SmartPDCode/truing_control/PDU-AC-235-NEW/FreeRTOS/include/queue.h

/*
 * FreeRTOS Kernel V10.5.1
 * Copyright (C) 2021 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
 *
 * SPDX-License-Identifier: MIT
 *
 */


#ifndef QUEUE_H
#define QUEUE_H

#ifndef INC_FREERTOS_H
    #error "include FreeRTOS.h" must appear in source files before "include queue.h"
#endif

#include "task.h"

/**
 * Type by which queues are referenced.  For example, a call to xQueueCreate()
 * returns an QueueHandle_t variable that can then be used as a parameter to
 * xQueueSend(), xQueueReceive(), etc.
 */
struct QueueDefinition; /* Using old naming convention so as not to break kernel aware debuggers. */
typedef struct QueueDefinition   *QueueHandle_t;

/**
 * Type by which queue sets are referenced.  For example, a call to
 * xQueueCreateSet() returns an xQueueSet variable that can then be used as a
 * parameter to xQueueSelectFromSet(), xQueueAddToSet(), etc.
 */
typedef struct QueueDefinition   *QueueSetHandle_t;

/**
 * Queue sets can contain both queues and semaphores, so the
 * QueueSetMemberHandle_t is defined as a type to be used where a parameter or
 * return value can be either an QueueHandle_t or an SemaphoreHandle_t.
 */
typedef struct QueueDefinition   *QueueSetMemberHandle_t;

/* For internal use only. */
#define queueSEND_TO_BACK                     ((BaseType_t)0)
#define queueSEND_TO_FRONT                    ((BaseType_t)1)
#define queueOVERWRITE                        ((BaseType_t)2)

/**
 * For internal use only.  These definitions *must* match those in queue.c.
 * 队列的类型
 */
#define queueQUEUE_TYPE_BASE                  ((uint8_t) 0U)        /* 基本队列 */
#define queueQUEUE_TYPE_SET                   ((uint8_t) 0U)        /* 队列集合 */
#define queueQUEUE_TYPE_MUTEX                 ((uint8_t) 1U)        /* 互斥锁 */
#define queueQUEUE_TYPE_COUNTING_SEMAPHORE    ((uint8_t) 2U)        /* 计数型信号量 */
#define queueQUEUE_TYPE_BINARY_SEMAPHORE      ((uint8_t) 3U)        /* 二值信号量 */
#define queueQUEUE_TYPE_RECURSIVE_MUTEX       ((uint8_t) 4U)

/**
 * 动态创建队列
 * @uxQueueLength: 队列中存放消息个数
 * @uxItemSize:    队列消息的长度
 */

#define xQueueCreate(uxQueueLength, uxItemSize) xQueueGenericCreate((uxQueueLength), (uxItemSize), (queueQUEUE_TYPE_BASE))

/*
 * 向队列的头部发送消息
 * @pvItemToQueue: 消息
 * @xTicksToWait: 等待发送超时tick
 */
#define xQueueSendToFront(xQueue, pvItemToQueue, xTicksToWait)  \
    xQueueGenericSend((xQueue), (pvItemToQueue), (xTicksToWait), queueSEND_TO_FRONT)

/*
 * 向队列的尾部发送消息
 * @pvItemToQueue: 消息
 * @xTicksToWait: 等待发送超时tick
 */
#define xQueueSendToBack(xQueue, pvItemToQueue, xTicksToWait) \
    xQueueGenericSend((xQueue), (pvItemToQueue), (xTicksToWait), queueSEND_TO_BACK)

/**
 *
 * 向队列发送消息
 * @pvItemToQueue: 消息
 * @xTicksToWait: 等待发送超时tick
 */
#define xQueueSend(xQueue, pvItemToQueue, xTicksToWait) \
    xQueueGenericSend((xQueue), (pvItemToQueue), (xTicksToWait), queueSEND_TO_BACK)

/**
 *
 * 向队列发送消息,覆盖消息的方式
 * @pvItemToQueue: 消息
 * @xTicksToWait: 等待发送超时tick
 */
#define xQueueOverwrite(xQueue, pvItemToQueue) \
    xQueueGenericSend((xQueue), (pvItemToQueue), 0, queueOVERWRITE)


/**
 * 向队列发送消息
 * @pvItemToQueue: 消息
 * @xTicksToWait: 等待发送超时tick
 * @xCopyPosition: 消息添加到队列的方式
 *      queueSEND_TO_FRONT: 添加到队列头
 *      queueSEND_TO_BACK: 添加到队列的尾部
 *      queueOVERWRITE: 覆盖消息
 */
BaseType_t xQueueGenericSend(QueueHandle_t xQueue,
                              const void * const pvItemToQueue,
                              TickType_t xTicksToWait,
                              const BaseType_t xCopyPosition) PRIVILEGED_FUNCTION;

/**
 * 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.
 *
 */
BaseType_t xQueuePeek(QueueHandle_t xQueue,
                       void * const pvBuffer,
                       TickType_t xTicksToWait) PRIVILEGED_FUNCTION;

/**
 * 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;

/**
 * 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.
 *
 */
BaseType_t xQueueReceive(QueueHandle_t xQueue,
                          void * const pvBuffer,
                          TickType_t xTicksToWait) PRIVILEGED_FUNCTION;

/**
 *
 * 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;

/**
 *
 * 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;

/**
 * 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;

/**
 * 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.
 *
 */
#define xQueueSendToFrontFromISR(xQueue, pvItemToQueue, pxHigherPriorityTaskWoken) \
    xQueueGenericSendFromISR((xQueue), (pvItemToQueue), (pxHigherPriorityTaskWoken), queueSEND_TO_FRONT )


/**
 * 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.
 *
 */
#define xQueueSendToBackFromISR(xQueue, pvItemToQueue, pxHigherPriorityTaskWoken) \
    xQueueGenericSendFromISR((xQueue), (pvItemToQueue), (pxHigherPriorityTaskWoken), queueSEND_TO_BACK)

/**
 * 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.
 *
 */
#define xQueueOverwriteFromISR(xQueue, pvItemToQueue, pxHigherPriorityTaskWoken) \
    xQueueGenericSendFromISR((xQueue), (pvItemToQueue), (pxHigherPriorityTaskWoken), queueOVERWRITE)

/**
 * 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.
 *
 */
#define xQueueSendFromISR(xQueue, pvItemToQueue, pxHigherPriorityTaskWoken) \
    xQueueGenericSendFromISR((xQueue), (pvItemToQueue), (pxHigherPriorityTaskWoken), queueSEND_TO_BACK)

/**
 * 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.
 *
 */
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;

/**
 * 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.
 *
 */
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 within 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 affect the number of queues, semaphores and mutexes that can be
 * created - just the number that the registry can hold.
 *
 * If vQueueAddToRegistry is called more than once with the same xQueue
 * parameter, the registry will store the pcQueueName parameter from the
 * most recent call to vQueueAddToRegistry.
 *
 * @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 pcQueueName 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;
#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;
#endif

/*
 * Generic version of the function used to create 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.
 */

QueueHandle_t xQueueGenericCreate(const UBaseType_t uxQueueLength,
                                    const UBaseType_t uxItemSize,
                                    const uint8_t ucQueueType) PRIVILEGED_FUNCTION;

/*
 * 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 https://www.FreeRTOS.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 https://www.FreeRTOS.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;


#endif /* QUEUE_H */