This error
*   								   indicates that you did not set the PIP higher (lower
*   								   number) than ALL the tasks that compete for the Mutex.
*   								   Unfortunately, this is something that could not be
*   								   detected when the Mutex is created because we don't know
*   								   what tasks will be using the Mutex.
*********************************************************************************************************
*/

INT8U OSMutexPost(OS_EVENT *pevent)
{
	INT8U      pip; 								  /* Priority inheritance priority  			   */
	INT8U      prio;
#if OS_CRITICAL_METHOD == 3 						  /* Allocate storage for CPU status register      */
	OS_CPU_SR  cpu_sr = 0;
#endif



	if (OSIntNesting > 0)
	{
		/* See if called from ISR ...   				 */
		return (OS_ERR_POST_ISR);   				  /* ... can't POST mutex from an ISR              */
	}
#if OS_ARG_CHK_EN > 0
	if (pevent == (OS_EVENT *) 0)
	{
		/* Validate 'pevent'							 */
		return (OS_ERR_PEVENT_NULL);
	}
#endif
	if (pevent->OSEventType != OS_EVENT_TYPE_MUTEX)
	{
		/* Validate event block type					 */
		return (OS_ERR_EVENT_TYPE);
	}
	OS_ENTER_CRITICAL();
	pip = (INT8U) (pevent->OSEventCnt >> 8);		  /* Get priority inheritance priority of mutex    */
	prio = (INT8U) (pevent->OSEventCnt & OS_MUTEX_KEEP_LOWER_8);  /* Get owner's original priority      */
	if (OSTCBCur != (OS_TCB *) pevent->OSEventPtr)
	{
		/* See if posting task owns the MUTEX   		 */
		OS_EXIT_CRITICAL();
		return (OS_ERR_NOT_MUTEX_OWNER);
	}
	if (OSTCBCur->OSTCBPrio == pip)
	{
		/* Did we have to raise current task's priority? */
		OSMutex_RdyAtPrio(OSTCBCur, prio);  		  /* Restore the task's original priority          */
	}
	OSTCBPrioTbl[pip] = OS_TCB_RESERVED;			  /* Reserve table entry						   */
	if (pevent->OSEventGrp != 0)
	{
		/* Any task waiting for the mutex?  			 */
		/* Yes, Make HPT waiting for mutex ready		 */
		prio = OS_EventTaskRdy(pevent, (void *) 0, OS_STAT_MUTEX, OS_STAT_PEND_OK);
		pevent->OSEventCnt &= OS_MUTEX_KEEP_UPPER_8;  /*	  Save priority of mutex's new owner       */
		pevent->OSEventCnt |= prio;
		pevent->OSEventPtr = OSTCBPrioTbl[prio];	 /* 	 Link to new mutex owner's OS_TCB         */
		if (prio <= pip)
		{
			/*  	PIP 'must' have a SMALLER prio ...  	 */
			OS_EXIT_CRITICAL(); 					  /*	  ... than current task!				   */
			OS_Sched(); 							  /*	  Find highest priority task ready to run  */
			return (OS_ERR_PIP_LOWER);
		}
		else
		{
			OS_EXIT_CRITICAL();
			OS_Sched(); 							  /*	  Find highest priority task ready to run  */
			return (OS_ERR_NONE);
		}
	}
	pevent->OSEventCnt |= OS_MUTEX_AVAILABLE;   	  /* No,  Mutex is now available				   */
	pevent->OSEventPtr = (void *) 0;
	OS_EXIT_CRITICAL();
	return (OS_ERR_NONE);
}
/*$PAGE*/
/*
*********************************************************************************************************
*   								  QUERY A MUTUAL EXCLUSION SEMAPHORE
*
* Description: This function obtains information about a mutex
*
* Arguments  : pevent   	   is a pointer to the event control block associated with the desired mutex
*
*   		   p_mutex_data    is a pointer to a structure that will contain information about the mutex
*
* Returns    : OS_ERR_NONE  		The call was successful and the message was sent
*   		   OS_ERR_QUERY_ISR 	If you called this function from an ISR
*   		   OS_ERR_PEVENT_NULL   If 'pevent' 	  is a NULL pointer
*   		   OS_ERR_PDATA_NULL	If 'p_mutex_data' is a NULL pointer
*   		   OS_ERR_EVENT_TYPE	If you are attempting to obtain data from a non mutex.
*********************************************************************************************************
*/

