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queue.c
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/*
* FreeRTOS Kernel V10.4.5
* Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* SPDX-License-Identifier: MIT
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* https://www.FreeRTOS.org
* https://github.com/FreeRTOS
*
*/
#include <stdlib.h>
#include <string.h>
/* Defining MPU_WRAPPERS_INCLUDED_FROM_API_FILE prevents task.h from redefining
* all the API functions to use the MPU wrappers. That should only be done when
* task.h is included from an application file. */
#define MPU_WRAPPERS_INCLUDED_FROM_API_FILE
#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"
#if ( configUSE_CO_ROUTINES == 1 )
#include "croutine.h"
#endif
/* Lint e9021, e961 and e750 are suppressed as a MISRA exception justified
* because the MPU ports require MPU_WRAPPERS_INCLUDED_FROM_API_FILE to be defined
* for the header files above, but not in this file, in order to generate the
* correct privileged Vs unprivileged linkage and placement. */
#undef MPU_WRAPPERS_INCLUDED_FROM_API_FILE /*lint !e961 !e750 !e9021. */
/* Constants used with the cRxLock and cTxLock structure members. */
#define queueUNLOCKED ( ( int8_t ) -1 )
#define queueLOCKED_UNMODIFIED ( ( int8_t ) 0 )
#define queueINT8_MAX ( ( int8_t ) 127 )
/* When the Queue_t structure is used to represent a base queue its pcHead and
* pcTail members are used as pointers into the queue storage area. When the
* Queue_t structure is used to represent a mutex pcHead and pcTail pointers are
* not necessary, and the pcHead pointer is set to NULL to indicate that the
* structure instead holds a pointer to the mutex holder (if any). Map alternative
* names to the pcHead and structure member to ensure the readability of the code
* is maintained. The QueuePointers_t and SemaphoreData_t types are used to form
* a union as their usage is mutually exclusive dependent on what the queue is
* being used for. */
#define uxQueueType pcHead
#define queueQUEUE_IS_MUTEX NULL
typedef struct QueuePointers
{
int8_t * pcTail; /*< Points to the byte at the end of the queue storage area. Once more byte is allocated than necessary to store the queue items, this is used as a marker. */
int8_t * pcReadFrom; /*< Points to the last place that a queued item was read from when the structure is used as a queue. */
} QueuePointers_t;
typedef struct SemaphoreData
{
TaskHandle_t xMutexHolder; /*< The handle of the task that holds the mutex. */
UBaseType_t uxRecursiveCallCount; /*< Maintains a count of the number of times a recursive mutex has been recursively 'taken' when the structure is used as a mutex. */
} SemaphoreData_t;
/* Semaphores do not actually store or copy data, so have an item size of
* zero. */
#define queueSEMAPHORE_QUEUE_ITEM_LENGTH ( ( UBaseType_t ) 0 )
#define queueMUTEX_GIVE_BLOCK_TIME ( ( TickType_t ) 0U )
#if ( configUSE_PREEMPTION == 0 )
/* If the cooperative scheduler is being used then a yield should not be
* performed just because a higher priority task has been woken. */
#define queueYIELD_IF_USING_PREEMPTION()
#else
#define queueYIELD_IF_USING_PREEMPTION() portYIELD_WITHIN_API()
#endif
/*
* Definition of the queue used by the scheduler.
* Items are queued by copy, not reference. See the following link for the
* rationale: https://www.FreeRTOS.org/Embedded-RTOS-Queues.html
*/
typedef struct QueueDefinition /* The old naming convention is used to prevent breaking kernel aware debuggers. */
{
int8_t * pcHead; /*< Points to the beginning of the queue storage area. */
int8_t * pcWriteTo; /*< Points to the free next place in the storage area. */
union
{
QueuePointers_t xQueue; /*< Data required exclusively when this structure is used as a queue. */
SemaphoreData_t xSemaphore; /*< Data required exclusively when this structure is used as a semaphore. */
} u;
List_t xTasksWaitingToSend; /*< List of tasks that are blocked waiting to post onto this queue. Stored in priority order. */
List_t xTasksWaitingToReceive; /*< List of tasks that are blocked waiting to read from this queue. Stored in priority order. */
volatile UBaseType_t uxMessagesWaiting; /*< The number of items currently in the queue. */
UBaseType_t uxLength; /*< The length of the queue defined as the number of items it will hold, not the number of bytes. */
UBaseType_t uxItemSize; /*< The size of each items that the queue will hold. */
volatile int8_t cRxLock; /*< Stores the number of items received from the queue (removed from the queue) while the queue was locked. Set to queueUNLOCKED when the queue is not locked. */
volatile int8_t cTxLock; /*< Stores the number of items transmitted to the queue (added to the queue) while the queue was locked. Set to queueUNLOCKED when the queue is not locked. */
#if ( ( configSUPPORT_STATIC_ALLOCATION == 1 ) && ( configSUPPORT_DYNAMIC_ALLOCATION == 1 ) )
uint8_t ucStaticallyAllocated; /*< Set to pdTRUE if the memory used by the queue was statically allocated to ensure no attempt is made to free the memory. */
#endif
#if ( configUSE_QUEUE_SETS == 1 )
struct QueueDefinition * pxQueueSetContainer;
#endif
#if ( configUSE_TRACE_FACILITY == 1 )
UBaseType_t uxQueueNumber;
uint8_t ucQueueType;
#endif
} xQUEUE;
/* The old xQUEUE name is maintained above then typedefed to the new Queue_t
* name below to enable the use of older kernel aware debuggers. */
typedef xQUEUE Queue_t;
/*-----------------------------------------------------------*/
/*
* The queue registry is just a means for kernel aware debuggers to locate
* queue structures. It has no other purpose so is an optional component.
