tasks.c

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				initialisation required.  We will not recover if this call
				fails, but we will report the failure. */
				prvInitialiseTaskLists();
			}
			else
			{	
				/* If the scheduler is not already running, make this task the
				current task if it is the highest priority task to be created
				so far. */
				if( xSchedulerRunning == pdFALSE )
				{
					if( pxCurrentTCB->uxPriority <= uxPriority )
					{
						pxCurrentTCB = pxNewTCB;	
					}
				}
			}				

			/* Remember the top priority to make context switching faster.  Use
			the priority in pxNewTCB as this has been capped to a valid value. */
			if( pxNewTCB->uxPriority > uxTopUsedPriority )
			{
				uxTopUsedPriority = pxNewTCB->uxPriority;
			}

			#if ( configUSE_TRACE_FACILITY == 1 )
			{
				/* Add a counter into the TCB for tracing only. */
				pxNewTCB->uxTCBNumber = uxTaskNumber;
				uxTaskNumber++;
			}
			#endif

			prvAddTaskToReadyQueue( pxNewTCB );

			xReturn = pdPASS;
			traceTASK_CREATE( pxNewTCB );
		}
		portEXIT_CRITICAL();
	}
	else
	{
		xReturn = errCOULD_NOT_ALLOCATE_REQUIRED_MEMORY;
		traceTASK_CREATE_FAILED( pxNewTCB );
	}

	if( xReturn == pdPASS )
	{
		if( ( void * ) pxCreatedTask != NULL )
		{
			/* Pass the TCB out - in an anonymous way.  The calling function/
			task can use this as a handle to delete the task later if
			required.*/
			*pxCreatedTask = ( xTaskHandle ) pxNewTCB;
		}

		if( xSchedulerRunning != pdFALSE )
		{
			/* If the created task is of a higher priority than the current task
			then it should run now. */
			if( pxCurrentTCB->uxPriority < uxPriority )
			{
				taskYIELD();
			}
		}
	}

	return xReturn;
}
/*-----------------------------------------------------------*/

#if ( INCLUDE_vTaskDelete == 1 )

	void vTaskDelete( xTaskHandle pxTaskToDelete )
	{
	tskTCB *pxTCB;

		taskENTER_CRITICAL();
		{
			/* Ensure a yield is performed if the current task is being
			deleted. */
			if( pxTaskToDelete == pxCurrentTCB )
			{
				pxTaskToDelete = NULL;
			}

			/* If null is passed in here then we are deleting ourselves. */
			pxTCB = prvGetTCBFromHandle( pxTaskToDelete );

			traceTASK_DELETE( pxTCB );

			/* Remove task from the ready list and place in the	termination list.
			This will stop the task from be scheduled.  The idle task will check
			the termination list and free up any memory allocated by the
			scheduler for the TCB and stack. */
			vListRemove( &( pxTCB->xGenericListItem ) );

			/* Is the task waiting on an event also? */												
			if( pxTCB->xEventListItem.pvContainer )
			{
				vListRemove( &( pxTCB->xEventListItem ) );
			}

			vListInsertEnd( ( xList * ) &xTasksWaitingTermination, &( pxTCB->xGenericListItem ) );

			/* Increment the ucTasksDeleted variable so the idle task knows
			there is a task that has been deleted and that it should therefore
			check the xTasksWaitingTermination list. */
			++uxTasksDeleted;
		}
		taskEXIT_CRITICAL();

		/* Force a reschedule if we have just deleted the current task. */
		if( xSchedulerRunning != pdFALSE )
		{
			if( ( void * ) pxTaskToDelete == NULL )
			{
				taskYIELD();
			}
		}
	}

#endif






/*-----------------------------------------------------------
 * TASK CONTROL API documented in task.h
 *----------------------------------------------------------*/

