2 FreeRTOS.org V4.0.2 - Copyright (C) 2003-2006 Richard Barry.
\r
4 This file is part of the FreeRTOS.org distribution.
\r
6 FreeRTOS.org is free software; you can redistribute it and/or modify
\r
7 it under the terms of the GNU General Public License as published by
\r
8 the Free Software Foundation; either version 2 of the License, or
\r
9 (at your option) any later version.
\r
11 FreeRTOS.org is distributed in the hope that it will be useful,
\r
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
\r
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
\r
14 GNU General Public License for more details.
\r
16 You should have received a copy of the GNU General Public License
\r
17 along with FreeRTOS.org; if not, write to the Free Software
\r
18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
\r
20 A special exception to the GPL can be applied should you wish to distribute
\r
21 a combined work that includes FreeRTOS.org, without being obliged to provide
\r
22 the source code for any proprietary components. See the licensing section
\r
23 of http://www.FreeRTOS.org for full details of how and when the exception
\r
26 ***************************************************************************
\r
27 See http://www.FreeRTOS.org for documentation, latest information, license
\r
28 and contact details. Please ensure to read the configuration and relevant
\r
29 port sections of the online documentation.
\r
30 ***************************************************************************
\r
34 * Creates six tasks that operate on three queues as follows:
\r
36 * The first two tasks send and receive an incrementing number to/from a queue.
\r
37 * One task acts as a producer and the other as the consumer. The consumer is a
\r
38 * higher priority than the producer and is set to block on queue reads. The queue
\r
39 * only has space for one item - as soon as the producer posts a message on the
\r
40 * queue the consumer will unblock, pre-empt the producer, and remove the item.
\r
42 * The second two tasks work the other way around. Again the queue used only has
\r
43 * enough space for one item. This time the consumer has a lower priority than the
\r
44 * producer. The producer will try to post on the queue blocking when the queue is
\r
45 * full. When the consumer wakes it will remove the item from the queue, causing
\r
46 * the producer to unblock, pre-empt the consumer, and immediately re-fill the
\r
49 * The last two tasks use the same queue producer and consumer functions. This time the queue has
\r
50 * enough space for lots of items and the tasks operate at the same priority. The
\r
51 * producer will execute, placing items into the queue. The consumer will start
\r
52 * executing when either the queue becomes full (causing the producer to block) or
\r
53 * a context switch occurs (tasks of the same priority will time slice).
\r
55 * \page BlockQC blockQ.c
\r
56 * \ingroup DemoFiles
\r
63 + Reversed the priority and block times of the second two demo tasks so
\r
64 they operate as per the description above.
\r
68 + Delay periods are now specified using variables and constants of
\r
69 portTickType rather than unsigned portLONG.
\r
75 /* Scheduler include files. */
\r
76 #include "FreeRTOS.h"
\r
80 /* Demo program include files. */
\r
84 #define blckqSTACK_SIZE ( ( unsigned portSHORT ) 128 )
\r
85 #define blckqNUM_TASK_SETS ( 3 )
\r
87 /* Structure used to pass parameters to the blocking queue tasks. */
\r
88 typedef struct BLOCKING_QUEUE_PARAMETERS
\r
90 xQueueHandle xQueue; /*< The queue to be used by the task. */
\r
91 portTickType xBlockTime; /*< The block time to use on queue reads/writes. */
\r
92 volatile portSHORT *psCheckVariable; /*< Incremented on each successful cycle to check the task is still running. */
\r
93 } xBlockingQueueParameters;
\r
95 /* Task function that creates an incrementing number and posts it on a queue. */
\r
96 static void vBlockingQueueProducer( void *pvParameters );
\r
98 /* Task function that removes the incrementing number from a queue and checks that
\r
99 it is the expected number. */
\r
100 static void vBlockingQueueConsumer( void *pvParameters );
\r
102 /* Variables which are incremented each time an item is removed from a queue, and
\r
103 found to be the expected value.
\r
104 These are used to check that the tasks are still running. */
\r
105 static volatile portSHORT sBlockingConsumerCount[ blckqNUM_TASK_SETS ] = { ( portSHORT ) 0, ( portSHORT ) 0, ( portSHORT ) 0 };
\r
107 /* Variable which are incremented each time an item is posted on a queue. These
\r
108 are used to check that the tasks are still running. */
\r
109 static volatile portSHORT sBlockingProducerCount[ blckqNUM_TASK_SETS ] = { ( portSHORT ) 0, ( portSHORT ) 0, ( portSHORT ) 0 };
\r
111 /*-----------------------------------------------------------*/
\r
113 void vStartBlockingQueueTasks( unsigned portBASE_TYPE uxPriority )
\r
115 xBlockingQueueParameters *pxQueueParameters1, *pxQueueParameters2;
\r
116 xBlockingQueueParameters *pxQueueParameters3, *pxQueueParameters4;
\r
117 xBlockingQueueParameters *pxQueueParameters5, *pxQueueParameters6;
\r
118 const unsigned portBASE_TYPE uxQueueSize1 = 1, uxQueueSize5 = 5;
\r
119 const portTickType xBlockTime = ( portTickType ) 1000 / portTICK_RATE_MS;
\r
120 const portTickType xDontBlock = ( portTickType ) 0;
\r
122 /* Create the first two tasks as described at the top of the file. */
\r
124 /* First create the structure used to pass parameters to the consumer tasks. */
\r
125 pxQueueParameters1 = ( xBlockingQueueParameters * ) pvPortMalloc( sizeof( xBlockingQueueParameters ) );
\r
127 /* Create the queue used by the first two tasks to pass the incrementing number.
