| /* |
| FreeRTOS V6.0.5 - Copyright (C) 2010 Real Time Engineers Ltd. |
| |
| *************************************************************************** |
| * * |
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| * "Using the FreeRTOS Real Time Kernel - a Practical Guide" * |
| * http://www.FreeRTOS.org/Documentation * |
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| * A pdf reference manual is also available. Both are usually delivered * |
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| *************************************************************************** |
| |
| 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 exception 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. See the GNU General Public License for |
| more details. You should have received a copy of the GNU General Public |
| License and the FreeRTOS license exception along with FreeRTOS; if not it |
| can be viewed here: http://www.freertos.org/a00114.html and also obtained |
| by writing to Richard Barry, contact details for whom are available on the |
| FreeRTOS WEB site. |
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| 1 tab == 4 spaces! |
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| http://www.FreeRTOS.org - Documentation, latest information, license and |
| contact details. |
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| http://www.SafeRTOS.com - A version that is certified for use in safety |
| critical systems. |
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| http://www.OpenRTOS.com - Commercial support, development, porting, |
| licensing and training services. |
| */ |
| |
| /* |
| * 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). |
| * |
| */ |
| |
| /* |
| |
| Changes from V4.1.1 |
| |
| + The second set of tasks were created the wrong way around. This has been |
| corrected. |
| */ |
| |
| |
| #include <stdlib.h> |
| |
| /* Scheduler include files. */ |
| #include "FreeRTOS.h" |
| #include "task.h" |
| #include "queue.h" |
| |
| /* Demo program include files. */ |
| #include "BlockQ.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 { |
| xQueueHandle xQueue; /*< The queue to be used by the task. */ |
| portTickType 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 ] = {(unsigned short) 0, (unsigned short) 0, (unsigned short) 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 ] = {(unsigned short) 0, (unsigned short) 0, (unsigned short) 0 }; |
| |
| /*-----------------------------------------------------------*/ |
| |
| void vStartBlockingQueueTasks(unsigned portBASE_TYPE uxPriority) |
| { |
| xBlockingQueueParameters *pxQueueParameters1, *pxQueueParameters2; |
| xBlockingQueueParameters *pxQueueParameters3, *pxQueueParameters4; |
| xBlockingQueueParameters *pxQueueParameters5, *pxQueueParameters6; |
| const unsigned portBASE_TYPE uxQueueSize1 = 1, uxQueueSize5 = 5; |
| const portTickType xBlockTime = (portTickType) 1000 / portTICK_RATE_MS; |
| const portTickType xDontBlock = (portTickType) 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, (unsigned portBASE_TYPE) sizeof(unsigned short)); |
| |
| /* 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, (signed char *) "QConsB1", blckqSTACK_SIZE, (void *) pxQueueParameters1, uxPriority, NULL); |
| xTaskCreate(vBlockingQueueProducer, (signed char *) "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, (unsigned portBASE_TYPE) sizeof(unsigned short)); |
| 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, (signed char *) "QProdB3", blckqSTACK_SIZE, (void *) pxQueueParameters3, tskIDLE_PRIORITY, NULL); |
| xTaskCreate(vBlockingQueueProducer, (signed char *) "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, (unsigned portBASE_TYPE) sizeof(unsigned short)); |
| 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, (signed char *) "QProdB5", blckqSTACK_SIZE, (void *) pxQueueParameters5, tskIDLE_PRIORITY, NULL); |
| xTaskCreate(vBlockingQueueConsumer, (signed char *) "QConsB6", blckqSTACK_SIZE, (void *) pxQueueParameters6, tskIDLE_PRIORITY, NULL); |
| } |
| /*-----------------------------------------------------------*/ |
| |
| static portTASK_FUNCTION(vBlockingQueueProducer, pvParameters) |
| { |
| unsigned short usValue = 0; |
| xBlockingQueueParameters *pxQueueParameters; |
| short sErrorEverOccurred = pdFALSE; |
| |
| pxQueueParameters = (xBlockingQueueParameters *) pvParameters; |
| |
| for (;;) { |
| if (xQueueSend(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) |
| { |
| unsigned short usData, usExpectedValue = 0; |
| xBlockingQueueParameters *pxQueueParameters; |
| short sErrorEverOccurred = pdFALSE; |
| |
| pxQueueParameters = (xBlockingQueueParameters *) pvParameters; |
| |
| for (;;) { |
| if (xQueueReceive(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. */ |
| portBASE_TYPE xAreBlockingQueuesStillRunning(void) |
| { |
| static short sLastBlockingConsumerCount[ blckqNUM_TASK_SETS ] = {(unsigned short) 0, (unsigned short) 0, (unsigned short) 0 }; |
| static short sLastBlockingProducerCount[ blckqNUM_TASK_SETS ] = {(unsigned short) 0, (unsigned short) 0, (unsigned short) 0 }; |
| portBASE_TYPE 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; |
| } |
| |