1655 lines
59 KiB
C
1655 lines
59 KiB
C
/*
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* FreeRTOS Kernel V10.1.1
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* Copyright (C) 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy of
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* this software and associated documentation files (the "Software"), to deal in
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* the Software without restriction, including without limitation the rights to
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* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
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* the Software, and to permit persons to whom the Software is furnished to do so,
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* subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all
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* copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
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* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
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* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
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* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*
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* http://www.FreeRTOS.org
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* http://aws.amazon.com/freertos
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*
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* 1 tab == 4 spaces!
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*/
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#ifndef QUEUE_H
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#define QUEUE_H
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#ifndef INC_FREERTOS_H
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#error "include FreeRTOS.h" must appear in source files before "include queue.h"
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#endif
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#ifdef __cplusplus
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extern "C" {
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#endif
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#include "task.h"
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/**
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* Type by which queues are referenced. For example, a call to xQueueCreate()
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* returns an QueueHandle_t variable that can then be used as a parameter to
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* xQueueSend(), xQueueReceive(), etc.
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*/
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struct QueueDefinition; /* Using old naming convention so as not to break kernel aware debuggers. */
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typedef struct QueueDefinition * QueueHandle_t;
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/**
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* Type by which queue sets are referenced. For example, a call to
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* xQueueCreateSet() returns an xQueueSet variable that can then be used as a
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* parameter to xQueueSelectFromSet(), xQueueAddToSet(), etc.
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*/
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typedef struct QueueDefinition * QueueSetHandle_t;
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/**
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* Queue sets can contain both queues and semaphores, so the
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* QueueSetMemberHandle_t is defined as a type to be used where a parameter or
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* return value can be either an QueueHandle_t or an SemaphoreHandle_t.
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*/
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typedef struct QueueDefinition * QueueSetMemberHandle_t;
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/* For internal use only. */
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#define queueSEND_TO_BACK ( ( BaseType_t ) 0 )
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#define queueSEND_TO_FRONT ( ( BaseType_t ) 1 )
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#define queueOVERWRITE ( ( BaseType_t ) 2 )
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/* For internal use only. These definitions *must* match those in queue.c. */
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#define queueQUEUE_TYPE_BASE ( ( uint8_t ) 0U )
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#define queueQUEUE_TYPE_SET ( ( uint8_t ) 0U )
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#define queueQUEUE_TYPE_MUTEX ( ( uint8_t ) 1U )
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#define queueQUEUE_TYPE_COUNTING_SEMAPHORE ( ( uint8_t ) 2U )
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#define queueQUEUE_TYPE_BINARY_SEMAPHORE ( ( uint8_t ) 3U )
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#define queueQUEUE_TYPE_RECURSIVE_MUTEX ( ( uint8_t ) 4U )
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/**
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* queue. h
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* <pre>
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QueueHandle_t xQueueCreate(
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UBaseType_t uxQueueLength,
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UBaseType_t uxItemSize
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);
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* </pre>
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*
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* Creates a new queue instance, and returns a handle by which the new queue
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* can be referenced.
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*
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* Internally, within the FreeRTOS implementation, queues use two blocks of
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* memory. The first block is used to hold the queue's data structures. The
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* second block is used to hold items placed into the queue. If a queue is
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* created using xQueueCreate() then both blocks of memory are automatically
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* dynamically allocated inside the xQueueCreate() function. (see
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* http://www.freertos.org/a00111.html). If a queue is created using
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* xQueueCreateStatic() then the application writer must provide the memory that
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* will get used by the queue. xQueueCreateStatic() therefore allows a queue to
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* be created without using any dynamic memory allocation.
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*
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* http://www.FreeRTOS.org/Embedded-RTOS-Queues.html
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*
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* @param uxQueueLength The maximum number of items that the queue can contain.
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*
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* @param uxItemSize The number of bytes each item in the queue will require.
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* Items are queued by copy, not by reference, so this is the number of bytes
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* that will be copied for each posted item. Each item on the queue must be
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* the same size.
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*
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* @return If the queue is successfully create then a handle to the newly
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* created queue is returned. If the queue cannot be created then 0 is
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* returned.
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*
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* Example usage:
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<pre>
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struct AMessage
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{
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char ucMessageID;
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char ucData[ 20 ];
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};
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void vATask( void *pvParameters )
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{
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QueueHandle_t xQueue1, xQueue2;
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// Create a queue capable of containing 10 uint32_t values.
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xQueue1 = xQueueCreate( 10, sizeof( uint32_t ) );
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if( xQueue1 == 0 )
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{
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// Queue was not created and must not be used.
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}
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// Create a queue capable of containing 10 pointers to AMessage structures.
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// These should be passed by pointer as they contain a lot of data.
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xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
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if( xQueue2 == 0 )
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{
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// Queue was not created and must not be used.
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}
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// ... Rest of task code.
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}
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</pre>
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* \defgroup xQueueCreate xQueueCreate
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* \ingroup QueueManagement
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*/
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#if( configSUPPORT_DYNAMIC_ALLOCATION == 1 )
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#define xQueueCreate( uxQueueLength, uxItemSize ) xQueueGenericCreate( ( uxQueueLength ), ( uxItemSize ), ( queueQUEUE_TYPE_BASE ) )
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#endif
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/**
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* queue. h
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* <pre>
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QueueHandle_t xQueueCreateStatic(
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UBaseType_t uxQueueLength,
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UBaseType_t uxItemSize,
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uint8_t *pucQueueStorageBuffer,
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StaticQueue_t *pxQueueBuffer
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);
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* </pre>
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*
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* Creates a new queue instance, and returns a handle by which the new queue
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* can be referenced.
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*
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* Internally, within the FreeRTOS implementation, queues use two blocks of
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* memory. The first block is used to hold the queue's data structures. The
|
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* second block is used to hold items placed into the queue. If a queue is
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* created using xQueueCreate() then both blocks of memory are automatically
|
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* dynamically allocated inside the xQueueCreate() function. (see
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* http://www.freertos.org/a00111.html). If a queue is created using
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* xQueueCreateStatic() then the application writer must provide the memory that
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* will get used by the queue. xQueueCreateStatic() therefore allows a queue to
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* be created without using any dynamic memory allocation.
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*
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* http://www.FreeRTOS.org/Embedded-RTOS-Queues.html
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*
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* @param uxQueueLength The maximum number of items that the queue can contain.
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*
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* @param uxItemSize The number of bytes each item in the queue will require.
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* Items are queued by copy, not by reference, so this is the number of bytes
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* that will be copied for each posted item. Each item on the queue must be
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* the same size.
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*
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* @param pucQueueStorageBuffer If uxItemSize is not zero then
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* pucQueueStorageBuffer must point to a uint8_t array that is at least large
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* enough to hold the maximum number of items that can be in the queue at any
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* one time - which is ( uxQueueLength * uxItemsSize ) bytes. If uxItemSize is
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* zero then pucQueueStorageBuffer can be NULL.
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*
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* @param pxQueueBuffer Must point to a variable of type StaticQueue_t, which
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* will be used to hold the queue's data structure.
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*
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* @return If the queue is created then a handle to the created queue is
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* returned. If pxQueueBuffer is NULL then NULL is returned.
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*
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* Example usage:
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<pre>
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struct AMessage
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{
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char ucMessageID;
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char ucData[ 20 ];
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};
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#define QUEUE_LENGTH 10
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#define ITEM_SIZE sizeof( uint32_t )
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// xQueueBuffer will hold the queue structure.
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StaticQueue_t xQueueBuffer;
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// ucQueueStorage will hold the items posted to the queue. Must be at least
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// [(queue length) * ( queue item size)] bytes long.
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uint8_t ucQueueStorage[ QUEUE_LENGTH * ITEM_SIZE ];
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void vATask( void *pvParameters )
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{
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QueueHandle_t xQueue1;
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// Create a queue capable of containing 10 uint32_t values.
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xQueue1 = xQueueCreate( QUEUE_LENGTH, // The number of items the queue can hold.
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ITEM_SIZE // The size of each item in the queue
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&( ucQueueStorage[ 0 ] ), // The buffer that will hold the items in the queue.
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&xQueueBuffer ); // The buffer that will hold the queue structure.
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// The queue is guaranteed to be created successfully as no dynamic memory
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// allocation is used. Therefore xQueue1 is now a handle to a valid queue.
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// ... Rest of task code.
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}
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</pre>
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* \defgroup xQueueCreateStatic xQueueCreateStatic
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* \ingroup QueueManagement
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*/
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#if( configSUPPORT_STATIC_ALLOCATION == 1 )
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#define xQueueCreateStatic( uxQueueLength, uxItemSize, pucQueueStorage, pxQueueBuffer ) xQueueGenericCreateStatic( ( uxQueueLength ), ( uxItemSize ), ( pucQueueStorage ), ( pxQueueBuffer ), ( queueQUEUE_TYPE_BASE ) )
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#endif /* configSUPPORT_STATIC_ALLOCATION */
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/**
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* queue. h
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* <pre>
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BaseType_t xQueueSendToToFront(
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QueueHandle_t xQueue,
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const void *pvItemToQueue,
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TickType_t xTicksToWait
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);
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* </pre>
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*
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* Post an item to the front of a queue. The item is queued by copy, not by
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* reference. This function must not be called from an interrupt service
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* routine. See xQueueSendFromISR () for an alternative which may be used
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* in an ISR.
