/* | |
* FreeRTOS Kernel V10.3.0 | |
* Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved. | |
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* 1 tab == 4 spaces! | |
*/ | |
/* | |
* 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 <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 ) | |
#if( configSUPPORT_DYNAMIC_ALLOCATION == 0 ) | |
#error This example cannot be used if dynamic allocation is not allowed. | |
#endif | |
/* 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 vStartBlockingQueueTasks( UBaseType_t uxPriority ) | |
{ | |
xBlockingQueueParameters *pxQueueParameters1, *pxQueueParameters2; | |
xBlockingQueueParameters *pxQueueParameters3, *pxQueueParameters4; | |
xBlockingQueueParameters *pxQueueParameters5, *pxQueueParameters6; | |
const UBaseType_t uxQueueSize1 = 1, uxQueueSize5 = 5; | |
const TickType_t xBlockTime = pdMS_TO_TICKS( ( TickType_t ) 1000 ); | |
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, "QConsB3", blckqSTACK_SIZE, ( void * ) pxQueueParameters3, tskIDLE_PRIORITY, NULL ); | |
xTaskCreate( vBlockingQueueProducer, "QProdB4", 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; | |
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; | |
#if configUSE_PREEMPTION == 0 | |
taskYIELD(); | |
#endif | |
} | |
} | |
} | |
/*-----------------------------------------------------------*/ | |
static portTASK_FUNCTION( vBlockingQueueConsumer, pvParameters ) | |
{ | |
uint16_t 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; | |
} | |
#if configUSE_PREEMPTION == 0 | |
{ | |
if( pxQueueParameters->xBlockTime == 0 ) | |
{ | |
taskYIELD(); | |
} | |
} | |
#endif | |
} | |
} | |
} | |
/*-----------------------------------------------------------*/ | |
/* This is called to check that all the created tasks are still running. */ | |
BaseType_t xAreBlockingQueuesStillRunning( 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; | |
} | |