*/
#if ( configQUEUE_REGISTRY_SIZE > 0 )
/* The type stored within the queue registry array. This allows a name
* to be assigned to each queue making kernel aware debugging a little
* more user friendly. */
typedef struct QUEUE_REGISTRY_ITEM
{
const char * pcQueueName; /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
QueueHandle_t xHandle;
} xQueueRegistryItem;
/* The old xQueueRegistryItem name is maintained above then typedefed to the
* new xQueueRegistryItem name below to enable the use of older kernel aware
* debuggers. */
typedef xQueueRegistryItem QueueRegistryItem_t;
/* The queue registry is simply an array of QueueRegistryItem_t structures.
* The pcQueueName member of a structure being NULL is indicative of the
* array position being vacant. */
PRIVILEGED_DATA QueueRegistryItem_t xQueueRegistry[ configQUEUE_REGISTRY_SIZE ];
#endif /* configQUEUE_REGISTRY_SIZE */
/*
* Unlocks a queue locked by a call to prvLockQueue. Locking a queue does not
* prevent an ISR from adding or removing items to the queue, but does prevent
* an ISR from removing tasks from the queue event lists. If an ISR finds a
* queue is locked it will instead increment the appropriate queue lock count
* to indicate that a task may require unblocking. When the queue in unlocked
* these lock counts are inspected, and the appropriate action taken.
*/
static void prvUnlockQueue( Queue_t * const pxQueue ) PRIVILEGED_FUNCTION;
/*
* Uses a critical section to determine if there is any data in a queue.
*
* @return pdTRUE if the queue contains no items, otherwise pdFALSE.
*/
static BaseType_t prvIsQueueEmpty( const Queue_t * pxQueue ) PRIVILEGED_FUNCTION;
/*
* Uses a critical section to determine if there is any space in a queue.
*
* @return pdTRUE if there is no space, otherwise pdFALSE;
*/
static BaseType_t prvIsQueueFull( const Queue_t * pxQueue ) PRIVILEGED_FUNCTION;
/*
* Copies an item into the queue, either at the front of the queue or the
* back of the queue.
*/
static BaseType_t prvCopyDataToQueue( Queue_t * const pxQueue,
const void * pvItemToQueue,
const BaseType_t xPosition ) PRIVILEGED_FUNCTION;
/*
* Copies an item out of a queue.
*/
static void prvCopyDataFromQueue( Queue_t * const pxQueue,
void * const pvBuffer ) PRIVILEGED_FUNCTION;
#if ( configUSE_QUEUE_SETS == 1 )
/*
* Checks to see if a queue is a member of a queue set, and if so, notifies
* the queue set that the queue contains data.
*/
static BaseType_t prvNotifyQueueSetContainer( const Queue_t * const pxQueue ) PRIVILEGED_FUNCTION;
#endif
/*
* Called after a Queue_t structure has been allocated either statically or
* dynamically to fill in the structure's members.
*/
static void prvInitialiseNewQueue( const UBaseType_t uxQueueLength,
const UBaseType_t uxItemSize,
uint8_t * pucQueueStorage,
const uint8_t ucQueueType,
Queue_t * pxNewQueue ) PRIVILEGED_FUNCTION;
/*
* Mutexes are a special type of queue. When a mutex is created, first the
* queue is created, then prvInitialiseMutex() is called to configure the queue
* as a mutex.