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*
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* @param xQueue The handle to the queue on which the item is to be posted.
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*
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* @param pvItemToQueue A pointer to the item that is to be placed on the
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* queue. The size of the items the queue will hold was defined when the
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* queue was created, so this many bytes will be copied from pvItemToQueue
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* into the queue storage area.
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*
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* @param xTicksToWait The maximum amount of time the task should block
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* waiting for space to become available on the queue, should it already
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* be full. The call will return immediately if this is set to 0 and the
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* queue is full. The time is defined in tick periods so the constant
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* portTICK_PERIOD_MS should be used to convert to real time if this is required.
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*
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* @return pdTRUE if the item was successfully posted, otherwise errQUEUE_FULL.
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*
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* Example usage:
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<pre>
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struct AMessage
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{
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char ucMessageID;
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char ucData[ 20 ];
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} xMessage;
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uint32_t ulVar = 10UL;
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void vATask( void *pvParameters )
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{
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QueueHandle_t xQueue1, xQueue2;
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struct AMessage *pxMessage;
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// Create a queue capable of containing 10 uint32_t values.
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xQueue1 = xQueueCreate( 10, sizeof( uint32_t ) );
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// Create a queue capable of containing 10 pointers to AMessage structures.
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// These should be passed by pointer as they contain a lot of data.
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xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
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// ...
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if( xQueue1 != 0 )
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{
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// Send an uint32_t. Wait for 10 ticks for space to become
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// available if necessary.
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if( xQueueSendToFront( xQueue1, ( void * ) &ulVar, ( TickType_t ) 10 ) != pdPASS )
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{
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// Failed to post the message, even after 10 ticks.
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}
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}
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if( xQueue2 != 0 )
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{
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// Send a pointer to a struct AMessage object. Don't block if the
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// queue is already full.
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pxMessage = & xMessage;
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xQueueSendToFront( xQueue2, ( void * ) &pxMessage, ( TickType_t ) 0 );
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}
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// ... Rest of task code.
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}
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</pre>
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* \defgroup xQueueSend xQueueSend
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* \ingroup QueueManagement
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*/
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#define xQueueSendToFront( xQueue, pvItemToQueue, xTicksToWait ) xQueueGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_FRONT )
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/**
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* queue. h
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* <pre>
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BaseType_t xQueueSendToBack(
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QueueHandle_t xQueue,
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const void *pvItemToQueue,
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TickType_t xTicksToWait
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);
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* </pre>
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*
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* This is a macro that calls xQueueGenericSend().
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*
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* Post an item to the back of a queue. The item is queued by copy, not by
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* reference. This function must not be called from an interrupt service
|
|
* routine. See xQueueSendFromISR () for an alternative which may be used
|
|
* in an ISR.
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|
*
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* @param xQueue The handle to the queue on which the item is to be posted.
|
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*
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* @param pvItemToQueue A pointer to the item that is to be placed on the
|
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* queue. The size of the items the queue will hold was defined when the
|
|
* queue was created, so this many bytes will be copied from pvItemToQueue
|
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* into the queue storage area.
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*
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* @param xTicksToWait The maximum amount of time the task should block
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* waiting for space to become available on the queue, should it already
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|
* be full. The call will return immediately if this is set to 0 and the queue
|
|
* is full. The time is defined in tick periods so the constant
|
|
* portTICK_PERIOD_MS should be used to convert to real time if this is required.
|
|
*
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* @return pdTRUE if the item was successfully posted, otherwise errQUEUE_FULL.
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*
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* Example usage:
|
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<pre>
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|
struct AMessage
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|
{
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char ucMessageID;
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char ucData[ 20 ];
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} xMessage;
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uint32_t ulVar = 10UL;
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void vATask( void *pvParameters )
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{
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QueueHandle_t xQueue1, xQueue2;
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struct AMessage *pxMessage;
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// Create a queue capable of containing 10 uint32_t values.
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xQueue1 = xQueueCreate( 10, sizeof( uint32_t ) );
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|
|
|
// Create a queue capable of containing 10 pointers to AMessage structures.
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// These should be passed by pointer as they contain a lot of data.
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xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
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// ...
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if( xQueue1 != 0 )
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{
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// Send an uint32_t. Wait for 10 ticks for space to become
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// available if necessary.
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if( xQueueSendToBack( xQueue1, ( void * ) &ulVar, ( TickType_t ) 10 ) != pdPASS )
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{
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// Failed to post the message, even after 10 ticks.
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}
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}
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|
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if( xQueue2 != 0 )
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{
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// Send a pointer to a struct AMessage object. Don't block if the
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// queue is already full.
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pxMessage = & xMessage;
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xQueueSendToBack( xQueue2, ( void * ) &pxMessage, ( TickType_t ) 0 );
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}
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// ... Rest of task code.
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}
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</pre>
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* \defgroup xQueueSend xQueueSend
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* \ingroup QueueManagement
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*/
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#define xQueueSendToBack( xQueue, pvItemToQueue, xTicksToWait ) xQueueGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_BACK )
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|
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/**
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|
* queue. h
|
|
* <pre>
|
|
BaseType_t xQueueSend(
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|
QueueHandle_t xQueue,
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|
const void * pvItemToQueue,
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|
TickType_t xTicksToWait
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|
);
|
|
* </pre>
|
|
*
|
|
* This is a macro that calls xQueueGenericSend(). It is included for
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|
* backward compatibility with versions of FreeRTOS.org that did not
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|
* include the xQueueSendToFront() and xQueueSendToBack() macros. It is
|
|
* equivalent to xQueueSendToBack().
|
|
*
|
|
* Post an item on a queue. The item is queued by copy, not by reference.
|
|
* This function must not be called from an interrupt service routine.
|
|
* See xQueueSendFromISR () for an alternative which may be used in an ISR.
|
|
*
|
|
* @param xQueue The handle to the queue on which the item is to be posted.
|
|
*
|
|
* @param pvItemToQueue A pointer to the item that is to be placed on the
|
|
* queue. The size of the items the queue will hold was defined when the
|
|
* queue was created, so this many bytes will be copied from pvItemToQueue
|
|
* into the queue storage area.
|
|
*
|
|
* @param xTicksToWait The maximum amount of time the task should block
|
|
* waiting for space to become available on the queue, should it already
|
|
* be full. The call will return immediately if this is set to 0 and the
|
|
* queue is full. The time is defined in tick periods so the constant
|
|
* portTICK_PERIOD_MS should be used to convert to real time if this is required.
|
|
*
|
|
* @return pdTRUE if the item was successfully posted, otherwise errQUEUE_FULL.
|
|
*
|
|
* Example usage:
|
|
<pre>
|
|
struct AMessage
|
|
{
|
|
char ucMessageID;
|
|
char ucData[ 20 ];
|
|
} xMessage;
|
|
|
|
uint32_t ulVar = 10UL;
|
|
|
|
void vATask( void *pvParameters )
|
|
{
|
|
QueueHandle_t xQueue1, xQueue2;
|
|
struct AMessage *pxMessage;
|
|
|
|
// Create a queue capable of containing 10 uint32_t values.
|
|
xQueue1 = xQueueCreate( 10, sizeof( uint32_t ) );
|
|
|
|
// Create a queue capable of containing 10 pointers to AMessage structures.
|
|
// These should be passed by pointer as they contain a lot of data.
|
|
xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
|
|
|
|
// ...
|
|
|
|
if( xQueue1 != 0 )
|
|
{
|
|
// Send an uint32_t. Wait for 10 ticks for space to become
|
|
// available if necessary.
|
|
if( xQueueSend( xQueue1, ( void * ) &ulVar, ( TickType_t ) 10 ) != pdPASS )
|
|
{
|
|
// Failed to post the message, even after 10 ticks.
|
|
}
|
|
}
|
|
|
|
if( xQueue2 != 0 )
|
|
{
|
|
// Send a pointer to a struct AMessage object. Don't block if the
|
|
// queue is already full.
|
|
pxMessage = & xMessage;
|
|
xQueueSend( xQueue2, ( void * ) &pxMessage, ( TickType_t ) 0 );
|
|
}
|
|
|
|
// ... Rest of task code.
|
|
}
|
|
</pre>
|
|
* \defgroup xQueueSend xQueueSend
|
|
* \ingroup QueueManagement
|
|
*/
|
|
#define xQueueSend( xQueue, pvItemToQueue, xTicksToWait ) xQueueGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_BACK )
|
|
|
|
/**
|
|
* queue. h
|
|
* <pre>
|
|
BaseType_t xQueueOverwrite(
|
|
QueueHandle_t xQueue,
|
|
const void * pvItemToQueue
|
|
);
|
|
* </pre>
|
|
*
|
|
* Only for use with queues that have a length of one - so the queue is either
|
|
* empty or full.
|
|
*
|
|
* Post an item on a queue. If the queue is already full then overwrite the
|
|
* value held in the queue. The item is queued by copy, not by reference.
