Naming rules for FreeRTOS

If it's just touching FreeRTOS, See its name , It's ridiculous , Like a heavenly book . therefore , It is still necessary to understand its naming rules .

Variable

1. uint32_t The defined variables are prefixed ul. u representative unsigned Unsigned ,l representative long Long integer .

   for example ：

   static portFORCE_INLINE uint32_t Atomic_CompareAndSwap_u32( 
       uint32_t volatile * pulDestination,
       uint32_t ulExchange,
       uint32_t ulComparand )
   

   ulExchange,ulComparand this is it

2. uint16_t The defined variables are prefixed us. u representative unsigned Unsigned ,s representative short Short .

   for example ： const uint16_t usStackDepth

3. uint8_t The defined variables are prefixed uc. u representative unsigned Unsigned ,c representative char Character .

   for example ：

       #if ( configUSE_TASK_NOTIFICATIONS == 1 )
           uint32_t ulDummy18[ configTASK_NOTIFICATION_ARRAY_ENTRIES ];
           uint8_t ucDummy19[ configTASK_NOTIFICATION_ARRAY_ENTRIES ];
       #endif
       #if ( tskSTATIC_AND_DYNAMIC_ALLOCATION_POSSIBLE != 0 )
           uint8_t uxDummy20;
       #endif
   

   ucDummy19 this is it ;

   But I don't understand ,uxDiummy20 Why is it used ux Well ？

4. int The defined variables are prefixed i.i representative int

   for example ：int iTaskErrno;

5. stdint.h Variable types not defined in the file , When defining variables, you need to prefix x.

   for example ：

   BaseType_t xCoRoutinePreviouslyWoken

   MiniListItem_t xListEnd

6. stdint.h Unsigned variable type not defined in the file , When defining variables, prefix them u, such as UBaseType_t Definition
   The variable of should be prefixed ux.

   for example ：

   typedef unsigned long UBaseType_t;

   UBaseType_t uxPriority;

7. Enumerating variables will be prefixed e.

   for example ：

   typedef enum
   {
         
       eRunning = 0, /* A task is querying the state of itself, so must be running. */
       eReady,       /* The task being queried is in a ready or pending ready list. */
       eBlocked,     /* The task being queried is in the Blocked state. */
       eSuspended,   /* The task being queried is in the Suspended state, or is in the Blocked state with an infinite time out. */
       eDeleted,     /* The task being queried has been deleted, but its TCB has not yet been freed. */
       eInvalid      /* Used as an 'invalid state' value. */
   } eTaskState;
   
   eTaskState eState;
   

8. Pointer variables are prefixed p.

   for example ：

   TCB_t * pxTCB;

   uint8_t * pucQueueStorage; // Because it's unsigned , So it is pu

9. according to MISRA (The Motor Industry Software Reliability Association, The Chinese name is Automobile Industry Software Reliability Association ) Code rules ,char Defined variables can only be used for ASCII character , Prefix usage c.

   for example ：

   char cRxedChar;

10. according to MISRA Code rules ,**char *** The defined pointer variable can only be used for ASCII character string , Prefix usage pc.

    for example ：

    char *pcStringToSend;

function

1. Combined with the static Declared function , Prefix the definition prv（ word private Abbreviation ）.

   for example ：

   static void prvInitialiseCoRoutineLists( void );

2. Function with return value , According to the data type of the return value , Add the corresponding prefix , If there is no return value , namely void type , Prefix functions with letters v.

   for example ：

   BaseType_t xQueueGenericReset( QueueHandle_t xQueue,
                                  BaseType_t xNewQueue );
   
   #define configRUN_TIME_COUNTER_TYPE uint32_t
   configRUN_TIME_COUNTER_TYPE ulTaskGetIdleRunTimePercent( void );
   
   StackType_t * pxPortInitialiseStack( StackType_t * pxTopOfStack,
                                                StackType_t * pxEndOfStack,
                                                TaskFunction_t pxCode,
                                                void * pvParameters,
                                                BaseType_t xRunPrivileged );
   
   const char * pcQueueGetName( QueueHandle_t xQueue );
   

3. According to the file name , When defining the corresponding function in the file, the file name may be added to the function name , such as tasks.c Functions in the file
   vTaskDelete, Function task Is in the file name task.

Macro definition

1. According to the file where the macro definition is located , The file name is also added to the macro definition when the macro definition in the file is declared , For example, macro definition
   configUSE_PREEMPTION Is defined in the file FreeRTOSConfig.h Inside . In the macro definition config It's Wen
   In the piece name config. Also note , Prefix should be lowercase .

2. Except for the prefix , The rest is capitalized , At the same time, separate with underline .

   for example ：

   // include\queue.h
   #define queueQUEUE_TYPE_SET ( ( uint8_t ) 0U )
   
   
   // include\list.h
   #define listINSERT_END( pxList, pxNewListItem ) \ {
            \ ListItem_t * const pxIndex = ( pxList )->pxIndex; \ ...
   
   // include\timers.h
   #define tmrCOMMAND_EXECUTE_CALLBACK_FROM_ISR ( ( BaseType_t ) -2 )
   
   // include\croutine.h
   #define crQUEUE_RECEIVE_FROM_ISR( pxQueue, pvBuffer, pxCoRoutineWoken ) \ xQueueCRReceiveFromISR( ( pxQueue ), ( pvBuffer ), ( pxCoRoutineWoken ) )
   

Conclusion

If you study it carefully FreeRTOS The name of , You will also see that some places do not conform to the above rules .

I don't know what the author thinks , Anyway, I don't like such a name .

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Reference material

FreeRTOS Coding standard and naming style - Rookie College