*/
#if ( configUSE_MUTEXES == 1 )
static void prvInitialiseMutex( Queue_t * pxNewQueue ) PRIVILEGED_FUNCTION;
#endif
#if ( configUSE_MUTEXES == 1 )
/*
* If a task waiting for a mutex causes the mutex holder to inherit a
* priority, but the waiting task times out, then the holder should
* disinherit the priority - but only down to the highest priority of any
* other tasks that are waiting for the same mutex. This function returns
* that priority.
*/
static UBaseType_t prvGetDisinheritPriorityAfterTimeout( const Queue_t * const pxQueue ) PRIVILEGED_FUNCTION;
#endif
/*-----------------------------------------------------------*/
/*
* Macro to mark a queue as locked. Locking a queue prevents an ISR from
* accessing the queue event lists.
*/
#define prvLockQueue( pxQueue ) \
taskENTER_CRITICAL(); \
{ \
if( ( pxQueue )->cRxLock == queueUNLOCKED ) \
{ \
( pxQueue )->cRxLock = queueLOCKED_UNMODIFIED; \
} \
if( ( pxQueue )->cTxLock == queueUNLOCKED ) \
{ \
( pxQueue )->cTxLock = queueLOCKED_UNMODIFIED; \
} \
} \
taskEXIT_CRITICAL()
/*-----------------------------------------------------------*/
BaseType_t xQueueGenericReset( QueueHandle_t xQueue,
BaseType_t xNewQueue )
{
BaseType_t xReturn = pdPASS;
Queue_t * const pxQueue = xQueue;
configASSERT( pxQueue );
if( ( pxQueue != NULL ) &&
( pxQueue->uxLength >= 1U ) &&
/* Check for multiplication overflow. */
( ( SIZE_MAX / pxQueue->uxLength ) >= pxQueue->uxItemSize ) )
{
taskENTER_CRITICAL();
{
pxQueue->u.xQueue.pcTail = pxQueue->pcHead + ( pxQueue->uxLength * pxQueue->uxItemSize ); /*lint !e9016 Pointer arithmetic allowed on char types, especially when it assists conveying intent. */
pxQueue->uxMessagesWaiting = ( UBaseType_t ) 0U;
pxQueue->pcWriteTo = pxQueue->pcHead;
pxQueue->u.xQueue.pcReadFrom = pxQueue->pcHead + ( ( pxQueue->uxLength - 1U ) * pxQueue->uxItemSize ); /*lint !e9016 Pointer arithmetic allowed on char types, especially when it assists conveying intent. */
pxQueue->cRxLock = queueUNLOCKED;
pxQueue->cTxLock = queueUNLOCKED;
if( xNewQueue == pdFALSE )
{
/* If there are tasks blocked waiting to read from the queue, then
* the tasks will remain blocked as after this function exits the queue
* will still be empty. If there are tasks blocked waiting to write to
* the queue, then one should be unblocked as after this function exits
* it will be possible to write to it. */
if( listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToSend ) ) == pdFALSE )
{
if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToSend ) ) != pdFALSE )
{
queueYIELD_IF_USING_PREEMPTION();
}
else
{
mtCOVERAGE_TEST_MARKER();
}
}
else
{
mtCOVERAGE_TEST_MARKER();
}
}
else
{
/* Ensure the event queues start in the correct state. */
vListInitialise( &( pxQueue->xTasksWaitingToSend ) );
vListInitialise( &( pxQueue->xTasksWaitingToReceive ) );
}
}
taskEXIT_CRITICAL();
}
else
{
xReturn = pdFAIL;
}
configASSERT( xReturn != pdFAIL );
/* A value is returned for calling semantic consistency with previous
* versions. */
return xReturn;
}
/*-----------------------------------------------------------*/
#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 )
{
Queue_t * pxNewQueue = NULL;
/* The StaticQueue_t structure and the queue storage area must be
* supplied. */
configASSERT( pxStaticQueue );
if( ( uxQueueLength > ( UBaseType_t ) 0 ) &&
( pxStaticQueue != NULL ) &&
/* A queue storage area should be provided if the item size is not 0, and
* should not be provided if the item size is 0. */
( !( ( pucQueueStorage != NULL ) && ( uxItemSize == 0 ) ) ) &&
( !( ( pucQueueStorage == NULL ) && ( uxItemSize != 0 ) ) ) )
{
#if ( configASSERT_DEFINED == 1 )
{
/* Sanity check that the size of the structure used to declare a
* variable of type StaticQueue_t or StaticSemaphore_t equals the size of
* the real queue and semaphore structures. */
volatile size_t xSize = sizeof( StaticQueue_t );
/* This assertion cannot be branch covered in unit tests */
configASSERT( xSize == sizeof( Queue_t ) ); /* LCOV_EXCL_BR_LINE */
( void ) xSize; /* Keeps lint quiet when configASSERT() is not defined. */
}
#endif /* configASSERT_DEFINED */
/* The address of a statically allocated queue was passed in, use it.
