2 FreeRTOS V7.4.2 - Copyright (C) 2013 Real Time Engineers Ltd.
\r
4 FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME. PLEASE VISIT
\r
5 http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
\r
7 ***************************************************************************
\r
9 * FreeRTOS tutorial books are available in pdf and paperback. *
\r
10 * Complete, revised, and edited pdf reference manuals are also *
\r
13 * Purchasing FreeRTOS documentation will not only help you, by *
\r
14 * ensuring you get running as quickly as possible and with an *
\r
15 * in-depth knowledge of how to use FreeRTOS, it will also help *
\r
16 * the FreeRTOS project to continue with its mission of providing *
\r
17 * professional grade, cross platform, de facto standard solutions *
\r
18 * for microcontrollers - completely free of charge! *
\r
20 * >>> See http://www.FreeRTOS.org/Documentation for details. <<< *
\r
22 * Thank you for using FreeRTOS, and thank you for your support! *
\r
24 ***************************************************************************
\r
27 This file is part of the FreeRTOS distribution.
\r
29 FreeRTOS is free software; you can redistribute it and/or modify it under
\r
30 the terms of the GNU General Public License (version 2) as published by the
\r
31 Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
\r
33 >>>>>>NOTE<<<<<< The modification to the GPL is included to allow you to
\r
34 distribute a combined work that includes FreeRTOS without being obliged to
\r
35 provide the source code for proprietary components outside of the FreeRTOS
\r
38 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
\r
39 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
\r
40 FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
\r
41 details. You should have received a copy of the GNU General Public License
\r
42 and the FreeRTOS license exception along with FreeRTOS; if not it can be
\r
43 viewed here: http://www.freertos.org/a00114.html and also obtained by
\r
44 writing to Real Time Engineers Ltd., contact details for whom are available
\r
45 on the FreeRTOS WEB site.
\r
49 ***************************************************************************
\r
51 * Having a problem? Start by reading the FAQ "My application does *
\r
52 * not run, what could be wrong?" *
\r
54 * http://www.FreeRTOS.org/FAQHelp.html *
\r
56 ***************************************************************************
\r
59 http://www.FreeRTOS.org - Documentation, books, training, latest versions,
\r
60 license and Real Time Engineers Ltd. contact details.
\r
62 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
\r
63 including FreeRTOS+Trace - an indispensable productivity tool, and our new
\r
64 fully thread aware and reentrant UDP/IP stack.
\r
66 http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
\r
67 Integrity Systems, who sell the code with commercial support,
\r
68 indemnification and middleware, under the OpenRTOS brand.
\r
70 http://www.SafeRTOS.com - High Integrity Systems also provide a safety
\r
71 engineered and independently SIL3 certified version for use in safety and
\r
72 mission critical applications that require provable dependability.
\r
76 * This is a version of PollQ.c that uses the alternative (Alt) API.
\r
78 * Creates two tasks that communicate over a single queue. One task acts as a
\r
79 * producer, the other a consumer.
\r
81 * The producer loops for three iteration, posting an incrementing number onto the
\r
82 * queue each cycle. It then delays for a fixed period before doing exactly the
\r
85 * The consumer loops emptying the queue. Each item removed from the queue is
\r
86 * checked to ensure it contains the expected value. When the queue is empty it
\r
87 * blocks for a fixed period, then does the same again.
\r
89 * All queue access is performed without blocking. The consumer completely empties
\r
90 * the queue each time it runs so the producer should never find the queue full.
\r
92 * An error is flagged if the consumer obtains an unexpected value or the producer
\r
93 * find the queue is full.
\r
99 + Delay periods are now specified using variables and constants of
\r
100 portTickType rather than unsigned portLONG.
\r
103 #include <stdlib.h>
\r
105 /* Scheduler include files. */
\r
106 #include "FreeRTOS.h"
\r
110 /* Demo program include files. */
\r
111 #include "AltPollQ.h"
\r
113 #define pollqSTACK_SIZE configMINIMAL_STACK_SIZE
\r
114 #define pollqQUEUE_SIZE ( 10 )
\r
115 #define pollqPRODUCER_DELAY ( ( portTickType ) 200 / portTICK_RATE_MS )
\r
116 #define pollqCONSUMER_DELAY ( pollqPRODUCER_DELAY - ( portTickType ) ( 20 / portTICK_RATE_MS ) )
\r
117 #define pollqNO_DELAY ( ( portTickType ) 0 )
\r
118 #define pollqVALUES_TO_PRODUCE ( ( signed portBASE_TYPE ) 3 )
\r
119 #define pollqINITIAL_VALUE ( ( signed portBASE_TYPE ) 0 )
\r
121 /* The task that posts the incrementing number onto the queue. */
\r
122 static portTASK_FUNCTION_PROTO( vPolledQueueProducer, pvParameters );
\r
124 /* The task that empties the queue. */
\r
125 static portTASK_FUNCTION_PROTO( vPolledQueueConsumer, pvParameters );
\r
127 /* Variables that are used to check that the tasks are still running with no