|
|
*
|
|
* This function must not be called from an interrupt service routine.
|
|
* See xQueueOverwriteFromISR () for an alternative which may be used in an ISR.
|
|
*
|
|
* @param xQueue The handle of the queue to which the data is being sent.
|
|
*
|
|
* @param pvItemToQueue A pointer to the item that is to be placed on the
|
|
* queue. The size of the items the queue will hold was defined when the
|
|
* queue was created, so this many bytes will be copied from pvItemToQueue
|
|
* into the queue storage area.
|
|
*
|
|
* @return xQueueOverwrite() is a macro that calls xQueueGenericSend(), and
|
|
* therefore has the same return values as xQueueSendToFront(). However, pdPASS
|
|
* is the only value that can be returned because xQueueOverwrite() will write
|
|
* to the queue even when the queue is already full.
|
|
*
|
|
* Example usage:
|
|
<pre>
|
|
|
|
void vFunction( void *pvParameters )
|
|
{
|
|
QueueHandle_t xQueue;
|
|
uint32_t ulVarToSend, ulValReceived;
|
|
|
|
// Create a queue to hold one uint32_t value. It is strongly
|
|
// recommended *not* to use xQueueOverwrite() on queues that can
|
|
// contain more than one value, and doing so will trigger an assertion
|
|
// if configASSERT() is defined.
|
|
xQueue = xQueueCreate( 1, sizeof( uint32_t ) );
|
|
|
|
// Write the value 10 to the queue using xQueueOverwrite().
|
|
ulVarToSend = 10;
|
|
xQueueOverwrite( xQueue, &ulVarToSend );
|
|
|
|
// Peeking the queue should now return 10, but leave the value 10 in
|
|
// the queue. A block time of zero is used as it is known that the
|
|
// queue holds a value.
|
|
ulValReceived = 0;
|
|
xQueuePeek( xQueue, &ulValReceived, 0 );
|
|
|
|
if( ulValReceived != 10 )
|
|
{
|
|
// Error unless the item was removed by a different task.
|
|
}
|
|
|
|
// The queue is still full. Use xQueueOverwrite() to overwrite the
|
|
// value held in the queue with 100.
|
|
ulVarToSend = 100;
|
|
xQueueOverwrite( xQueue, &ulVarToSend );
|
|
|
|
// This time read from the queue, leaving the queue empty once more.
|
|
// A block time of 0 is used again.
|
|
xQueueReceive( xQueue, &ulValReceived, 0 );
|
|
|
|
// The value read should be the last value written, even though the
|
|
// queue was already full when the value was written.
|
|
if( ulValReceived != 100 )
|
|
{
|
|
// Error!
|
|
}
|
|
|
|
// ...
|
|
}
|
|
</pre>
|
|
* \defgroup xQueueOverwrite xQueueOverwrite
|
|
* \ingroup QueueManagement
|
|
*/
|
|
#define xQueueOverwrite( xQueue, pvItemToQueue ) xQueueGenericSend( ( xQueue ), ( pvItemToQueue ), 0, queueOVERWRITE )
|
|
|
|
|
|
/**
|
|
* queue. h
|
|
* <pre>
|
|
BaseType_t xQueueGenericSend(
|
|
QueueHandle_t xQueue,
|
|
const void * pvItemToQueue,
|
|
TickType_t xTicksToWait
|
|
BaseType_t xCopyPosition
|
|
);
|
|
* </pre>
|
|
*
|
|
* It is preferred that the macros xQueueSend(), xQueueSendToFront() and
|
|
* xQueueSendToBack() are used in place of calling this function directly.
|
|
*
|
|
* Post an item on a queue. The item is queued by copy, not by reference.
|
|
* This function must not be called from an interrupt service routine.
|
|
* See xQueueSendFromISR () for an alternative which may be used in an ISR.
|
|
*
|
|
* @param xQueue The handle to the queue on which the item is to be posted.
|
|
*
|
|
* @param pvItemToQueue A pointer to the item that is to be placed on the
|
|
* queue. The size of the items the queue will hold was defined when the
|
|
* queue was created, so this many bytes will be copied from pvItemToQueue
|
|
* into the queue storage area.
|
|
*
|
|
* @param xTicksToWait The maximum amount of time the task should block
|
|
* waiting for space to become available on the queue, should it already
|
|
* be full. The call will return immediately if this is set to 0 and the
|
|
* queue is full. The time is defined in tick periods so the constant
|
|
* portTICK_PERIOD_MS should be used to convert to real time if this is required.
|
|
*
|
|
* @param xCopyPosition Can take the value queueSEND_TO_BACK to place the
|
|
* item at the back of the queue, or queueSEND_TO_FRONT to place the item
|
|
* at the front of the queue (for high priority messages).
|
|
*
|
|
* @return pdTRUE if the item was successfully posted, otherwise errQUEUE_FULL.
|
|
*
|
|
* Example usage:
|
|
<pre>
|
|
struct AMessage
|
|
{
|
|
char ucMessageID;
|
|
char ucData[ 20 ];
|
|
} xMessage;
|
|
|
|
uint32_t ulVar = 10UL;
|
|
|
|
void vATask( void *pvParameters )
|
|
{
|
|
QueueHandle_t xQueue1, xQueue2;
|
|
struct AMessage *pxMessage;
|
|
|
|
// Create a queue capable of containing 10 uint32_t values.
|
|
xQueue1 = xQueueCreate( 10, sizeof( uint32_t ) );
|
|
|
|
// Create a queue capable of containing 10 pointers to AMessage structures.
|
|
// These should be passed by pointer as they contain a lot of data.
|
|
xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
|
|
|
|
// ...
|
|
|
|
if( xQueue1 != 0 )
|
|
{
|
|
// Send an uint32_t. Wait for 10 ticks for space to become
|
|
// available if necessary.
|
|
if( xQueueGenericSend( xQueue1, ( void * ) &ulVar, ( TickType_t ) 10, queueSEND_TO_BACK ) != pdPASS )
|
|
{
|
|
// Failed to post the message, even after 10 ticks.
|
|
}
|
|
}
|
|
|
|
if( xQueue2 != 0 )
|
|
{
|
|
// Send a pointer to a struct AMessage object. Don't block if the
|
|
// queue is already full.
|
|
pxMessage = & xMessage;
|
|
xQueueGenericSend( xQueue2, ( void * ) &pxMessage, ( TickType_t ) 0, queueSEND_TO_BACK );
|
|
}
|
|
|
|
// ... Rest of task code.
|
|
}
|
|
</pre>
|
|
* \defgroup xQueueSend xQueueSend
|
|
* \ingroup QueueManagement
|
|
*/
|
|
BaseType_t xQueueGenericSend( QueueHandle_t xQueue, const void * const pvItemToQueue, TickType_t xTicksToWait, const BaseType_t xCopyPosition ) PRIVILEGED_FUNCTION;
|
|
|
|
/**
|
|
* queue. h
|
|
* <pre>
|
|
BaseType_t xQueuePeek(
|
|
QueueHandle_t xQueue,
|
|
void * const pvBuffer,
|
|
TickType_t xTicksToWait
|
|
);</pre>
|
|
*
|
|
* Receive an item from a queue without removing the item from the queue.
|
|
* The item is received by copy so a buffer of adequate size must be
|
|
* provided. The number of bytes copied into the buffer was defined when
|
|
* the queue was created.
|
|
*
|
|
* Successfully received items remain on the queue so will be returned again
|
|
* by the next call, or a call to xQueueReceive().
|
|
*
|
|
* This macro must not be used in an interrupt service routine. See
|
|
* xQueuePeekFromISR() for an alternative that can be called from an interrupt
|
|
* service routine.
|
|
*
|
|
* @param xQueue The handle to the queue from which the item is to be
|
|
* received.
|
|
*
|
|
* @param pvBuffer Pointer to the buffer into which the received item will
|
|
* be copied.
|
|
*
|
|
* @param xTicksToWait The maximum amount of time the task should block
|
|
* waiting for an item to receive should the queue be empty at the time
|
|
* of the call. The time is defined in tick periods so the constant
|
|
* portTICK_PERIOD_MS should be used to convert to real time if this is required.
|
|
* xQueuePeek() will return immediately if xTicksToWait is 0 and the queue
|
|
* is empty.
|
|
*
|
|
* @return pdTRUE if an item was successfully received from the queue,
|
|
* otherwise pdFALSE.
|
|
*
|
|
* Example usage:
|
|
<pre>
|
|
struct AMessage
|
|
{
|
|
char ucMessageID;
|
|
char ucData[ 20 ];
|
|
} xMessage;
|
|
|
|
QueueHandle_t xQueue;
|
|
|
|
// Task to create a queue and post a value.
|
|
void vATask( void *pvParameters )
|
|
{
|
|
struct AMessage *pxMessage;
|
|
|
|
// Create a queue capable of containing 10 pointers to AMessage structures.
|
|
// These should be passed by pointer as they contain a lot of data.
|
|
xQueue = xQueueCreate( 10, sizeof( struct AMessage * ) );
|
|
if( xQueue == 0 )
|
|
{
|
|
// Failed to create the queue.
|
|
}
|
|
|
|
// ...