* The address of a statically allocated storage area was also passed in
* but is already set. */
pxNewQueue = ( Queue_t * ) pxStaticQueue; /*lint !e740 !e9087 Unusual cast is ok as the structures are designed to have the same alignment, and the size is checked by an assert. */
#if ( configSUPPORT_DYNAMIC_ALLOCATION == 1 )
{
/* Queues can be allocated wither statically or dynamically, so
* note this queue was allocated statically in case the queue is
* later deleted. */
pxNewQueue->ucStaticallyAllocated = pdTRUE;
}
#endif /* configSUPPORT_DYNAMIC_ALLOCATION */
prvInitialiseNewQueue( uxQueueLength, uxItemSize, pucQueueStorage, ucQueueType, pxNewQueue );
}
else
{
configASSERT( pxNewQueue );
mtCOVERAGE_TEST_MARKER();
}
return pxNewQueue;
}
#endif /* configSUPPORT_STATIC_ALLOCATION */
/*-----------------------------------------------------------*/
#if ( configSUPPORT_DYNAMIC_ALLOCATION == 1 )
QueueHandle_t xQueueGenericCreate( const UBaseType_t uxQueueLength,
const UBaseType_t uxItemSize,
const uint8_t ucQueueType )
{
Queue_t * pxNewQueue = NULL;
size_t xQueueSizeInBytes;
uint8_t * pucQueueStorage;
if( ( uxQueueLength > ( UBaseType_t ) 0 ) &&
/* Check for multiplication overflow. */
( ( SIZE_MAX / uxQueueLength ) >= uxItemSize ) &&
/* Check for addition overflow. */
( ( SIZE_MAX - sizeof( Queue_t ) ) >= ( uxQueueLength * uxItemSize ) ) )
{
/* Allocate enough space to hold the maximum number of items that
* can be in the queue at any time. It is valid for uxItemSize to be
* zero in the case the queue is used as a semaphore. */
xQueueSizeInBytes = ( size_t ) ( uxQueueLength * uxItemSize ); /*lint !e961 MISRA exception as the casts are only redundant for some ports. */
/* Allocate the queue and storage area. Justification for MISRA
* deviation as follows: pvPortMalloc() always ensures returned memory
* blocks are aligned per the requirements of the MCU stack. In this case
* pvPortMalloc() must return a pointer that is guaranteed to meet the
* alignment requirements of the Queue_t structure - which in this case
* is an int8_t *. Therefore, whenever the stack alignment requirements
* are greater than or equal to the pointer to char requirements the cast
* is safe. In other cases alignment requirements are not strict (one or
* two bytes). */
pxNewQueue = ( Queue_t * ) pvPortMalloc( sizeof( Queue_t ) + xQueueSizeInBytes ); /*lint !e9087 !e9079 see comment above. */
if( pxNewQueue != NULL )
{
/* Jump past the queue structure to find the location of the queue
* storage area. */
pucQueueStorage = ( uint8_t * ) pxNewQueue;
pucQueueStorage += sizeof( Queue_t ); /*lint !e9016 Pointer arithmetic allowed on char types, especially when it assists conveying intent. */
#if ( configSUPPORT_STATIC_ALLOCATION == 1 )
{
/* Queues can be created either statically or dynamically, so
* note this task was created dynamically in case it is later
* deleted. */
pxNewQueue->ucStaticallyAllocated = pdFALSE;
}
#endif /* configSUPPORT_STATIC_ALLOCATION */
prvInitialiseNewQueue( uxQueueLength, uxItemSize, pucQueueStorage, ucQueueType, pxNewQueue );
}
else
{
traceQUEUE_CREATE_FAILED( ucQueueType );
mtCOVERAGE_TEST_MARKER();
}
}
else
{
configASSERT( pxNewQueue );
mtCOVERAGE_TEST_MARKER();
}
return pxNewQueue;
}
#endif /* configSUPPORT_STATIC_ALLOCATION */
/*-----------------------------------------------------------*/
static void prvInitialiseNewQueue( const UBaseType_t uxQueueLength,
const UBaseType_t uxItemSize,
uint8_t * pucQueueStorage,
const uint8_t ucQueueType,
Queue_t * pxNewQueue )
{
/* Remove compiler warnings about unused parameters should
* configUSE_TRACE_FACILITY not be set to 1. */
( void ) ucQueueType;
if( uxItemSize == ( UBaseType_t ) 0 )
{