#if ( INCLUDE_vTaskDelayUntil == 1 )

	void vTaskDelayUntil( portTickType * const pxPreviousWakeTime, portTickType xTimeIncrement )
	{
	portTickType xTimeToWake;
	portBASE_TYPE xAlreadyYielded, xShouldDelay = pdFALSE;

		vTaskSuspendAll();
		{
			/* Generate the tick time at which the task wants to wake. */
			xTimeToWake = *pxPreviousWakeTime + xTimeIncrement;

			if( xTickCount < *pxPreviousWakeTime )
			{
				/* The tick count has overflowed since this function was
				lasted called.  In this case the only time we should ever
				actually delay is if the wake time has also	overflowed,
				and the wake time is greater than the tick time.  When this
				is the case it is as if neither time had overflowed. */
				if( ( xTimeToWake < *pxPreviousWakeTime ) && ( xTimeToWake > xTickCount ) )
				{
					xShouldDelay = pdTRUE;
				}
			}
			else
			{
				/* The tick time has not overflowed.  In this case we will
				delay if either the wake time has overflowed, and/or the
				tick time is less than the wake time. */
				if( ( xTimeToWake < *pxPreviousWakeTime ) || ( xTimeToWake > xTickCount ) )
				{
					xShouldDelay = pdTRUE;
				}
			}

			/* Update the wake time ready for the next call. */
			*pxPreviousWakeTime = xTimeToWake;

			if( xShouldDelay )
			{
				traceTASK_DELAY_UNTIL();

				/* We must remove ourselves from the ready list before adding
				ourselves to the blocked list as the same list item is used for
				both lists. */
				vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );

				/* The list item will be inserted in wake time order. */
				listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );

				if( xTimeToWake < xTickCount )
				{
					/* Wake time has overflowed.  Place this item in the
					overflow list. */
					vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );
				}
				else
				{
					/* The wake time has not overflowed, so we can use the
					current block list. */
					vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );
				}
			}
		}
		xAlreadyYielded = xTaskResumeAll();

		/* Force a reschedule if xTaskResumeAll has not already done so, we may
		have put ourselves to sleep. */
		if( !xAlreadyYielded )
		{
			taskYIELD();
		}
	}	
	
#endif
/*-----------------------------------------------------------*/

#if ( INCLUDE_vTaskDelay == 1 )

	void vTaskDelay( portTickType xTicksToDelay )
	{
	portTickType xTimeToWake;
	signed portBASE_TYPE xAlreadyYielded = pdFALSE;

		/* A delay time of zero just forces a reschedule. */
		if( xTicksToDelay > ( portTickType ) 0 )
		{
			vTaskSuspendAll();
			{
				traceTASK_DELAY();

				/* A task that is removed from the event list while the
				scheduler is suspended will not get placed in the ready
				list or removed from the blocked list until the scheduler
				is resumed.
				
				This task cannot be in an event list as it is the currently
				executing task. */

				/* Calculate the time to wake - this may overflow but this is
				not a problem. */
				xTimeToWake = xTickCount + xTicksToDelay;

				/* We must remove ourselves from the ready list before adding
				ourselves to the blocked list as the same list item is used for
				both lists. */
				vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );

				/* The list item will be inserted in wake time order. */
				listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );

				if( xTimeToWake < xTickCount )
				{
					/* Wake time has overflowed.  Place this item in the
					overflow list. */
					vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );
				}
				else
				{
					/* The wake time has not overflowed, so we can use the
					current block list. */
					vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );
				}
			}
			xAlreadyYielded = xTaskResumeAll();
		}
		
		/* Force a reschedule if xTaskResumeAll has not already done so, we may
		have put ourselves to sleep. */
		if( !xAlreadyYielded )
		{
			taskYIELD();
		}
	}
	