|
|
|
|
// Send a pointer to a struct AMessage object. Don't block if the
|
|
// queue is already full.
|
|
pxMessage = & xMessage;
|
|
xQueueSend( xQueue, ( void * ) &pxMessage, ( TickType_t ) 0 );
|
|
|
|
// ... Rest of task code.
|
|
}
|
|
|
|
// Task to peek the data from the queue.
|
|
void vADifferentTask( void *pvParameters )
|
|
{
|
|
struct AMessage *pxRxedMessage;
|
|
|
|
if( xQueue != 0 )
|
|
{
|
|
// Peek a message on the created queue. Block for 10 ticks if a
|
|
// message is not immediately available.
|
|
if( xQueuePeek( xQueue, &( pxRxedMessage ), ( TickType_t ) 10 ) )
|
|
{
|
|
// pcRxedMessage now points to the struct AMessage variable posted
|
|
// by vATask, but the item still remains on the queue.
|
|
}
|
|
}
|
|
|
|
// ... Rest of task code.
|
|
}
|
|
</pre>
|
|
* \defgroup xQueuePeek xQueuePeek
|
|
* \ingroup QueueManagement
|
|
*/
|
|
BaseType_t xQueuePeek( QueueHandle_t xQueue, void * const pvBuffer, TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;
|
|
|
|
/**
|
|
* queue. h
|
|
* <pre>
|
|
BaseType_t xQueuePeekFromISR(
|
|
QueueHandle_t xQueue,
|
|
void *pvBuffer,
|
|
);</pre>
|
|
*
|
|
* A version of xQueuePeek() that can be called from an interrupt service
|
|
* routine (ISR).
|
|
*
|
|
* Receive an item from a queue without removing the item from the queue.
|
|
* The item is received by copy so a buffer of adequate size must be
|
|
* provided. The number of bytes copied into the buffer was defined when
|
|
* the queue was created.
|
|
*
|
|
* Successfully received items remain on the queue so will be returned again
|
|
* by the next call, or a call to xQueueReceive().
|
|
*
|
|
* @param xQueue The handle to the queue from which the item is to be
|
|
* received.
|
|
*
|
|
* @param pvBuffer Pointer to the buffer into which the received item will
|
|
* be copied.
|
|
*
|
|
* @return pdTRUE if an item was successfully received from the queue,
|
|
* otherwise pdFALSE.
|
|
*
|
|
* \defgroup xQueuePeekFromISR xQueuePeekFromISR
|
|
* \ingroup QueueManagement
|
|
*/
|
|
BaseType_t xQueuePeekFromISR( QueueHandle_t xQueue, void * const pvBuffer ) PRIVILEGED_FUNCTION;
|
|
|
|
/**
|
|
* queue. h
|
|
* <pre>
|
|
BaseType_t xQueueReceive(
|
|
QueueHandle_t xQueue,
|
|
void *pvBuffer,
|
|
TickType_t xTicksToWait
|
|
);</pre>
|
|
*
|
|
* Receive an item from a queue. The item is received by copy so a buffer of
|
|
* adequate size must be provided. The number of bytes copied into the buffer
|
|
* was defined when the queue was created.
|
|
*
|
|
* Successfully received items are removed from the queue.
|
|
*
|
|
* This function must not be used in an interrupt service routine. See
|
|
* xQueueReceiveFromISR for an alternative that can.
|
|
*
|
|
* @param xQueue The handle to the queue from which the item is to be
|
|
* received.
|
|
*
|
|
* @param pvBuffer Pointer to the buffer into which the received item will
|
|
* be copied.
|
|
*
|
|
* @param xTicksToWait The maximum amount of time the task should block
|
|
* waiting for an item to receive should the queue be empty at the time
|
|
* of the call. xQueueReceive() will return immediately if xTicksToWait
|
|
* is zero and the queue is empty. The time is defined in tick periods so the
|
|
* constant portTICK_PERIOD_MS should be used to convert to real time if this is
|
|
* required.
|
|
*
|
|
* @return pdTRUE if an item was successfully received from the queue,
|
|
* otherwise pdFALSE.
|
|
*
|
|
* Example usage:
|
|
<pre>
|
|
struct AMessage
|
|
{
|
|
char ucMessageID;
|
|
char ucData[ 20 ];
|
|
} xMessage;
|
|
|
|
QueueHandle_t xQueue;
|
|
|
|
// Task to create a queue and post a value.
|
|
void vATask( void *pvParameters )
|
|
{
|
|
struct AMessage *pxMessage;
|
|
|
|
// Create a queue capable of containing 10 pointers to AMessage structures.
|
|
// These should be passed by pointer as they contain a lot of data.
|
|
xQueue = xQueueCreate( 10, sizeof( struct AMessage * ) );
|
|
if( xQueue == 0 )
|
|
{
|
|
// Failed to create the queue.
|
|
}
|
|
|
|
// ...
|
|
|
|
// Send a pointer to a struct AMessage object. Don't block if the
|
|
// queue is already full.
|
|
pxMessage = & xMessage;
|
|
xQueueSend( xQueue, ( void * ) &pxMessage, ( TickType_t ) 0 );
|
|
|
|
// ... Rest of task code.
|
|
}
|
|
|
|
// Task to receive from the queue.
|
|
void vADifferentTask( void *pvParameters )
|
|
{
|
|
struct AMessage *pxRxedMessage;
|
|
|
|
if( xQueue != 0 )
|
|
{
|
|
// Receive a message on the created queue. Block for 10 ticks if a
|
|
// message is not immediately available.
|
|
if( xQueueReceive( xQueue, &( pxRxedMessage ), ( TickType_t ) 10 ) )
|
|
{
|
|
// pcRxedMessage now points to the struct AMessage variable posted
|
|
// by vATask.
|
|
}
|
|
}
|
|
|
|
// ... Rest of task code.
|
|
}
|
|
</pre>
|
|
* \defgroup xQueueReceive xQueueReceive
|
|
* \ingroup QueueManagement
|
|
*/
|
|
BaseType_t xQueueReceive( QueueHandle_t xQueue, void * const pvBuffer, TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;
|
|
|
|
/**
|
|
* queue. h
|
|
* <pre>UBaseType_t uxQueueMessagesWaiting( const QueueHandle_t xQueue );</pre>
|
|
*
|
|
* Return the number of messages stored in a queue.
|
|
*
|
|
* @param xQueue A handle to the queue being queried.
|
|
*
|
|
* @return The number of messages available in the queue.
|
|
*
|
|
* \defgroup uxQueueMessagesWaiting uxQueueMessagesWaiting
|
|
* \ingroup QueueManagement
|
|
*/
|
|
UBaseType_t uxQueueMessagesWaiting( const QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
|
|
|
|
/**
|
|
* queue. h
|
|
* <pre>UBaseType_t uxQueueSpacesAvailable( const QueueHandle_t xQueue );</pre>
|
|
*
|
|
* Return the number of free spaces available in a queue. This is equal to the
|
|
* number of items that can be sent to the queue before the queue becomes full
|
|
* if no items are removed.
|
|
*
|
|
* @param xQueue A handle to the queue being queried.
|
|
*
|
|
* @return The number of spaces available in the queue.
|
|
*
|
|
* \defgroup uxQueueMessagesWaiting uxQueueMessagesWaiting
|
|
* \ingroup QueueManagement
|
|
*/
|
|
UBaseType_t uxQueueSpacesAvailable( const QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
|
|
|
|
/**
|
|
* queue. h
|
|
* <pre>void vQueueDelete( QueueHandle_t xQueue );</pre>
|
|
*
|
|
* Delete a queue - freeing all the memory allocated for storing of items
|
|
* placed on the queue.
|
|
*
|
|
* @param xQueue A handle to the queue to be deleted.
|
|
*
|
|
* \defgroup vQueueDelete vQueueDelete
|
|
* \ingroup QueueManagement
|
|
*/
|
|
void vQueueDelete( QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
|
|
|
|
/**
|
|
* queue. h
|
|
* <pre>
|
|
BaseType_t xQueueSendToFrontFromISR(
|
|
QueueHandle_t xQueue,
|
|
const void *pvItemToQueue,
|
|
BaseType_t *pxHigherPriorityTaskWoken
|
|
);
|
|
</pre>
|
|
*
|
|
* This is a macro that calls xQueueGenericSendFromISR().
|
|
*
|
|
* Post an item to the front of a queue. It is safe to use this macro from
|
|
* within an interrupt service routine.
|
|
*
|
|
* Items are queued by copy not reference so it is preferable to only
|
|
* queue small items, especially when called from an ISR. In most cases
|
|
* it would be preferable to store a pointer to the item being queued.
|
|
*
|
|
* @param xQueue The handle to the queue on which the item is to be posted.
|
|
*
|
|
* @param pvItemToQueue A pointer to the item that is to be placed on the
|
|
* queue. The size of the items the queue will hold was defined when the
|
|
* queue was created, so this many bytes will be copied from pvItemToQueue
|
|
* into the queue storage area.