/* No RAM was allocated for the queue storage area, but PC head cannot
* be set to NULL because NULL is used as a key to say the queue is used as
* a mutex. Therefore just set pcHead to point to the queue as a benign
* value that is known to be within the memory map. */
pxNewQueue->pcHead = ( int8_t * ) pxNewQueue;
}
else
{
/* Set the head to the start of the queue storage area. */
pxNewQueue->pcHead = ( int8_t * ) pucQueueStorage;
}
/* Initialise the queue members as described where the queue type is
* defined. */
pxNewQueue->uxLength = uxQueueLength;
pxNewQueue->uxItemSize = uxItemSize;
( void ) xQueueGenericReset( pxNewQueue, pdTRUE );
#if ( configUSE_TRACE_FACILITY == 1 )
{
pxNewQueue->ucQueueType = ucQueueType;
}
#endif /* configUSE_TRACE_FACILITY */
#if ( configUSE_QUEUE_SETS == 1 )
{
pxNewQueue->pxQueueSetContainer = NULL;
}
#endif /* configUSE_QUEUE_SETS */
traceQUEUE_CREATE( pxNewQueue );
}
/*-----------------------------------------------------------*/
#if ( configUSE_MUTEXES == 1 )
static void prvInitialiseMutex( Queue_t * pxNewQueue )
{
if( pxNewQueue != NULL )
{
/* The queue create function will set all the queue structure members
* correctly for a generic queue, but this function is creating a
* mutex. Overwrite those members that need to be set differently -
* in particular the information required for priority inheritance. */
pxNewQueue->u.xSemaphore.xMutexHolder = NULL;
pxNewQueue->uxQueueType = queueQUEUE_IS_MUTEX;
/* In case this is a recursive mutex. */
pxNewQueue->u.xSemaphore.uxRecursiveCallCount = 0;
traceCREATE_MUTEX( pxNewQueue );
/* Start with the semaphore in the expected state. */
( void ) xQueueGenericSend( pxNewQueue, NULL, ( TickType_t ) 0U, queueSEND_TO_BACK );
}
else
{
traceCREATE_MUTEX_FAILED();
}
}
#endif /* configUSE_MUTEXES */
/*-----------------------------------------------------------*/
#if ( ( configUSE_MUTEXES == 1 ) && ( configSUPPORT_DYNAMIC_ALLOCATION == 1 ) )
QueueHandle_t xQueueCreateMutex( const uint8_t ucQueueType )
{
QueueHandle_t xNewQueue;
const UBaseType_t uxMutexLength = ( UBaseType_t ) 1, uxMutexSize = ( UBaseType_t ) 0;
xNewQueue = xQueueGenericCreate( uxMutexLength, uxMutexSize, ucQueueType );
prvInitialiseMutex( ( Queue_t * ) xNewQueue );
return xNewQueue;
}
#endif /* configUSE_MUTEXES */
/*-----------------------------------------------------------*/
#if ( ( configUSE_MUTEXES == 1 ) && ( configSUPPORT_STATIC_ALLOCATION == 1 ) )
QueueHandle_t xQueueCreateMutexStatic( const uint8_t ucQueueType,
StaticQueue_t * pxStaticQueue )
{
QueueHandle_t xNewQueue;
const UBaseType_t uxMutexLength = ( UBaseType_t ) 1, uxMutexSize = ( UBaseType_t ) 0;
/* Prevent compiler warnings about unused parameters if
* configUSE_TRACE_FACILITY does not equal 1. */
( void ) ucQueueType;
xNewQueue = xQueueGenericCreateStatic( uxMutexLength, uxMutexSize, NULL, pxStaticQueue, ucQueueType );
prvInitialiseMutex( ( Queue_t * ) xNewQueue );
return xNewQueue;
}
#endif /* configUSE_MUTEXES */
/*-----------------------------------------------------------*/
#if ( ( configUSE_MUTEXES == 1 ) && ( INCLUDE_xSemaphoreGetMutexHolder == 1 ) )
TaskHandle_t xQueueGetMutexHolder( QueueHandle_t xSemaphore )
{
TaskHandle_t pxReturn;
Queue_t * const pxSemaphore = ( Queue_t * ) xSemaphore;
configASSERT( xSemaphore );
/* This function is called by xSemaphoreGetMutexHolder(), and should not
* be called directly. Note: This is a good way of determining if the
* calling task is the mutex holder, but not a good way of determining the
* identity of the mutex holder, as the holder may change between the
* following critical section exiting and the function returning. */
taskENTER_CRITICAL();
{
if( pxSemaphore->uxQueueType == queueQUEUE_IS_MUTEX )
{
pxReturn = pxSemaphore->u.xSemaphore.xMutexHolder;
