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queue.c
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/*
* FreeRTOS Kernel V10.3.1
* Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* 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.
*
* http://www.FreeRTOS.org
* http://aws.amazon.com/freertos
*
* 1 tab == 4 spaces!
*/
#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 )
/* 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 )
{
Queue_t * const pxQueue = xQueue;
configASSERT( pxQueue );
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();
/* A value is returned for calling semantic consistency with previous
versions. */
return pdPASS;
}
/*-----------------------------------------------------------*/
#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;
configASSERT( uxQueueLength > ( UBaseType_t ) 0 );
/* The StaticQueue_t structure and the queue storage area must be
supplied. */
configASSERT( 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. */
configASSERT( !( ( pucQueueStorage != NULL ) && ( uxItemSize == 0 ) ) );
configASSERT( !( ( 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 );
configASSERT( xSize == sizeof( Queue_t ) );
( 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( pxNewQueue != NULL )
{
#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
{
traceQUEUE_CREATE_FAILED( ucQueueType );
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;
size_t xQueueSizeInBytes;
uint8_t *pucQueueStorage;
configASSERT( uxQueueLength > ( UBaseType_t ) 0 );
/* 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();
}
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;
/* 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 ) )
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_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;
configASSERT( uxMaxCount != 0 );
configASSERT( 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();
}
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;
configASSERT( uxMaxCount != 0 );
configASSERT( 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();
}
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 last 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 a 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 );
( void ) xTaskResumeAll();
}
}
else
{
/* The timeout has expired. */
prvUnlockQueue( pxQueue );
( void ) xTaskResumeAll();
traceQUEUE_SEND_FAILED( pxQueue );
return errQUEUE_FULL;
}
} /*lint -restore */
}
/*-----------------------------------------------------------*/
BaseType_t xQueueGenericSendFromISR( QueueHandle_t xQueue, const void * const pvItemToQueue, BaseType_t * const pxHigherPriorityTaskWoken, const BaseType_t xCopyPosition )
{
BaseType_t xReturn;
UBaseType_t uxSavedInterruptStatus;
Queue_t * const pxQueue = xQueue;
configASSERT( pxQueue );
configASSERT( !( ( pvItemToQueue == NULL ) && ( pxQueue->uxItemSize != ( UBaseType_t ) 0U ) ) );
configASSERT( !( ( xCopyPosition == queueOVERWRITE ) && ( pxQueue->uxLength != 1 ) ) );
/* RTOS ports that support interrupt nesting have the concept of a maximum
system call (or maximum API call) interrupt priority. Interrupts that are
above the maximum system call priority are kept permanently enabled, even
when the RTOS kernel is in a critical section, but cannot make any calls to
FreeRTOS API functions. If configASSERT() is defined in FreeRTOSConfig.h
then portASSERT_IF_INTERRUPT_PRIORITY_INVALID() will result in an assertion
failure if a FreeRTOS API function is called from an interrupt that has been
assigned a priority above the configured maximum system call priority.
Only FreeRTOS functions that end in FromISR can be called from interrupts
that have been assigned a priority at or (logically) below the maximum
system call interrupt priority. FreeRTOS maintains a separate interrupt
safe API to ensure interrupt entry is as fast and as simple as possible.
More information (albeit Cortex-M specific) is provided on the following
link: http://www.freertos.org/RTOS-Cortex-M3-M4.html */
portASSERT_IF_INTERRUPT_PRIORITY_INVALID();
/* Similar to xQueueGenericSend, except without blocking if there is no room
in the queue. Also don't directly wake a task that was blocked on a queue
read, instead return a flag to say whether a context switch is required or
not (i.e. has a task with a higher priority than us been woken by this
post). */
uxSavedInterruptStatus = portSET_INTERRUPT_MASK_FROM_ISR();
{
if( ( pxQueue->uxMessagesWaiting < pxQueue->uxLength ) || ( xCopyPosition == queueOVERWRITE ) )
{
const int8_t cTxLock = pxQueue->cTxLock;
const UBaseType_t uxPreviousMessagesWaiting = pxQueue->uxMessagesWaiting;
traceQUEUE_SEND_FROM_ISR( pxQueue );
/* Semaphores use xQueueGiveFromISR(), so pxQueue will not be a
semaphore or mutex. That means prvCopyDataToQueue() cannot result
in a task disinheriting a priority and prvCopyDataToQueue() can be
called here even though the disinherit function does not check if
the scheduler is suspended before accessing the ready lists. */
( void ) prvCopyDataToQueue( pxQueue, pvItemToQueue, xCopyPosition );
/* The event list is not altered if the queue is locked. This will
be done when the queue is unlocked later. */
if( cTxLock == queueUNLOCKED )
{