/* FreeRTOS V8.1.2 - 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 is a version of BlockQ.c that uses the alternative (Alt) API. * * Creates six tasks that operate on three queues as follows: * * The first two tasks send and receive an incrementing number to/from a queue. * One task acts as a producer and the other as the consumer. The consumer is a * higher priority than the producer and is set to block on queue reads. The queue * only has space for one item - as soon as the producer posts a message on the * queue the consumer will unblock, pre-empt the producer, and remove the item. * * The second two tasks work the other way around. Again the queue used only has * enough space for one item. This time the consumer has a lower priority than the * producer. The producer will try to post on the queue blocking when the queue is * full. When the consumer wakes it will remove the item from the queue, causing * the producer to unblock, pre-empt the consumer, and immediately re-fill the * queue. * * The last two tasks use the same queue producer and consumer functions. This time the queue has * enough space for lots of items and the tasks operate at the same priority. The * producer will execute, placing items into the queue. The consumer will start * executing when either the queue becomes full (causing the producer to block) or * a context switch occurs (tasks of the same priority will time slice). * */ #include /* Scheduler include files. */ #include "FreeRTOS.h" #include "task.h" #include "queue.h" /* Demo program include files. */ #include "AltBlckQ.h" #define blckqSTACK_SIZE configMINIMAL_STACK_SIZE #define blckqNUM_TASK_SETS ( 3 ) /* Structure used to pass parameters to the blocking queue tasks. */ typedef struct BLOCKING_QUEUE_PARAMETERS { QueueHandle_t xQueue; /*< The queue to be used by the task. */ TickType_t xBlockTime; /*< The block time to use on queue reads/writes. */ volatile short *psCheckVariable; /*< Incremented on each successful cycle to check the task is still running. */ } xBlockingQueueParameters; /* Task function that creates an incrementing number and posts it on a queue. */ static portTASK_FUNCTION_PROTO( vBlockingQueueProducer, pvParameters ); /* Task function that removes the incrementing number from a queue and checks that it is the expected number. */ static portTASK_FUNCTION_PROTO( vBlockingQueueConsumer, pvParameters ); /* Variables which are incremented each time an item is removed from a queue, and found to be the expected value. These are used to check that the tasks are still running. */ static volatile short sBlockingConsumerCount[ blckqNUM_TASK_SETS ] = { ( uint16_t ) 0, ( uint16_t ) 0, ( uint16_t ) 0 }; /* Variable which are incremented each time an item is posted on a queue. These are used to check that the tasks are still running. */ static volatile short sBlockingProducerCount[ blckqNUM_TASK_SETS ] = { ( uint16_t ) 0, ( uint16_t ) 0, ( uint16_t ) 0 }; /*-----------------------------------------------------------*/ void vStartAltBlockingQueueTasks( UBaseType_t uxPriority ) { xBlockingQueueParameters *pxQueueParameters1, *pxQueueParameters2; xBlockingQueueParameters *pxQueueParameters3, *pxQueueParameters4; xBlockingQueueParameters *pxQueueParameters5, *pxQueueParameters6; const UBaseType_t uxQueueSize1 = 1, uxQueueSize5 = 5; const TickType_t xBlockTime = ( TickType_t ) 1000 / portTICK_PERIOD_MS; const TickType_t xDontBlock = ( TickType_t ) 0; /* Create the first two tasks as described at the top of the file. */ /* First