}
else
{
pxReturn = NULL;
}
}
taskEXIT_CRITICAL();
return pxReturn;
} /*lint !e818 xSemaphore cannot be a pointer to const because it is a typedef. */
#endif /* if ( ( configUSE_MUTEXES == 1 ) && ( INCLUDE_xSemaphoreGetMutexHolder == 1 ) ) */
/*-----------------------------------------------------------*/
#if ( ( configUSE_MUTEXES == 1 ) && ( INCLUDE_xSemaphoreGetMutexHolder == 1 ) )
TaskHandle_t xQueueGetMutexHolderFromISR( QueueHandle_t xSemaphore )
{
TaskHandle_t pxReturn;
configASSERT( xSemaphore );
/* Mutexes cannot be used in interrupt service routines, so the mutex
* holder should not change in an ISR, and therefore a critical section is
* not required here. */
if( ( ( Queue_t * ) xSemaphore )->uxQueueType == queueQUEUE_IS_MUTEX )
{
pxReturn = ( ( Queue_t * ) xSemaphore )->u.xSemaphore.xMutexHolder;
}
else
{
pxReturn = NULL;
}
return pxReturn;
} /*lint !e818 xSemaphore cannot be a pointer to const because it is a typedef. */
#endif /* if ( ( configUSE_MUTEXES == 1 ) && ( INCLUDE_xSemaphoreGetMutexHolder == 1 ) ) */
/*-----------------------------------------------------------*/
#if ( configUSE_RECURSIVE_MUTEXES == 1 )
BaseType_t xQueueGiveMutexRecursive( QueueHandle_t xMutex )
{
BaseType_t xReturn;
Queue_t * const pxMutex = ( Queue_t * ) xMutex;
configASSERT( pxMutex );
/* If this is the task that holds the mutex then xMutexHolder will not
* change outside of this task. If this task does not hold the mutex then
* pxMutexHolder can never coincidentally equal the tasks handle, and as
* this is the only condition we are interested in it does not matter if
* pxMutexHolder is accessed simultaneously by another task. Therefore no
* mutual exclusion is required to test the pxMutexHolder variable. */
if( pxMutex->u.xSemaphore.xMutexHolder == xTaskGetCurrentTaskHandle() )
{
traceGIVE_MUTEX_RECURSIVE( pxMutex );
/* uxRecursiveCallCount cannot be zero if xMutexHolder is equal to
* the task handle, therefore no underflow check is required. Also,
* uxRecursiveCallCount is only modified by the mutex holder, and as
* there can only be one, no mutual exclusion is required to modify the
* uxRecursiveCallCount member. */
( pxMutex->u.xSemaphore.uxRecursiveCallCount )--;
/* Has the recursive call count unwound to 0? */
if( pxMutex->u.xSemaphore.uxRecursiveCallCount == ( UBaseType_t ) 0 )
{
/* Return the mutex. This will automatically unblock any other
* task that might be waiting to access the mutex. */
( void ) xQueueGenericSend( pxMutex, NULL, queueMUTEX_GIVE_BLOCK_TIME, queueSEND_TO_BACK );
}
else
{
mtCOVERAGE_TEST_MARKER();
}
xReturn = pdPASS;
}
else
{
/* The mutex cannot be given because the calling task is not the
* holder. */
xReturn = pdFAIL;
traceGIVE_MUTEX_RECURSIVE_FAILED( pxMutex );
}
return xReturn;
}
#endif /* configUSE_RECURSIVE_MUTEXES */
/*-----------------------------------------------------------*/
#if ( configUSE_RECURSIVE_MUTEXES == 1 )
BaseType_t xQueueTakeMutexRecursive( QueueHandle_t xMutex,
TickType_t xTicksToWait )
{
BaseType_t xReturn;
Queue_t * const pxMutex = ( Queue_t * ) xMutex;
configASSERT( pxMutex );
/* Comments regarding mutual exclusion as per those within
* xQueueGiveMutexRecursive(). */
traceTAKE_MUTEX_RECURSIVE( pxMutex );
if( pxMutex->u.xSemaphore.xMutexHolder == xTaskGetCurrentTaskHandle() )
{
( pxMutex->u.xSemaphore.uxRecursiveCallCount )++;
xReturn = pdPASS;
}
else
{
xReturn = xQueueSemaphoreTake( pxMutex, xTicksToWait );
/* pdPASS will only be returned if the mutex was successfully
* obtained. The calling task may have entered the Blocked state
* before reaching here. */
if( xReturn != pdFAIL )
{
( pxMutex->u.xSemaphore.uxRecursiveCallCount )++;
}
else
{
traceTAKE_MUTEX_RECURSIVE_FAILED( pxMutex );
