...
Deletes a mutex. This function should be used with care because multiple tasks may rely on the presence of the mutex. Generally makes all pending tasks ready to run and clears the mutex data. It also sets the owning task's priority to the highest priority in the owner's task mutex group or its base priority, whichever is higher. Generally speaking, before deleting a mutex, first delete all the tasks that access the mutex. However, as a general ruleguideline, do not delete kernel objects at run-time.
Files
os.h/os_mutex.c
Prototype
Code Block |
---|
OS_OBJ_QTY OSMutexDel (OS_MUTEX *p_mutex,
OS_OPT opt,
OS_ERR *p_err) |
Arguments
p_mutex
is a pointer to the mutex to delete.
...
If OS_CFG_CALLED_FROM_ISR_CHK_EN
set to 1
in DEF_ENABLED
in os_cfg.h
: if attempting to delete a mutex from an ISR.
OS_ERR_ILLEGAL_DEL_RUN_TIME
If OS_SAFETY_CRITICAL_IEC61508
is defined: you are trying to delete the mutex after you called OSStart()
.
OS_ERR_OBJ_PTR_NULL
If OS_CFG_ARG_CHK_EN
is set to 1
in DEF_ENABLED
in os_cfg.h
: if p_mutex
is a NULL
pointer.
...
If OS_CFG_OBJ_TYPE_CHK_EN
is set to 1
in DEF_ENABLED
in os_cfg.h
: if p_mutex
is not pointing to a mutex.
OS_ERR_OPT_INVALID
If the user does not specify one of the two options mentioned in the opt argumentIf OS_CFG_ARG_CHK_EN
is set to DEF_ENABLED
in os_cfg.h
: if a valid option is not specified.
OS_ERR_OS_NOT_RUNNING
If OS_CFG_INVALID_OS_CALLS_CHK_EN
is set to DEF_ENABLED
in os_cfg.h
: If µC/OS-III is not running yet.
OS_ERR_TASK_WAITING
If one or more task are waiting on the mutex and OS_OPT_DEL_NO_PEND
is specified.
...
The number of tasks that were waiting for the mutex and 0 if an error occurred. Zero either indicates an error or that no tasks were pending on the mutex.
Required Configuration
OS_CFG_MUTEX_EN
and OS_CFG_MUTEX_DEL_EN
must be enabled in os_cfg.h
. Refer to uCµC-OS-III Configuration Manual.
Callers
Application.
Notes/Warnings
- Use this call with care as other tasks may expect the presence of the mutex.
Example Usage
Code Block | ||
---|---|---|
| ||
OS_MUTEX DispMutex;
void Task (void *p_arg)
{
OS_ERR err;
OS_OBJ_QTY qty;
(void)&p_arg;
while (DEF_ON) {
:
:
qty = OSMutexDel(&DispMutex,
OS_OPT_DEL_ALWAYS,
&err);
/* Check "err" */
:
:
}
} |