2 FreeRTOS V7.2.0 - Copyright (C) 2012 Real Time Engineers Ltd.
\r
5 ***************************************************************************
\r
7 * FreeRTOS tutorial books are available in pdf and paperback. *
\r
8 * Complete, revised, and edited pdf reference manuals are also *
\r
11 * Purchasing FreeRTOS documentation will not only help you, by *
\r
12 * ensuring you get running as quickly as possible and with an *
\r
13 * in-depth knowledge of how to use FreeRTOS, it will also help *
\r
14 * the FreeRTOS project to continue with its mission of providing *
\r
15 * professional grade, cross platform, de facto standard solutions *
\r
16 * for microcontrollers - completely free of charge! *
\r
18 * >>> See http://www.FreeRTOS.org/Documentation for details. <<< *
\r
20 * Thank you for using FreeRTOS, and thank you for your support! *
\r
22 ***************************************************************************
\r
25 This file is part of the FreeRTOS distribution.
\r
27 FreeRTOS is free software; you can redistribute it and/or modify it under
\r
28 the terms of the GNU General Public License (version 2) as published by the
\r
29 Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
\r
30 >>>NOTE<<< The modification to the GPL is included to allow you to
\r
31 distribute a combined work that includes FreeRTOS without being obliged to
\r
32 provide the source code for proprietary components outside of the FreeRTOS
\r
33 kernel. FreeRTOS is distributed in the hope that it will be useful, but
\r
34 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
\r
35 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
\r
36 more details. You should have received a copy of the GNU General Public
\r
37 License and the FreeRTOS license exception along with FreeRTOS; if not it
\r
38 can be viewed here: http://www.freertos.org/a00114.html and also obtained
\r
39 by writing to Richard Barry, contact details for whom are available on the
\r
44 ***************************************************************************
\r
46 * Having a problem? Start by reading the FAQ "My application does *
\r
47 * not run, what could be wrong? *
\r
49 * http://www.FreeRTOS.org/FAQHelp.html *
\r
51 ***************************************************************************
\r
54 http://www.FreeRTOS.org - Documentation, training, latest information,
\r
55 license and contact details.
\r
57 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
\r
58 including FreeRTOS+Trace - an indispensable productivity tool.
\r
60 Real Time Engineers ltd license FreeRTOS to High Integrity Systems, who sell
\r
61 the code with commercial support, indemnification, and middleware, under
\r
62 the OpenRTOS brand: http://www.OpenRTOS.com. High Integrity Systems also
\r
63 provide a safety engineered and independently SIL3 certified version under
\r
64 the SafeRTOS brand: http://www.SafeRTOS.com.
\r
68 * This is a version of BlockQ.c that uses the alternative (Alt) API.
\r
70 * Creates six tasks that operate on three queues as follows:
\r
72 * The first two tasks send and receive an incrementing number to/from a queue.
\r
73 * One task acts as a producer and the other as the consumer. The consumer is a
\r
74 * higher priority than the producer and is set to block on queue reads. The queue
\r
75 * only has space for one item - as soon as the producer posts a message on the
\r
76 * queue the consumer will unblock, pre-empt the producer, and remove the item.
\r
78 * The second two tasks work the other way around. Again the queue used only has
\r
79 * enough space for one item. This time the consumer has a lower priority than the
\r
80 * producer. The producer will try to post on the queue blocking when the queue is
\r
81 * full. When the consumer wakes it will remove the item from the queue, causing
\r
82 * the producer to unblock, pre-empt the consumer, and immediately re-fill the
\r
85 * The last two tasks use the same queue producer and consumer functions. This time the queue has
\r
86 * enough space for lots of items and the tasks operate at the same priority. The
\r
87 * producer will execute, placing items into the queue. The consumer will start
\r
88 * executing when either the queue becomes full (causing the producer to block) or
\r
89 * a context switch occurs (tasks of the same priority will time slice).
