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Files

os.h/os_task.c

Prototype

Code Block
OS_MSG_QTY  OSTaskQFlush (OS_TCB  *p_tcb,
                          OS_ERR  *p_err)

Arguments

p_tcb

is a pointer to the TCB of the task that contains the queue to flush. Specifying a NULL pointer tells OSTaskQFlush() to flush the queue of the calling task’s built-in message queue.

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  1. Use this function with great care. When flushing a queue, you lose the references to what the queue entries are pointing to, potentially causing 'memory leaks'. The data that the user is pointing to that is referenced by the queue entries should, most likely, be de-allocated (i.e., freed).

Example Usage

Code Block
titleOSTaskQFlush() example usage
          void Task (void *p_arg)
          {
              OS_ERR      err;
              OS_MSG_QTY  entries;
           
              (void)&p_arg;
              while (DEF_ON) {
                  :
                  :
                  entries = OSTaskQFlush((OS_TCB *)0,
                                         &err);
                  /* Check "err" */
                  :
                  :
              }
          }
    

or, to flush a queue that contains entries, instead you can use OSTaskQPend() and specify the OS_OPT_PEND_NON_BLOCKING option.

Code Block
titleNon-blocking pend example usage
          void Task (void *p_arg)
          {
              OS_ERR       err;
              CPU_TS       ts;
              OS_MSG_SIZE  msg_size;
           
           
              (void)&p_arg;
              :
              do {
                  OSTaskQPend(0,
                              OS_OPT_PEND_NON_BLOCKING,
                             &msg_size,
                             &ts,
                             &err);
              } while (err != OS_ERR_PEND_WOULD_BLOCK);
              :
              :
          }