/* FreeRTOS V8.0.1 - Copyright (C) 2014 Real Time Engineers Ltd. All rights reserved VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION. *************************************************************************** * * * FreeRTOS provides completely free yet professionally developed, * * robust, strictly quality controlled, supported, and cross * * platform software that has become a de facto standard. * * * * Help yourself get started quickly and support the FreeRTOS * * project by purchasing a FreeRTOS tutorial book, reference * * manual, or both from: http://www.FreeRTOS.org/Documentation * * * * Thank you! * * * *************************************************************************** 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 modification 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. Full license text is available from the following link: http://www.freertos.org/a00114.html 1 tab == 4 spaces! *************************************************************************** * * * Having a problem? Start by reading the FAQ "My application does * * not run, what could be wrong?" * * * * http://www.FreeRTOS.org/FAQHelp.html * * * *************************************************************************** http://www.FreeRTOS.org - Documentation, books, training, latest versions, license and Real Time Engineers Ltd. contact details. http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products, including FreeRTOS+Trace - an indispensable productivity tool, a DOS compatible FAT file system, and our tiny thread aware UDP/IP stack. http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS licenses offer ticketed support, indemnification and middleware. http://www.SafeRTOS.com - High Integrity Systems also provide a safety engineered and independently SIL3 certified version for use in safety and mission critical applications that require provable dependability. 1 tab == 4 spaces! */ /* * This version of PollQ. c is for use on systems that have limited stack * space and no display facilities. The complete version can be found in * the Demo/Common/Full directory. * * Creates two tasks that communicate over a single queue. One task acts as a * producer, the other a consumer. * * The producer loops for three iteration, posting an incrementing number onto the * queue each cycle. It then delays for a fixed period before doing exactly the * same again. * * The consumer loops emptying the queue. Each item removed from the queue is * checked to ensure it contains the expected value. When the queue is empty it * blocks for a fixed period, then does the same again. * * All queue access is performed without blocking. The consumer completely empties * the queue each time it runs so the producer should never find the queue full. * * An error is flagged if the consumer obtains an unexpected value or the producer * find the queue is full. */ /* Changes from V2.0.0 + Delay periods are now specified using variables and constants of TickType_t rather than unsigned long. */ #include /* Scheduler include files. */ #include "FreeRTOS.h" #include "task.h" #include "queue.h" /* Demo program include files. */ #include "PollQ.h" #define pollqSTACK_SIZE configMINIMAL_STACK_SIZE #define pollqQUEUE_SIZE ( 10 ) #define pollqPRODUCER_DELAY ( ( TickType_t ) 200 / portTICK_PERIOD_MS ) #define pollqCONSUMER_DELAY ( pollqPRODUCER_DELAY - ( TickType_t ) ( 20 / portTICK_PERIOD_MS ) ) #define pollqNO_DELAY ( ( TickType_t ) 0 ) #define pollqVALUES_TO_PRODUCE ( ( signed portBASE_TYPE ) 3 ) #define pollqINITIAL_VALUE ( ( signed portBASE_TYPE ) 0 ) /* The task that posts the incrementing number onto the queue. */ static portTASK_FUNCTION_PROTO( vPolledQueueProducer, pvParameters ); /* The task that empties the queue. */ static portTASK_FUNCTION_PROTO( vPolledQueueConsumer, pvParameters ); /* Variables that are used to check that the tasks are still running with no errors. */ static volatile signed portBASE_TYPE xPollingConsumerCount = pollqINITIAL_VALUE, xPollingProducerCount = pollqINITIAL_VALUE; /*-----------------------------------------------------------*/ void vStartPolledQueueTasks( unsigned portBASE_TYPE uxPriority ) { static QueueHandle_t xPolledQueue; /* Create the queue used by the producer and consumer. */ xPolledQueue = xQueueCreate( pollqQUEUE_SIZE, ( unsigned portBASE_TYPE ) sizeof( unsigned short ) ); /* vQueueAddToRegistry() adds the queue to the queue registry, if one is in use. The queue registry is provided as a means for kernel aware debuggers to locate queues and has no purpose if a kernel aware debugger is not being used. The call to vQueueAddToRegistry() will be removed by the pre-processor if configQUEUE_REGISTRY_SIZE is not defined or is defined to be less than 1. */ vQueueAddToRegistry( xPolledQueue, "Poll_Test_Queue" ); /* Spawn the producer and consumer. */ xTaskCreate( vPolledQueueConsumer, "QConsNB", pollqSTACK_SIZE, ( void * ) &xPolledQueue, uxPriority, ( TaskHandle_t * ) NULL ); xTaskCreate( vPolledQueueProducer, "QProdNB", pollqSTACK_SIZE, ( void * ) &xPolledQueue, uxPriority, ( TaskHandle_t * ) NULL ); } /*-----------------------------------------------------------*/ static portTASK_FUNCTION( vPolledQueueProducer, pvParameters ) { unsigned short usValue = ( unsigned short ) 0; signed portBASE_TYPE xError = pdFALSE, xLoop; for( ;; ) { for( xLoop = 0; xLoop < pollqVALUES_TO_PRODUCE; xLoop++ ) { /* Send an incrementing number on the queue without blocking. */ if( xQueueSend( *( ( QueueHandle_t * ) pvParameters ), ( void * ) &usValue, pollqNO_DELAY ) != pdPASS ) { /* We should never find the queue full so if we get here there has been an error. */ xError = pdTRUE; } else { if( xError == pdFALSE ) { /* If an error has ever been recorded we stop incrementing the check variable. */ portENTER_CRITICAL(); xPollingProducerCount++; portEXIT_CRITICAL(); } /* Update the value we are going to post next time around. */ usValue++; } } /* Wait before we start posting again to ensure the consumer runs and empties the queue. */ vTaskDelay( pollqPRODUCER_DELAY ); } } /*lint !e818 Function prototype must conform to API. */ /*-----------------------------------------------------------*/ static portTASK_FUNCTION( vPolledQueueConsumer, pvParameters ) { unsigned short usData, usExpectedValue = ( unsigned short ) 0; signed portBASE_TYPE xError = pdFALSE; for( ;; ) { /* Loop until the queue is empty. */ while( uxQueueMessagesWaiting( *( ( QueueHandle_t * ) pvParameters ) ) ) { if( xQueueReceive( *( ( QueueHandle_t * ) pvParameters ), &usData, pollqNO_DELAY ) == pdPASS ) { if( usData != usExpectedValue ) { /* This is not what we expected to receive so an error has occurred. */ xError = pdTRUE; /* Catch-up to the value we received so our next expected value should again be correct. */ usExpectedValue = usData; } else { if( xError == pdFALSE ) { /* Only increment the check variable if no errors have occurred. */ portENTER_CRITICAL(); xPollingConsumerCount++; portEXIT_CRITICAL(); } } /* Next time round we would expect the number to be one higher. */ usExpectedValue++; } } /* Now the queue is empty we block, allowing the producer to place more items in the queue. */ vTaskDelay( pollqCONSUMER_DELAY ); } } /*lint !e818 Function prototype must conform to API. */ /*-----------------------------------------------------------*/ /* This is called to check that all the created tasks are still running with no errors. */ portBASE_TYPE xArePollingQueuesStillRunning( void ) { portBASE_TYPE xReturn; /* Check both the consumer and producer poll count to check they have both been changed since out last trip round. We do not need a critical section around the check variables as this is called from a higher priority than the other tasks that access the same variables. */ if( ( xPollingConsumerCount == pollqINITIAL_VALUE ) || ( xPollingProducerCount == pollqINITIAL_VALUE ) ) { xReturn = pdFALSE; } else { xReturn = pdTRUE; } /* Set the check variables back down so we know if they have been incremented the next time around. */ xPollingConsumerCount = pollqINITIAL_VALUE; xPollingProducerCount = pollqINITIAL_VALUE; return xReturn; }