|
|
*
|
|
* @param pxHigherPriorityTaskWoken xQueueSendToFrontFromISR() will set
|
|
* *pxHigherPriorityTaskWoken to pdTRUE if sending to the queue caused a task
|
|
* to unblock, and the unblocked task has a priority higher than the currently
|
|
* running task. If xQueueSendToFromFromISR() sets this value to pdTRUE then
|
|
* a context switch should be requested before the interrupt is exited.
|
|
*
|
|
* @return pdTRUE if the data was successfully sent to the queue, otherwise
|
|
* errQUEUE_FULL.
|
|
*
|
|
* Example usage for buffered IO (where the ISR can obtain more than one value
|
|
* per call):
|
|
<pre>
|
|
void vBufferISR( void )
|
|
{
|
|
char cIn;
|
|
BaseType_t xHigherPrioritTaskWoken;
|
|
|
|
// We have not woken a task at the start of the ISR.
|
|
xHigherPriorityTaskWoken = pdFALSE;
|
|
|
|
// Loop until the buffer is empty.
|
|
do
|
|
{
|
|
// Obtain a byte from the buffer.
|
|
cIn = portINPUT_BYTE( RX_REGISTER_ADDRESS );
|
|
|
|
// Post the byte.
|
|
xQueueSendToFrontFromISR( xRxQueue, &cIn, &xHigherPriorityTaskWoken );
|
|
|
|
} while( portINPUT_BYTE( BUFFER_COUNT ) );
|
|
|
|
// Now the buffer is empty we can switch context if necessary.
|
|
if( xHigherPriorityTaskWoken )
|
|
{
|
|
taskYIELD ();
|
|
}
|
|
}
|
|
</pre>
|
|
*
|
|
* \defgroup xQueueSendFromISR xQueueSendFromISR
|
|
* \ingroup QueueManagement
|
|
*/
|
|
#define xQueueSendToFrontFromISR( xQueue, pvItemToQueue, pxHigherPriorityTaskWoken ) xQueueGenericSendFromISR( ( xQueue ), ( pvItemToQueue ), ( pxHigherPriorityTaskWoken ), queueSEND_TO_FRONT )
|
|
|
|
|
|
/**
|
|
* queue. h
|
|
* <pre>
|
|
BaseType_t xQueueSendToBackFromISR(
|
|
QueueHandle_t xQueue,
|
|
const void *pvItemToQueue,
|
|
BaseType_t *pxHigherPriorityTaskWoken
|
|
);
|
|
</pre>
|
|
*
|
|
* This is a macro that calls xQueueGenericSendFromISR().
|
|
*
|
|
* Post an item to the back of a queue. It is safe to use this macro from
|
|
* within an interrupt service routine.
|
|
*
|
|
* Items are queued by copy not reference so it is preferable to only
|
|
* queue small items, especially when called from an ISR. In most cases
|
|
* it would be preferable to store a pointer to the item being queued.
|
|
*
|
|
* @param xQueue The handle to the queue on which the item is to be posted.
|
|
*
|
|
* @param pvItemToQueue A pointer to the item that is to be placed on the
|
|
* queue. The size of the items the queue will hold was defined when the
|
|
* queue was created, so this many bytes will be copied from pvItemToQueue
|
|
* into the queue storage area.
|
|
*
|
|
* @param pxHigherPriorityTaskWoken xQueueSendToBackFromISR() will set
|
|
* *pxHigherPriorityTaskWoken to pdTRUE if sending to the queue caused a task
|
|
* to unblock, and the unblocked task has a priority higher than the currently
|
|
* running task. If xQueueSendToBackFromISR() sets this value to pdTRUE then
|
|
* a context switch should be requested before the interrupt is exited.
|
|
*
|
|
* @return pdTRUE if the data was successfully sent to the queue, otherwise
|
|
* errQUEUE_FULL.
|
|
*
|
|
* Example usage for buffered IO (where the ISR can obtain more than one value
|
|
* per call):
|
|
<pre>
|
|
void vBufferISR( void )
|
|
{
|
|
char cIn;
|
|
BaseType_t xHigherPriorityTaskWoken;
|
|
|
|
// We have not woken a task at the start of the ISR.
|
|
xHigherPriorityTaskWoken = pdFALSE;
|
|
|
|
// Loop until the buffer is empty.
|
|
do
|
|
{
|
|
// Obtain a byte from the buffer.
|
|
cIn = portINPUT_BYTE( RX_REGISTER_ADDRESS );
|
|
|
|
// Post the byte.
|
|
xQueueSendToBackFromISR( xRxQueue, &cIn, &xHigherPriorityTaskWoken );
|
|
|
|
} while( portINPUT_BYTE( BUFFER_COUNT ) );
|
|
|
|
// Now the buffer is empty we can switch context if necessary.
|
|
if( xHigherPriorityTaskWoken )
|
|
{
|
|
taskYIELD ();
|
|
}
|
|
}
|
|
</pre>
|
|
*
|
|
* \defgroup xQueueSendFromISR xQueueSendFromISR
|
|
* \ingroup QueueManagement
|
|
*/
|
|
#define xQueueSendToBackFromISR( xQueue, pvItemToQueue, pxHigherPriorityTaskWoken ) xQueueGenericSendFromISR( ( xQueue ), ( pvItemToQueue ), ( pxHigherPriorityTaskWoken ), queueSEND_TO_BACK )
|
|
|
|
/**
|
|
* queue. h
|
|
* <pre>
|
|
BaseType_t xQueueOverwriteFromISR(
|
|
QueueHandle_t xQueue,
|
|
const void * pvItemToQueue,
|
|
BaseType_t *pxHigherPriorityTaskWoken
|
|
);
|
|
* </pre>
|
|
*
|
|
* A version of xQueueOverwrite() that can be used in an interrupt service
|
|
* routine (ISR).
|
|
*
|
|
* Only for use with queues that can hold a single item - so the queue is either
|
|
* empty or full.
|
|
*
|
|
* Post an item on a queue. If the queue is already full then overwrite the
|
|
* value held in the queue. The item is queued by copy, not by reference.
|
|
*
|
|
* @param xQueue The handle to the queue on which the item is to be posted.
|
|
*
|
|
* @param pvItemToQueue A pointer to the item that is to be placed on the
|
|
* queue. The size of the items the queue will hold was defined when the
|
|
* queue was created, so this many bytes will be copied from pvItemToQueue
|
|
* into the queue storage area.
|
|
*
|
|
* @param pxHigherPriorityTaskWoken xQueueOverwriteFromISR() will set
|
|
* *pxHigherPriorityTaskWoken to pdTRUE if sending to the queue caused a task
|
|
* to unblock, and the unblocked task has a priority higher than the currently
|
|
* running task. If xQueueOverwriteFromISR() sets this value to pdTRUE then
|
|
* a context switch should be requested before the interrupt is exited.
|
|
*
|
|
* @return xQueueOverwriteFromISR() is a macro that calls
|
|
* xQueueGenericSendFromISR(), and therefore has the same return values as
|
|
* xQueueSendToFrontFromISR(). However, pdPASS is the only value that can be
|
|
* returned because xQueueOverwriteFromISR() will write to the queue even when
|
|
* the queue is already full.
|
|
*
|
|
* Example usage:
|
|
<pre>
|
|
|
|
QueueHandle_t xQueue;
|
|
|
|
void vFunction( void *pvParameters )
|
|
{
|
|
// Create a queue to hold one uint32_t value. It is strongly
|
|
// recommended *not* to use xQueueOverwriteFromISR() on queues that can
|
|
// contain more than one value, and doing so will trigger an assertion
|
|
// if configASSERT() is defined.
|
|
xQueue = xQueueCreate( 1, sizeof( uint32_t ) );
|
|
}
|
|
|
|
void vAnInterruptHandler( void )
|
|
{
|
|
// xHigherPriorityTaskWoken must be set to pdFALSE before it is used.
|
|
BaseType_t xHigherPriorityTaskWoken = pdFALSE;
|
|
uint32_t ulVarToSend, ulValReceived;
|
|
|
|
// Write the value 10 to the queue using xQueueOverwriteFromISR().
|
|
ulVarToSend = 10;
|
|
xQueueOverwriteFromISR( xQueue, &ulVarToSend, &xHigherPriorityTaskWoken );
|
|
|
|
// The queue is full, but calling xQueueOverwriteFromISR() again will still
|
|
// pass because the value held in the queue will be overwritten with the
|
|
// new value.
|
|
ulVarToSend = 100;
|
|
xQueueOverwriteFromISR( xQueue, &ulVarToSend, &xHigherPriorityTaskWoken );
|
|
|
|
// Reading from the queue will now return 100.
|
|
|
|
// ...
|
|
|
|
if( xHigherPrioritytaskWoken == pdTRUE )
|
|
{
|
|
// Writing to the queue caused a task to unblock and the unblocked task
|
|
// has a priority higher than or equal to the priority of the currently
|
|
// executing task (the task this interrupt interrupted). Perform a context
|
|
// switch so this interrupt returns directly to the unblocked task.
|
|
portYIELD_FROM_ISR(); // or portEND_SWITCHING_ISR() depending on the port.