\r
96 /* Scheduler include files. */
\r
97 #include "FreeRTOS.h"
\r
101 /* Demo program include files. */
\r
102 #include "AltBlckQ.h"
\r
104 #define blckqSTACK_SIZE configMINIMAL_STACK_SIZE
\r
105 #define blckqNUM_TASK_SETS ( 3 )
\r
107 /* Structure used to pass parameters to the blocking queue tasks. */
\r
108 typedef struct BLOCKING_QUEUE_PARAMETERS
\r
110 xQueueHandle xQueue; /*< The queue to be used by the task. */
\r
111 portTickType xBlockTime; /*< The block time to use on queue reads/writes. */
\r
112 volatile portSHORT *psCheckVariable; /*< Incremented on each successful cycle to check the task is still running. */
\r
113 } xBlockingQueueParameters;
\r
115 /* Task function that creates an incrementing number and posts it on a queue. */
\r
116 static portTASK_FUNCTION_PROTO( vBlockingQueueProducer, pvParameters );
\r
118 /* Task function that removes the incrementing number from a queue and checks that
\r
119 it is the expected number. */
\r
120 static portTASK_FUNCTION_PROTO( vBlockingQueueConsumer, pvParameters );
\r
122 /* Variables which are incremented each time an item is removed from a queue, and
\r
123 found to be the expected value.
\r
124 These are used to check that the tasks are still running. */
\r
125 static volatile portSHORT sBlockingConsumerCount[ blckqNUM_TASK_SETS ] = { ( unsigned portSHORT ) 0, ( unsigned portSHORT ) 0, ( unsigned portSHORT ) 0 };
\r
127 /* Variable which are incremented each time an item is posted on a queue. These
\r
128 are used to check that the tasks are still running. */
\r
129 static volatile portSHORT sBlockingProducerCount[ blckqNUM_TASK_SETS ] = { ( unsigned portSHORT ) 0, ( unsigned portSHORT ) 0, ( unsigned portSHORT ) 0 };
\r
131 /*-----------------------------------------------------------*/
\r
133 void vStartAltBlockingQueueTasks( unsigned portBASE_TYPE uxPriority )
\r
135 xBlockingQueueParameters *pxQueueParameters1, *pxQueueParameters2;
\r
136 xBlockingQueueParameters *pxQueueParameters3, *pxQueueParameters4;
\r
137 xBlockingQueueParameters *pxQueueParameters5, *pxQueueParameters6;
\r
138 const unsigned portBASE_TYPE uxQueueSize1 = 1, uxQueueSize5 = 5;
\r
139 const portTickType xBlockTime = ( portTickType ) 1000 / portTICK_RATE_MS;
\r
140 const portTickType xDontBlock = ( portTickType ) 0;
\r
142 /* Create the first two tasks as described at the top of the file. */
\r
144 /* First create the structure used to pass parameters to the consumer tasks. */
\r
145 pxQueueParameters1 = ( xBlockingQueueParameters * ) pvPortMalloc( sizeof( xBlockingQueueParameters ) );
\r
147 /* Create the queue used by the first two tasks to pass the incrementing number.
