PollQ.c File Reference

#include <stdlib.h>
#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"
#include "PollQ.h"

Go to the source code of this file.

Defines
#define	pollqCONSUMER_DELAY   ( pollqPRODUCER_DELAY - ( portTickType ) ( 20 / portTICK_RATE_MS ) )
#define	pollqINITIAL_VALUE   ( ( signed portBASE_TYPE ) 0 )
#define	pollqNO_DELAY   ( ( portTickType ) 0 )
#define	pollqPRODUCER_DELAY   ( ( portTickType ) 200 / portTICK_RATE_MS )
#define	pollqQUEUE_SIZE   ( 10 )
#define	pollqSTACK_SIZE   configMINIMAL_STACK_SIZE
#define	pollqVALUES_TO_PRODUCE   ( ( signed portBASE_TYPE ) 3 )
Functions
static	portTASK_FUNCTION (vPolledQueueConsumer, pvParameters)
static	portTASK_FUNCTION (vPolledQueueProducer, pvParameters)
static	portTASK_FUNCTION_PROTO (vPolledQueueConsumer, pvParameters)
static	portTASK_FUNCTION_PROTO (vPolledQueueProducer, pvParameters)
void	vStartPolledQueueTasks (unsigned portBASE_TYPE uxPriority)
portBASE_TYPE	xArePollingQueuesStillRunning (void)
Variables
static volatile signed portBASE_TYPE	xPollingConsumerCount = pollqINITIAL_VALUE
static volatile signed portBASE_TYPE	xPollingProducerCount = pollqINITIAL_VALUE

---

Define Documentation

#define pollqCONSUMER_DELAY   ( pollqPRODUCER_DELAY - ( portTickType ) ( 20 / portTICK_RATE_MS ) )

Definition at line 97 of file PollQ.c.

#define pollqINITIAL_VALUE   ( ( signed portBASE_TYPE ) 0 )

Definition at line 100 of file PollQ.c.

#define pollqNO_DELAY   ( ( portTickType ) 0 )

Definition at line 98 of file PollQ.c.

#define pollqPRODUCER_DELAY   ( ( portTickType ) 200 / portTICK_RATE_MS )

Definition at line 96 of file PollQ.c.

#define pollqQUEUE_SIZE   ( 10 )

Definition at line 95 of file PollQ.c.

#define pollqSTACK_SIZE   configMINIMAL_STACK_SIZE

Definition at line 94 of file PollQ.c.

#define pollqVALUES_TO_PRODUCE   ( ( signed portBASE_TYPE ) 3 )

Definition at line 99 of file PollQ.c.

---

Function Documentation

static portTASK_FUNCTION	(	vPolledQueueConsumer	,
		pvParameters
	)			[static]

Definition at line 174 of file PollQ.c.

References pdFALSE, pdPASS, pdTRUE, pollqCONSUMER_DELAY, pollqNO_DELAY, portBASE_TYPE, portENTER_CRITICAL, portEXIT_CRITICAL, uxQueueMessagesWaiting(), vTaskDelay(), xPollingConsumerCount, and xQueueReceive.

{
unsigned short usData, usExpectedValue = ( unsigned short ) 0;
signed portBASE_TYPE xError = pdFALSE;

    for( ;; )
    {       
        /* Loop until the queue is empty. */
        while( uxQueueMessagesWaiting( *( ( xQueueHandle * ) pvParameters ) ) )
        {
            if( xQueueReceive( *( ( xQueueHandle * ) 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. */

static portTASK_FUNCTION	(	vPolledQueueProducer	,
		pvParameters
	)			[static]

Definition at line 135 of file PollQ.c.

References pdFALSE, pdPASS, pdTRUE, pollqNO_DELAY, pollqPRODUCER_DELAY, pollqVALUES_TO_PRODUCE, portBASE_TYPE, portENTER_CRITICAL, portEXIT_CRITICAL, vTaskDelay(), xPollingProducerCount, and xQueueSend.

{
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( *( ( xQueueHandle * ) 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_PROTO	(	vPolledQueueConsumer	,
		pvParameters
	)			[static]

static portTASK_FUNCTION_PROTO	(	vPolledQueueProducer	,
		pvParameters
	)			[static]

void vStartPolledQueueTasks

(

unsigned portBASE_TYPE

uxPriority

)

Definition at line 114 of file PollQ.c.

References pollqQUEUE_SIZE, pollqSTACK_SIZE, portBASE_TYPE, vQueueAddToRegistry, xQueueCreate(), and xTaskCreate.

Referenced by main().

{
static xQueueHandle 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, ( signed char * ) "Poll_Test_Queue" );

    /* Spawn the producer and consumer. */
    xTaskCreate( vPolledQueueConsumer, ( signed char * ) "QConsNB", pollqSTACK_SIZE, ( void * ) &xPolledQueue, uxPriority, ( xTaskHandle * ) NULL );
    xTaskCreate( vPolledQueueProducer, ( signed char * ) "QProdNB", pollqSTACK_SIZE, ( void * ) &xPolledQueue, uxPriority, ( xTaskHandle * ) NULL );
}

portBASE_TYPE xArePollingQueuesStillRunning

(

void

)

Definition at line 221 of file PollQ.c.

References pdFALSE, pdTRUE, pollqINITIAL_VALUE, portBASE_TYPE, xPollingConsumerCount, and xPollingProducerCount.

Referenced by prvCheckOtherTasksAreStillRunning().

{
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;
}

---

Variable Documentation

volatile signed portBASE_TYPE xPollingConsumerCount = pollqINITIAL_VALUE [static]

Definition at line 110 of file PollQ.c.

volatile signed portBASE_TYPE xPollingProducerCount = pollqINITIAL_VALUE [static]

Definition at line 110 of file PollQ.c.