|
|
}
|
|
}
|
|
</pre>
|
|
* \defgroup xQueueOverwriteFromISR xQueueOverwriteFromISR
|
|
* \ingroup QueueManagement
|
|
*/
|
|
#define xQueueOverwriteFromISR( xQueue, pvItemToQueue, pxHigherPriorityTaskWoken ) xQueueGenericSendFromISR( ( xQueue ), ( pvItemToQueue ), ( pxHigherPriorityTaskWoken ), queueOVERWRITE )
|
|
|
|
/**
|
|
* queue. h
|
|
* <pre>
|
|
BaseType_t xQueueSendFromISR(
|
|
QueueHandle_t xQueue,
|
|
const void *pvItemToQueue,
|
|
BaseType_t *pxHigherPriorityTaskWoken
|
|
);
|
|
</pre>
|
|
*
|
|
* This is a macro that calls xQueueGenericSendFromISR(). It is included
|
|
* for backward compatibility with versions of FreeRTOS.org that did not
|
|
* include the xQueueSendToBackFromISR() and xQueueSendToFrontFromISR()
|
|
* macros.
|
|
*
|
|
* Post an item to the back of a queue. It is safe to use this function from
|
|
* within an interrupt service routine.
|
|
*
|
|
* Items are queued by copy not reference so it is preferable to only
|
|
* queue small items, especially when called from an ISR. In most cases
|
|
* it would be preferable to store a pointer to the item being queued.
|
|
*
|
|
* @param xQueue The handle to the queue on which the item is to be posted.
|
|
*
|
|
* @param pvItemToQueue A pointer to the item that is to be placed on the
|
|
* queue. The size of the items the queue will hold was defined when the
|
|
* queue was created, so this many bytes will be copied from pvItemToQueue
|
|
* into the queue storage area.
|
|
*
|
|
* @param pxHigherPriorityTaskWoken xQueueSendFromISR() will set
|
|
* *pxHigherPriorityTaskWoken to pdTRUE if sending to the queue caused a task
|
|
* to unblock, and the unblocked task has a priority higher than the currently
|
|
* running task. If xQueueSendFromISR() sets this value to pdTRUE then
|
|
* a context switch should be requested before the interrupt is exited.
|
|
*
|
|
* @return pdTRUE if the data was successfully sent to the queue, otherwise
|
|
* errQUEUE_FULL.
|
|
*
|
|
* Example usage for buffered IO (where the ISR can obtain more than one value
|
|
* per call):
|
|
<pre>
|
|
void vBufferISR( void )
|
|
{
|
|
char cIn;
|
|
BaseType_t xHigherPriorityTaskWoken;
|
|
|
|
// We have not woken a task at the start of the ISR.
|
|
xHigherPriorityTaskWoken = pdFALSE;
|
|
|
|
// Loop until the buffer is empty.
|
|
do
|
|
{
|
|
// Obtain a byte from the buffer.
|
|
cIn = portINPUT_BYTE( RX_REGISTER_ADDRESS );
|
|
|
|
// Post the byte.
|
|
xQueueSendFromISR( xRxQueue, &cIn, &xHigherPriorityTaskWoken );
|
|
|
|
} while( portINPUT_BYTE( BUFFER_COUNT ) );
|
|
|
|
// Now the buffer is empty we can switch context if necessary.
|
|
if( xHigherPriorityTaskWoken )
|
|
{
|
|
// Actual macro used here is port specific.
|
|
portYIELD_FROM_ISR ();
|
|
}
|
|
}
|
|
</pre>
|
|
*
|
|
* \defgroup xQueueSendFromISR xQueueSendFromISR
|
|
* \ingroup QueueManagement
|
|
*/
|
|
#define xQueueSendFromISR( xQueue, pvItemToQueue, pxHigherPriorityTaskWoken ) xQueueGenericSendFromISR( ( xQueue ), ( pvItemToQueue ), ( pxHigherPriorityTaskWoken ), queueSEND_TO_BACK )
|
|
|
|
/**
|
|
* queue. h
|
|
* <pre>
|
|
BaseType_t xQueueGenericSendFromISR(
|
|
QueueHandle_t xQueue,
|
|
const void *pvItemToQueue,
|
|
BaseType_t *pxHigherPriorityTaskWoken,
|
|
BaseType_t xCopyPosition
|
|
);
|
|
</pre>
|
|
*
|
|
* It is preferred that the macros xQueueSendFromISR(),
|
|
* xQueueSendToFrontFromISR() and xQueueSendToBackFromISR() be used in place
|
|
* of calling this function directly. xQueueGiveFromISR() is an
|
|
* equivalent for use by semaphores that don't actually copy any data.
|
|
*
|
|
* Post an item on a queue. It is safe to use this function from within an
|
|
* interrupt service routine.
|
|
*
|
|
* Items are queued by copy not reference so it is preferable to only
|
|
* queue small items, especially when called from an ISR. In most cases
|
|
* it would be preferable to store a pointer to the item being queued.
|
|
*
|
|
* @param xQueue The handle to the queue on which the item is to be posted.
|
|
*
|
|
* @param pvItemToQueue A pointer to the item that is to be placed on the
|
|
* queue. The size of the items the queue will hold was defined when the
|
|
* queue was created, so this many bytes will be copied from pvItemToQueue
|
|
* into the queue storage area.
|
|
*
|
|
* @param pxHigherPriorityTaskWoken xQueueGenericSendFromISR() will set
|
|
* *pxHigherPriorityTaskWoken to pdTRUE if sending to the queue caused a task
|
|
* to unblock, and the unblocked task has a priority higher than the currently
|
|
* running task. If xQueueGenericSendFromISR() sets this value to pdTRUE then
|
|
* a context switch should be requested before the interrupt is exited.
|
|
*
|
|
* @param xCopyPosition Can take the value queueSEND_TO_BACK to place the
|
|
* item at the back of the queue, or queueSEND_TO_FRONT to place the item
|
|
* at the front of the queue (for high priority messages).
|
|
*
|
|
* @return pdTRUE if the data was successfully sent to the queue, otherwise
|
|
* errQUEUE_FULL.
|
|
*
|
|
* Example usage for buffered IO (where the ISR can obtain more than one value
|
|
* per call):
|
|
<pre>
|
|
void vBufferISR( void )
|
|
{
|
|
char cIn;
|
|
BaseType_t xHigherPriorityTaskWokenByPost;
|
|
|
|
// We have not woken a task at the start of the ISR.
|
|
xHigherPriorityTaskWokenByPost = pdFALSE;
|
|
|
|
// Loop until the buffer is empty.
|
|
do
|
|
{
|
|
// Obtain a byte from the buffer.
|
|
cIn = portINPUT_BYTE( RX_REGISTER_ADDRESS );
|
|
|
|
// Post each byte.
|
|
xQueueGenericSendFromISR( xRxQueue, &cIn, &xHigherPriorityTaskWokenByPost, queueSEND_TO_BACK );
|
|
|
|
} while( portINPUT_BYTE( BUFFER_COUNT ) );
|
|
|
|
// Now the buffer is empty we can switch context if necessary. Note that the
|
|
// name of the yield function required is port specific.
|
|
if( xHigherPriorityTaskWokenByPost )
|
|
{
|
|
taskYIELD_YIELD_FROM_ISR();
|
|
}
|
|
}
|
|
</pre>
|
|
*
|
|
* \defgroup xQueueSendFromISR xQueueSendFromISR
|
|
* \ingroup QueueManagement
|
|
*/
|
|
BaseType_t xQueueGenericSendFromISR( QueueHandle_t xQueue, const void * const pvItemToQueue, BaseType_t * const pxHigherPriorityTaskWoken, const BaseType_t xCopyPosition ) PRIVILEGED_FUNCTION;
|
|
BaseType_t xQueueGiveFromISR( QueueHandle_t xQueue, BaseType_t * const pxHigherPriorityTaskWoken ) PRIVILEGED_FUNCTION;
|
|
|
|
/**
|
|
* queue. h
|
|
* <pre>
|
|
BaseType_t xQueueReceiveFromISR(
|
|
QueueHandle_t xQueue,
|
|
void *pvBuffer,
|
|
BaseType_t *pxTaskWoken
|
|
);
|
|
* </pre>
|
|
*
|
|
* Receive an item from a queue. It is safe to use this function from within an
|
|
* interrupt service routine.
|
|
*
|
|
* @param xQueue The handle to the queue from which the item is to be
|
|
* received.
|
|
*
|
|
* @param pvBuffer Pointer to the buffer into which the received item will
|
|
* be copied.
|
|
*
|
|
* @param pxTaskWoken A task may be blocked waiting for space to become
|
|
* available on the queue. If xQueueReceiveFromISR causes such a task to
|
|
* unblock *pxTaskWoken will get set to pdTRUE, otherwise *pxTaskWoken will
|
|
* remain unchanged.
|
|
*
|
|
* @return pdTRUE if an item was successfully received from the queue,
|
|
* otherwise pdFALSE.
|
|
*
|
|
* Example usage:
|
|
<pre>
|
|
|
|
QueueHandle_t xQueue;
|
|
|
|
// Function to create a queue and post some values.
|
|
void vAFunction( void *pvParameters )
|
|
{
|
|
char cValueToPost;
|
|
const TickType_t xTicksToWait = ( TickType_t )0xff;
|
|
|
|
// Create a queue capable of containing 10 characters.