\r
148 Pass a pointer to the queue in the parameter structure. */
\r
149 pxQueueParameters1->xQueue = xQueueCreate( uxQueueSize1, ( unsigned portBASE_TYPE ) sizeof( unsigned portSHORT ) );
\r
151 /* The consumer is created first so gets a block time as described above. */
\r
152 pxQueueParameters1->xBlockTime = xBlockTime;
\r
154 /* Pass in the variable that this task is going to increment so we can check it
\r
155 is still running. */
\r
156 pxQueueParameters1->psCheckVariable = &( sBlockingConsumerCount[ 0 ] );
\r
158 /* Create the structure used to pass parameters to the producer task. */
\r
159 pxQueueParameters2 = ( xBlockingQueueParameters * ) pvPortMalloc( sizeof( xBlockingQueueParameters ) );
\r
161 /* Pass the queue to this task also, using the parameter structure. */
\r
162 pxQueueParameters2->xQueue = pxQueueParameters1->xQueue;
\r
164 /* The producer is not going to block - as soon as it posts the consumer will
\r
165 wake and remove the item so the producer should always have room to post. */
\r
166 pxQueueParameters2->xBlockTime = xDontBlock;
\r
168 /* Pass in the variable that this task is going to increment so we can check
\r
169 it is still running. */
\r
170 pxQueueParameters2->psCheckVariable = &( sBlockingProducerCount[ 0 ] );
\r
173 /* Note the producer has a lower priority than the consumer when the tasks are
\r
175 xTaskCreate( vBlockingQueueConsumer, ( signed portCHAR * ) "QConsB1", blckqSTACK_SIZE, ( void * ) pxQueueParameters1, uxPriority, NULL );
\r
176 xTaskCreate( vBlockingQueueProducer, ( signed portCHAR * ) "QProdB2", blckqSTACK_SIZE, ( void * ) pxQueueParameters2, tskIDLE_PRIORITY, NULL );
\r
180 /* Create the second two tasks as described at the top of the file. This uses
\r
181 the same mechanism but reverses the task priorities. */
\r
183 pxQueueParameters3 = ( xBlockingQueueParameters * ) pvPortMalloc( sizeof( xBlockingQueueParameters ) );
\r
184 pxQueueParameters3->xQueue = xQueueCreate( uxQueueSize1, ( unsigned portBASE_TYPE ) sizeof( unsigned portSHORT ) );
\r
185 pxQueueParameters3->xBlockTime = xDontBlock;
\r
186 pxQueueParameters3->psCheckVariable = &( sBlockingProducerCount[ 1 ] );
\r
188 pxQueueParameters4 = ( xBlockingQueueParameters * ) pvPortMalloc( sizeof( xBlockingQueueParameters ) );
\r
189 pxQueueParameters4->xQueue = pxQueueParameters3->xQueue;
\r
190 pxQueueParameters4->xBlockTime = xBlockTime;
\r
191 pxQueueParameters4->psCheckVariable = &( sBlockingConsumerCount[ 1 ] );
\r
193 xTaskCreate( vBlockingQueueConsumer, ( signed portCHAR * ) "QProdB3", blckqSTACK_SIZE, ( void * ) pxQueueParameters3, tskIDLE_PRIORITY, NULL );
\r
194 xTaskCreate( vBlockingQueueProducer, ( signed portCHAR * ) "QConsB4", blckqSTACK_SIZE, ( void * ) pxQueueParameters4, uxPriority, NULL );
\r
198 /* Create the last two tasks as described above. The mechanism is again just
\r
199 the same. This time both parameter structures are given a block time. */
\r
200 pxQueueParameters5 = ( xBlockingQueueParameters * ) pvPortMalloc( sizeof( xBlockingQueueParameters ) );
\r
201 pxQueueParameters5->xQueue = xQueueCreate( uxQueueSize5, ( unsigned portBASE_TYPE ) sizeof( unsigned portSHORT ) );
\r
202 pxQueueParameters5->xBlockTime = xBlockTime;
\r
203 pxQueueParameters5->psCheckVariable = &( sBlockingProducerCount[ 2 ] );
\r
205 pxQueueParameters6 = ( xBlockingQueueParameters * ) pvPortMalloc( sizeof( xBlockingQueueParameters ) );
\r
206 pxQueueParameters6->xQueue = pxQueueParameters5->xQueue;
\r
207 pxQueueParameters6->xBlockTime = xBlockTime;
\r
208 pxQueueParameters6->psCheckVariable = &( sBlockingConsumerCount[ 2 ] );
\r
210 xTaskCreate( vBlockingQueueProducer, ( signed portCHAR * ) "QProdB5", blckqSTACK_SIZE, ( void * ) pxQueueParameters5, tskIDLE_PRIORITY, NULL );
\r