#endif
/*-----------------------------------------------------------*/

#if ( INCLUDE_uxTaskPriorityGet == 1 )

	unsigned portBASE_TYPE uxTaskPriorityGet( xTaskHandle pxTask )
	{
	tskTCB *pxTCB;
	unsigned portBASE_TYPE uxReturn;

		taskENTER_CRITICAL();
		{
			/* If null is passed in here then we are changing the
			priority of the calling function. */
			pxTCB = prvGetTCBFromHandle( pxTask );
			uxReturn = pxTCB->uxPriority;
		}
		taskEXIT_CRITICAL();

		return uxReturn;
	}

#endif
/*-----------------------------------------------------------*/

#if ( INCLUDE_vTaskPrioritySet == 1 )

	void vTaskPrioritySet( xTaskHandle pxTask, unsigned portBASE_TYPE uxNewPriority )
	{
	tskTCB *pxTCB;
	unsigned portBASE_TYPE uxCurrentPriority, xYieldRequired = pdFALSE;

		/* Ensure the new priority is valid. */
		if( uxNewPriority >= configMAX_PRIORITIES )
		{
			uxNewPriority = configMAX_PRIORITIES - 1;
		}

		taskENTER_CRITICAL();
		{
			if( pxTask == pxCurrentTCB )
			{
				pxTask = NULL;
			}

			/* If null is passed in here then we are changing the
			priority of the calling function. */
			pxTCB = prvGetTCBFromHandle( pxTask );
			
			traceTASK_PRIORITY_SET( pxTask, uxNewPriority );

			#if ( configUSE_MUTEXES == 1 )
			{
				uxCurrentPriority = pxTCB->uxBasePriority;
			}
			#else
			{
				uxCurrentPriority = pxTCB->uxPriority;
			}
			#endif

			if( uxCurrentPriority != uxNewPriority )
			{
				/* The priority change may have readied a task of higher
				priority than the calling task. */
				if( uxNewPriority > uxCurrentPriority )
				{
					if( pxTask != NULL )
					{
						/* The priority of another task is being raised.  If we
						were raising the priority of the currently running task
						there would be no need to switch as it must have already
						been the highest priority task. */
						xYieldRequired = pdTRUE;
					}
				}
				else if( pxTask == NULL )
				{
					/* Setting our own priority down means there may now be another
					task of higher priority that is ready to execute. */
					xYieldRequired = pdTRUE;
				}
			
				

				#if ( configUSE_MUTEXES == 1 )
				{
					/* Only change the priority being used if the task is not
					currently using an inherited priority. */
					if( pxTCB->uxBasePriority == pxTCB->uxPriority )
					{
						pxTCB->uxPriority = uxNewPriority;
					}
					
					/* The base priority gets set whatever. */
					pxTCB->uxBasePriority = uxNewPriority;					
				}
				#else
				{
					pxTCB->uxPriority = uxNewPriority;
				}
				#endif

				listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), ( configMAX_PRIORITIES - ( portTickType ) uxNewPriority ) );

				/* If the task is in the blocked or suspended list we need do
				nothing more than change it's priority variable. However, if
				the task is in a ready list it needs to be removed and placed
				in the queue appropriate to its new priority. */
				if( listIS_CONTAINED_WITHIN( &( pxReadyTasksLists[ uxCurrentPriority ] ), &( pxTCB->xGenericListItem ) ) )
				{
					/* The task is currently in its ready list - remove before adding
					it to it's new ready list.  As we are in a critical section we
					can do this even if the scheduler is suspended. */
					vListRemove( &( pxTCB->xGenericListItem ) );
					prvAddTaskToReadyQueue( pxTCB );
				}			
				
				if( xYieldRequired == pdTRUE )
				{
					taskYIELD();
				}				
			}
		}
		taskEXIT_CRITICAL();
	}

#endif
/*-----------------------------------------------------------*/

#if ( INCLUDE_vTaskSuspend == 1 )

	void vTaskSuspend( xTaskHandle pxTaskToSuspend )
	{
	tskTCB *pxTCB;

		taskENTER_CRITICAL();
		{
			/* Ensure a yield is performed if the current task is being
			suspended. */