\r
128 Pass a pointer to the queue in the parameter structure. */
\r
129 pxQueueParameters1->xQueue = xQueueCreate( uxQueueSize1, ( unsigned portBASE_TYPE ) sizeof( unsigned portSHORT ) );
\r
131 /* The consumer is created first so gets a block time as described above. */
\r
132 pxQueueParameters1->xBlockTime = xBlockTime;
\r
134 /* Pass in the variable that this task is going to increment so we can check it
\r
135 is still running. */
\r
136 pxQueueParameters1->psCheckVariable = &( sBlockingConsumerCount[ 0 ] );
\r
138 /* Create the structure used to pass parameters to the producer task. */
\r
139 pxQueueParameters2 = ( xBlockingQueueParameters * ) pvPortMalloc( sizeof( xBlockingQueueParameters ) );
\r
141 /* Pass the queue to this task also, using the parameter structure. */
\r
142 pxQueueParameters2->xQueue = pxQueueParameters1->xQueue;
\r
144 /* The producer is not going to block - as soon as it posts the consumer will
\r
145 wake and remove the item so the producer should always have room to post. */
\r
146 pxQueueParameters2->xBlockTime = xDontBlock;
\r
148 /* Pass in the variable that this task is going to increment so we can check
\r
149 it is still running. */
\r
150 pxQueueParameters2->psCheckVariable = &( sBlockingProducerCount[ 0 ] );
\r
153 /* Note the producer has a lower priority than the consumer when the tasks are
\r
155 xTaskCreate( vBlockingQueueConsumer, "QConsB1", blckqSTACK_SIZE, ( void * ) pxQueueParameters1, uxPriority, NULL );
\r
156 xTaskCreate( vBlockingQueueProducer, "QProdB2", blckqSTACK_SIZE, ( void * ) pxQueueParameters2, tskIDLE_PRIORITY, NULL );
\r
160 /* Create the second two tasks as described at the top of the file. This uses
\r
161 the same mechanism but reverses the task priorities. */
\r
163 pxQueueParameters3 = ( xBlockingQueueParameters * ) pvPortMalloc( sizeof( xBlockingQueueParameters ) );
\r
164 pxQueueParameters3->xQueue = xQueueCreate( uxQueueSize1, ( unsigned portBASE_TYPE ) sizeof( unsigned portSHORT ) );
\r
165 pxQueueParameters3->xBlockTime = xDontBlock;
\r
166 pxQueueParameters3->psCheckVariable = &( sBlockingProducerCount[ 1 ] );
\r
168 pxQueueParameters4 = ( xBlockingQueueParameters * ) pvPortMalloc( sizeof( xBlockingQueueParameters ) );
\r
169 pxQueueParameters4->xQueue = pxQueueParameters3->xQueue;
\r
170 pxQueueParameters4->xBlockTime = xBlockTime;
\r
171 pxQueueParameters4->psCheckVariable = &( sBlockingConsumerCount[ 1 ] );
\r
173 xTaskCreate( vBlockingQueueProducer, "QProdB3", blckqSTACK_SIZE, ( void * ) pxQueueParameters3, tskIDLE_PRIORITY, NULL );
\r
174 xTaskCreate( vBlockingQueueConsumer, "QConsB4", blckqSTACK_SIZE, ( void * ) pxQueueParameters4, uxPriority, NULL );
\r
178 /* Create the last two tasks as described above. The mechanism is again just
\r
179 the same. This time both parameter structures are given a block time. */
\r
180 pxQueueParameters5 = ( xBlockingQueueParameters * ) pvPortMalloc( sizeof( xBlockingQueueParameters ) );
\r
181 pxQueueParameters5->xQueue = xQueueCreate( uxQueueSize5, ( unsigned portBASE_TYPE ) sizeof( unsigned portSHORT ) );
\r
182 pxQueueParameters5->xBlockTime = xBlockTime;
\r
183 pxQueueParameters5->psCheckVariable = &( sBlockingProducerCount[ 2 ] );
\r
185 pxQueueParameters6 = ( xBlockingQueueParameters * ) pvPortMalloc( sizeof( xBlockingQueueParameters ) );
\r
186 pxQueueParameters6->xQueue = pxQueueParameters5->xQueue;
\r
187 pxQueueParameters6->xBlockTime = xBlockTime;
\r
188 pxQueueParameters6->psCheckVariable = &( sBlockingConsumerCount[ 2 ] );
\r
190 xTaskCreate( vBlockingQueueProducer, "QProdB5", blckqSTACK_SIZE, ( void * ) pxQueueParameters5, tskIDLE_PRIORITY, NULL );
\r