\r
129 static volatile signed portBASE_TYPE xPollingConsumerCount = pollqINITIAL_VALUE, xPollingProducerCount = pollqINITIAL_VALUE;
\r
131 /*-----------------------------------------------------------*/
\r
133 void vStartAltPolledQueueTasks( unsigned portBASE_TYPE uxPriority )
\r
135 static xQueueHandle xPolledQueue;
\r
137 /* Create the queue used by the producer and consumer. */
\r
138 xPolledQueue = xQueueCreate( pollqQUEUE_SIZE, ( unsigned portBASE_TYPE ) sizeof( unsigned portSHORT ) );
\r
140 /* vQueueAddToRegistry() adds the queue to the queue registry, if one is
\r
141 in use. The queue registry is provided as a means for kernel aware
\r
142 debuggers to locate queues and has no purpose if a kernel aware debugger
\r
143 is not being used. The call to vQueueAddToRegistry() will be removed
\r
144 by the pre-processor if configQUEUE_REGISTRY_SIZE is not defined or is
\r
145 defined to be less than 1. */
\r
146 vQueueAddToRegistry( xPolledQueue, ( signed portCHAR * ) "AltPollQueue" );
\r
149 /* Spawn the producer and consumer. */
\r
150 xTaskCreate( vPolledQueueConsumer, ( signed portCHAR * ) "QConsNB", pollqSTACK_SIZE, ( void * ) &xPolledQueue, uxPriority, ( xTaskHandle * ) NULL );
\r
151 xTaskCreate( vPolledQueueProducer, ( signed portCHAR * ) "QProdNB", pollqSTACK_SIZE, ( void * ) &xPolledQueue, uxPriority, ( xTaskHandle * ) NULL );
\r
153 /*-----------------------------------------------------------*/
\r
155 static portTASK_FUNCTION( vPolledQueueProducer, pvParameters )
\r
157 unsigned portSHORT usValue = ( unsigned portSHORT ) 0;
\r
158 signed portBASE_TYPE xError = pdFALSE, xLoop;
\r
161 void vPrintDisplayMessage( const portCHAR * const * ppcMessageToSend );
\r
163 const portCHAR * const pcTaskStartMsg = "Alt polling queue producer task started.\r\n";
\r
165 /* Queue a message for printing to say the task has started. */
\r
166 vPrintDisplayMessage( &pcTaskStartMsg );
\r
171 for( xLoop = 0; xLoop < pollqVALUES_TO_PRODUCE; xLoop++ )
\r
173 /* Send an incrementing number on the queue without blocking. */
\r
174 if( xQueueAltSendToBack( *( ( xQueueHandle * ) pvParameters ), ( void * ) &usValue, pollqNO_DELAY ) != pdPASS )
\r
176 /* We should never find the queue full so if we get here there
\r
177 has been an error. */
\r
182 if( xError == pdFALSE )
\r
184 /* If an error has ever been recorded we stop incrementing the
\r
186 portENTER_CRITICAL();
\r
187 xPollingProducerCount++;
\r
188 portEXIT_CRITICAL();
\r
191 /* Update the value we are going to post next time around. */
\r
196 /* Wait before we start posting again to ensure the consumer runs and
\r
197 empties the queue. */
\r
198 vTaskDelay( pollqPRODUCER_DELAY );
\r
200 } /*lint !e818 Function prototype must conform to API. */
\r
201 /*-----------------------------------------------------------*/
\r
203 static portTASK_FUNCTION( vPolledQueueConsumer, pvParameters )
\r
205 unsigned portSHORT usData, usExpectedValue = ( unsigned portSHORT ) 0;
\r
206 signed portBASE_TYPE xError = pdFALSE;
\r
209 void vPrintDisplayMessage( const portCHAR * const * ppcMessageToSend );
\r
211 const portCHAR * const pcTaskStartMsg = "Alt blocking queue consumer task started.\r\n";
\r
213 /* Queue a message for printing to say the task has started. */
\r
214 vPrintDisplayMessage( &pcTaskStartMsg );
\r
219 /* Loop until the queue is empty. */
\r
220 while( uxQueueMessagesWaiting( *( ( xQueueHandle * ) pvParameters ) ) )
\r
222 if( xQueueAltReceive( *( ( xQueueHandle * ) pvParameters ), &usData, pollqNO_DELAY ) == pdPASS )
\r
224 if( usData != usExpectedValue )
\r
226 /* This is not what we expected to receive so an error has
\r
230 /* Catch-up to the value we received so our next expected
\r
231 value should again be correct. */
\r
232 usExpectedValue = usData;
\r
236 if( xError == pdFALSE )
\r
238 /* Only increment the check variable if no errors have
\r
240 portENTER_CRITICAL();
\r
241 xPollingConsumerCount++;
\r
242 portEXIT_CRITICAL();
\r
246 /* Next time round we would expect the number to be one higher. */
\r
251 /* Now the queue is empty we block, allowing the producer to place more
\r
252 items in the queue. */
\r
253 vTaskDelay( pollqCONSUMER_DELAY );
\r
255 } /*lint !e818 Function prototype must conform to API. */
\r
256 /*-----------------------------------------------------------*/
\r
258 /* This is called to check that all the created tasks are still running with no errors. */
\r
259 portBASE_TYPE xAreAltPollingQueuesStillRunning( void )
\r
261 portBASE_TYPE xReturn;
\r
263 /* Check both the consumer and producer poll count to check they have both
\r
264 been changed since out last trip round. We do not need a critical section
\r
265 around the check variables as this is called from a higher priority than
\r
266 the other tasks that access the same variables. */
\r
267 if( ( xPollingConsumerCount == pollqINITIAL_VALUE ) ||
\r
268 ( xPollingProducerCount == pollqINITIAL_VALUE )
\r
278 /* Set the check variables back down so we know if they have been
\r
279 incremented the next time around. */
\r
280 xPollingConsumerCount = pollqINITIAL_VALUE;
\r
281 xPollingProducerCount = pollqINITIAL_VALUE;
\r