Diff: FreeRTOS/Source/list.c

Revision:

0:d4960fcea8ff

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/FreeRTOS/Source/list.c	Sat Jan 01 11:17:45 2011 +0000
@@ -0,0 +1,191 @@
+/*
+    FreeRTOS V6.0.3 - Copyright (C) 2010 Real Time Engineers Ltd.
+
+    ***************************************************************************
+    *                                                                         *
+    * If you are:                                                             *
+    *                                                                         *
+    *    + New to FreeRTOS,                                                   *
+    *    + Wanting to learn FreeRTOS or multitasking in general quickly       *
+    *    + Looking for basic training,                                        *
+    *    + Wanting to improve your FreeRTOS skills and productivity           *
+    *                                                                         *
+    * then take a look at the FreeRTOS eBook                                  *
+    *                                                                         *
+    *        "Using the FreeRTOS Real Time Kernel - a Practical Guide"        *
+    *                  http://www.FreeRTOS.org/Documentation                  *
+    *                                                                         *
+    * A pdf reference manual is also available.  Both are usually delivered   *
+    * to your inbox within 20 minutes to two hours when purchased between 8am *
+    * and 8pm GMT (although please allow up to 24 hours in case of            *
+    * exceptional circumstances).  Thank you for your support!                *
+    *                                                                         *
+    ***************************************************************************
+
+    This file is part of the FreeRTOS distribution.
+
+    FreeRTOS is free software; you can redistribute it and/or modify it under
+    the terms of the GNU General Public License (version 2) as published by the
+    Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
+    ***NOTE*** The exception to the GPL is included to allow you to distribute
+    a combined work that includes FreeRTOS without being obliged to provide the
+    source code for proprietary components outside of the FreeRTOS kernel.
+    FreeRTOS is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+    more details. You should have received a copy of the GNU General Public 
+    License and the FreeRTOS license exception along with FreeRTOS; if not it 
+    can be viewed here: http://www.freertos.org/a00114.html and also obtained 
+    by writing to Richard Barry, contact details for whom are available on the
+    FreeRTOS WEB site.
+
+    1 tab == 4 spaces!
+
+    http://www.FreeRTOS.org - Documentation, latest information, license and
+    contact details.
+
+    http://www.SafeRTOS.com - A version that is certified for use in safety
+    critical systems.
+
+    http://www.OpenRTOS.com - Commercial support, development, porting,
+    licensing and training services.
+*/
+
+
+#include "stdlib.h"
+#include "./FreeRTOS/Source/include/FreeRTOS.h"
+#include "./FreeRTOS/Source/include/list.h"
+
+/*-----------------------------------------------------------
+ * PUBLIC LIST API documented in list.h
+ *----------------------------------------------------------*/
+
+void vListInitialise( xList *pxList )
+{
+    /* The list structure contains a list item which is used to mark the
+    end of the list.  To initialise the list the list end is inserted
+    as the only list entry. */
+    pxList->pxIndex = ( xListItem * ) &( pxList->xListEnd );
+
+    /* The list end value is the highest possible value in the list to
+    ensure it remains at the end of the list. */
+    pxList->xListEnd.xItemValue = portMAX_DELAY;
+
+    /* The list end next and previous pointers point to itself so we know
+    when the list is empty. */
+    pxList->xListEnd.pxNext = ( xListItem * ) &( pxList->xListEnd );
+    pxList->xListEnd.pxPrevious = ( xListItem * ) &( pxList->xListEnd );
+
+    pxList->uxNumberOfItems = 0;
+}
+/*-----------------------------------------------------------*/
+
+void vListInitialiseItem( xListItem *pxItem )
+{
+    /* Make sure the list item is not recorded as being on a list. */
+    pxItem->pvContainer = NULL;
+}
