OS_TLS_SetValue
Description
Sets the value of a TLS (thread-local storage) entry in the specified task’s OS_TCB
. Specifically, this function assigns value to 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
void OS_TLS_SetValue (OS_TCB *p_tcb, OS_TLS_ID id, OS_TLS value, OS_ERR *p_err)
Arguments
p_tcb
is a pointer to the OS_TCB
of the task you wish to assign the TLS value to. value
will thus be assigned to p_tcb->TLS_Tbl[id]
.
id
is the TLS ID of the entry you are setting.
value
is the value to store at p_tcb->TLS_Tbl[id]
.
p_err
is a pointer to a variable that contains an error code returned by this function. Possible values are:
OS_ERR_NONE
If the call was successful and the caller was returned the value.
OS_ERR_OS_NOT_RUNNING
If you called OS_TLS_SetValue()
and the kernel has not started yet. However, it’s acceptable to call this function prior to starting multitasking but in this case, you must specify a non-NULL
pointer for p_tcb
.
OS_ERR_TLS_ID_INVALID
If you called OS_TLS_GetValue()
and specified a TLS ID that has not been assigned. See OS_TLS_GetID()
about assigning TLS IDs.
OS_ERR_TLS_NOT_EN
If you called OS_TLS_SetValue()
but the task was created with the option OS_OPT_TASK_NO_TLS
indicating that the task does not need TLS support.
Returned Value
None
Required Configuration
OS_CFG_TLS_TBL_SIZE
must greater than 0 in os_cfg.h
. Refer to µC-OS-III Configuration Manual.
Callers
Application.
Notes/Warnings
- You cannot call
OS_TLS_SetValue()
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 = OSTLS_GetValue((OS_TCB *)0, (OS_TLS_ID)MyTLS_ID, (OS_ERR *)&err); /* Check "err" */ : : } }