211 xTaskCreate( vBlockingQueueConsumer, ( signed portCHAR * ) "QConsB6", blckqSTACK_SIZE, ( void * ) pxQueueParameters6, tskIDLE_PRIORITY, NULL );
\r
213 /*-----------------------------------------------------------*/
\r
215 static portTASK_FUNCTION( vBlockingQueueProducer, pvParameters )
\r
217 unsigned portSHORT usValue = 0;
\r
218 xBlockingQueueParameters *pxQueueParameters;
\r
219 portSHORT sErrorEverOccurred = pdFALSE;
\r
222 void vPrintDisplayMessage( const portCHAR * const * ppcMessageToSend );
\r
224 const portCHAR * const pcTaskStartMsg = "Alt blocking queue producer task started.\r\n";
\r
226 /* Queue a message for printing to say the task has started. */
\r
227 vPrintDisplayMessage( &pcTaskStartMsg );
\r
230 pxQueueParameters = ( xBlockingQueueParameters * ) pvParameters;
\r
234 if( xQueueAltSendToBack( pxQueueParameters->xQueue, ( void * ) &usValue, pxQueueParameters->xBlockTime ) != pdPASS )
\r
236 sErrorEverOccurred = pdTRUE;
\r
240 /* We have successfully posted a message, so increment the variable
\r
241 used to check we are still running. */
\r
242 if( sErrorEverOccurred == pdFALSE )
\r
244 ( *pxQueueParameters->psCheckVariable )++;
\r
247 /* Increment the variable we are going to post next time round. The
\r
248 consumer will expect the numbers to follow in numerical order. */
\r
253 /*-----------------------------------------------------------*/
\r
255 static portTASK_FUNCTION( vBlockingQueueConsumer, pvParameters )
\r
257 unsigned portSHORT usData, usExpectedValue = 0;
\r
258 xBlockingQueueParameters *pxQueueParameters;
\r
259 portSHORT sErrorEverOccurred = pdFALSE;
\r
262 void vPrintDisplayMessage( const portCHAR * const * ppcMessageToSend );
\r
264 const portCHAR * const pcTaskStartMsg = "Alt blocking queue consumer task started.\r\n";
\r
266 /* Queue a message for printing to say the task has started. */
\r
267 vPrintDisplayMessage( &pcTaskStartMsg );
\r
270 pxQueueParameters = ( xBlockingQueueParameters * ) pvParameters;
\r
274 if( xQueueAltReceive( pxQueueParameters->xQueue, &usData, pxQueueParameters->xBlockTime ) == pdPASS )
\r
276 if( usData != usExpectedValue )
\r
279 usExpectedValue = usData;
\r
281 sErrorEverOccurred = pdTRUE;
\r
285 /* We have successfully received a message, so increment the
\r
286 variable used to check we are still running. */
\r
287 if( sErrorEverOccurred == pdFALSE )
\r
289 ( *pxQueueParameters->psCheckVariable )++;
\r
292 /* Increment the value we expect to remove from the queue next time
\r
299 /*-----------------------------------------------------------*/
\r
301 /* This is called to check that all the created tasks are still running. */
\r
302 portBASE_TYPE xAreAltBlockingQueuesStillRunning( void )
\r
304 static portSHORT sLastBlockingConsumerCount[ blckqNUM_TASK_SETS ] = { ( unsigned portSHORT ) 0, ( unsigned portSHORT ) 0, ( unsigned portSHORT ) 0 };
\r
305 static portSHORT sLastBlockingProducerCount[ blckqNUM_TASK_SETS ] = { ( unsigned portSHORT ) 0, ( unsigned portSHORT ) 0, ( unsigned portSHORT ) 0 };
\r
306 portBASE_TYPE xReturn = pdPASS, xTasks;
\r
308 /* Not too worried about mutual exclusion on these variables as they are 16
\r
309 bits and we are only reading them. We also only care to see if they have
\r
312 Loop through each check variable to and return pdFALSE if any are found not
\r
313 to have changed since the last call. */
\r
315 for( xTasks = 0; xTasks < blckqNUM_TASK_SETS; xTasks++ )
\r
317 if( sBlockingConsumerCount[ xTasks ] == sLastBlockingConsumerCount[ xTasks ] )
\r
321 sLastBlockingConsumerCount[ xTasks ] = sBlockingConsumerCount[ xTasks ];
\r
324 if( sBlockingProducerCount[ xTasks ] == sLastBlockingProducerCount[ xTasks ] )
\r
328 sLastBlockingProducerCount[ xTasks ] = sBlockingProducerCount[ xTasks ];
\r