|
|
xQueue = xQueueCreate( 10, sizeof( char ) );
|
|
if( xQueue == 0 )
|
|
{
|
|
// Failed to create the queue.
|
|
}
|
|
|
|
// ...
|
|
|
|
// Post some characters that will be used within an ISR. If the queue
|
|
// is full then this task will block for xTicksToWait ticks.
|
|
cValueToPost = 'a';
|
|
xQueueSend( xQueue, ( void * ) &cValueToPost, xTicksToWait );
|
|
cValueToPost = 'b';
|
|
xQueueSend( xQueue, ( void * ) &cValueToPost, xTicksToWait );
|
|
|
|
// ... keep posting characters ... this task may block when the queue
|
|
// becomes full.
|
|
|
|
cValueToPost = 'c';
|
|
xQueueSend( xQueue, ( void * ) &cValueToPost, xTicksToWait );
|
|
}
|
|
|
|
// ISR that outputs all the characters received on the queue.
|
|
void vISR_Routine( void )
|
|
{
|
|
BaseType_t xTaskWokenByReceive = pdFALSE;
|
|
char cRxedChar;
|
|
|
|
while( xQueueReceiveFromISR( xQueue, ( void * ) &cRxedChar, &xTaskWokenByReceive) )
|
|
{
|
|
// A character was received. Output the character now.
|
|
vOutputCharacter( cRxedChar );
|
|
|
|
// If removing the character from the queue woke the task that was
|
|
// posting onto the queue cTaskWokenByReceive will have been set to
|
|
// pdTRUE. No matter how many times this loop iterates only one
|
|
// task will be woken.
|
|
}
|
|
|
|
if( cTaskWokenByPost != ( char ) pdFALSE;
|
|
{
|
|
taskYIELD ();
|
|
}
|
|
}
|
|
</pre>
|
|
* \defgroup xQueueReceiveFromISR xQueueReceiveFromISR
|
|
* \ingroup QueueManagement
|
|
*/
|
|
BaseType_t xQueueReceiveFromISR( QueueHandle_t xQueue, void * const pvBuffer, BaseType_t * const pxHigherPriorityTaskWoken ) PRIVILEGED_FUNCTION;
|
|
|
|
/*
|
|
* Utilities to query queues that are safe to use from an ISR. These utilities
|
|
* should be used only from witin an ISR, or within a critical section.
|
|
*/
|
|
BaseType_t xQueueIsQueueEmptyFromISR( const QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
|
|
BaseType_t xQueueIsQueueFullFromISR( const QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
|
|
UBaseType_t uxQueueMessagesWaitingFromISR( const QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
|
|
|
|
/*
|
|
* The functions defined above are for passing data to and from tasks. The
|
|
* functions below are the equivalents for passing data to and from
|
|
* co-routines.
|
|
*
|
|
* These functions are called from the co-routine macro implementation and
|
|
* should not be called directly from application code. Instead use the macro
|
|
* wrappers defined within croutine.h.
|
|
*/
|
|
BaseType_t xQueueCRSendFromISR( QueueHandle_t xQueue, const void *pvItemToQueue, BaseType_t xCoRoutinePreviouslyWoken );
|
|
BaseType_t xQueueCRReceiveFromISR( QueueHandle_t xQueue, void *pvBuffer, BaseType_t *pxTaskWoken );
|
|
BaseType_t xQueueCRSend( QueueHandle_t xQueue, const void *pvItemToQueue, TickType_t xTicksToWait );
|
|
BaseType_t xQueueCRReceive( QueueHandle_t xQueue, void *pvBuffer, TickType_t xTicksToWait );
|
|
|
|
/*
|
|
* For internal use only. Use xSemaphoreCreateMutex(),
|
|
* xSemaphoreCreateCounting() or xSemaphoreGetMutexHolder() instead of calling
|
|
* these functions directly.
|
|
*/
|
|
QueueHandle_t xQueueCreateMutex( const uint8_t ucQueueType ) PRIVILEGED_FUNCTION;
|
|
QueueHandle_t xQueueCreateMutexStatic( const uint8_t ucQueueType, StaticQueue_t *pxStaticQueue ) PRIVILEGED_FUNCTION;
|
|
QueueHandle_t xQueueCreateCountingSemaphore( const UBaseType_t uxMaxCount, const UBaseType_t uxInitialCount ) PRIVILEGED_FUNCTION;
|
|
QueueHandle_t xQueueCreateCountingSemaphoreStatic( const UBaseType_t uxMaxCount, const UBaseType_t uxInitialCount, StaticQueue_t *pxStaticQueue ) PRIVILEGED_FUNCTION;
|
|
BaseType_t xQueueSemaphoreTake( QueueHandle_t xQueue, TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;
|
|
TaskHandle_t xQueueGetMutexHolder( QueueHandle_t xSemaphore ) PRIVILEGED_FUNCTION;
|
|
TaskHandle_t xQueueGetMutexHolderFromISR( QueueHandle_t xSemaphore ) PRIVILEGED_FUNCTION;
|
|
|
|
/*
|
|
* For internal use only. Use xSemaphoreTakeMutexRecursive() or
|
|
* xSemaphoreGiveMutexRecursive() instead of calling these functions directly.
|
|
*/
|
|
BaseType_t xQueueTakeMutexRecursive( QueueHandle_t xMutex, TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;
|
|
BaseType_t xQueueGiveMutexRecursive( QueueHandle_t xMutex ) PRIVILEGED_FUNCTION;
|
|
|
|
/*
|
|
* Reset a queue back to its original empty state. The return value is now
|
|
* obsolete and is always set to pdPASS.
|
|
*/
|
|
#define xQueueReset( xQueue ) xQueueGenericReset( xQueue, pdFALSE )
|
|
|
|
/*
|
|
* The registry is provided as a means for kernel aware debuggers to
|
|
* locate queues, semaphores and mutexes. Call vQueueAddToRegistry() add
|
|
* a queue, semaphore or mutex handle to the registry if you want the handle
|
|
* to be available to a kernel aware debugger. If you are not using a kernel
|
|
* aware debugger then this function can be ignored.
|
|
*
|
|
* configQUEUE_REGISTRY_SIZE defines the maximum number of handles the
|
|
* registry can hold. configQUEUE_REGISTRY_SIZE must be greater than 0
|
|
* within FreeRTOSConfig.h for the registry to be available. Its value
|
|
* does not effect the number of queues, semaphores and mutexes that can be
|
|
* created - just the number that the registry can hold.
|
|
*
|
|
* @param xQueue The handle of the queue being added to the registry. This
|
|
* is the handle returned by a call to xQueueCreate(). Semaphore and mutex
|
|
* handles can also be passed in here.
|
|
*
|
|
* @param pcName The name to be associated with the handle. This is the
|
|
* name that the kernel aware debugger will display. The queue registry only
|
|
* stores a pointer to the string - so the string must be persistent (global or
|
|
* preferably in ROM/Flash), not on the stack.
|
|
*/
|
|
#if( configQUEUE_REGISTRY_SIZE > 0 )
|
|
void vQueueAddToRegistry( QueueHandle_t xQueue, const char *pcQueueName ) PRIVILEGED_FUNCTION; /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
|
|
#endif
|
|
|
|
/*
|
|
* The registry is provided as a means for kernel aware debuggers to
|
|
* locate queues, semaphores and mutexes. Call vQueueAddToRegistry() add
|
|
* a queue, semaphore or mutex handle to the registry if you want the handle
|
|
* to be available to a kernel aware debugger, and vQueueUnregisterQueue() to
|
|
* remove the queue, semaphore or mutex from the register. If you are not using
|
|
* a kernel aware debugger then this function can be ignored.
|
|
*
|
|
* @param xQueue The handle of the queue being removed from the registry.
|
|
*/
|
|
#if( configQUEUE_REGISTRY_SIZE > 0 )
|
|
void vQueueUnregisterQueue( QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
|
|
#endif
|
|
|
|
/*
|
|
* The queue registry is provided as a means for kernel aware debuggers to
|
|
* locate queues, semaphores and mutexes. Call pcQueueGetName() to look
|
|
* up and return the name of a queue in the queue registry from the queue's
|
|
* handle.
|
|
*
|
|
* @param xQueue The handle of the queue the name of which will be returned.
|
|
* @return If the queue is in the registry then a pointer to the name of the
|
|
* queue is returned. If the queue is not in the registry then NULL is
|
|
* returned.
|
|
*/
|
|
#if( configQUEUE_REGISTRY_SIZE > 0 )
|
|
const char *pcQueueGetName( QueueHandle_t xQueue ) PRIVILEGED_FUNCTION; /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
|
|
#endif
|
|
|
|
/*
|
|
* Generic version of the function used to creaet a queue using dynamic memory
|
|
* allocation. This is called by other functions and macros that create other
|
|
* RTOS objects that use the queue structure as their base.
|
|
*/
|
|
#if( configSUPPORT_DYNAMIC_ALLOCATION == 1 )
|
|
QueueHandle_t xQueueGenericCreate( const UBaseType_t uxQueueLength, const UBaseType_t uxItemSize, const uint8_t ucQueueType ) PRIVILEGED_FUNCTION;
|
|
#endif
|
|
|
|
/*
|
|
* Generic version of the function used to creaet a queue using dynamic memory
|
|
* allocation. This is called by other functions and macros that create other
|
|
* RTOS objects that use the queue structure as their base.