#if OS_MUTEX_QUERY_EN > 0
INT8U OSMutexQuery(OS_EVENT *pevent, OS_MUTEX_DATA *p_mutex_data)
{
	INT8U      i;
#if OS_LOWEST_PRIO <= 63
	INT8U     *psrc;
	INT8U     *pdest;
#else
	INT16U    *psrc;
	INT16U    *pdest;
#endif
#if OS_CRITICAL_METHOD == 3 					 /* Allocate storage for CPU status register		   */
	OS_CPU_SR  cpu_sr = 0;
#endif



	if (OSIntNesting > 0)
	{
		/* See if called from ISR ...   			*/
		return (OS_ERR_QUERY_ISR);  					   /* ... can't QUERY mutex from an ISR        */
	}
#if OS_ARG_CHK_EN > 0
	if (pevent == (OS_EVENT *) 0)
	{
		/* Validate 'pevent'						*/
		return (OS_ERR_PEVENT_NULL);
	}
	if (p_mutex_data == (OS_MUTEX_DATA *) 0)
	{
		/* Validate 'p_mutex_data'  				*/
		return (OS_ERR_PDATA_NULL);
	}
#endif
	if (pevent->OSEventType != OS_EVENT_TYPE_MUTEX)
	{
		/* Validate event block type				*/
		return (OS_ERR_EVENT_TYPE);
	}
	OS_ENTER_CRITICAL();
	p_mutex_data->OSMutexPIP = (INT8U) (pevent->OSEventCnt >> 8);
	p_mutex_data->OSOwnerPrio = (INT8U) (pevent->OSEventCnt & OS_MUTEX_KEEP_LOWER_8);
	if (p_mutex_data->OSOwnerPrio == 0xFF)
	{
		p_mutex_data->OSValue = OS_TRUE;
	}
	else
	{
		p_mutex_data->OSValue = OS_FALSE;
	}
	p_mutex_data->OSEventGrp = pevent->OSEventGrp;  	  /* Copy wait list 						  */
	psrc = &pevent->OSEventTbl[0];
	pdest = &p_mutex_data->OSEventTbl[0];
	for (i = 0; i < OS_EVENT_TBL_SIZE; i++)
	{
		*pdest++ = *psrc++;
	}
	OS_EXIT_CRITICAL();
	return (OS_ERR_NONE);
}
#endif  												   /* OS_MUTEX_QUERY_EN 					   */

/*$PAGE*/
/*
*********************************************************************************************************
*   							 RESTORE A TASK BACK TO ITS ORIGINAL PRIORITY
*
* Description: This function makes a task ready at the specified priority
*
* Arguments  : ptcb 		   is a pointer to OS_TCB of the task to make ready
*
*   		   prio 		   is the desired priority
*
* Returns    : none
*********************************************************************************************************
*/

static  void OSMutex_RdyAtPrio(OS_TCB *ptcb, INT8U prio)
{
	INT8U   y;


	y = ptcb->OSTCBY;   					   /* Remove owner from ready list at 'pip'    */
	OSRdyTbl[y] &= ~ptcb->OSTCBBitX;
	if (OSRdyTbl[y] == 0)
	{
		OSRdyGrp &= ~ptcb->OSTCBBitY;
	}
	ptcb->OSTCBPrio = prio;
#if OS_LOWEST_PRIO <= 63
	ptcb->OSTCBY = (INT8U) ((prio >> (INT8U) 3) & (INT8U) 0x07);
	ptcb->OSTCBX = (INT8U) (prio & (INT8U) 0x07);
	ptcb->OSTCBBitY = (INT8U) (1 << ptcb->OSTCBY);
	ptcb->OSTCBBitX = (INT8U) (1 << ptcb->OSTCBX);
#else
	ptcb->OSTCBY = (INT8U) ((prio >> (INT8U) 4) & (INT8U) 0x0F);
	ptcb->OSTCBX = (INT8U) (prio & (INT8U) 0x0F);
	ptcb->OSTCBBitY = (INT16U) (1 << ptcb->OSTCBY);
	ptcb->OSTCBBitX = (INT16U) (1 << ptcb->OSTCBX);
#endif
	OSRdyGrp |= ptcb->OSTCBBitY;			 /* Make task ready at original priority	 */
	OSRdyTbl[ptcb->OSTCBY] |= ptcb->OSTCBBitX;
	OSTCBPrioTbl[prio] = ptcb;
}


#endif  												   /* OS_MUTEX_EN   						   */