}
}
return xReturn;
}
#endif /* configUSE_RECURSIVE_MUTEXES */
/*-----------------------------------------------------------*/
#if ( ( configUSE_COUNTING_SEMAPHORES == 1 ) && ( configSUPPORT_STATIC_ALLOCATION == 1 ) )
QueueHandle_t xQueueCreateCountingSemaphoreStatic( const UBaseType_t uxMaxCount,
const UBaseType_t uxInitialCount,
StaticQueue_t * pxStaticQueue )
{
QueueHandle_t xHandle = NULL;
if( ( uxMaxCount != 0 ) &&
( uxInitialCount <= uxMaxCount ) )
{
xHandle = xQueueGenericCreateStatic( uxMaxCount, queueSEMAPHORE_QUEUE_ITEM_LENGTH, NULL, pxStaticQueue, queueQUEUE_TYPE_COUNTING_SEMAPHORE );
if( xHandle != NULL )
{
( ( Queue_t * ) xHandle )->uxMessagesWaiting = uxInitialCount;
traceCREATE_COUNTING_SEMAPHORE();
}
else
{
traceCREATE_COUNTING_SEMAPHORE_FAILED();
}
}
else
{
configASSERT( xHandle );
mtCOVERAGE_TEST_MARKER();
}
return xHandle;
}
#endif /* ( ( configUSE_COUNTING_SEMAPHORES == 1 ) && ( configSUPPORT_DYNAMIC_ALLOCATION == 1 ) ) */
/*-----------------------------------------------------------*/
#if ( ( configUSE_COUNTING_SEMAPHORES == 1 ) && ( configSUPPORT_DYNAMIC_ALLOCATION == 1 ) )
QueueHandle_t xQueueCreateCountingSemaphore( const UBaseType_t uxMaxCount,
const UBaseType_t uxInitialCount )
{
QueueHandle_t xHandle = NULL;
if( ( uxMaxCount != 0 ) &&
( uxInitialCount <= uxMaxCount ) )
{
xHandle = xQueueGenericCreate( uxMaxCount, queueSEMAPHORE_QUEUE_ITEM_LENGTH, queueQUEUE_TYPE_COUNTING_SEMAPHORE );
if( xHandle != NULL )
{
( ( Queue_t * ) xHandle )->uxMessagesWaiting = uxInitialCount;
traceCREATE_COUNTING_SEMAPHORE();
}
else
{
traceCREATE_COUNTING_SEMAPHORE_FAILED();
}
}
else
{
configASSERT( xHandle );
mtCOVERAGE_TEST_MARKER();
}
return xHandle;
}
#endif /* ( ( configUSE_COUNTING_SEMAPHORES == 1 ) && ( configSUPPORT_DYNAMIC_ALLOCATION == 1 ) ) */
/*-----------------------------------------------------------*/
BaseType_t xQueueGenericSend( QueueHandle_t xQueue,
const void * const pvItemToQueue,
TickType_t xTicksToWait,
const BaseType_t xCopyPosition )
{
BaseType_t xEntryTimeSet = pdFALSE, xYieldRequired;
TimeOut_t xTimeOut;
Queue_t * const pxQueue = xQueue;
configASSERT( pxQueue );
configASSERT( !( ( pvItemToQueue == NULL ) && ( pxQueue->uxItemSize != ( UBaseType_t ) 0U ) ) );
configASSERT( !( ( xCopyPosition == queueOVERWRITE ) && ( pxQueue->uxLength != 1 ) ) );
#if ( ( INCLUDE_xTaskGetSchedulerState == 1 ) || ( configUSE_TIMERS == 1 ) )
{
configASSERT( !( ( xTaskGetSchedulerState() == taskSCHEDULER_SUSPENDED ) && ( xTicksToWait != 0 ) ) );
}
#endif
/*lint -save -e904 This function relaxes the coding standard somewhat to
* allow return statements within the function itself. This is done in the
* interest of execution time efficiency. */
for( ; ; )
{
taskENTER_CRITICAL();
{
/* Is there room on the queue now? The running task must be the
* highest priority task wanting to access the queue. If the head item
* in the queue is to be overwritten then it does not matter if the
* queue is full. */
if( ( pxQueue->uxMessagesWaiting < pxQueue->uxLength ) || ( xCopyPosition == queueOVERWRITE ) )
{
traceQUEUE_SEND( pxQueue );
#if ( configUSE_QUEUE_SETS == 1 )
{
const UBaseType_t uxPreviousMessagesWaiting = pxQueue->uxMessagesWaiting;
xYieldRequired = prvCopyDataToQueue( pxQueue, pvItemToQueue, xCopyPosition );
if( pxQueue->pxQueueSetContainer != NULL )
{
if( ( xCopyPosition == queueOVERWRITE ) && ( uxPreviousMessagesWaiting != ( UBaseType_t ) 0 ) )
{
/* Do not notify the queue set as an existing item
* was overwritten in the queue so the number of items
* in the queue has not changed. */
mtCOVERAGE_TEST_MARKER();
}
else if( prvNotifyQueueSetContainer( pxQueue ) != pdFALSE )
{
/* The queue is a member of a queue set, and posting
