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Description

Returns the current value of a task’s TLS (thread-local storage) stored in the task’s p_tcb->TLS_Tbl[id]. See Chapter 20, “Thread Safety of the Compiler’s Run-Time Library” for details on TLS.

Files

os.h/os_tls.c

Prototype

OS_TLS  OS_TLS_GetValue (OS_TCB    *p_tcb,

...

                         OS_TLS_ID  id,

...

                         OS_ERR    *p_err);

OS_TLS_GetValue() is called by the application to retrieve the current value of a task’s TLS (thread-local storage) stored in the task’s p_tcb->TLS_Tbl[id]. See Chapter 20, “Thread Safety of the Compiler’s Run-Time Library” for details on TLS.

Arguments

p_tcb

is a pointer to the OS_TCB of the task you wish to retrieve the TLS from. You will get a copy of the p_tcb->TLS_Tbl[id] entry and of course, the entry will not be changed.

...

If you called OS_TLS_GetValue() but the task was created with the option OS_OPT_TASK_NO_TLS indicating that the task does not need TLS support.

Returned Value

The value store in p_tcb->TLS_Tbl[id] or NULL if an error occurred.

Required Configuration

OS_CFG_TLS_TBL_SIZE must be greater than 0 in os_cfg.h. Refer to µC-OS-III Configuration Manual.

Callers

Application.

Notes/Warnings

1. You cannot call OS_TLS_GetValue() for a task until that task gets created.

Example Usage

          OS_TLS_ID   MyTLS_ID;
           
           
          void MyTask (void *p_arg)
          {
              OS_ERR      err;
              OS_TLS      p_tls;
           
           
              :
              :
              while (DEF_TRUE) {
                  p_tls = OS_TLS_GetValue((OS_TCB   *)0,
                                         (OS_TLS_ID)MyTLS_ID,
                                         (OS_ERR  *)&err);
                  /* Check "err" */
                  :
                  :
              }
          }