191 xTaskCreate( vBlockingQueueConsumer, "QConsB6", blckqSTACK_SIZE, ( void * ) pxQueueParameters6, tskIDLE_PRIORITY, NULL );
\r
193 /*-----------------------------------------------------------*/
\r
195 static void vBlockingQueueProducer( void *pvParameters )
\r
197 unsigned portSHORT usValue = 0;
\r
198 xBlockingQueueParameters *pxQueueParameters;
\r
199 const portCHAR * const pcTaskStartMsg = "Blocking queue producer started.\r\n";
\r
200 const portCHAR * const pcTaskErrorMsg = "Could not post on blocking queue\r\n";
\r
201 portSHORT sErrorEverOccurred = pdFALSE;
\r
203 pxQueueParameters = ( xBlockingQueueParameters * ) pvParameters;
\r
205 /* Queue a message for printing to say the task has started. */
\r
206 vPrintDisplayMessage( &pcTaskStartMsg );
\r
210 if( xQueueSend( pxQueueParameters->xQueue, ( void * ) &usValue, pxQueueParameters->xBlockTime ) != pdPASS )
\r
212 vPrintDisplayMessage( &pcTaskErrorMsg );
\r
213 sErrorEverOccurred = pdTRUE;
\r
217 /* We have successfully posted a message, so increment the variable
\r
218 used to check we are still running. */
\r
219 if( sErrorEverOccurred == pdFALSE )
\r
221 ( *pxQueueParameters->psCheckVariable )++;
\r
224 /* Increment the variable we are going to post next time round. The
\r
225 consumer will expect the numbers to follow in numerical order. */
\r
230 /*-----------------------------------------------------------*/
\r
232 static void vBlockingQueueConsumer( void *pvParameters )
\r
234 unsigned portSHORT usData, usExpectedValue = 0;
\r
235 xBlockingQueueParameters *pxQueueParameters;
\r
236 const portCHAR * const pcTaskStartMsg = "Blocking queue consumer started.\r\n";
\r
237 const portCHAR * const pcTaskErrorMsg = "Incorrect value received on blocking queue.\r\n";
\r
238 portSHORT sErrorEverOccurred = pdFALSE;
\r
240 /* Queue a message for printing to say the task has started. */
\r
241 vPrintDisplayMessage( &pcTaskStartMsg );
\r
243 pxQueueParameters = ( xBlockingQueueParameters * ) pvParameters;
\r
247 if( xQueueReceive( pxQueueParameters->xQueue, &usData, pxQueueParameters->xBlockTime ) == pdPASS )
\r
249 if( usData != usExpectedValue )
\r
251 vPrintDisplayMessage( &pcTaskErrorMsg );
\r
254 usExpectedValue = usData;
\r
256 sErrorEverOccurred = pdTRUE;
\r
260 /* We have successfully received a message, so increment the
\r
261 variable used to check we are still running. */
\r
262 if( sErrorEverOccurred == pdFALSE )
\r
264 ( *pxQueueParameters->psCheckVariable )++;
\r
267 /* Increment the value we expect to remove from the queue next time
\r
274 /*-----------------------------------------------------------*/
\r
276 /* This is called to check that all the created tasks are still running. */
\r
277 portBASE_TYPE xAreBlockingQueuesStillRunning( void )
\r
279 static portSHORT sLastBlockingConsumerCount[ blckqNUM_TASK_SETS ] = { ( portSHORT ) 0, ( portSHORT ) 0, ( portSHORT ) 0 };
\r
280 static portSHORT sLastBlockingProducerCount[ blckqNUM_TASK_SETS ] = { ( portSHORT ) 0, ( portSHORT ) 0, ( portSHORT ) 0 };
\r
281 portBASE_TYPE xReturn = pdPASS, xTasks;
\r
283 /* Not too worried about mutual exclusion on these variables as they are 16
\r
284 bits and we are only reading them. We also only care to see if they have
\r
287 Loop through each check variable and return pdFALSE if any are found not
\r
288 to have changed since the last call. */
\r
290 for( xTasks = 0; xTasks < blckqNUM_TASK_SETS; xTasks++ )
\r
292 if( sBlockingConsumerCount[ xTasks ] == sLastBlockingConsumerCount[ xTasks ] )
\r
296 sLastBlockingConsumerCount[ xTasks ] = sBlockingConsumerCount[ xTasks ];
\r
299 if( sBlockingProducerCount[ xTasks ] == sLastBlockingProducerCount[ xTasks ] )
\r
303 sLastBlockingProducerCount[ xTasks ] = sBlockingProducerCount[ xTasks ];
\r