+/*-----------------------------------------------------------*/
+
+void vListInsertEnd( xList *pxList, xListItem *pxNewListItem )
+{
+volatile xListItem * pxIndex;
+
+    /* Insert a new list item into pxList, but rather than sort the list,
+    makes the new list item the last item to be removed by a call to
+    pvListGetOwnerOfNextEntry.  This means it has to be the item pointed to by
+    the pxIndex member. */
+    pxIndex = pxList->pxIndex;
+
+    pxNewListItem->pxNext = pxIndex->pxNext;
+    pxNewListItem->pxPrevious = pxList->pxIndex;
+    pxIndex->pxNext->pxPrevious = ( volatile xListItem * ) pxNewListItem;
+    pxIndex->pxNext = ( volatile xListItem * ) pxNewListItem;
+    pxList->pxIndex = ( volatile xListItem * ) pxNewListItem;
+
+    /* Remember which list the item is in. */
+    pxNewListItem->pvContainer = ( void * ) pxList;
+
+    ( pxList->uxNumberOfItems )++;
+}
+/*-----------------------------------------------------------*/
+
+void vListInsert( xList *pxList, xListItem *pxNewListItem )
+{
+volatile xListItem *pxIterator;
+portTickType xValueOfInsertion;
+
+    /* Insert the new list item into the list, sorted in ulListItem order. */
+    xValueOfInsertion = pxNewListItem->xItemValue;
+
+    /* If the list already contains a list item with the same item value then
+    the new list item should be placed after it.  This ensures that TCB's which
+    are stored in ready lists (all of which have the same ulListItem value)
+    get an equal share of the CPU.  However, if the xItemValue is the same as 
+    the back marker the iteration loop below will not end.  This means we need
+    to guard against this by checking the value first and modifying the 
+    algorithm slightly if necessary. */
+    if( xValueOfInsertion == portMAX_DELAY )
+    {
+        pxIterator = pxList->xListEnd.pxPrevious;
+    }
+    else
+    {
+        /* *** NOTE ***********************************************************
+        If you find your application is crashing here then likely causes are:
+            1) Stack overflow - 
+               see http://www.freertos.org/Stacks-and-stack-overflow-checking.html
+            2) Incorrect interrupt priority assignment, especially on Cortex M3 
+               parts where numerically high priority values denote low actual 
+               interrupt priories, which can seem counter intuitive.  See 
+               configMAX_SYSCALL_INTERRUPT_PRIORITY on http://www.freertos.org/a00110.html
+            3) Calling an API function from within a critical section or when
+               the scheduler is suspended.
+            4) Using a queue or semaphore before it has been initialised or
+               before the scheduler has been started (are interrupts firing
+               before vTaskStartScheduler() has been called?).
+        See http://www.freertos.org/FAQHelp.html for more tips. 
+        **********************************************************************/
+        
+        for( pxIterator = ( xListItem * ) &( pxList->xListEnd ); pxIterator->pxNext->xItemValue <= xValueOfInsertion; pxIterator = pxIterator->pxNext )
+        {
+            /* There is nothing to do here, we are just iterating to the
+            wanted insertion position. */
+        }
+    }
+
+    pxNewListItem->pxNext = pxIterator->pxNext;
+    pxNewListItem->pxNext->pxPrevious = ( volatile xListItem * ) pxNewListItem;
+    pxNewListItem->pxPrevious = pxIterator;
+    pxIterator->pxNext = ( volatile xListItem * ) pxNewListItem;
+
+    /* Remember which list the item is in.  This allows fast removal of the
+    item later. */
+    pxNewListItem->pvContainer = ( void * ) pxList;
+
+    ( pxList->uxNumberOfItems )++;
+}
+/*-----------------------------------------------------------*/
+
+void vListRemove( xListItem *pxItemToRemove )
+{
+xList * pxList;
+
+    pxItemToRemove->pxNext->pxPrevious = pxItemToRemove->pxPrevious;
+    pxItemToRemove->pxPrevious->pxNext = pxItemToRemove->pxNext;
+    
+    /* The list item knows which list it is in.  Obtain the list from the list
+    item. */
+    pxList = ( xList * ) pxItemToRemove->pvContainer;
+
+    /* Make sure the index is left pointing to a valid item. */
+    if( pxList->pxIndex == pxItemToRemove )
+    {
+        pxList->pxIndex = pxItemToRemove->pxPrevious;
+    }
+
+    pxItemToRemove->pvContainer = NULL;
+    ( pxList->uxNumberOfItems )--;
+}
+/*-----------------------------------------------------------*/
+