create the structure used to pass parameters to the consumer tasks. */ pxQueueParameters1 = ( xBlockingQueueParameters * ) pvPortMalloc( sizeof( xBlockingQueueParameters ) ); /* Create the queue used by the first two tasks to pass the incrementing number. Pass a pointer to the queue in the parameter structure. */ pxQueueParameters1->xQueue = xQueueCreate( uxQueueSize1, ( UBaseType_t ) sizeof( uint16_t ) ); /* The consumer is created first so gets a block time as described above. */ pxQueueParameters1->xBlockTime = xBlockTime; /* Pass in the variable that this task is going to increment so we can check it is still running. */ pxQueueParameters1->psCheckVariable = &( sBlockingConsumerCount[ 0 ] ); /* Create the structure used to pass parameters to the producer task. */ pxQueueParameters2 = ( xBlockingQueueParameters * ) pvPortMalloc( sizeof( xBlockingQueueParameters ) ); /* Pass the queue to this task also, using the parameter structure. */ pxQueueParameters2->xQueue = pxQueueParameters1->xQueue; /* The producer is not going to block - as soon as it posts the consumer will wake and remove the item so the producer should always have room to post. */ pxQueueParameters2->xBlockTime = xDontBlock; /* Pass in the variable that this task is going to increment so we can check it is still running. */ pxQueueParameters2->psCheckVariable = &( sBlockingProducerCount[ 0 ] ); /* Note the producer has a lower priority than the consumer when the tasks are spawned. */ xTaskCreate( vBlockingQueueConsumer, "QConsB1", blckqSTACK_SIZE, ( void * ) pxQueueParameters1, uxPriority, NULL ); xTaskCreate( vBlockingQueueProducer, "QProdB2", blckqSTACK_SIZE, ( void * ) pxQueueParameters2, tskIDLE_PRIORITY, NULL ); /* Create the second two tasks as described at the top of the file. This uses the same mechanism but reverses the task priorities. */ pxQueueParameters3 = ( xBlockingQueueParameters * ) pvPortMalloc( sizeof( xBlockingQueueParameters ) ); pxQueueParameters3->xQueue = xQueueCreate( uxQueueSize1, ( UBaseType_t ) sizeof( uint16_t ) ); pxQueueParameters3->xBlockTime = xDontBlock; pxQueueParameters3->psCheckVariable = &( sBlockingProducerCount[ 1 ] ); pxQueueParameters4 = ( xBlockingQueueParameters * ) pvPortMalloc( sizeof( xBlockingQueueParameters ) ); pxQueueParameters4->xQueue = pxQueueParameters3->xQueue; pxQueueParameters4->xBlockTime = xBlockTime; pxQueueParameters4->psCheckVariable = &( sBlockingConsumerCount[ 1 ] ); xTaskCreate( vBlockingQueueConsumer, "QProdB3", blckqSTACK_SIZE, ( void * ) pxQueueParameters3, tskIDLE_PRIORITY, NULL ); xTaskCreate( vBlockingQueueProducer, "QConsB4", blckqSTACK_SIZE, ( void * ) pxQueueParameters4, uxPriority, NULL ); /* Create the last two tasks as described above. The mechanism is again just the same. This time both parameter structures are given a block time. */ pxQueueParameters5 = ( xBlockingQueueParameters * ) pvPortMalloc( sizeof( xBlockingQueueParameters ) ); pxQueueParameters5->xQueue = xQueueCreate( uxQueueSize5, ( UBaseType_t ) sizeof( uint16_t ) ); pxQueueParameters5->xBlockTime = xBlockTime; pxQueueParameters5->psCheckVariable = &( sBlockingProducerCount[ 2 ] ); pxQueueParameters6 = ( xBlockingQueueParameters * ) pvPortMalloc( sizeof( xBlockingQueueParameters ) ); pxQueueParameters6->xQueue = pxQueueParameters5->xQueue; pxQueueParameters6->xBlockTime = xBlockTime; pxQueueParameters6->psCheckVariable = &( sBlockingConsumerCount[ 2 ] ); xTaskCreate( vBlockingQueueProducer, "QProdB5", blckqSTACK_SIZE, ( void * ) pxQueueParameters5, tskIDLE_PRIORITY, NULL ); xTaskCreate( vBlockingQueueConsumer, "QConsB6", blckqSTACK_SIZE, ( void * ) pxQueueParameters6, tskIDLE_PRIORITY, NULL ); } /*-----------------------------------------------------------*/ static portTASK_FUNCTION( vBlockingQueueProducer, pvParameters ) { uint16_t usValue = 0; xBlockingQueueParameters *pxQueueParameters; short sErrorEverOccurred = pdFALSE; #ifdef USE_STDIO void vPrintDisplayMessage( const char * const * ppcMessageToSend ); const char * const pcTaskStartMsg = "Alt blocking queue producer task started.\r\n"; /* Queue a message for printing to say the task has started. */ vPrintDisplayMessage( &pcTaskStartMsg ); #endif pxQueueParameters = ( xBlockingQueueParameters * ) pvParameters; for( ;; ) { if( xQueueAltSendToBack( pxQueueParameters->xQueue, ( void * ) &usValue, pxQueueParameters->xBlockTime ) != pdPASS ) { sErrorEverOccurred = pdTRUE; } else { /* We have successfully posted a message, so increment the variable used to check we are still running. */ if( sErrorEverOccurred == pdFALSE ) { ( *pxQueueParameters->psCheckVariable )++; } /* Increment the variable we are going to post next time round. The consumer will expect the numbers to follow in numerical order. */ ++usValue; } } } /*-----------------------------------------------------------*/ static portTASK_FUNCTION( vBlockingQueueConsumer, pvParameters ) { uint16_t usData, usExpectedValue = 0; xBlockingQueueParameters *pxQueueParameters; short sErrorEverOccurred = pdFALSE; #ifdef USE_STDIO void vPrintDisplayMessage( const char * const * ppcMessageToSend ); const char * const pcTaskStartMsg = "Alt blocking queue consumer task started.\r\n"; /* Queue a message for printing to say the task has started. */ vPrintDisplayMessage( &pcTaskStartMsg ); #endif pxQueueParameters = ( xBlockingQueueParameters * ) pvParameters; for( ;; ) { if( xQueueAltReceive( pxQueueParameters->xQueue, &usData, pxQueueParameters->xBlockTime ) == pdPASS ) { if( usData != usExpectedValue ) { /* Catch-up. */ usExpectedValue = usData; sErrorEverOccurred = pdTRUE; } else { /* We have successfully received a message, so increment the variable used to check we are still running. */ if( sErrorEverOccurred == pdFALSE ) { ( *pxQueueParameters->psCheckVariable )++; } /* Increment the value we expect to remove from the queue next time round. */ ++usExpectedValue; } } } } /*-----------------------------------------------------------*/ /* This is called to check that all the created tasks are still running. */ BaseType_t xAreAltBlockingQueuesStillRunning( void ) { static short sLastBlockingConsumerCount[ blckqNUM_TASK_SETS ] = { ( uint16_t ) 0, ( uint16_t ) 0, ( uint16_t ) 0 }; static short sLastBlockingProducerCount[ blckqNUM_TASK_SETS ] = { ( uint16_t ) 0, ( uint16_t ) 0, ( uint16_t ) 0 }; BaseType_t xReturn = pdPASS, xTasks; /* Not too worried about mutual exclusion on these variables as they are 16 bits and we are only reading them. We also only care to see if they have changed or not. Loop through each check variable to and return pdFALSE if any are found not to have changed since the last call. */ for( xTasks = 0; xTasks < blckqNUM_TASK_SETS; xTasks++ ) { if( sBlockingConsumerCount[ xTasks ] == sLastBlockingConsumerCount[ xTasks ] ) { xReturn = pdFALSE; } sLastBlockingConsumerCount[ xTasks ] = sBlockingConsumerCount[ xTasks ]; if( sBlockingProducerCount[ xTasks ] == sLastBlockingProducerCount[ xTasks ] ) { xReturn = pdFALSE; } sLastBlockingProducerCount[ xTasks ] = sBlockingProducerCount[ xTasks ]; } return xReturn; }