UCOSIII事件标志组

拼搏现实的明天。 2022-06-02 03:22 215阅读 0赞

**两种同步机制**

> “或”同步  
> “与”同步

**使能**

#define OS_CFG_FLAG_EN 1u /* Enable (1) or Disable (0) code generation for EVENT FLAGS */

**主结构体**

typedef struct os_flag_grp OS_FLAG_GRP;
    struct  os_flag_grp {                          /* Event Flag Group */
    
        OS_OBJ_TYPE          Type;                 /* Should be set to OS_OBJ_TYPE_FLAG */
        CPU_CHAR            *NamePtr;              /* Pointer to Event Flag Name (NUL terminated ASCII) */
        OS_PEND_LIST         PendList;             /* List of tasks waiting on event flag group */
    #if OS_CFG_DBG_EN > 0u
        OS_FLAG_GRP         *DbgPrevPtr;
        OS_FLAG_GRP         *DbgNextPtr;
        CPU_CHAR            *DbgNamePtr;
    #endif
    
        OS_FLAGS             Flags;                /* 8, 16 or 32 bit flags */
        CPU_TS               TS;                   /* Timestamp of when last post occurred */
    };

**API函数**

//创建
    void OSFlagCreate (OS_FLAG_GRP *p_grp,
                       CPU_CHAR *p_name,
                       OS_FLAGS flags,
                       OS_ERR *p_err);
    
    #if OS_CFG_FLAG_DEL_EN > 0u
    //删除
    OS_OBJ_QTY OSFlagDel (OS_FLAG_GRP *p_grp,
                          OS_OPT opt,
                          OS_ERR *p_err);
    #endif
    
    /* * opt specifies whether you want ALL bits to be set or ANY of the bits to be set. * You can specify the 'ONE' of the following arguments: * * OS_OPT_PEND_FLAG_CLR_ALL You will wait for ALL bits in 'flags' to be clear (0) * OS_OPT_PEND_FLAG_CLR_ANY You will wait for ANY bit in 'flags' to be clear (0) * OS_OPT_PEND_FLAG_SET_ALL You will wait for ALL bits in 'flags' to be set (1) * OS_OPT_PEND_FLAG_SET_ANY You will wait for ANY bit in 'flags' to be set (1) * * You can 'ADD' OS_OPT_PEND_FLAG_CONSUME if you want the event flag to be 'consumed' by * the call. Example, to wait for any flag in a group AND then clear * the flags that are present, set 'wait_opt' to: * * OS_OPT_PEND_FLAG_SET_ANY + OS_OPT_PEND_FLAG_CONSUME * * You can also 'ADD' the type of pend with 'ONE' of the two option: * * OS_OPT_PEND_NON_BLOCKING Task will NOT block if flags are not available * OS_OPT_PEND_BLOCKING Task will block if flags are not available */
    //等待-1
    OS_FLAGS OSFlagPend (OS_FLAG_GRP *p_grp,
                         OS_FLAGS flags,
                         OS_TICK timeout,
                         OS_OPT opt,
                         CPU_TS *p_ts,
                         OS_ERR *p_err);
    
    #if OS_CFG_FLAG_PEND_ABORT_EN > 0u
    //取消等待
    OS_OBJ_QTY OSFlagPendAbort (OS_FLAG_GRP *p_grp,
                                OS_OPT opt,
                                OS_ERR *p_err);
    #endif
    
    //获取使任务就绪的事件标志
    OS_FLAGS OSFlagPendGetFlagsRdy (OS_ERR *p_err);
    
    //发送+1
    OS_FLAGS OSFlagPost (OS_FLAG_GRP *p_grp,
                         OS_FLAGS flags,
                         OS_OPT opt,
                         OS_ERR *p_err);

**应用举例**

#define FLAG1 (1 << 0)
    #define FLAG2 (1 << 1)
    OS_FLAG_GRP EventFlags;     //定义一个事件标志组
    
    void task1(void *p_arg)
    {
        while(1)
        {
            //向事件标志组EventFlags发送标志
            flags_num=OSFlagPost((OS_FLAG_GRP*)&EventFlags,
                                 (OS_FLAGS    )FLAG1,
                                 (OS_OPT      )OS_OPT_POST_FLAG_SET,
                                 (OS_ERR*     )&err);
            printf("task1事件标志组EventFlags的值:%d\r\n",flags_num);
    
            OSTimeDlyHMSM(0,0,2,0,OS_OPT_TIME_PERIODIC,&err);
    
            //向事件标志组EventFlags发送标志
            flags_num=OSFlagPost((OS_FLAG_GRP*)&EventFlags,
                                 (OS_FLAGS    )FLAG2,
                                 (OS_OPT      )OS_OPT_POST_FLAG_SET,
                                 (OS_ERR*     )&err);
            printf("task1事件标志组EventFlags的值:%d\r\n",flags_num);
    
            OSTimeDlyHMSM(0,0,2,0,OS_OPT_TIME_PERIODIC,&err);
        }
    }
    
    void task2(void *p_arg)
    {
        while(1)
        {
            //等待事件标志组
            OSFlagPend((OS_FLAG_GRP*)&EventFlags,
                       (OS_FLAGS    )FLAG1|FLAG2,
                       (OS_TICK     )0,
                       (OS_OPT      )OS_OPT_PEND_FLAG_SET_ALL+OS_OPT_PEND_FLAG_CONSUME,
                       (CPU_TS*     )0,
                       (OS_ERR*     )&err);
            printf("task2事件标志组EventFlags的值:%d\r\n",EventFlags.Flags);
        }
    }

**实验现象**  
![1][]

[1]: /images/20220602/2aea4d5e0b2d4de8a40a34560a9493ae.png