|
|
*/
|
|
#if( configSUPPORT_STATIC_ALLOCATION == 1 )
|
|
QueueHandle_t xQueueGenericCreateStatic( const UBaseType_t uxQueueLength, const UBaseType_t uxItemSize, uint8_t *pucQueueStorage, StaticQueue_t *pxStaticQueue, const uint8_t ucQueueType ) PRIVILEGED_FUNCTION;
|
|
#endif
|
|
|
|
/*
|
|
* Queue sets provide a mechanism to allow a task to block (pend) on a read
|
|
* operation from multiple queues or semaphores simultaneously.
|
|
*
|
|
* See FreeRTOS/Source/Demo/Common/Minimal/QueueSet.c for an example using this
|
|
* function.
|
|
*
|
|
* A queue set must be explicitly created using a call to xQueueCreateSet()
|
|
* before it can be used. Once created, standard FreeRTOS queues and semaphores
|
|
* can be added to the set using calls to xQueueAddToSet().
|
|
* xQueueSelectFromSet() is then used to determine which, if any, of the queues
|
|
* or semaphores contained in the set is in a state where a queue read or
|
|
* semaphore take operation would be successful.
|
|
*
|
|
* Note 1: See the documentation on http://wwwFreeRTOS.org/RTOS-queue-sets.html
|
|
* for reasons why queue sets are very rarely needed in practice as there are
|
|
* simpler methods of blocking on multiple objects.
|
|
*
|
|
* Note 2: Blocking on a queue set that contains a mutex will not cause the
|
|
* mutex holder to inherit the priority of the blocked task.
|
|
*
|
|
* Note 3: An additional 4 bytes of RAM is required for each space in a every
|
|
* queue added to a queue set. Therefore counting semaphores that have a high
|
|
* maximum count value should not be added to a queue set.
|
|
*
|
|
* Note 4: A receive (in the case of a queue) or take (in the case of a
|
|
* semaphore) operation must not be performed on a member of a queue set unless
|
|
* a call to xQueueSelectFromSet() has first returned a handle to that set member.
|
|
*
|
|
* @param uxEventQueueLength Queue sets store events that occur on
|
|
* the queues and semaphores contained in the set. uxEventQueueLength specifies
|
|
* the maximum number of events that can be queued at once. To be absolutely
|
|
* certain that events are not lost uxEventQueueLength should be set to the
|
|
* total sum of the length of the queues added to the set, where binary
|
|
* semaphores and mutexes have a length of 1, and counting semaphores have a
|
|
* length set by their maximum count value. Examples:
|
|
* + If a queue set is to hold a queue of length 5, another queue of length 12,
|
|
* and a binary semaphore, then uxEventQueueLength should be set to
|
|
* (5 + 12 + 1), or 18.
|
|
* + If a queue set is to hold three binary semaphores then uxEventQueueLength
|
|
* should be set to (1 + 1 + 1 ), or 3.
|
|
* + If a queue set is to hold a counting semaphore that has a maximum count of
|
|
* 5, and a counting semaphore that has a maximum count of 3, then
|
|
* uxEventQueueLength should be set to (5 + 3), or 8.
|
|
*
|
|
* @return If the queue set is created successfully then a handle to the created
|
|
* queue set is returned. Otherwise NULL is returned.
|
|
*/
|
|
QueueSetHandle_t xQueueCreateSet( const UBaseType_t uxEventQueueLength ) PRIVILEGED_FUNCTION;
|
|
|
|
/*
|
|
* Adds a queue or semaphore to a queue set that was previously created by a
|
|
* call to xQueueCreateSet().
|
|
*
|
|
* See FreeRTOS/Source/Demo/Common/Minimal/QueueSet.c for an example using this
|
|
* function.
|
|
*
|
|
* Note 1: A receive (in the case of a queue) or take (in the case of a
|
|
* semaphore) operation must not be performed on a member of a queue set unless
|
|
* a call to xQueueSelectFromSet() has first returned a handle to that set member.
|
|
*
|
|
* @param xQueueOrSemaphore The handle of the queue or semaphore being added to
|
|
* the queue set (cast to an QueueSetMemberHandle_t type).
|
|
*
|
|
* @param xQueueSet The handle of the queue set to which the queue or semaphore
|
|
* is being added.
|
|
*
|
|
* @return If the queue or semaphore was successfully added to the queue set
|
|
* then pdPASS is returned. If the queue could not be successfully added to the
|
|
* queue set because it is already a member of a different queue set then pdFAIL
|
|
* is returned.
|
|
*/
|
|
BaseType_t xQueueAddToSet( QueueSetMemberHandle_t xQueueOrSemaphore, QueueSetHandle_t xQueueSet ) PRIVILEGED_FUNCTION;
|
|
|
|
/*
|
|
* Removes a queue or semaphore from a queue set. A queue or semaphore can only
|
|
* be removed from a set if the queue or semaphore is empty.
|
|
*
|
|
* See FreeRTOS/Source/Demo/Common/Minimal/QueueSet.c for an example using this
|
|
* function.
|
|
*
|
|
* @param xQueueOrSemaphore The handle of the queue or semaphore being removed
|
|
* from the queue set (cast to an QueueSetMemberHandle_t type).
|
|
*
|
|
* @param xQueueSet The handle of the queue set in which the queue or semaphore
|
|
* is included.
|
|
*
|
|
* @return If the queue or semaphore was successfully removed from the queue set
|
|
* then pdPASS is returned. If the queue was not in the queue set, or the
|
|
* queue (or semaphore) was not empty, then pdFAIL is returned.
|
|
*/
|
|
BaseType_t xQueueRemoveFromSet( QueueSetMemberHandle_t xQueueOrSemaphore, QueueSetHandle_t xQueueSet ) PRIVILEGED_FUNCTION;
|
|
|
|
/*
|
|
* xQueueSelectFromSet() selects from the members of a queue set a queue or
|
|
* semaphore that either contains data (in the case of a queue) or is available
|
|
* to take (in the case of a semaphore). xQueueSelectFromSet() effectively
|
|
* allows a task to block (pend) on a read operation on all the queues and
|
|
* semaphores in a queue set simultaneously.
|
|
*
|
|
* See FreeRTOS/Source/Demo/Common/Minimal/QueueSet.c for an example using this
|
|
* function.
|
|
*
|
|
* Note 1: See the documentation on http://wwwFreeRTOS.org/RTOS-queue-sets.html
|
|
* for reasons why queue sets are very rarely needed in practice as there are
|
|
* simpler methods of blocking on multiple objects.
|
|
*
|
|
* Note 2: Blocking on a queue set that contains a mutex will not cause the
|
|
* mutex holder to inherit the priority of the blocked task.
|
|
*
|
|
* Note 3: A receive (in the case of a queue) or take (in the case of a
|
|
* semaphore) operation must not be performed on a member of a queue set unless
|
|
* a call to xQueueSelectFromSet() has first returned a handle to that set member.
|
|
*
|
|
* @param xQueueSet The queue set on which the task will (potentially) block.
|
|
*
|
|
* @param xTicksToWait The maximum time, in ticks, that the calling task will
|
|
* remain in the Blocked state (with other tasks executing) to wait for a member
|
|
* of the queue set to be ready for a successful queue read or semaphore take
|
|
* operation.
|
|
*
|
|
* @return xQueueSelectFromSet() will return the handle of a queue (cast to
|
|
* a QueueSetMemberHandle_t type) contained in the queue set that contains data,
|
|
* or the handle of a semaphore (cast to a QueueSetMemberHandle_t type) contained
|
|
* in the queue set that is available, or NULL if no such queue or semaphore
|
|
* exists before before the specified block time expires.
|
|
*/
|
|
QueueSetMemberHandle_t xQueueSelectFromSet( QueueSetHandle_t xQueueSet, const TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;
|
|
|
|
/*
|
|
* A version of xQueueSelectFromSet() that can be used from an ISR.
|
|
*/
|
|
QueueSetMemberHandle_t xQueueSelectFromSetFromISR( QueueSetHandle_t xQueueSet ) PRIVILEGED_FUNCTION;
|
|
|
|
/* Not public API functions. */
|
|
void vQueueWaitForMessageRestricted( QueueHandle_t xQueue, TickType_t xTicksToWait, const BaseType_t xWaitIndefinitely ) PRIVILEGED_FUNCTION;
|
|
BaseType_t xQueueGenericReset( QueueHandle_t xQueue, BaseType_t xNewQueue ) PRIVILEGED_FUNCTION;
|
|
void vQueueSetQueueNumber( QueueHandle_t xQueue, UBaseType_t uxQueueNumber ) PRIVILEGED_FUNCTION;
|
|
UBaseType_t uxQueueGetQueueNumber( QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
|
|
uint8_t ucQueueGetQueueType( QueueHandle_t xQueue ) PRIVILEGED_FUNCTION;
|
|
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif /* QUEUE_H */
|
|
|