* to the queue set caused a higher priority task to
* unblock. A context switch is required. */
queueYIELD_IF_USING_PREEMPTION();
}
else
{
mtCOVERAGE_TEST_MARKER();
}
}
else
{
/* If there was a task waiting for data to arrive on the
* queue then unblock it now. */
if( listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) == pdFALSE )
{
if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )
{
/* The unblocked task has a priority higher than
* our own so yield immediately. Yes it is ok to
* do this from within the critical section - the
* kernel takes care of that. */
queueYIELD_IF_USING_PREEMPTION();
}
else
{
mtCOVERAGE_TEST_MARKER();
}
}
else if( xYieldRequired != pdFALSE )
{
/* This path is a special case that will only get
* executed if the task was holding multiple mutexes
* and the mutexes were given back in an order that is
* different to that in which they were taken. */
queueYIELD_IF_USING_PREEMPTION();
}
else
{
mtCOVERAGE_TEST_MARKER();
}
}
}
#else /* configUSE_QUEUE_SETS */
{
xYieldRequired = prvCopyDataToQueue( pxQueue, pvItemToQueue, xCopyPosition );
/* If there was a task waiting for data to arrive on the
* queue then unblock it now. */
if( listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) == pdFALSE )
{
if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )
{
/* The unblocked task has a priority higher than
* our own so yield immediately. Yes it is ok to do
* this from within the critical section - the kernel
* takes care of that. */
queueYIELD_IF_USING_PREEMPTION();
}
else
{
mtCOVERAGE_TEST_MARKER();
}
}
else if( xYieldRequired != pdFALSE )
{
/* This path is a special case that will only get
* executed if the task was holding multiple mutexes and
* the mutexes were given back in an order that is
* different to that in which they were taken. */
queueYIELD_IF_USING_PREEMPTION();
}
else
{
mtCOVERAGE_TEST_MARKER();
}
}
#endif /* configUSE_QUEUE_SETS */
taskEXIT_CRITICAL();
return pdPASS;
}
else
{
if( xTicksToWait == ( TickType_t ) 0 )
{
/* The queue was full and no block time is specified (or
* the block time has expired) so leave now. */
taskEXIT_CRITICAL();
/* Return to the original privilege level before exiting
* the function. */
traceQUEUE_SEND_FAILED( pxQueue );
return errQUEUE_FULL;
}
else if( xEntryTimeSet == pdFALSE )
{
/* The queue was full and a block time was specified so
* configure the timeout structure. */
vTaskInternalSetTimeOutState( &xTimeOut );
xEntryTimeSet = pdTRUE;
}
else
{
/* Entry time was already set. */
mtCOVERAGE_TEST_MARKER();
}
}
}
taskEXIT_CRITICAL();
/* Interrupts and other tasks can send to and receive from the queue
* now the critical section has been exited. */
vTaskSuspendAll();
prvLockQueue( pxQueue );
/* Update the timeout state to see if it has expired yet. */
if( xTaskCheckForTimeOut( &xTimeOut, &xTicksToWait ) == pdFALSE )
{
if( prvIsQueueFull( pxQueue ) != pdFALSE )
{
traceBLOCKING_ON_QUEUE_SEND( pxQueue );
vTaskPlaceOnEventList( &( pxQueue->xTasksWaitingToSend ), xTicksToWait );
/* Unlocking the queue means queue events can effect the
* event list. It is possible that interrupts occurring now
* remove this task from the event list again - but as the
* scheduler is suspended the task will go onto the pending
* ready list instead of the actual ready list. */
prvUnlockQueue( pxQueue );
/* Resuming the scheduler will move tasks from the pending
* ready list into the ready list - so it is feasible that this
* task is already in the ready list before it yields - in which
* case the yield will not cause a context switch unless there
* is also a higher priority task in the pending ready list. */
if( xTaskResumeAll() == pdFALSE )
{
portYIELD_WITHIN_API();
}
}
else
{
/* Try again. */
prvUnlockQueue( pxQueue );